...the coil, without itself coming into contact with the raw material. The condensate water is thus discharged, in an entirely clean form, through pipeline \(r\) and can again be used to feed the steam boiler. The advantages associated with this reuse of the condensate water are twofold. First, water condensed from steam is completely free of mineral impurities and therefore cannot produce boiler scale. Second, it still possesses so considerable a store of heat that feeding the boiler with this hot water represents an unquestionable advantage. If we take into consideration that the steam from the boiler enters the coil at a pressure of 5 atmospheres, i.e., at a temperature of about \(158^\circ\mathrm{C}\), while the surrounding gluey liquid is evaporated under a pressure of 4 atmospheres and therefore at a temperature of about \(151^\circ\mathrm{C}\), it is clear that the steam condenses at \(151^\circ\mathrm{C}\), and the water flows out of the condensation outlet at the same temperature. Since the total heat of 1 kg of steam at a pressure of 5 atmospheres is approximately 655 calories, the condensate water retains approximately one quarter of the heat of fresh steam, and by reusing it about 25% of the amount of heat expended is returned to the steam boiler.

Since water of such a high temperature cannot be supplied to the boiler either by a pump or by an injector, a special combination is most often used for this purpose, shown schematically in Fig. 35a.

The vessels \(a\), \(b\), and \(c\) constitute the entire system of apparatus for utilization by the Otto-Hartmann method. From the steam boiler \(d\) to the coil lying in evaporator \(c\) runs pipe \(e\). The water condensed in the coil is removed through condensation outlet \(f\) and passes through pipe \(g\) into feed apparatus \(h\), placed above the steam boiler. The latter, in turn, is connected by pipe \(i\) with the water space and by pipe \(k\) with the steam dome of the boiler. The check valves \(e\) and \(m\) open only in one direction. On the cover of apparatus \(h\) there is an air cock \(n\).

The apparatus operates as follows. When air cock \(n\) is open, the steam pressure in the coil drives the condensed water through pipe \(g\), through valve \(l\), into apparatus \(h\). As soon as the latter has filled, which is visible in the water-gauge glass, the air cock \(n\) is closed, and valve \(k\) is opened, connecting the apparatus with the steam boiler. From this moment the steam boiler \(d\) and apparatus \(h\) are under one and the same pressure; they form communicating vessels, as a result of which water enters through pipe \(i\) from \(h\) into boiler \(d\). When reservoir \(h\) has emptied, valve \(k\) closes again, and thereafter the inflow into reservoir \(h\) of con-

condensation water. The servicing of this apparatus does not entail an increase in the labor of the workers who service the boiler and the other apparatus. It requires only the closing and opening of valves approximately every quarter of an hour. Of course, this time depends on the size of the feed reservoir; the larger the latter, the less frequent the manipulations.

In drawing 34 is shown a plan of a very good arrangement of the premises of a rendering plant according to the Otte-Hartmann system, built in the city of Düsseldorf by the firm Rud. Hartmann. In this, the following letter designations are adopted:

A—approaches for bringing in the material;
a—sterilizers;
b—receivers;
c—glue boilers;
d—vessel for clarifying fat;
e—condenser;
f—exhauster;
g—pipeline to the cremator;
h—cremator;
i—steam boiler;
k—engine;
l—reservoir for feed water;
m—mill;
n—apparatus for feeding the boiler with condensation water;
o—smokestack.

Drawings 35–36 present, in plan and in section, the arrangement of an institution for the utilization of slaughterhouse waste, built in 1899 in Berlin at the barracks slaughterhouse. The plan shows only the processing room itself, attached to the previously existing slaughterhouse building. The material is brought into the front room (preparatory chamber) on small carts and from there is directed into the apparatus. The steam boiler, the apparatus for feeding with water, and the incinerating furnace for gases are located in the adjacent old buildings. This institution processes 150 centners of raw material daily.

The letters used in the drawings have the following meaning:

a—utilization apparatus of the Otte-Hartmann system, with a useful volume of 50 centners;
b—fat receivers;
c—evaporator for glue liquid;
d—apparatus for purifying fat;
e—condensers for destroying the vapors and gases released;
f—mill for grinding the coarser residues;
g—steam engine of 20 horsepower;
h—fan directing the non-condensable gases into the incinerating furnace.

The above-described utilization apparatuses of the systems of Podewils, Hartmann, Otte, and Otte-Hartmann (besides them, also the apparatus of the Delacroix system, which was mentioned above) enjoy a certain reputation and a more or less wide application in practice. But there also exists a series of utilization apparatuses whose use has so far been limited to isolated cases—whether because of their novelty, or for other reasons—or which exist only in the inventors’ projects. In any case, these diverse attempts to resolve the question that concerns us by means of other designs are of no less interest, and we shall devote the following exposition to a description of such less widely disseminated utilization apparatuses for which information is available*).

Among universal utilization apparatuses one may first of all include the last, newest type of kaffil-disinfector of the Ritschel and Henneberg system, with a device for drying and comminuting the solid products of thermal treatment, which was described above with the corresponding comment. It should be mentioned here, among other reasons, because the Ritschel and Henneberg disinfector is, in general, the undoubted prototype of utilization apparatuses of the Hartmann type, and the latter merely successfully anticipated that process of development which was emerging in the subsequent change in the designs of the kaffil-disinfectors themselves. And indeed, the disinfector that appeared on French soil (the Delacroix system) and was borrowed from there by the firm of Ritschel and Henneberg, in the final form worked out by the inventor and Mr. Voevodsky, is close to the type of universal utilization apparatus. On the other hand, in an undoubted and close connection with the same disinfector (of the Ritschel and Henneberg system) is the utilization apparatus designed by Tejero (C. Tejero) in Brussels.

The utilization apparatus of the Tejero system is shown, partly in external view and partly in section, in drawing 37. It resembles the new type of kaffil-disinfector of Ritschel and Henneberg described above. Drawing 37 shows a vertically standing sterilizer with double walls, having in the upper bottom a large charging hatch, which is tightly closed by a bolted cover. The lower bottom has a hemispherical shape. On the front and rear (not visible in the drawing) sides there is one opening each.

*) We must state in advance that in some of the apparatuses described below the principle of universality is not fully clearly expressed, and therefore their place among the others may be debatable.

From the upper edge of one opening to the lower edge of another there runs an inclined grate, which divides the interior of the sterilizer into an upper and a lower space. In the lower part there rotates a horizontal shaft, equipped with stirrers and driven by a gear transmission. These stirrers are of different lengths, corresponding to the spherical shape of the bottom. In addition to the openings mentioned, one more opening leads into the lower part of the sterilizer, shown on Drawing 37 at the right; it is also closed with a lid. In the very lowest part of the spherical bottom there is a conically narrowing discharge opening, closed by a slide valve. Above this slide valve a pipeline branches off, leading to a receiving reservoir with double walls and closed by a valve.

The operating process, according to the inventor’s proposals, should be as follows. The raw material intended for processing is loaded into the apparatus from above and occupies there the upper space above the inclined grate. Then, after the lid has been hermetically closed, the steam jacket of the sterilizer is heated with steam at a pressure of 1½ atmospheres, in order to separate fat from the raw material. The latter flows through the inclined grate into the lower spherical part of the disinfector and from there through the pipeline into the receiver. Here it is purified while the steam jacket is heated with steam at a pressure of 6 atmospheres.

Meanwhile the valve of the pipeline leading to the receiver is closed, and steam at a pressure of 5½–6 atmospheres is admitted into the sterilizer, in order to extract glue substances from the material being processed. The glue liquid flows through the inclined grate and, when it has collected in the lower part of the sterilizer, is discharged through the slide valve, in order subsequently to be processed into glue. Sometimes, however, without discharging this liquid from the apparatus, foreign substances (phosphates, etc.) are mixed into it, introduced through the side opening, and, by stirring the resulting mass with the aid of the stirrers, it is converted into a fertilizer mixture. Emptying also takes place through the lower slide valve.

The discharge of the steamed meat-and-bone mass is carried out through the side opening. As to drying the product obtained in the apparatus, the inventor says nothing in his patent. This is undoubtedly a weak point of the projected system.

In connection with the apparatuses of the Hartmann system there are also the methods proposed by the firm Venulet and Ellenberger (Venulet & Ellenberger) in Darmstadt and by the firm Zettritz in Britz (Zettritz in Britz bei Berlin). The first method, which so far has been applied only in an isolated case, is essentially very similar to the exp—

...by the method of treatment described above, using an ordinary Hartmann disinfecting apparatus. The separation of fat and gluey substances and the drying take place in separate but interconnected apparatuses—namely, in a sterilizer equipped with an internal perforated cylinder, and in a drying apparatus with moving agitators. The material remaining after the separation of the fat and glue liquid is conveyed, without reloading, from the sterilizer into the drying apparatus.

In the Petritsch method, also known as the David Grove system (David Grove, Berlin), a rotating drum with double walls is used; but instead of an internal perforated cylinder, a perforated trough-shaped receiver is placed inside the drum. During the sterilization period the latter hangs in the lower part of the drum; when the drying period begins, after the discharge of the fat and glue liquid, it begins to rotate up and down, so that all its contents come into direct contact with the entire surface of the heated steam jacket.

There are several other types of apparatus intended for the sterilization and utilization of slaughterhouse waste which, because of their similarity to the more widely used apparatuses described above in the general idea of thermal treatment, stand somewhat apart with respect to the details of their construction. Such are the apparatuses of the systems of Garth, Pfleiderer, Eilke, and Golthaus.

The apparatus of Dr. Garth’s system (Dr. Garth in Darmstadt) (Fig. 38) consists of an iron drum, provided with double walls, which rotates about a transverse axis. When treatment is not being carried out, the opening located at the top is turned so that it is at the height of a man. The material intended for treatment, as it arrives, is placed in the drum through a specially arranged closure, which does not allow it to be taken back out. When the apparatus has thus been filled, the closure is removed and the opening is tightly closed with a cover on screws. Steam at a pressure of 5 atmospheres is then admitted for approximately 10 hours both into the interior of the apparatus and into the jacket. The fat and glue liquid are from time to time led off into a special receiver, where the fat separates and is then discharged. The glue liquid is pumped out by means of a water-jet pump and, because of this, being mixed with a large quantity of water, is discharged into the sewer. During steaming, the drum is turned over from time to time in order to change the position of the contents and give the steam new points of contact. It is difficult to call this method of treatment perfect, as is also confirmed by practice,

since the apparatus described operates not entirely successfully and, moreover, with the release of unpleasant odors.

The firm Hermann Pfützner (Hermann Pfützner in Leipzig-Connewitz) has constructed an apparatus for processing carcasses of animals of every kind, in an uncut state, or slaughterhouse refuse into fat and glue, with drying of the solid residues and their crushing into fertilizer meal. For this purpose there serves, first of all, a high-pressure sterilizer (Fig. 39) with double walls, the lower conical part of which is closed by a fine-meshed screen in order to retain, during boiling, the boiled-out fleshy and bony parts. For removing and inserting the screen there is a special opening. A box is attached to the conical part of the apparatus; into it enters a hollow slide valve with an opening on the upper side, moved by hand by a handwheel. A special opening makes it possible, when necessary, to clean the surface of the slide valve. From this slide valve a pipe leads to a vessel for collecting fat and glue liquor. Beneath the box are a crusher and a mill, serving to grind the dry product. Inside the sterilizer there is a rotating, mutually connected system of grates. From above the apparatus is closed by a lid, which can be lifted and moved aside by a traveling crane. In the same way, the three upper grates can be taken out of the apparatus. The same lifting device serves for moving and charging the material. The admission of live steam from the boiler takes place through a valve seated on a cross-shaped box. On the latter there is also a shut-off valve for the exhaust pipe of the fan, a valve for reducing the pressure in the apparatus, as well as a safety valve and a pressure gauge. A second exhaust opening, likewise closed by a valve, is located above the lower grate. In addition to the steam pipe into the interior of the apparatus, there is also a branch for admitting steam into the steam jacket; and in the very lowest part of the jacket there is a valve for draining the condensation water. A little door with three air cocks and a thermometer makes it possible to observe the course of the process during drying.

Each separate grate rotates freely and has two points of support, of which one is fixed, while the other can be moved by means of a hand drive. In order to remove the material from the grates after drying, they are rotated through an angle of about 60° by a transmission acting on the extension of the axis of rotation of the lower grate, which passes outward through the steam jacket.

The receiver for the fat and glue liquor consists of a cylindrical boiler with double walls, closed at the top and bottom. From the upper cover an exhaust pipe leads to the fan.

The side-mounted cock is used for draining off fat, while the cock located in the lower part is for draining the glue liquor.

The operation of the apparatus, according to the inventor, is as follows. After removing the cover of the apparatus and taking out the three upper grates, small pieces of meat are placed on the lower grate. If necessary, the next grate serves to receive the same material; the third and fourth grates, inserted one after another, serve to receive the undissected carcasses of small animals. If it is necessary to process an entire large carcass, the three upper grates are taken out in order to free the required space. After loading is completed, the cover and door of the apparatus, the exhaust pipes leading to the fan, the air cocks and the slide valve are carefully closed; the thermometer is removed, and the opening for it is likewise tightly closed. After this the steam valve leading into the apparatus is opened. The incoming steam drives the air contained in the apparatus through the slide valve, the pipe, and the valve at the bottom into the receiver for fat and glue water, which must previously have been half-filled with water. When all the air has been expelled from the sterilizer and it is filled with steam, the valve leading to the receiver is closed and the pressure in the apparatus is brought up to 5 atmospheres, which corresponds to a temperature of 150–160° C. Depending on the quality of the material and the size of the carcasses, the apparatus remains under this pressure for a longer or shorter time, usually 5–6 hours for small animals and 8–9 hours for large animals. During this time the fat, glue, and condensed water collecting in the lower conical part of the apparatus are transferred every half hour into the receiver.

When the steaming of the material is finished, and the last remainder of liquid has been transferred into the receiver, the valve admitting steam is closed and the pressure is lowered by means of the discharge valve. Following this, the fan is set in motion to draw out foul-smelling gases, and drying is begun by heating with steam in the steam jacket. To monitor the drying, the thermometer is screwed in and, from time to time, the little door is opened for direct observation of the product being dried.

When the solid residues have been dried, the valves are closed, the mesh bottom is removed through a specially arranged opening, the latter is closed again, the slide valve is opened, and finally the crusher and mill are set in motion. After this, the system of grates is turned through an angle of 60°, so that the dried mass falls into the conical part of the apparatus.

During the drying, the separation of fat and glue water has time to finish in the receiver, so that both products can be

released. The steam jacket surrounding the receiver is heated in order to facilitate the discharge of fat.

There are no data on cases of application of the Pfleiderer-system utilization apparatus, the quality of its operation, or the products.

The utilization apparatus invented by Henri Wilcké, in Saint-Étienne on the Loire, consists of four separate vessels: a sterilizer, a receiver, a glue evaporator, and a drying apparatus connected to the lower part of the sterilizer. Drawing 40 schematically depicts the arrangement of the entire system of these apparatuses and the construction of the individual elements. A is a vertically standing sterilizer, conically narrowing downward; B is the receiver for the liquid products that separate out; C is the glue evaporator; D is the drying apparatus, intended for drying boiled meat and bone masses.

The sterilizer A is single-walled. At a short distance from the walls of the latter, at a, there is another perforated reservoir b, of the same form as the outer walls of the apparatus. From above the sterilizer is hermetically closed with a removable lid, which in turn is provided with an opening e for loading dismembered carcasses. In the middle of the apparatus a vertically mounted shaft rotates, passing through the lid. Its lower end constitutes a crushing mill. In addition, along the lower two-thirds of this shaft there is a spiral, serving during boiling to lift upward, scatter, and mix the material being processed. This shaft is set in rotary motion by means of the toothed wheel f. The sterilizer is open below and allows, depending on whether the slide valve g is open or closed, either liquid products to be discharged into the receiver through pipe k, or solid residues to be transferred into the drying apparatus D. Steam is supplied to the sterilizer from the steam boiler through valve h.

The receiver B is a simple vertical cylinder of such strength as to withstand a pressure of 5–6 atmospheres. It is equipped with a movable pipe d, serving for the discharge of fat. At the upper end of the hermetically closing lid, the receiver is provided with a steam-safety valve l.

The glue evaporator c is likewise a vertical cylindrical iron vessel, which can withstand the same pressure. Inside it, at the bottom, there is a coil p, heated by steam from the boiler through valve m.

The drying apparatus D consists of a horizontally arranged iron cylinder v, inside which, around an axis, rotates a system t, consisting of a large number of heating—

of heating tubes. On the outer surface of this system there is arranged a row of stirrers \(u\), which are to mix the material undergoing drying and move it from one end of the apparatus to the other. Steam is supplied through valve \(i\) and the trunnion of the apparatus into the interior of the tubular system. The vapors released from the product are drawn off through valve \(r\) by a fan. At the end of the apparatus, opposite the steam line, there is a pulley that drives the tubular system. The dried material is discharged from the apparatus through opening \(w\) and enters a pit located near the apparatus, from which it is raised from time to time by an elevator.

The operation in the Wilke apparatus is carried out in the following manner. The cut-up carcasses are loaded into the sterilizer through opening \(e\) and are placed there between the perforated wall and the axis provided with a spiral. Having closed slide \(g\) and opening \(e\), steam is introduced into the apparatus through valve \(h\). At first, condensation of the steam takes place, continuing until the material being steamed reaches the temperature of the introduced steam; the condensate is discharged into receiver \(B\) through pipe \(k\). Thereafter, under the action of high-pressure steam, the material being treated releases liquid products—fat and glue liquor—which flow through the screen and, through pipe \(k\), likewise enter the receiver. To accelerate the process, the spiral \(c\) mounted on the axis is set in motion in such a way that it moves the material upward. The constant mixing of the material must, of course, accelerate the boiling and ensure completeness of extraction. At the same time, there is no need to fear that the material will fall into the mill located at the lower end of the axis, since, when the axis rotates in the indicated direction, the mill does not exert a crushing action.

The boiling process lasts no more than 4 hours. When it is finished, pipe \(k\) is closed and, instead, slide \(g\) is opened. At the same time, the vertical axis is set in motion in the opposite direction. Then the spiral begins to feed the material downward; the boiled meat and bone masses in the apparatus are pressed into its conical part, seized by the mill located there, and ground. As it is ground, it passes through the opening of slide \(g\) into the drying apparatus. Here, owing to the heating of the rotating tubular system, the steamed meat-and-bone masses are gradually dried. The stirrers pick up the product that falls through the tubes and collects below, raise it, mix it, and again drop it onto the hot tubes. Meanwhile, the vapors and gases being released are carried off by a fan into the condenser. Thanks to the screw-like arrangement

mixing and the arrival of new material, the drying product is gradually conveyed to the outlet end of the drying apparatus, until at last it passes out through opening \(W\) in a completely dry and powdery state.

Meanwhile, in receiver \(B\), the fat is separated from the glue liquor. The former, owing to its lower specific gravity, floats on the surface of the glue and can be discharged through pipe \(d\). The glue liquor is driven, after valves \(n\) and \(e\) are opened, by steam pressure into the glue evaporator. Here valve \(m\) is opened, and the coil \(p\) is heated by steam from the boiler, so that evaporation of the water contained in the glue liquor immediately begins in the vessel. The foul-smelling vapors released during this process are at once carried off by a fan into a condenser. The dried glue is discharged at the end of the operation through cock \(o\).

In constructing the apparatus, the inventor, according to his own words, was guided by the consideration that in France the number of slaughterhouse owners possessing the necessary means to install expensive devices for the destruction and utilization of animal refuse is very limited, and that in most cases they have only very modest funds at their disposal. Therefore the apparatus is built of such a size that its cost is considerably lower than that of the devices described earlier. The inventor also took into account the circumstance that in France the requirement is often made for the careful separation of the fat of different animals. Therefore the inventor had to devise a method that would permit each kind of livestock to be processed separately in small quantities. This appears possible in the apparatus just described. The period of steaming in the sterilizer takes about 4 hours, after which, with the transfer of the treated product into the drying apparatus, the sterilizer can again be filled. It is then possible, simultaneously with the drying of the material from the first charge, to begin steaming a second charge, and the two processes do not in the least interfere with one another. It goes without saying that the fat accumulated in receiver \(B\) from the first charge must first be drained off, in case a different kind of livestock is to be processed in the second charge.

To what extent the inventor’s hopes have been fulfilled is difficult to say, for lack of data. In any case, an apparatus of the Wilke system has been installed and is in operation at the slaughterhouse established in St. Étienne.

Emil Holthaus, in Canarsie, State of New York, has taken out a patent for an apparatus for the sterilization and drying of meat refuse—

...of tallow and similar materials. The material to be processed is first softened and steamed; then the fat is separated, and finally the residues are freed of water by pressing and are thoroughly dried with steam, yielding a fertilizing cake.

The apparatus serving this purpose (Fig. 41) consists of a horizontal iron cylinder \(A\), inside which there are devices for mixing, and of two vertical cylinders \(H H\). Fig. 41 shows the elements of the apparatus partly in external view and partly in section. Cylinder \(A\) is provided with a steam jacket \(B\), into which steam is admitted through pipe \(b\); through \(d^1\) the steam may be removed from it. Openings \(A^1\) and \(A^2\) give access into the boiler \(A\). A horizontal shaft \(D\), set in motion by the toothed wheel \(D^1\), passes into the cylinder through stuffing boxes in the centers of the covers. At the ends this shaft is made hollow, and steam pipes \(e\) and \(e^1\) adjoin these cavities. The internal cavities of the shaft extend only as far as points \(g\), where helically bent steam pipes \(G\) branch off from the shaft; these pipes thus connect the pipe lines \(e\) and \(e^1\) with each other. These pipes change the direction of curvature, so that alternately one turn is directed to the right and the next to the left. The spiral rings \(F\), arranged symmetrically with respect to the tubular spiral, are constructed in exactly the same manner.

Both vertical cylinders \(H\) in their lower part constitute iron funnel-shaped vessels, which by their lower cylindrical opening \(I^1\) enter cylinder \(A\) and are hermetically closed by sleeve \(I^2\). By means of slide valve \(I\), the communication between \(H\) and \(A\) can be established or interrupted at will. The cylinders \(H\) rest, by means of lugs \(H^1\), on supports \(H^2 H^4\), as is seen on the right-hand cylinder. From above the cylinders are closed tightly with covers \(K\), through the centers of which passes a screw rod \(N\), with a press \(M\) attached below. By means of the belt drive \(r r^1 V V^1\), the rods can, as desired, be raised or lowered by wheels \(P p^1\) (the hub of the latter has a screw thread). Pulley \(V^1\) is freely mounted on the shaft. From it the belt may be shifted to any of the fixed pulleys \(V\), whereby the rod of the left or right cylinder is lowered; at the same time the free and fixed pulleys \(r r^1\), by means of a crossed driving belt, carry out the raising of the rods. Since the raising of the rods must take place faster than their immersion, the size of pulleys \(r r^1\) is taken smaller than that of pulleys \(V V^1\). Funnels \(J\), closed by cover \(A^3\), which are arranged on the side of each cylinder, serve for

reception of raw material. Inside, each cylinder has, at the very bottom of the cylindrical part, a tubular ring \(L\), perforated with holes, which is connected by a branch pipe \(c^3\) with the valves \(c\), \(c^1\), and \(c^2\), of which \(c\) admits steam, \(c^1\) water, and \(c^2\) closes the discharge pipe. Several vertical pipes \(l\), closed at the top, are connected with the tubular ring \(L\); their surfaces are likewise perforated with small holes. Corresponding to the positions of these pipes, the press piston \(M\) has notches along its edge, which at the same time serve to guide the piston. Instead of these pipes \(l\) and the tubular ring \(L\), one could also insert into the cylinder, as shown by dotted lines, a perforated iron cylinder \(L^1\), through which the funnel \(J\) must then pass.

The apparatus operates as follows. After closing the slide valves \(I\) and raising the pistons \(M\), one of the cylinders \(H\) is filled through the funnel \(J\) with the material intended for processing, the latter first being moistened with diluted sulfuric acid. After closing the cover \(A^3\), water is admitted into the cylinder through the valve \(c^1\) and the pipe \(c^3\); passing through the small holes of the pipes \(Ll\), it uniformly penetrates the contents of the cylinder. Then \(c^1\) is closed, the steam valve \(c\) is opened, and the mass is steamed for 4–5 hours. The vapors released in this process are led off through the valve and pipeline \(Ss\). The fat that is released rises to the surface of the mass and can be discharged through the upper valve \(a\). After steaming is complete, valve \(c\) is closed, \(c^2\) is opened, part of the liquid is discharged, and the rod \(N\) is made to move downward. Then the liquid still contained in considerable quantity is squeezed out by the piston \(M\) and flows through the holes \(Ll\) and the pipeline \(c^2c^3\). As the mass is compressed ever more strongly, the valves \(a^1\) and \(a^2\) are opened one after the other in order to allow the fat to escape. When the material has been freed of water as far as possible by pressing, the slide valve \(I\) is opened, so that it passes into cylinder \(A\), into the jacket of which and into the heating coil \(G\) steam has been admitted. Next, the agitators formed by \(G\) and \(F\) are set in motion in order to paralyze the adhesion of the masses undergoing drying, to mix the material, and to accelerate its drying. The gases released during drying are collected in the dome \(T\) located on cylinder \(A\), whence they are led off through the valve and pipe \(tt^1\). During drying, the second cylinder \(H\) is filled, so as to have new material ready by the end of the drying process for the same purpose.

There is likewise no information on the use of Gotthaus’s apparatus, on the quality of its operation, or on the products.

In addition to the special apparatuses described above for the sterilization and utilization of slaughterhouse waste by processing it into fat and

animal meal; in small-scale production, apparatuses for the sterilization of meat parts (Kochapparate) may, of course, be used, for example those manufactured by D. Rohrbeck in Berlin, by Buddenberg in Dortmund, and by Prollius in Görlitz.

Although our task included only an account of the mechanical and thermal methods for the destruction, decontamination, and utilization of slaughterhouse waste, for the sake of completeness we shall say a few more words about the method of treatment sometimes employed with the aid of sulfuric acid.

In this case the material to be sterilized and treated is placed in barrels or in lead-lined boxes about 1.25 m in width and height and 2–2.50 meters in length. Sulfuric acid of 45° Baumé strength is poured onto the raw material, and steam is then admitted. After the passage of steam, fat begins to separate, and no emission of steam or foul-smelling gases is observed. The process of decomposition and fat separation continues for several hours at a temperature of about 80° C. When it is completed, the fat that has collected on the surface is drawn off into special receivers. To the mass remaining in the vats and to the acidic water, glue-free bone meal, phosphoric-acid calcium, and similar substances are admixed, whereby the excess sulfuric acid is bound and the content of phosphoric acid in the material is increased. The mixture thus obtained becomes sufficiently thick after some time. It is then dried in drying apparatuses and, after being converted into powder, is used as fertilizer. Sometimes this meat-and-bone mass and the acidic water are directed into filtration boxes filled with straw on a wooden grating, where the liquid is separated from the solid parts. The filtered acidic water is then used for diluting the acid in a new application. The remaining mass is neutralized and then sent, as in the preceding method, to drying apparatuses.

It must be said that, in treatment with sulfuric acid, the process of decomposition remains almost imperceptible as regards nuisances to the surrounding area; however, the drying process is accompanied by the emission of extremely unpleasant-smelling gases. Therefore, during drying, all measures must be taken to address this nuisance—hermetic closure of the apparatuses, ventilation, condensation, and incineration. Condensation water may be discharged only after preliminary purification.

The question of the comparative merits and shortcomings of the individual systems of utilization apparatuses is highly debatable. The matter is complicated by the fact that this question must be decided not only from—

from the technical point of view, but even more from the hygienic point of view, while the practice of life transfers it also onto economic ground. Therefore, in order to judge one system or another, reliable and accurate information is needed not only on the technical serviceability, but also on the hygienic perfection of the work of the apparatuses, as well as on the quantity and quality of the products of processing. Such information exists only with respect to a few of the more widespread apparatuses, and even then in insufficient quantity and, moreover, in a fragmentary form that does not lend itself to systematization and is not always exact (sometimes for the purpose of mitigating a defect, sometimes for advertising purposes). With respect to a considerable number of apparatuses, however, there is no such information at all. This circumstance necessarily forces one to narrow the scope of the question under discussion and does not provide reliable ground for categorical and indisputable conclusions.

All the disinfectors and utilization apparatuses described above have the common principle that they operate with saturated water vapor at high pressure. By the action of this steam the raw material is sterilized, and fat, glue, and other substances of organic origin are extracted from it. The meat-and-bone masses remaining after the extraction of the liquid products are dried and then ground; the fat is separated, owing to the difference in specific weights, from the glue liquor, and the latter (if it is not removed) is condensed and processed into glue. All the apparatuses described follow this principle, irrespective of their structural features, which have gradually developed out of modifications and improvements.

The prototype of these apparatuses should be recognized as a simple high-pressure digester, in which sterilization and extraction take place in a simple cylindrical vessel. From this digester, by means of a series of structural additions, there arose disinfectors. Their main component is likewise a high-pressure digester, but it is provided with a steam jacket and an internal perforated cylinder and is connected with other auxiliary thermal apparatuses. For receiving the liquid products of extraction, a second vessel is attached to the main apparatus—that is, to the disinfector or sterilizer—a receiver, fat separator, or glue digester. For the removal of vapors and foul-smelling gases there is a third vessel, a condenser. It is clear that such a combination of apparatuses presents substantial advantages in comparison with work by means of a simple digester.

However, in disinfectors the shortcomings of the original type were still not fully eliminated. The periodic distillation of the extracted—

...of liquid substances into the receiver by means of pressure in the disinfector is irrational, since as a result not only is the already accomplished separation of fat from the glue liquor disturbed, but a new mixing of these substances is even produced. Moreover, when working with the disinfector, the necessity is not eliminated of transferring the steamed meat and bone masses into a special drying apparatus in order to free them from the water contained in them—a manipulation undesirable in every respect. Finally, the action of the spray condenser proved incomplete, since it was not capable of absorbing all the incoming foul-smelling gases.

Thus, in designing new apparatuses, the task of engineering was, first of all, to eliminate the transfer of semi-finished products, then to establish a more rational extraction of fat, and finally to achieve the complete destruction of foul-smelling vapors and gases.

To achieve these aims, attempts were made in different, though closely related, directions, and their result was expressed in the creation of so-called universal utilization apparatuses: first of all, apparatuses of the Podewils system, then a series of apparatuses of the Delacroix, Hartmann, and Otte types, and finally several apparatuses by other inventors, which have not received any more or less wide application, or exist only in projects. In all these devices the stated aims have been attained to a greater or lesser degree. As for the comparative merits of the individual systems, we are, first of all, at a loss to say anything about systems for whose application and operation we have no information. Nor can we speak of such transitional forms as the Hartmann and Otte apparatuses, since they are superseded by the new Otte-Hartmann system and, with its appearance, will have no new applications. Thus there remains the question of the comparative merits of firmly established systems that have received wide application and compete with one another: on the one hand, Podewils, and on the other, Otte-Hartmann (“Hartmann-Trebertrocknung”).

The first utilization apparatus to accomplish the task of sterilization and universal processing of meat refuse and animal carcasses was the Podewils apparatus. Here the sterilizer consists of a horizontally positioned drum with double walls, rotating around its axis. Steaming is carried out by the direct introduction of steam from the boiler, while the removal of the liquid products that are released takes place either after the end of the process, or periodically during it, by means of a trans...

movable pipe into a collecting vessel kept under ordinary atmospheric pressure. Drying of the meat-and-bone masses in this apparatus is carried out without transferring the material from the sterilizer. The destruction of foul-smelling gases and vapors is effected by means of a condenser, while the gases not subject to condensation are led off and burned in the furnace of the boiler. Thus, in Podewils’s apparatus, all the shortcomings charged against disinfectors are undoubtedly eliminated. The merit of the apparatus, compared with apparatuses of other systems, is its simplicity of construction, which may be important both in the initial equipment and in the subsequent servicing of a utilization establishment. A special feature of this system is the complete exclusion, in principle, of independent treatment of the glue liquor.

The fact is that, in the opinion of the firm Podewils, the technical processing of glue liquor into glue is so imperfect, and the sale of the product obtained so difficult, that this matter is not worth the trouble. The glue obtained from glue liquor is heterogeneous in composition, of poor quality, and, moreover, gives off a bad odor when handled. This is entirely understandable if one takes into account that this substance is a mixture of mucilaginous elements of bones and skin with a considerable quantity of meat extract, and therefore is a material of the very lowest grade. The above-mentioned inconveniences explain the fact that some establishments equipped with Hartmann apparatuses have discontinued the production of glue. For the same reasons, the firm Podewils is in principle opposed to extracting it. The glutinous substances extracted from the material being treated are partly dried and utilized, when the drum is refilled with glue liquor from the glue (pressure) apparatus, together with the solid substances (especially when producing fertilizing meal); partly, however, they are discharged into the sewer during the periodic emptying of the contents of the pressure apparatus.

Podewils’s apparatus is not, however, without certain defects, which are strongly emphasized by supporters of Hartmann apparatuses. The defects include, above all, the somewhat different principle on which the separation of fat from the material being treated is based. Whereas in Hartmann apparatuses (and even in disinfectors) this separation takes place in such a way that the masses lying on the perforated bottom are treated with steam, so that the liquids released continually flow downward and collect beneath the perforated bottom, the process in Podewils’s apparatus is essentially different. The high-pressure steam entering from the boiler enters the material located in the drum and conden—

Destruction and Utilization of Slaughterhouse Waste

…is condensed here the entire time, until the temperature of the material rises to the temperature of the steam. As the process continues, the loaded material gives off its own water, so that a mush-like mass is gradually formed, consisting of condensation water and gluey liquid, in which the meaty-bony parts are located. The fat released from the material must here rise to the top of this mass, owing to its specific gravity, whereas in Hartmann’s apparatus the fat, according to the law of gravity, flows down through the perforated bottom. Because of this circumstance, insufficient fat separation must be expected in Podewils’s apparatus. The degree of separation of the fat may be judged by its content in the finished product. And indeed, it has been observed that animal meal obtained, for example, from the Ritschel and Henneberg kafill-disinfector contains only 8–14% fat, whereas the same meal from Podewils’s apparatus contains no less than 14–17% fat, and sometimes more. This is quite significant, since fat is the most valuable of the products obtained, and one must strive to extract as large a part of it as possible. However, the supporters of Podewils’s apparatus consider the reproach just cited to be of little evidential value, at least for comparison with Hartmann’s system. They point, with figures in hand, to the fact that the meal obtained by Hartmann’s apparatus (at the municipal rendering establishment of the city of Kiel, according to analyses from 1902) contains more fat than the meal obtained from Podewils’s apparatus (at the same kind of establishment in the city of Dresden, according to analyses from 1903). And in fact, a comparison of the analyses gives the following results, shown in the form of a table.

Podewils apparatus (Dresden). Months, 1903	Water, %	Nitrogen, %	Phosphoric acid, %	Fat, %	Hartmann apparatus (Kiel). Months, 1902	Water, %	Nitrogen, %	Phosphoric acid, %	Fat, %
January	5,14	8,84	8,14	14,67	January	5,80	6,9	5,88	25,3
February	6,31	9,11	7,17	16,49	February	10,10	8,01	4,2	19,8
March	4,78	9,12	7,89	15,20	March	9,98	7,23	4,9	18,5
April	4,66	9,48	7,36	16,18	April	7,6	6,92	6,62	18,3
May	4,88	9,62	7,57	14,86	May	10,09	7,36	5,91	18,9
June	5,15	9,48	7,25	13,99	June	7,7	8,16	5,75	16,4
July	5,07	9,29	7,78	14,95	July	7,7	7,33	5,33	20,3
August	5,90	9,52	7,24	14,15	August	11,07	7,20	4,23	21,78
September	5,30	9,04	7,19	17,15	September	7,9	7,52	5,06	22,2
October	6,74	9,21	6,78	16,00	October	8,06	8,07	4,63	19,08
November	6,15	8,93	9,17	13,20	November	7,04	8,08	5,22	19,81
December	6,10	9,00	7,90	17,00	December	9,70	7,47	4,95	22,4
Average	5,52	9,22	7,57	15,92	Average	8,48	7,44	5,22	20,23

In order to draw an impartial conclusion from these data, it must be noted that the quantity of fat separated depends on the duration of the process. Taking into account that the process of separating fat in Podewils’s apparatus lasted considerably longer, we come to the conclusion that, although with respect to the quantity of fat separated the advantage proves to be on the side of Podewils’s system, nevertheless the separation of fat in this apparatus undoubtedly proceeds less vigorously than in Hartmann’s apparatus. It must be added that in both apparatuses, at the duration of the process usual for them, the separation of fat is far from perfect.

Further, the supporters of Hartmann’s system point out that Podewils’s apparatus works irrationally with respect to drying the material and therefore consumes too large a quantity of coal. Since the rendering here is carried out by the direct introduction of steam from the boiler, the quantity of glue liquor is increased by the addition of condensed water. This, of course, could be of great importance if, during drying, it were necessary to evaporate the entire quantity of water or to boil down the glue liquor to obtain glue syrup. But since in Podewils’s system no further utilization of the glue-yielding elements takes place, and part of the glue liquor is always discharged, the indicated feature of the apparatus’s operation apparently does not have an especially serious effect with respect to drying. However, it cannot be denied that it is reflected to some extent in the consumption of water and coal for feeding the boiler and in the formation of boiler scale from the excessive quantity of fresh water introduced. Finally, a certain disadvantage of Podewils’s apparatus is the excessively long duration of drying.

Hartmann’s system apparatus appeared later than Podewils’s apparatus and underwent repeated constructive improvements. In this, the inventor had the desire and the possibility of combining the advantageous features of his system with the merits of the Otte and Podewils systems. Therefore the apparatus ultimately developed by Otte-Hartmann is unquestionably a good design. Its chief difference from Podewils’s apparatus consists in the internal movable perforated drum. The use of the perforated drum, above all, allows the fatty and other liquid substances extracted during the steaming process to flow downward and separate from the solid elements. Another advantage is that, during the steaming process, the position of the material may be changed at will, and thus the steam obtains new points of contact with the substances being treated. By this means not only is a more complete extraction of liquid products achieved,

but also a great saving of time, since steaming the material at rest lasts 8–10 hours, whereas under the given conditions only 4–5 hours are required for the same purpose. The further processing of the by-products has also been substantially improved with the introduction of the perforated drum and the devices connected with it. The drying of the materials remaining in the drum in the Otte-Hartmann apparatus proceeds more simply and more rapidly than in other apparatuses. As the drum moves, the softened meat-and-bone masses continually rub against one another, quickly disintegrate, and fall through the holes of the drum into the space between it and the walls of the cylinder. Here they are comminuted and mixed by stirrers arranged on the outer surface of the drum. Thanks to all these devices, the drying and comminution of the material is completed within 4 hours, whereas the drying process in Podewils’s apparatus takes considerably longer.

It should be noted that, in the Otte-Hartmann system, the drying process can, as desired, be carried out either so that the glue liquor is concentrated in the evaporator and the steamed meat-and-bone masses are dried in the sterilizer, or in such a way that, together with these masses, the glue syrup obtained in the preceding operation is dried at the same time. Thus the distinctive feature of Podewils’s apparatus, namely that in it the glue substances are partly processed together with the solid residue and only two products are obtained—fat and animal meal—cannot be regarded as a special advantage over the Otte-Hartmann system. Such a method of operation is entirely possible in this latter system as well, and is often employed, either constantly or depending on demand. Thus, when there is good demand for second-grade glue, the apparatus operates in the usual manner. If there is no such demand, and the solid material is being processed into fertilizer tallow, the glue substances are treated and dried together with this material. When, however, feed meal is being prepared, especially for certain animals, the admixture of glue substances with it is considered harmful, and they are either processed separately, or removed for fertilizer, or, finally, discharged into the sewer.

The evaporation and drying by secondary steam introduced into the Otte-Hartmann system, described above, represents a very notable advantage in the ordinary operation of the apparatus. When the glue liquor is then evaporated, the preliminary dilution of the latter with condensation water naturally causes a corresponding increase in

coal consumption. This aspect of the matter is of serious economic importance, if one takes into account that the raw material itself contains up to 70% water, and that this quantity, with the introduction of steam over the course of 4–8 hours, is doubled and even more. In the case of evaporation of the glue water after such dilution, there would be a large overconsumption of fuel, not even counting the increase in the dimensions of the boiler. All these inconveniences are eliminated by the introduction of the above-mentioned method of heating with secondary steam. With the reduction, due to the same circumstance, in the boiler’s consumption of fresh water, the amount of boiler scale is reduced, which is also of importance, especially in small installations.

As for the removal of foul-smelling vapors and gases, here too a useful innovation has been made in the Otte-Hartmann system. The most unpleasant vapors are produced during the concentration of the glue liquid, and in other systems large quantities of fresh water are required for their condensation. In the Otte-Hartmann system this condensation takes place inside the apparatus itself, with the heat released during the concentration of the vapors being used for the process.

In general, the Otte-Hartmann utilization apparatus makes a captivating impression by the completeness and harmony with which the idea of universal utilization is carried out, and by the thoughtfulness of all the details of its design. It may be said that, even in comparison with the deservedly well-reputed Podewils system, it represents a certain step forward. Thus we may regard the three types of apparatus that were chiefly addressed in our comparison—namely, disinfectors, the Podewils apparatus, and the Otte-Hartmann apparatus—as three stages of successive progress that have been passed through by devices for the sterilization and processing of confiscated materials and animal carcasses. It must be noted, however, that there is no great difference in favor of the Otte-Hartmann system as compared with the Podewils system, especially in practical terms. On the contrary, if, in particular, one excludes the processing of glue liquid, which is certainly not very productive, then both systems become very close in their practical operating results. Reports from institutions equipped with apparatuses of both systems also emphasize this similarity, since the economic balances of their operation prove to be almost identical, with fluctuations now in favor of one system, now in favor of the other, depending on local circumstances.

XII. Products of the Processing of Confiscated Materials and Animal Carcasses.

The products of processing in utilization apparatuses are: fat, animal feed meal, animal fertilizer meal, and

glue liquid or glue syrup. Of these, fat is a substance of uniform and quite definite composition which, after cooling and drying in the form of tallow, is sold to soap-making factories or used as a lubricant. Glue liquid or syrup is used, as already stated, for the production of lower grades of glue. The composition of these products varies, depending on the method of production, and in general is of no interest.

Of greatest interest are feed meal and fertilizing tallow. In terms of composition, however, these products do not differ from one another. Their composition, as well as the methods of production, are one and the same. Only the carcasses of animals known to be free from infection, freed from entrails, and parts of such same animals, should be processed into feed meal; for fertilizing tallow, any animal material is used.

To acquaint ourselves with the composition of these latter products, we shall present data from a series of analyses carried out at different times on products from various utilization apparatuses and disinfectors. In doing so, of course, the analyses make no distinction between feed meal and fertilizing tallow, understanding both under the general name of animal meal. We arrange these analyses in the order, adopted by us, of the systems of apparatuses.

An analysis of animal meal obtained with the aid of the ordinary kafill-disinfector of the Rietschel and Henneberg system at the slaughterhouse in Karlsruhe showed the following composition of this product:

Component	Content
water	4.70%
dry substances	95.30%

The latter consist of:

Component	Content
nitrogenous substances	52.55% (nitrogen 8.36%)
fatty substances	10.45%
mineral substances	37.30%

including:

Component	Content
phosphoric acid	16.40%
potassium	0.91%

An analysis of the same kind of meal, obtained at the slaughterhouse in Spandau, gave the following figures:

Component	Content
nitrogen	7.56%
phosphoric acid	10.24%
potassium	0.78%
water	6.96%

The firm Rietschel & Henneberg itself, in calculating the profitability of the Kafil disinfector, assumes the following composition of animal meal:

phosphoric acid . . . . . . . . . . . . 9.75%
nitrogen . . . . . . . . . . . . . . . 9.15%
potash . . . . . . . . . . . . . . . . 0.28%
moisture . . . . . . . . . . . . . . . 1.43%.

Meal obtained with the aid of the Hartmann-system extraction apparatus, in experiments carried out with this apparatus by Dr. Kolberg, showed a different composition, depending on the raw material. When the apparatus was charged with meat with bones and internal organs, the analysis gave:

nitrogen . . . . . . . . . . . . . . . 7.99%
phosphoric acid . . . . . . . . . . . 10.39%.

When, however, the charge consisted only of internal organs, the result obtained was:

nitrogen . . . . . . . . . . . . . . . 9.54%
phosphoric acid . . . . . . . . . . . 3.41%.

With regard to animal meal obtained from the Podewils apparatus, there are a number of analyses from the Hamburg utilization plant. The annual averages from these analyses for the years 1894–1903 are placed in the following table:

Year	Nitrogen, %	Crude protein, %	Phosphoric acid, %	Water, %	Fat, %
1894	7,866	49,1625	6,5	8,834	18,344
1895	8,505	53,156	6,21	8,393	18,158
1896	8,187	51,1687	6,02	6,59	18,03
1897	9,414	58,838	6,144	7,306	18,456
1898	8,082	50,512	6,268	8,672	18,696
1899	8,592	53,7	6,1	8,175	18,107
1900	8,593	53,706	6,463	8,108	15,975
1901	8,642	54,0125	6,047	9,325	16,33
1902	8,52	53,25	5,84	8,17	19,65
1903	8,64	54,0	5,92	7,44	20,08

Flour obtained by means of the same apparatus at the Dresden rendering plant had the following composition, on average for 1903:

water . . . . . . . . . . . . . . . . 5.52%
nitrogen . . . . . . . . . . . . . . 9.22%
phosphoric acid . . . . . . . . . . . 7.57%
fat . . . . . . . . . . . . . . . . . 15.92%.

The following table presents the results of a series of analyses performed on samples of animal meal obtained in the rendering establishments of the cities of Hanover (I, II), Pomerania (III, IV), Altona (V, VI), and Angalt (VII, VIII) by means of the Otto-system apparatus. (During processing, the glue liquor was added to the meat-and-bone mass.)

Constituent parts	I.	II.	III.	IV.	V	VI.	VII.	VIII.
Dry substances	93.17	97.10	91.52	85.98	94.05	92.11	92.86	92.25
Total nitrogen	6.82	7.16	8.95	7.96	7.40	7.33	7.28	7.44
Crude protein	42.63	44.75	55.94	49.75	46.25	45.81	45.50	46.50
Fat	3.70	11.39	12.85	13.29	13.05	16.41	8.48	12.23
Phosphoric acid	14.34	14.70	7.75	—	11.44	—	13.25	24.47

In 1898, experiments were carried out at the slaughterhouse in the city of Stettin with the Otto-Hartmann apparatus. The animal meal then obtained from this apparatus had, on average, the following composition:

dry substances . . . . . . . . . . . 94.33%
phosphoric acid . . . . . . . . . . . 15.84%
nitrogen . . . . . . . . . . . . . . 6.31%
crude protein . . . . . . . . . . . . 39.46%
fat . . . . . . . . . . . . . . . . . 14.75%.

At the same time, an investigation undertaken incidentally showed that the fine particles of meal separated by sieving and the coarser constituent parts of it had different compositions, namely:

I. Fine animal meal:

dry substances . . . . . . . . . . . 97.71%
ash . . . . . . . . . . . . . . . . . 26.42%
organic substances . . . . . . . . . 71.29%

nitrogen . . . . . . . . . . . . . . . . . . . 8.92%
phosphoric acid . . . . . . . . . . . . . . 10.67%
potash . . . . . . . . . . . . . . . . . . . 0.10%
lime . . . . . . . . . . . . . . . . . . . 12.82%
fat . . . . . . . . . . . . . . . . . . . . 12.50%

II. Coarser component parts of the meal:

dry matter . . . . . . . . . . . . . . . . 94.58%
ash . . . . . . . . . . . . . . . . . . . . 43.82%
organic matter . . . . . . . . . . . . . . 50.76%
nitrogen . . . . . . . . . . . . . . . . . 6.43%
phosphoric acid . . . . . . . . . . . . . . 17.09%
potash . . . . . . . . . . . . . . . . . . 0.14%
lime . . . . . . . . . . . . . . . . . . . 22.58%
fat . . . . . . . . . . . . . . . . . . . . 9.22%

Analyses of animal meal obtained with the aid of the same Otte-Hartmann apparatus at the slaughterhouse in the city of Kiel showed the following composition, on average for the year 1902:

water . . . . . . . . . . . . . . . . . . . 8.48%
nitrogen . . . . . . . . . . . . . . . . . 7.44%
phosphoric acid . . . . . . . . . . . . . . 5.22%
fat . . . . . . . . . . . . . . . . . . . . 20.23%

To this we consider it necessary to add some information on the use of animal meal obtained in the utilization of condemned materials and carcasses as a feedstuff.

The idea of using dry powder from slaughterhouse refuse for animal feed belongs to the celebrated J. Liebig, who, as is known, attached the utmost importance to the utilization of all kinds of refuse from urban life. In 1872 J. Liebig proposed drying the wastes from the manufacture of meat extract at the well-known establishment of Frey-Bentos (which we have mentioned), grinding them, and using them as feed for domestic animals. Since that time, the meat residues from this and other similar factories have been dried, turned into powder, and exported under the name of meat meal.

This product contains, as might have been expected from its origin, very few extractive substances and salts. This circumstance at first gave grounds for denying the very possibility of using such material as a nutritive substance. For the same reason, common salt and acid potassium phosphate are sometimes added to meat meal, in order thereby to provide it with satisfactory—

ness. However, in the end, feeding meat meal proved permissible without any additives, since, when relatively small quantities of it are consumed, the missing constituent parts are supplied from other nutritive substances.

The approximate composition of Liebig’s meat meal is as follows:

Component	Content
dry substances	89.0%
nitrogenous substances	73.0%
fat	11.7%
ash	3.7%

At the present time, Liebig’s meat meal is strongly competed with by animal meal, obtained from confiscated materials, meat refuse, and animal carcasses by means of the utilization apparatuses described above; it is almost identical with meat meal in external qualities and close to it in composition. The aforementioned apparatuses process whole carcasses together with the skeletons, so that the product they produce differs from meat meal by a more or less high content of calcium phosphate. At first there were attempts to present the higher content of this substance in animal meal as a defect in comparison with American meat meal. But it soon had to be recognized rather as an advantage, since, when animals are fed with the new product, phosphorus and lime, necessary for the organism, are introduced. The introduction of animal meal as a feed for domestic animals also, of course, encountered obstacles because of its origin, but this prejudice did not last long. When, after incessantly repeated feeding experiments with pigs, cattle, horses, dogs, birds, and fish, the outstanding qualities of this nutritive substance had been demonstrated, the possibility of its use was everywhere acknowledged. Thus, the establishments now existing in Germany that produce animal meal sell the greater part of their output as a feed, and its use is continually expanding.

This product has become so well known and ordinary that German farmers, at deliberative congresses, recognized the need to standardize production and, for this purpose, expressed wishes reducible to the following points.

1. Glue liquor should not be processed into feed-grade animal meal, since its constituent parts exert an irritating effect on the digestive organs of animals.

2. The contents of the stomach and intestines should be removed from animal carcasses before the latter are introduced into the disinfector, since this material contains a large quantity of various

doubtful and harmful chemical compounds and other substances, which may have a harmful and irritating effect on the digestive organs.

1. Work in apparatuses for the production of animal feed meal should not be carried out at excessively high temperatures, so as, insofar as possible, not to reduce the digestibility of the protein.

These recommendations are formulated on the basis of the results of scientific investigations carried out on this question by Professors Zuntz and Lehmann.

Alongside ordinary animal meal, feed substances have recently appeared for sale on the German market which represent a mixture of animal meal with other nutritive products. Such, for example, is a feed substance consisting of a mixture of animal meal with black molasses.

XIII. Data on the Economic Results of Processing Confiscates and Animal Carcasses

The question of the productivity and profitability of establishments for the decontamination and utilization of slaughterhouse refuse is extremely important and interesting, especially when it comes to practical decisions in municipal administrations. Unfortunately, information about utilization plants and about the organization of the work in these establishments very rarely makes its way into the technical press. This is explained, on the one hand, by the generally insufficient attention paid to the collection and systematization of information on the work of utilization plants; on the other hand, also by the fact that information of this kind, having first reached the organs of municipal administrations, most often sinks there without a trace amid a mass of heterogeneous material. In any case, for persons practically interested in the matter, we can provide some, albeit very limited, material that could be drawn from the technical literature, the prospectuses of various firms, and also from the records concerning the arrangement of the Odessa utilization plant.

With respect to the operation of Ritthaler and Henneberg system cauldron-disinfectors, we have information collected at the slaughterhouses in the cities of Karlsruhe and Spandau. In both cases the work was carried out with an ordinary disinfector (without an internal drying device), with the subsequent use of drying cabinets.

On the basis of experience with such an apparatus, the director of the slaughterhouse in Karlsruhe, Bauersdörfer, arrived at the following results.

For 7 fillings of the apparatus, a total of 4,060 kg of material was used. From this latter amount there was obtained a boiled and sterilized mass in the amount of 1,654 kg, i.e., 40.7% of the raw material. After drying this mass, 1,058 kg of powder for fertilizer remained, which constitutes 26% of the material. Fat was obtained in the amount of 166 kg, i.e., 4% of the material.

The percentage ratios mentioned may, of course, fluctuate, depending on the nature of the substances being processed. It was necessary to abandon the extraction of glue syrup, since, owing to the high temperature of the steam, the glue liquid became unsuitable for further processing.

If it is assumed that the apparatus is put into operation 100 times a year, i.e., about 2 times a week, and that it is filled entirely, then 2,400 centners*) will be available for processing during the year. According to the percentage ratios calculated by us, from this quantity there will be obtained:

Product	Quantity
4% fat	96 centners
26% finished fertilizer meal	624 “

The analysis (given above) showed that 100 parts of fertilizer meal contain 8.36 parts nitrogen, 16.40 parts phosphoric acid, and 0.91 parts potassium.

If one proceeds from the usual value of these substances, the fertilizer meal obtained will have a sale value of approximately 9 marks per centner**). Thus:

Item	Calculation	Amount
For fertilizer meal there will be received	9 × 624	5,616 marks
For fat, having a sale price of 10 marks per centner	10 × 96	960 “
Total		6,576 marks

At the same time, approximately the following expenses must be incurred:

Expense	Amount
Cost of fuel (gas), reckoned each time at 6 marks, for 100 times	600 marks
Labor personnel, about	1,500 “
Repairs	200 “
5% on the capital expended, 13,000 marks	650 “
10% amortization	1,300 “
Total	4,250 marks

Thus there remains a net profit of 2,326 marks, i.e., 17.8% on the capital expended.

At the slaughterhouse in the city of Spandau a Kafill disinfector is being installed

*) 1 centner = 50 kilograms.

**) This figure is taken as too high, and the price of fat as too low. Ya. N.

Ya. I. Nikolin.

Ritschel and Henneberg, with a capacity of 1,200 kg, which is used for the decontamination and utilization of confiscated materials, animal carcasses, and meat refuse. With this apparatus, slaughterhouse inspector A. Liebe carried out a series of trial processing runs, with corresponding records. The results of these experiments are brought together in a general table, which (with some abbreviations) is placed on p. 125.

In all, the apparatus was put into operation 20 times, and in total 10,030 kg were processed. Each time the apparatus was filled only to 500 kg. Thus an apparatus holding 1,200 kg was not used even to half its capacity. Despite these unfavorable production conditions, the value of the products covered all expenses, and there was even a net profit (unfortunately, the calculation was not published in full). But since a significant part of the production costs, interest on the capital expended, and amortization remain unchanged regardless of whether the capacity of the apparatus is used wholly or in part, under normal working conditions a greater profit should be obtained.

The calculation of profitability was made on the basis of an analysis which showed that the animal meal obtained contains 7.56% nitrogen, 10.24% phosphoric acid, and 0.78% potash. Calculated on the basis of these data, the value of the meal will be 12.00 to 13.00 marks per 100 kg. The price of fat in Spandau was calculated at 40 marks per 100 kg. On the basis of these prices, and also of the average data derived from the table, with complete filling of the apparatus to 1,200 kilograms, the following can be obtained:

12.7% fertilizer meal, from 1,200 kg—152.4 kg,
counting at 0.13 m., for a sum of . . . . . . . . . . 19.8 marks;
6.25% fat, from 1,200 kg—75 kg, at 0.40 m., for a sum of 30.00

Total products from one charge, for a sum of 49.8 marks.

The firm Ritschel and Henneberg itself gives the following calculation of the profitability of the Kafill disinfecting apparatus of its system.

Profitability varies according to the quality of the raw material; it is lower the more internal organs it contains and the less meat and bones. On average, the following figures may be accepted as the basis for calculating profitability.

100 kg of raw material yield:

18 kg of fertilizer material, priced at 13–15 marks per 100 kg.*)
5 “ fat . . . . . . . . . . . . . . at 40–46 “ “ 100 kg.
8 “ glue . . . . . . . . . . . . . at 12–16 “ “ 100 kg.

In accordance with these prices, the profitability of an establishment with an apparatus of 1,200 kg capacity is determined as follows.

*) The price is too high. Ya. N.

Results of work with kaferfil apparatuses by Ritschel and Henneberg at the slaughterhouse of G. Schandau.

Trial no.	Process duration, hours	Costs A: dull and mill parts, kg	Costs A: internal heating of the contents, kg	Costs A: total quantity of material, kg	Process B: in raw form, kg	Process B: in raw form, % of load	Product: dry substance, kg	Product: animal meal, kg	Product: animal meal, % of load	Product: fat, kg	Product: fat, % of load	Product: bone meal, kg	Product: bone meal, % of load
1	9.00	271	268	539	173	32.09	91	89	16.88	23	4.26	23	4.26
2	8.00	438	219	657	213	32.37	120	115	18.23	90	13.66	90	13.66
3	8.00	157	315	472	113	23.89	65	62	13.76	27	5.72	27	5.72
4	14.00	135	540	675	211	31.25	87	84	12.88	18	2.66	18	2.66
5	11.00	435	435	870	335	38.48	140	132	16.00	40	4.59	40	4.59
6	8.00	230	—	230	46	20.00	25	21	10.86	13	5.65	13	5.65
7	9.00	365	121	485	165	34.02	78	74	16.08	10	2.06	10	2.06
8	13.00	—	450	450	86	19.11	45	43	10.00	31	6.88	31	6.88
9	6.00	508	—	508	152	29.92	69	67	13.58	92	18.31	92	18.31
10	17.00	—	633	633	122	19.27	64	61	10.11	36	5.68	36	5.68
11	8.00	200	—	200	65	32.50	36	33	18.00	9	4.50	9	4.50
12	14.00	370	610	980	160	16.32	89	86	9.08	83	8.46	83	8.46
13	6.00	190	—	190	32	16.84	18	16	9.42	12	6.31	12	6.31
14	11.00	650	183	833	219	26.21	106	102	12.72	27	3.24	27	3.24
15	8.00	—	164	164	55	33.53	28	26	17.07	6	3.65	6	3.65
16	10.00	80	501	581	103	17.72	65	63	11.18	25	4.30	25	4.30
17	10.00	736	190	926	237	25.59	135	133	14.57	42	4.53	42	4.53
18	4.00	23	—	23	5	21.73	1 1/2	1 1/2	15.21	—	—	—	—
19	9.00	190	320	510	127	24.90	63	61	12.35	40	7.84	40	7.84
20	8.00	—	103	103	33	32.03	9	8	8.73	1	0.97	1	0.97
—	—	4978	5052	10030	2652	—	1334 1/2	1277 1/2	12.70	625	6.25	625	6.25

If it is assumed that the apparatus will operate at complete filling only three times a week, or 150 times annually, then over the course of a year \(1200 \times 150 = 180000\) kg of raw material will be processed, which will yield:

fertilizer tallow 18%, i.e. 32,800 kg, in the amount of . . . 4,212 marks;
fat 5%, i.e. 9,000 kg, in the amount of . . . . . . . . . . 3,600 »

Thus the gross income will be . . . . . . . . . . . . . 7,812 marks.

In calculating expenses, the firm assumes that one man is sufficient to service the apparatus, who will need the help of another for at most 1 hour in the morning during loading. Thus, for sterilization, drying, and grinding the solid masses into meal, and for evaporating the gluey liquid, the following are required per one charge:

working time . . . . . . . . . . . . . . . from 8 to 10 hours;
coal, counted as 29% of the weight of the raw material . . . . 350 kg.

The heating surface of the boiler should be no more than 15 sq. m., and the total expense for the equipment (excluding the building) reaches 16,000 marks.

Under these conditions the expenses may be counted as follows:

wages, reckoned at 4 marks per day, \(150 \times 4\) . . 600 marks;
coal consumption \(350 \times 150 = 52500\) kg, at 1 mark
    per centner . . . . . . . . . . . . . . . . . . 1050 »
maintenance and repair, \(1 \tfrac{1}{2}\%\) of 16,000 marks . . . . 240 »
5% on capital of 16,000 marks . . . . . . . . . . . . . 800 »
10% amortization on 16,000 marks . . . . . . . . . . . 1600 »

Total . . . . 4,290 marks.

Thus, in the firm’s opinion, the net profit should be 3,522 marks, or 22% on the capital expended.

If daily use of the apparatus at complete filling is possible, the net profit rises still more considerably, since the income is then doubled, while the expenses double only for the first three items.

Income:

\(7812 \times 2 =\) . . . . . . . . . . . . . . . . . . 15,624 marks.

Expense:

wages \(300 \times 4\) . . . . . . . . . . . . . . . . 1200 marks.
coal consumption \(300 \times 350 = 105000\) kg . . . . . 2100 »
maintenance and repair . . . . . . . . . . . . . . . 500 »
%% on capital . . . . . . . . . . . . . . . . . . . 800 »
%% for amortization . . . . . . . . . . . . . . . . 1600 »

Total . . . 6,200 marks.

The net profit in this case reaches 9,424 marks.

Finally, if the income from the production of glue is taken into account, this sum receives a further increase. Assuming that the glue-containing material was processed over the course of 200 production days, it may be calculated that 8% of glue will be obtained from 1200 kg—96 kg. Taking the value per 100 kg as 12 marks, we obtain a daily income of 11.50 marks, and in 200 days \(200 \times 11.50 = 2300\) marks*).

One may think, of course, that these enticing calculations are not without a certain measure of optimism.

We have some information on utilization plants equipped with apparatus of the Podewils system for such establishments in the cities of Munich, Hamburg, Dresden, Freiburg, and Barmen, not counting Odessa, which we shall discuss separately.

The following table contains data on the production of the utilization plant in the city of Munich for the annual period from November 1893 to November 1894.

Results of operation with apparatus of the Podewils system at the utilization plant in the city of Munich.

Year	Months	Number of fillings	Total quantity of processed material, kg	Products: fertilizer cake, kg	Products: fat, kg
1893	November	8	10885,5	3107,5	85,0
—	December	10	13070,5	3741,5	778,0
1894	January	12	14935,0	4655,0	1150,0
—	February	12	14510,5	4955,0	910,0
—	March	10	12199,0	4045,0	1324,0
—	April	13	15862,5	5285,0	1128,0
—	May	10	13467,5	3987,5	1122,5
—	June	12	16633,0	5327,5	1187,0
—	July	13	15140,5	5088,0	1562,0
—	August	12	12356,5	4410,0	1113,5
—	September	11	13738,5	4490,0	1181,5
—	October	11	14355,0	4835,0	942,0
—	November	8	9960,0	3560,5	687,6
	In all	142	177114,0	57487,5	13171,0
	On average per filling	—	1247,3	404,8	92,8
	Average yield in %	—	--	32,5%	7,39%

*) From this, of course, the costs of evaporation must be deducted.

The same two tables contain information on the results of work at the municipal utilization plant in Hamburg for 1894 and 1895. In 1894 one Podewils-system apparatus operated here; in 1895 there were already two apparatuses, and a third had been ordered.

Results of operation with the Podewils-system apparatus at the municipal utilization plant in Hamburg for 1894.

Months. 1894	Number of charges	Total quantity of material processed, kg	Average quantity per charge, kg	Quantity of products obtained: fat, kg	Quantity of products obtained: fertilizer meal, kg	Average quantity per charge: fat, kg	Average quantity per charge: fertilizer meal, kg
January	8	23023	2878	1755	5798	219,5	725
February	10	27358	2736	1945	6405	194,5	640,5
March	18	48603	2700	4580	11840	254,5	658
April	16	38889	2430,5	4485	10261	280	641
May	20	49592	2479,5	5625	12167	281	608
June	22	59455	2702,5	5715	14478	260	658
July	19	51150	2692	5170	12300	272	647
August	26	72440	2786	7180	17160	276	660
September	25	68000	2720	6380	16150	255	646
October	33	75135	2277	6195	18460	188	560
November	29	66560	2293	5530	16827	190,5	580
December	31	68155	2198,5	5970	19464	192,5	628
In all	219	648360	2574,6	60530	161310	—	—
Average yield in %	—	—	—	9,33%	24,88%	—	—

Results of work at the municipal utilization plant in Hamburg in 1895.

Months. 1895	Number of charges	Amount of material processed: Total, kg	Amount of material processed: Average per charge, kg	Quantity of products: Animal meal, kg	Quantity of products: Fat, kg	Analyses of animal meal: Nitrogen, %	Analyses of animal meal: Phosphoric acid, %
January	38	86000	2263	21917	8625	8,12	5,20
February	34	81360	2393	20254	10365	10,34	6,52
March	37	88025	2,79	22493	11353	8,42	6,20
April	28	73085	2610	18327	9185	6,44	7,02
May	38	86920	2287	20580	10335	9,24	5,08
June	33	70370	2132	14725	7965	8,35	5,53
July	32	69955	2186	15578	7550	8,36	6,17
August	32	73150	2286	15160	10315	8,78	6,36
September	40	91856	2296	16950	10745	8,52	6,82
October	27	55340	2050	13545	6215	8.99	6,39
November	25	48385	1935	12505	5075	8,26	7,01
December	49	104606	2135	23250	10795	8,24	6,22
Total	413	929052	—	215284	108523	—	—
Average per charge	1	2250	—	521	263	—	—
Average yield, in %	—	—	—	23,17%	11,68%	8,51%	6,21%

There is no more or less detailed information on the profitability of the aforementioned establishments with Podewils apparatuses. It is known, however, that according to reports for 1903 the Hamburg plant processed 493687 kg of raw material and yielded a net income of 5931 marks; the Dresden plant processed 343673 kg and yielded an income of 8106 marks; and the Munich plant processed 244187 kg and yielded an income of 2255 marks. With respect to the Hamburg plant it is also known that at first it operated at a deficit, which at the beginning reached 11895 marks.

The table placed on p. 130 presents the results of the work of the utilization plant equipped with Podewils apparatuses in Friedberg (Hesse) from September 1894 to December 1896. The table also shows the institution’s revenues, expenditures, and balance, which gave a small income. It should be noted here that the expenditures include rent, payment for the carcasses of fallen animals, and expenses for transporting carrion, etc. These additional expenses amount to a substantial figure. Thus, for 1896:

Item	Amount
rent	1500 marks
payment for carrion	3300 ”
expenses for transporting carrion, keeping horses, etc.	3500 ”
Total	8300 marks

Thus, the basic expenses for operating the plant amount, instead of 17000 marks, to only 8700 marks. This gives the matter a different aspect.

Ya. I. Nikolin.

Results of the work at the utilization plant in the city of Fridberg (Hesse) from September 1, 1894, to December 31, 1896.

Year	Month	Number of processed animals: large	Number of processed animals: small	Number of charges	Quantity of processed raw material	Obtained from rendering: animal meal	Obtained from rendering: fat	Income: meal	Income: fat	Income: hides	Income: total	Expenses: remuneration	Expenses: total	Balance: marks
1894	September and October	79	167	44	25230	7549	862	905	310	849	2066	518	2504	—
1894	November and December	70	189	45	25000	7705	1359	924	489	866	2357	501	2584	—
1895	January and February	67	173	40	24000	7691	1488	922	533	725	2249	428	2500	—
1895	March and April	69	297	57	34200	9591	2218	1148	816	1143	3170	582	2771	401
1895	May and June	68	277	50	29935	8972	1909	1077	755	1159	3056	541	2609	447
1895	July and August	70	263	50	30000	8996	1827	1078	730	1083	2968	540	2716	252
1895	September–December	147	462	88	52800	15476	3196	1857	1278	2285	5541	959	5269	272
1895	For all 16 months	570	1828	374	221165	63980	12859	7911	4913	8110	21407	4069	20953	—
1896	I quarter	84	389	68	40800	12289	2580	1474	980	1374	3913	664	3846	67
1896	II quarter	114	474	78	46800	13589	2807	1630	954	1958	4627	908	4248	379
1896	III quarter	91	427	70	42000	12863	2629	1543	831	1563	4035	702	4003	31
1896	IV quarter	138	571	101	60600	18104	3271	2118	947	2700	5910	1033	4903	1007
1896	Total	427	1861	317	190200	56847	11287	6765	3712	7595	18485	3307	17000	1485
1896	Average per 1 charge	—	—	1	600	180	36	—	—	—	—	—	—	—
1896	Average yield, %	—	—	—	—	30%	6%	—	—	—	—	—	—	—

Of the smaller institutions working with apparatuses of the Podewils system, Schwartz’s book (“Bau, Einrichtung und Betrieb öffentlicher Schlacht und Viehhöfe”) contains information that such an installation at the slaughterhouse in the city of Barmen yields 1.5% net income, while in the city of Kattowitz it only covers its expenses.

In developing the question of the construction of a utilization plant in the city of Odessa, the firm Arthur Koppel (which represents the Podewils plant) submitted a preliminary estimate of the profitability of an institution equipped with Podewils apparatuses, as applied to the quantity of material expected in Odessa. I believe it is not without interest to present this calculation here.

The income obtained from the sale of products (for lack of Russian data, German prices were taken), when processing 60,000 poods of carcasses per year, converted into Russian money, is calculated as follows:

Item	Amount
fat, 10%—6,000 poods, at 3 rubles 50 kopecks	21,000 rubles
animal meal, 25%—15,000 poods, at 1 ruble	15,000 rubles
Total	36,000 rubles

The expenses are assumed to be the following:

Item	Amount
remuneration for a mechanic and 3–4 assistants (the duties of the latter include skinning, preparation for processing, keeping the building clean, etc.)	2,000 rubles
expenditure on coal, assuming that steam consumption will amount to from 120,000 to 130,000 poods, and taking the steam-producing capacity of coal as 6, and the price of coal as 18 kopecks per pood, about	3,600 rubles
bags for animal meal, in the amount of 1,500 pieces	300 rubles
lubricating and packing material and various other expenses, about	1,000 rubles
depreciation and repair of machines and apparatuses	2,500 rubles
depreciation and repair of the building	1,500 rubles
Total, the total amount of operating expenses and depreciation of buildings and machines	10,900 rubles

The actual profitability of the Odessa plant will be indicated when it is described.

With regard to the operation of the extraction apparatus of the Hartmann system, experiments were carried out in 1896 at the Magdeburg slaughterhouse. In all, 24 experiments were performed. Their results are collected in the table placed on p. 132.

Results of work with the Hartmann extraction-apparatus system at the utilization institution at the Magdeburg slaughterhouse, in 1896

No. of experiment	MATERIAL: fallen and slaughtered animals—Horses, kg	MATERIAL: fallen and slaughtered animals—Pigs, kg	MATERIAL: fallen and slaughtered animals—Sheep, kg	MATERIAL: removed at slaughter—Cattle, kg	MATERIAL: removed at slaughter—Horses, kg	MATERIAL: killed by disease—Pigs, kg	MATERIAL: killed by disease—Calves, kg	MATERIAL: killed by disease—Sheep, kg	MATERIAL: killed by disease—Goats, kg	MATERIAL: Confiscated material, kg	MATERIAL: Entrails, kg	Total amount of material, kg	TIME: Sterilization, hours	TIME: Sterilization, min.	TIME: Boiling down, hours	TIME: Boiling down, min.	TIME: Drying and grinding, hours	TIME: Drying and grinding, min.	PRODUCTS: Fat, kg	PRODUCTS: Glue, kg	PRODUCTS: Fertilizing substances—Superph., kg	PRODUCTS: Fertilizing substances—Meat, kg	EXPENSE: Coal, kg	EXPENSE: Water, kg	EXPENSE: Lubricating material, kg
1–16	293,0	258,0	120,0	454,0	89,4	114,4	246,0	—	—	220,3	10021,0	11876,1	—	—	—	—	—	—	614,5	1010,0	3095,5	1318,2	3151,0	45,75	8,0
17	—	—	—	506,0	—	92,0	—	—	—	—	512,0	1110,0	9	—	1	—	7	30	101,0	100,0	336,0	169,0	300,0	3,0	0,5
18	—	—	—	250,0	—	—	—	—	—	—	640,0	890,0	8	15	—	30	4	30	23,0	80,0	261,0	108,0	280,0	3,0	0,5
19	104,0	—	—	—	—	—	—	—	—	—	726,0	830,0	8	—	2	—	4	—	66,5	81,0	224,5	120,0	260,0	2,5	0,5
20	—	—	—	—	—	—	—	—	—	—	629,0	629,0	7	—	1	—	3	—	23,0	60,0	174,0	90,0	200,0	2,0	0,5
21	—	—	—	—	—	—	—	—	—	131,0	628,0	659,0	8	—	2	—	2	30	15,5	62,0	203,0	121,0	180,0	2,0	0,5
22	—	—	—	—	—	—	—	—	—	—	478,0	478,0	7	—	3	—	3	30	12,0	42,0	160,0	70,0	160,0	2,0	0,5
23	—	89,0	—	204,0	—	—	—	—	—	206,0	402,0	901,0	8	—	1	—	4	30	75,5	75,0	*)	153,0	180,0	2,5	0,5
24	—	93,5	—	221,0	225,0	—	—	—	11,0	—	347,0	897,5	8	—	2	—	4	—	58,5	108,0	*)	133,0	180,0	2,5	0,5

*) Weight unknown.

The slaughterhouse director Kohlberg, who carried out the experiments, adds the following information to this table.

“The table contains the weight of the material used, classified by kinds of animals, with an indication of whether they were carcasses, meat parts, or entrails. In order to make it possible to determine the profitability as accurately as possible, the duration of production is indicated. In addition, the table lists the weight of the products—fat, fertilizer cake in raw and dry form, and glue. For special reasons, chiefly entrails, bones, and other small meat parts were subjected to processing. In order to establish, as fully as possible, the productivity of the apparatus, whole carcasses of fallen animals and material richer in fat were also processed, although on a smaller scale. In general it may be said that the decomposition and sterilization of whole carcasses presented the least difficulty and required the shortest duration of the process. Lungs and liver require 7–8 hours at full load for complete processing.

Let us suppose that the yield of fat does not exceed, on average, 50% of its content, which, of course, is below the actual figure. Then 100,000 kg of material will yield about 8%, or 8,000 kg, of this product. Thus, from fat alone one should expect 2,880 marks of income, since 100 kilograms of fat are paid for by soap factories at an average price of 36 marks.

The glue obtained during processing currently has a sale value of 10–12 marks per double centner*). 100 kg of raw material yield about 8 kg of glue. From 100,000 kg, 8,000 kg of glue will be obtained, which, if reckoned at 11 marks per 100 kg, represents 880 marks of income. The glue put on sale up to now yielded, after deduction of the cost of transport to Berlin, 11–11.50 marks per double centner.

100 kilograms of raw material yield 26.7 kg of raw meat-and-bone residue. During drying and grinding this mass is reduced by approximately half, so that the yield of fertilizer cake is expressed by the figure 12–13%. A double centner of this cake has a sale value of 8.50 marks. In Berlin and Hamburg, for a similar commodity, 10–12 marks per double centner are paid.

It may be assumed, on the basis of analyses, that on average 100 kilograms of fertilizer cake contain at least 8.50 kg of nitrogen and 8.50 kg of phosphoric acid. The cost of a kilogram of nitrogen is approximately 0.80 m.; the cost of 1 kg of phosphoric acid is 0.22 marks.

*) 100 kilograms.

Therefore, 100 kg of fertilizer meal have a value, at the lowest estimate, of 8.50 marks, or rather, 8.67 marks. Since from 100,000 kg of material about 12,000 kg of fertilizer meal are produced, then, valuing 100 kg of it at 8.50 marks, the proceeds may be reckoned at 1,020 marks.

In all, for the products manufactured during the course of a year, with the final organization of the institution, one should expect a gross income of 4,780 marks.

The amount of expenditures is calculated as follows. According to the preliminary estimate, the entire machinery installation should cost no more than 17,000 marks. Taking interest on the capital and amortization at 10%, 1,700 marks must be included in the annual expenditure. A separate building with all appurtenances belonging to it should cost, according to the preliminary estimate, 5,000 marks. Interest on the capital and its amortization may be reckoned at 5%, which amounts to 250 marks annually. Wages for servicing the apparatus, for 104 days (two days weekly, at three marks), will be 312 marks. It is best if the apparatus is serviced by one person. For the payment of fallen animal carcasses, 1,000 marks may be reckoned annually. Coal, with an appropriate boiler installation, should be consumed at about 20 kg per 100 kg of raw material. For 100,000 kg this amounts to approximately 400 centners and will cost up to 400 marks. It is true that in the processing experiments up to 27 kg were required; but it should be taken into account that the locomobile used during the experiments, and moreover in winter, must be regarded as an unsatisfactory and very expensive boiler installation. For water, 50 marks are allotted, and for lubricating material, 33 marks. For maintenance of the machinery installation, repairs, etc., 400 marks may be reckoned, which amounts to about 2.5% of the cost of the installation, and for unforeseen expenses, 100 marks.

Thus the expenditure is calculated at a total of 4,245 marks. Consequently, with an assumed gross income of 4,780 marks, one may expect a net income of 535 marks.

With regard to the operation of the apparatus of the Otte-Hartmann system, experiments are known which were conducted at the rendering establishment of the city of Stettin. The results of these experiments are summarized in the table placed on p. 135.

Destruction and Utilization of Slaughterhouse Waste

Results of operation of the Otte-Hartmann system apparatus at the Štětín rendering plant in 1898.

No.	Time of experiments	Total duration of sterilization and drying, hours	Total quantity of raw material, kg	Animal meal with particle size up to 3 mm, kg	Coarser particles of animal meal, kg	Total quantity of animal meal, kg	Same, as % of charge	Animal fat, kg	Same, as % of charge	Glue syrup, kg	Same, as % of charge	Coal consumption, kg	Same, as % of charge
1	August 1898	10.15	2480	306,5	115	421,5	17,00	165	6,65	235	9,48	380	15,32
2	August 1898	10	2395	287	98	385	16,08	255	10,65	248	10,35	325	13,57
3	August 1898	10	2285	265	127,5	392,5	17,18	225	9,84	180	7,88	387	16,94
4	August 1898	10.15	2021	215	127,5	342,5	16,94	213	10,54	310	15,34	290	14,35
5	August 1898	10.45	2371	392,5	50,5	443	18,70	322,5	13,60	193	8,14	360	15,19
6	August 1898	10	2285	345	130	475	20,80	382	16,72	212	9,28	370	16,19
7	August 1898	10.15	2078	243	117,5	360,5	17,35	178	8,57	253	12,17	374	18,00
	Total	—	15915	2054	766	2820	—	1740,5	—	1631	—	2486	—
	Average	—	2273,5	293,5	109,5	403	17,72	248,6	10,94	233	10,38	355	15,65

Of other data on the profitability of institutions equipped with the Otte-Hartmann apparatus, we have at our disposal only a reference to the report of the utilization plant in Düsseldorf for 1903. In that year the plant processed 232,000 kg of raw material and had a deficit of 16,565 marks, which, however, is reduced—if payment of interest and debts is excluded—to 8,430 marks. The preceding years likewise ended with a deficit, although the size of the deficit for so large an institution is not great.

The information cited above, being necessarily brief and fragmentary, nevertheless shows that the processing of slaughterhouse wastes and animal carcasses by means of utilization apparatuses, when the work is properly organized, while bringing great benefit in sanitary terms, can not only cover its costs but even yield a net income, sometimes a fairly considerable one. Of course, there are cases in which the expectation of deriving income from this operation is not justified, and there are also cases of deficit. But, first, this is apparently explained most often by an irrational organization of the work, sometimes by accidental local conditions, and by no means by the essence of the process. On the other hand, even in the case of an undoubted deficit (which cannot be large), it should never be forgotten that utilization plants are not industrial institutions but sanitary-technical ones, and that their value is determined not by monetary income but by those undoubted benefits which they contribute to the general sanitary improvement of cities.

XIV. Information on the Development of the Work of Rendering Harmless and Utilizing Confiscated Products and Animal Carcasses in the City of Odessa.

Until the 1880s of the past century, the practice in the city of Odessa for removing animal wastes and the carcasses of fallen animals was the one customary for most Russian cities—namely, burial. The carcasses of animals recognized as infectious were buried in the ground together with their hides. With regard to the carcasses of healthy animals, utilization was limited to the removal of hides, hair, horns, hooves, and surface fat, which was carried out in primitive knackeries located at Peresyp; the carcasses themselves were also buried. The place of burial was a part of the Peresyp lowland (between the city and the limans), not far from the place where the water-lifting station for the irrigation fields is now located.

This practice, which had been followed for decades, had long since begun to make its inconveniences felt, above all from the sanitary point of view. Not to mention the extreme imperfection

…of this method of removal in principle, the character of local conditions made it especially inconvenient. The fact is that the Peresyp lowland is a sandy strip of land, rising at the dumping sites only 2–3 feet above sea level, and at this depth, in the layer of sand, there is already salty seawater. It is understandable that under such conditions the carcasses were buried at an insignificant depth and, moreover, directly in seawater. The consequence of this was that the conditions for the decomposition of the carcasses were extremely unfavorable. The carcasses, so to speak, were marinated in the water, remained undecomposed for a number of years, and in the summer heat, slowly decomposing in their upper parts, infected the air with a stench.

On the other hand, the economic side of the matter also began to attract attention. The quantity of carcasses of fallen livestock subject to removal increased more and more over the years, especially thanks to the strengthening of sanitary supervision, and by the end of the 1880s had reached very large figures. Taking into account that the average norm for the 1890s was:

for infected carcasses . . . . . . . . . . . . . 28160 poods.
for uninfected carcasses . . . . . . . . . . . . 34130 ”,

and in all 62290 poods, it must be thought that by the end of the existence of the “old regime” the quantity of carcasses reached no less than 50,000 poods per year. It is understandable that the cost of removing such a quantity of carcasses must have reached considerable proportions. Further, with the development by that time in the West of more advanced methods for the utilization of animal carcasses, which was expressed in the establishment of a number of public and private utilization plants, the throwing away of significant values in the form of such a mass of animal carcasses could not escape the attention of persons in charge of the municipal economy.

Be that as it may, the question of a more advanced method of removing and utilizing meat waste and fallen animals was, at the end of the 1880s, placed on the agenda and, after discussion, led to a certain practical improvement. At the beginning of the 1890s a new method of dealing with animal carcasses began to be used—the method of boiling. There, on the Peresyp lowland, a small plant was built, in the simplest form, for rendering fat from the carcasses of uninfected animals by boiling in open cauldrons. This method was evidently adopted as a temporary measure, since simultaneously with the opening of the plant, on the proposal of the City Administration, work was begun on the question of new, more advanced methods for the destruction and exploitation of animal carcasses.

In 1893, as a result of discussion of the question, there appeared a project, drawn up by the city engineer Mr. Paevsky (subsequently a member of the Board), for a crematorium for the carcasses of infected animals, without any utilization of these carcasses. The matter of this crematorium dragged on until 1895, but did not receive approval, since by that time proposals had appeared for the construction of a complete utilization plant on the European model.

In 1895 the French firm Durand et Miomandre, in Marseilles, made a proposal to the Odessa City Board to set up a utilization plant for processing animal carcasses for a known remuneration. In doing so, it proposed to equip the plant with apparatus of the Delacroix system. But no agreement was reached with this firm, because the Board found the conditions proposed by the firm Durand et Miomandre disadvantageous for the city.

At the same time, work was proceeding on the question of a truly rational arrangement for the destruction and utilization of animal refuse and carcasses; this work was being carried out both in the City Board and personally by Engineer Paevsky. The result of the discussion of the question was the decision to send Engineer Paevsky abroad to acquaint himself with the existing methods of rendering harmless and utilizing materials of this kind, and to choose the most suitable type of apparatus and organization of the plant.

Engineer Paevsky’s trip took place in 1895, and he succeeded in gathering considerable material relating to the arrangement of the matter of rational utilization of animal refuse in the cities of Western Europe. The outcome of this material and of his personal observations was a design for the construction of a utilization plant and an explanatory note, submitted to the City Board, which later served as the basis for the project that is being carried out at the present time.

The consideration of the report, its discussion, the drafting, discussion, and correction of the project, and its submission to the Ministry of Internal Affairs dragged on; however, the realization of Engineer Paevsky’s proposal was undertaken. Only in 1897 was the project for a utilization plant for the city of Odessa finally approved. But here, in carrying out the already completed project, obstacles of a financial nature were encountered, and the matter was again postponed until 1903.

In 1903, finally, thanks to the replenishment of the city’s funds by a 10-million loan, the opportunity arose to return to this matter. In that year it was decided to proceed with the implementation of the approved project of Engineer Paevsky, with the introduction of certain changes (construction next to the water-lifting buil—

of the irrigation fields, the use of mechanical power shared with this station, etc.). The mechanical equipment was entrusted to the firm Arthur Koppel. In 1904 and partly in 1905, work was carried out on the construction of the plant building and on its mechanical equipment, in the form in which it exists at the present time.

The operation of the utilization plant began in April 1905.

XV. Location and internal arrangement of the Odessa municipal utilization plant.

The utilization plant of the city of Odessa for the processing of animal carcasses and meat waste, together with the structures belonging to it, is located outside the city, along the Kuyalnik branch of the Southwestern Railways, in the Peresyp lowland, in the immediate vicinity of the irrigation fields.

The utilization plant itself (with a sanitary slaughterhouse) was built directly next to the water-lifting building of the irrigation fields, on an estate shared with it, bounded on one side by the right-of-way of the Kuyalnik branch, on another by the road from the city to the irrigation fields, and on a third by the area of the irrigation fields. Here, on this same estate, all the buildings relating to the utilization plant have been erected: namely, adjoining the plant building (see drawing 42), a stable for holding horses suspected of glanders, barracks for the employees of the plant, and also services. In addition, somewhat to the side, farther from the railway, there are two separate buildings indirectly connected with the same utilization plant and under the control of the general administration. These are, first, the old fat-rendering plant, now abolished with the opening of the utilization plant and converted into a drying room and a storehouse for hides removed from non-infected animals, horsehair, etc.; and second, premises for keeping captured stray dogs. Leaving these premises aside, since the latter has no direct relation to our task, and the former is equipped in the most primitive manner and is of no interest, we shall turn to a description of the utilization plant itself and the installations connected with it.

The main building of the utilization plant comprises (drawings 42 and 43) four parts: a sanitary slaughterhouse with a sectional chamber, the utilization plant proper with a shop (storehouse for fats), a veterinary-sanitary laboratory, and an office. It is a two-story stone building attached to the one-story water-lifting building of the irrigation fields, and is additionally provided with a bright attic room for storage.

The lower story (Fig. 42) is divided at the front into two halves. In the left half, beginning from the corner, there is first of all the so-called cadaver room, or sanitary slaughterhouse, i.e., the place for storing incoming carcasses and meat refuse and for slaughtering sick animals. A large part of this room is not covered by a ceiling, for the purpose of lifting material directly to the upper story, for transfer to the dissecting and loading rooms located there. The remaining part of the left half of the lower story is occupied by the veterinary-sanitary laboratory.

Part of the front section has been separated off to form two small rooms: first, an office connected with the laboratory of the utilization plant; second, the so-called tallow department, i.e., the room where the finished tallow is cooled, condensed, and discharged.

The right part of the lower story is occupied by the machine hall of the utilization plant. In it are located the following parts of the plant’s mechanical equipment:

1 Poddevils apparatus for non-infected animals (marked in Fig. 42 by the numeral 1);

2 Poddevils apparatuses for infected animals (2, 3);

2 pressure reservoirs (4, 5);

a mill for grinding oil cake (6);

a hoisting machine in the attic room for lifting the oil cake (7);

a gas apparatus (8);

a heating reservoir for water (9);

a collector for condensation water from the steam jackets of the apparatuses;

an electric motor (10);

an air pump (11).

In addition, in the floor of the machine hall there is a receiver for the runoff of all plant waters subject to sterilization (14); in the tallow department, a cooler and receiver for fat (12); in the yard, a reservoir for collecting and discharging finished tallow (13); in the discharge channel at the water-lifting building, a condenser; and near it, attached to the wall of the building, a gas separator.

The upper story is divided into three parts. The far left part, located above the cadaver room, as already stated, is not separated from the latter by a ceiling and forms a single whole with it. This part of the room communicates with the dissecting chamber by two wide and high openings, sufficient for the passage of whole carcasses. Therefore, instead of a floor, in this part of the upper story there are only iron platforms, serving, on one side, for direct—

...of a natural chute; by iron ladders, however, into the carcass room, and by another—for manipulations with winches (drawing 43, 8, 9), serving to raise carcasses from the lower floor. To the ceiling of this part of the upper floor are fastened beams along which, over the entire length of the room, with gates to the door openings into the dissection room, blocks with chains and hooks move for lifting the carcasses and transferring them into the rooms of the upper floor. These blocks are moved by the same winches.

The next part of the upper floor, above the laboratories, is occupied by the dissection chamber, i.e., the room where the carcasses of non-infected animals are cut up for loading into the apparatus, and where autopsies of carcasses are also performed. In the floor of this chamber hatches (6, 7) are made for draining the bloody fluid obtained during the operations into the utilization apparatus.

The part of the upper floor situated above the front and machine halls is occupied by the loading room, i.e., the room from which whole carcasses of infected animals or separate parts of non-infected carcasses are loaded into the apparatus. For this purpose, in the floor of the loading room, above each apparatus, hatches of the appropriate size are arranged (1, 2, 3). In addition, there are also openings for draining blood and dirty water into the utilization apparatus (4, 5). In the same direction beams are laid (11, 12), supporting a track for the movement of blocks, for the purpose of moving whole carcasses.

The attic room, illuminated by an upper skylight, serves as a storehouse for the solid products of the processing of carcasses, i.e., for feed and fertilizer meal. The latter are transported here by means of a hoisting machine through a hatch (drawing 43, 10) and are stored partly in sacks and partly in bulk.

All the rooms of the utilization plant are spacious and well lit. The walls of the rooms are painted with oil paint; the floor in the machine hall is made of terracotta tiles, in the laboratory it is parquet, and in the other rooms it is asphalt. All this makes it possible to maintain the required cleanliness in all the rooms.

The heating is by steam, by means of exhaust steam from the machines of the water-lifting station of the irrigation fields. The lighting is electric, by means of the plant’s own dynamo. Ventilation, extremely necessary in operations of this kind, is carried out by a mechanical fan located in the attic room and driven by an electric motor. Unfortunately, the operation of the apparatus, during my visit, was not entirely satisfactory.

The plant is supplied with water from a branch of the water main, pro-

conducted from the city main to the irrigation fields. A sewer has been installed beneath the building, discharging wastewater directly into the basin under the machines of the pumping station of the irrigation fields.

Adjoining the main building of the utilization plant, behind the carcass room, is a one-story stone annex, the isolation stable. The building is divided into two parts. One of them, the larger, is a room for keeping horses suspected of infectious diseases. It is divided by partitions into 7 stalls. To avoid contact between people and the suspect animals during feeding, fodder is placed from a special longitudinal corridor, separated from the stalls by a wall with openings in which rotating feeders are placed. The other, smaller part serves as a quarantine section for glanders-infected horses. Both rooms are high and bright. The walls and partitions are painted with oil paint; the floor is asphalt. The entire premises are kept irreproachably clean.

XVI. Mechanical equipment of the Odessa plant and the processing procedure.

Turning now to the mechanical equipment of the Odessa utilization plant, we shall begin with the machine room. Here, first of all, there are two Podewils system No. V utilization apparatuses for processing whole animal carcasses. The length of each apparatus is 3300 mm, the internal diameter 1500 mm. Its arrangement in all respects corresponds to the description of the Podewils apparatuses given above, with the sole difference that it is provided with a special large manhole of special design, measuring 1000 × 1200 mm, for loading large carcasses, independently of the ordinary manhole with an opening of 400 × 500 mm. The apparatuses are covered on the outside, to prevent cooling, with a poor conductor of heat and are sheathed on top with sheet iron. They have been tested at 3 atmospheres working pressure, i.e., at a test pressure of 6 atmospheres.

Each apparatus is equipped with two cast-steel trunnions rotating in ball bearings, a gear drive, and also the necessary pipelines, fittings, and a complete driving mechanism. Both are placed on special iron frames, supported on one side by the wall of the building and on the other by cast-iron columns. The supporting frame is furnished with an iron platform surrounding the apparatus and making it possible to walk around it for inspection and operations; this platform is enclosed by railings and provided with an iron stairway for ascending to it.

The fittings of each apparatus consist of the following parts:

1) two hollow trunnions which, independently of their direct function—supporting the drum during rotation—serve for the passage of pipelines into the apparatus;

2) pipe \(D\) for introducing live steam into the jacket of the apparatus; it approaches the right trunnion (cf. Drawing 22) at an angle and passes through this right trunnion into the right bottom;

3) a valve on pipe \(D\) for admitting live steam;

4) pipe \(C\) for discharging condensed water from the jacket; it exits through the same right trunnion, being located inside pipe \(D\) for the admission of live steam;

5) a valve on pipe \(C\);

6) two pipes, \(D^1\) and \(C^1\), for connecting the cavity of the steam jacket with the cavities of the bottoms;

7) elbow pipe \(a\), with openings at the end part, for introducing water and steam into the apparatus, pumping air out of it, and removing vapors and gases; it passes through the left trunnion and, by means of a stuffing box, enters with its outer end into steam box \(V\), connected with pipes leading to the steam boiler, the pressure apparatus, the air pump, and the condenser;

8) lever \(h\) for turning this elbow pipe into the upper position when removing tallow, and into the lower position when discharging glue liquor;

9) steam box \(V\);

10) a pipeline conducting water from the pressure vessel into the apparatus and back (Drawing 23, \(Z\)), with three valves and a device for separating the pipeline from the lower part of the apparatus while the latter is rotating;

11) branch pipe \(d\) (Drawing 22), bringing live steam through the steam box into the apparatus, with a valve;

12) branch pipe \(e\), leading from steam box \(V\) to the air pump and compressor, with a valve;

13) branch pipe \(F\) (Drawing 23) for discharging fatty substances from the apparatus into the cooler \((K)\), with a valve and a device for detaching it from the apparatus;

14) a large hatch for loading whole carcasses, with a device for hermetic closure;

15) a small hatch for loading carcasses in parts and for emptying the apparatus of the processed products;

16) a heavy shaft inside the apparatus for crushing the boiled parts of carcasses;

17) a toothed driving wheel.

The third rendering apparatus, also of caliber No. V, is intended for processing animal carcasses in parts. The length of the apparatus is 3500 mm, the internal diameter 1500 mm. Its construction is the same as that of the two preceding ones. The only difference is that it has no large manhole, but one ordinary manhole with an opening of 400 × 500 mm. The apparatus is fitted with the same fittings and devices and is mounted on an iron frame constructed in a similar manner.

A necessary supplement to the rendering apparatuses consists of two pressure reservoirs. They are cylinders of sheet iron, each 3000 mm high, with an internal diameter of 1500 mm, with dished bottoms, a manhole, and a water-gauge device. They are intended for storing and heating the glue liquor released during processing and introduced into the apparatus in place of hot water. These reservoirs have been tested at a working pressure of 6 atmospheres.

Each of them is fitted with the following equipment:

1) two steam-inlet valves in the lower part of the vessel for heating the liquid;

2) two steam-inlet valves for establishing the required pressure;

3) an injector for pumping liquid waste from the sump (see above);

4) a water-gauge glass and water-gauge cocks at three levels;

5) two pressure gauges;

6) a manhole for inspecting the interior of the device;

7) a pipe for carrying blood and other liquid residues from above, with a valve;

8) a pipe to the air pump, with a valve;

9) a pipe leading to the steam boiler, connected with the above-mentioned 4 valves;

10) pipelines to all Poděbrady apparatuses, with the corresponding valves.

The clean water feeding the pressure reservoirs is first collected in a special tank, where it is heated by exhaust steam. This water-heating reservoir is an iron cylinder fitted with a coil and equipped with the following devices:

1) a pressure gauge;

2) a water-measuring glass and two water-gauge cocks;

3) a hatch for inspection;

4) a pipe bringing water from the water supply;

5) pipelines to both pressure apparatuses, for conveying heated water into them;

6) a pipeline for bringing in steam;

7) cocks and valves on the corresponding pipelines.

The collecting vessel for clean hot water coming from the steam jackets of the apparatuses, from the condensation of steam, consists of an iron cylinder 800 mm in diameter and 1000 mm high. The water collected in it serves to feed the steam boilers. The cooler for cooling the obtained fat (Fig. 23, K) consists of a pipe with fittings for the pipelines bringing in and carrying away cold water.

The mill for finely grinding the animal meal obtained from the Podewils apparatuses—the Grusonwerk plant in Magdeburg-Buckau, “Excelsior,” model III. The diameter of the millstones is 400 mm; productivity per hour with fine grinding is 400–500 kilograms, and with coarser grinding 700–800 kilograms. It is set in motion by a belt drive from the main shaft.

Inside the apparatus room, and partly outside it, are the following pipelines:

a steam line from the steam boilers to 3 apparatuses and 2 pressure reservoirs;

a water line from 2 pressure reservoirs to the apparatuses; the line from the blood collector is also connected to it;

a water line leading back from the apparatuses to the pressure reservoirs;

a hot condensation-water line from 3 apparatuses to the collecting reservoir;

a hot-water line from this collecting reservoir to the boiler feed pump;

a pipeline for fat;

a cold-water line to the fat cooler, the air pump, the pressure vessels, the water-heating reservoir, and the hot-water collector;

pipelines from the apparatuses to the air pump and condenser;

a gas line from the gas separator into the furnace of the steam boilers.

The motive power and steam for the utilization plant are supplied from the water-lifting station of the irrigation fields. The latter is equipped with three steam engines and three boilers. Of the steam engines, two are small high-pressure engines of 20 nominal horsepower each, from the Bellino-Fenderich plant in Odessa, making 70 revolutions per minute;

the third machine is a compound machine, of 80 horsepower, made by Ruston-Proctor, making 90 revolutions per minute. Steam for the machines of the station and for the apparatus of the utilization plant is supplied by 3 steam boilers. Of these, two boilers are of the Paucksch system, with 1 steam-dome and 32 smoke tubes, made by Bellino-Fenderich in Odessa. The diameter of each of these boilers is 3′3″, length 10′1″; diameter of the steam-dome 2′, length 10′5″; diameter of the smoke tubes 3″, full heating surface 375 sq. ft.; working pressure 4 atm. The third steam boiler, with two steam-domes and 62 smoke tubes, was made by Bellino-Fenderich in Odessa. Boiler diameter 4′2½″; length 10′2″; diameter of the steam-domes 2′, length 10′8¾″; tube diameter 2¾″; working pressure 5 atm.

For transmitting power to the utilization plant, and also for the electric lighting of the water-pumping station and the plant, a Siemens & Halske dynamo machine (220 V., 40 A., 1750 rev.) has been installed, driven by a belt from the pulley of machine No. 1 (the large one), and giving, at 1500 revolutions, 10 horsepower. For the time when there is no need for machine No. 1 to operate, electric lighting is provided by a small Schuckert dynamo machine (240 V., 8.3 A., 1500 rev.), which is driven by a Laval brothers steam turbine, operating with steam from the boilers.

The greatest energy that the engine must develop is calculated approximately as follows:

Purpose	Power
for two Podewils apparatus operating simultaneously	3 horsepower
for the air pump	2–3 horsepower
for the mill (periodically)	6–7 horsepower
Total	11–13 horsepower

The necessary steam pressure for processing the material is 3–4 atmospheres. The amount of steam for the complete processing of one charge of 120 poods is up to 270 poods. On average, the utilization plant requires a daily steam consumption of 500 to 550 poods. The necessary mechanical power for the operation of one Podewils apparatus during the drying process is on average 1 horsepower, at most 1½ horsepower. For the air pump 2 to 3 horsepower are required, and for the mill, at times, 6 to 7 horsepower. The steam engines available in the water-pumping station can easily provide the necessary power for the utilization plant when two apparatus are engaged in drying, since the mill operates for only one hour during the day and works only when the steam engines are lightly loaded.

The transmission from the driving machine to the main shaft and from the main shaft to the moving parts consists of the following elements:

1) the main transmission shaft, making about 200 revolutions per minute;

2) a transmission shaft, 6.1 meters long and 60 mm in diameter;

3) a transmission shaft, 8 meters long and 60 mm in diameter;

4) a cast-iron split pulley for the air pump, 400 mm in diameter and 350 mm wide;

5) a cast-iron pulley for apparatuses \(A_1\) and \(A_3\) (for infected carcasses), 400 mm in diameter and 400 mm wide;

6) a cast-iron pulley for driving apparatus \(A_2\) (for non-infected carcasses), 400 mm in diameter and 200 mm wide;

7) a cast-iron pulley for driving the mill, 800 mm in diameter and 260 mm wide;

8) a cast-iron pulley for the hoist, 300 mm in diameter and 250 mm wide;

9) belts 120—100—90 mm wide.

The equipment of the sanitary slaughterhouse (cadaver chamber), the sectional room, and the loading room consists of the following parts.

1) Two winches for raising carcasses from the cadaver room, moving them along an overhead transport track, and transferring them to the sectional room. Each of them consists of the winch itself, in a lockable wall cabinet, a steel cable about 20 meters long, made of crucible cast steel, ending in hooks, 2 wall anchors with rollers, 2 ordinary fixed rope blocks, and double movable rope rollers. The lifting capacity of each winch is 1,250 kilograms. The winches are provided with automatic brakes that allow a uniform lowering speed, devices for convenient lowering without load, and for bringing parts of carcasses together when placing them on carts.

2) 83 linear meters of overhead transport track made of double-T beams along the ceiling above the slaughterhouse itself, the sectional room, and the loading room, for moving carcasses whole or in parts.

3) 4 movable carts running on this track, with suspended pulley blocks of different lifting capacities, for moving carcasses whole and in parts.

4) Ordinary four-wheeled carts for transporting dismembered carcasses.

5) Pulley blocks for suspending carcasses when removing the hide.

6) Hoppers for loading small cadaver material into the apparatuses.

7) 2 collecting vessels for blood and wash water, placed

in the sectional floor, with pipes for direct emptying and for conveying the blood with the wash water into the apparatus.

8) Wall-mounted washing bowls, with taps and a water drain.

The equipment of the storehouse (the warehouse for dry products) shall have the following composition.

1) A lifting device, leading from the apparatus room into the attic, for delivering animal meal to the storehouse. It is a friction hoist, driven by the transmission, and consists of two guide rails of box iron, with proper curves, an iron lifting platform moving along these rails, two rope pulleys, and a hoisting drum with the appropriate mechanism.

2) Three tipping iron carts, each with a capacity of up to 200 liters.

3) A device for lowering sacks of animal meal from the storehouse onto carts. It consists of a drum driven by hand, with a hand brake, guide rollers, and a hoisting rope with a hook.

The arrangement of the principal parts of the mechanical equipment of the plant is shown schematically in drawings 42 and 43. In addition, I consider it not superfluous to attach a view from the original design of the Odessa utilization plant, prepared by the firm Arthur Koppel in Petersburg (drawing 44).

The procedure for processing animal material at the Odessa utilization plant is as follows.

The animal carcasses delivered to the plant are, before processing, subjected to a veterinary-sanitary examination to determine whether the animal died of a contagious disease. For the preservation of carcasses awaiting dissection, a receiving room is provided (the carcass chamber), which also serves as a sanitary slaughterhouse.

The carcasses of animals that died of a contagious disease enter the Podewils apparatus intended for them whole, together with the hide, hair, and viscera. For transporting infected carcasses there is also a separate rail track with movable blocks, which deliver such carcasses from the receiving room to the upper floor, and thence into the apparatus. The blood flowing from them, and the water washing it away, are likewise immediately discharged into the apparatus for sterilization.

Uninfected carcasses are first moved into the other half of the same receiving room, where the hide is removed from them and the viscera are taken out. The contents of the intestines, the so-called dung, are carted away in carts to the dumping place, whence the peasants take it away for [[unclear: continuation cut off at bottom of page]]

this material for fertilizer. The hides are sold, after some treatment in the drying room. The entrails are moved, in tipping carts, directly to the loading room, where they go into the apparatuses. The opened carcasses are lifted and conveyed on blocks, in a suspended position, to the cutting room. Here they are cut up into parts, and the latter are loaded into the apparatus through funnels.

When the filling of the apparatus (“loading, charging”) is completed, hatch \(M\) (Fig. 23) is tightly closed, and the air is driven out of the apparatus by means of an air pump. At this time the liquid in the pressure vessel (glue liquor from the preceding charge) is heated with steam from the boiler, at a pressure of 3–4 atmospheres. After this the process of sterilization and steaming begins. For this purpose, on one side, through pipe \(Z\), a portion of the heated liquid is driven from the pressure vessel into the apparatus, in an amount approximately equal to \(1/3\) of the internal volume of the drum. On the other side, live steam is admitted into the jacket of the apparatus, and also into its interior, and a constant circulation of steam is established. Owing to this, a constant temperature and pressure are obtained inside the apparatus, corresponding to 3 atmospheres (\(140^\circ\)C). This pressure is maintained in the apparatus for 4 hours. During this time the apparatus is from time to time set into rotary motion.

Through the intensive action of the hot liquid all pathogenic elements are destroyed. Further, a fairly complete separation of fatty, as well as glue-forming, substances takes place. Bones, sinews, and hooves lose their hardness, and the entire mass being treated is ultimately transformed into a kind of gruel. Owing to the rotation of the drum, this mass comes into slow motion, and the softened parts are mixed, the result of which is a more thorough separation of fat.

The glue liquor remaining in the pressure vessel is then finally driven into the apparatus, so that the interior of the drum is filled to the very top. At the same time a second washing of the material takes place, intensifying the separation of fat. In this way all the fatty elements contained in the mass are extracted by the hot liquid and rise to the top. After such steaming-out, the content of liquid substances in the apparatus amounts to approximately \(2/3\) of its volume, while at the bottom there is a digested meat-and-bone mass. The fat floats in a thin layer on top.

Practice has shown that shortly after washing, further separation of fat ceases; therefore it is most convenient to take off the fat immediately after this washing. To obtain this fat the following simple method is used. Owing to the greater

Owing to its light weight, all the fat rises upward, to the manhole, where it collects in the narrowest part of the apparatus in a rather thick layer. From there it is expelled, by opening the valve, through pipe F, and then, after passing through refrigerator K and the gas separator G, flows down through the discharge pipe into the receiver. The fat obtained here is perfectly clean in appearance and can immediately be put on sale. For convenience, from the receiver it is directed into a large reservoir in the yard, from which it is taken by buyers.

The fat, which boils at a temperature of 160° C., leaves the apparatus at a temperature of 130° C., quite calmly and without emulsion. But when, together with the last remnants of fat, the glue liquor also begins to appear, then at a temperature above 100° C. such a phenomenon may occur that part of the water, on leaving the pipe, evaporates and produces mixing of the fat with the glue liquor, which assumes the appearance of an emulsion. In order to obtain these last residues of fat in a clean form as well, a refrigerator is placed on the pipe carrying off the fat, in which the product passing through is cooled below 100° C., thereby eliminating the appearance of emulsion.

After the fat has been discharged, the glue liquor is driven from the drum back into the pressure reservoir by rotating pipe a and lowering the pressure in the reservoir. At the next charge this liquid is again let into the work. After this begins the process of drying the defatted solid substances remaining in the apparatus. The drum is rotated, and its walls and bottoms are heated with steam. At the same time, the material is dried and crushed by means of a heavy roller rolling inside the drum. The vapors formed inside the drum during the drying process are led off through pipe a into the condenser. There these vapors are condensed and converted into water. This water, perfectly clear, is discharged into the receiving well of the water-lifting building. The small quantity of gases that do not undergo condensation is led under the grate of the steam boiler and burned there. The clean hot water formed in the steam jacket from condensation of the boiler steam is used for feeding the steam boilers. Steam drying, with the drum constantly rotating, continues for approximately 6–7 hours, until the entire mass is finally crushed and converted into powder.

When drying is complete, the manhole is opened, and the drum, after making about 40 more revolutions, automatically pours the obtained meal into the tip-carts placed beneath it. After this the material is passed once more through a mill and then lifted into the store—

magazine, where it is piled in heaps or loaded into sacks for sale.

The duration of the entire operation is from 10 to 12 hours. The glue liquor is kept in the pressure vessel until the next charge and, when the drum is filled again, is used anew. In this way, part of the glutinous substances is each time combined with the solid residue, is dried, and turns into meal. Periodically the pressure reservoir is emptied of the glue liquor, and then, of course, the first operation begins with clean hot water.

XVII. Information on the products of the work and on the economic aspect of the enterprise at the Odessa plant.

Having thus completed the description of the technical arrangement and equipment of the Odessa utilization plant, we consider it necessary to dwell on questions relating to its operation. This will give us the opportunity to clarify the administrative organization of the plant, its present and anticipated productivity, as well as the economic results of its operation. The consideration of these questions, it seems to me, should have a place in a work that counts on the attention not only of technicians, but also of municipal administrators, for whom economic questions must play an especially important role.

The Odessa utilization plant, whose equipment was completed at the beginning of 1905, began to function in April of that year. I had occasion to visit it twice during 1906, namely in May and in September. I made use of my stay in order to gather the information presented below. Unfortunately, it covers a very short period, namely actual data on operation for 9 months of 1905 and only certain preliminary data relating to 1906. I was unable to obtain later information and reports for the subsequent years.

At the head of the Odessa utilization plant stands the manager of the plant and of the veterinary-sanitary laboratory. Besides him, the plant’s personnel consists of the following persons:

Personnel	Salary
1 machinist with a salary	65 rubles per month
1 assistant machinist with a salary	45 rubles per month
1 clerk with a salary	35 rubles per month
2 workers in the machine department, at	30 rubles per month
2 workers in the section department, at	30 rubles per month
2 assistants to them with a salary, at	22 rubles per month

The salary scale is according to the estimate for 1905 and 1906. But in 1906 the sa-

workers; at their demand, it was increased by 1½ times. For all expenses connected with the maintenance of the utilization plant, according to the estimate of the City Administration, 10,000 rubles are allocated, of which 4,250 rubles are specifically for coal.

As for the amount of work of the utilization plant, it was calculated, on the basis of data collected in 1903 for the last 5 years, for the annual processing of about 60,000 poods of material. The following statement gives an idea of the quantity now actually arriving: the number of carcasses of animals that fell and were killed under veterinary supervision, from April 9, 1905 to January 1, 1906, arranged by months of the year.

Months	Fallen unskinned	Fallen skinned	Fallen poisoned animals	Killed unskinned	Total
April 1905	93	23	2	14	132
May	172	22	13	30	237
June	181	31	1	50	263
July	156	48	3	38	245
August	150	16	15	41	222
September	158	21	18	57	254
October	117	23	11	28	179
November	125	15	9	31	180
December	155	18	18	24	215
Total	1306	217	90	313	1927

The table presented does not give the weight quantity of carcass material arriving at the plant. But this figure can be determined approximately from the statement given below, concerning the number of charges (loadings) of the apparatus processed over 9 months. It turns out that there were 286 charges in all. Consequently, counting each loading at 120 poods, it may be assumed that in 9 months 34,320 poods arrived at the plant. The figure corresponding to a whole year will be 45,760 poods.

The character and intensity of the work of the apparatus are clarified by the fol—

…in the following table, showing the number of working days and hours of operation of the plant’s apparatuses, from April 9, 1905, to January 1, 1906.

Months	Quantity: Charges	Quantity: Days	Quantity: Nights	Quantity: Hours	Quantity: Minutes	Average duration: Charge	Average duration: Working days
From 11/IV to 11/V	25	22	—	273	—	10.9	12.4
From 12/V to 11/VI	30	26	1	333	—	11.1	12.8
From 12/VI to 12/VII	38	26	11	418	45	11.0	16.1
From 13/VII to 12/VIII	46	28	17	525	—	11.4	18.75
From 13/VIII to 12/IX	37	27	14	462	—	12.5	17.1
From 13/IX to 12/X	38	25	12	490	30	12.9	19.6
From 13/X to 12/XI	34	25	7	401	50	11.8	16.2
From 13/XI to 12/XII	27	25	5	320	30	11.8	12.8
From 13/XII to 1/I	11	13	3	141	15	12.8	10.9
Total	286	217	70	3368	50	12.2	15.5

As regards the products of the utilization plant, in the processing of animal material fat and dry ground animal meal are obtained; moreover, from non-infected carcasses there remain hides, horsehair, bristles, and similar materials. Fat, owing to its purity and good quality, is readily purchased by soap-making and candle factories. Animal meal obtained from non-infected carcasses, as was indicated earlier, represents excellent material for feeding domestic animals, while the same meal from infected carcasses must be sold as fertilizing guano. Unfortunately, the sale of animal meal from the Odessa plant locally and in Russia encountered difficulties, since we have too few farms using this product. Therefore, at first it was necessary to sell this meal at a price below its cost to middlemen who shipped it abroad.

The productivity of the plant is characterized by the following statement, in which are listed the quantities of products manufactured and the prices received for them, from April 8, 1905, to January 1, 1906.

	Rubles	Kop.	Rubles	Kop.
For meat-and-bone tallow, 7,698 poods	2931	25
Remaining as of 1/I 1906, 130 poods	65	—
For fertilizer tallow, 1,069 poods	235	15	3231	40
For fat, 975 poods	3580	80
“ ” 250 poods, remaining by 1/I	1075	—
For hides	5475	07
“ manes and tails	396	12
“ horseshoes	42	70	10569	69
	—	—	13801	09

At the same time, operating expenses amounted to 10,877 rubles 43 kopecks. Thus, in the first 9 months of its existence the utilization plant brought in a net income of 2,323 rubles 66 kopecks.

The estimates for 1906 and 1907, made by the manager of the plant and communicated to me, lead one to think that the profitability of the plant should subsequently rise still further. According to the preliminary estimate for 1906, gross income was expected to be 21,000 rubles, operating expenses 14,000 rubles, and net income 7,000 rubles. According to the estimates for 1907, it was intended to receive a gross income of from 25,000 to 30,000, on average 27,500 rubles, with expenses of 13,000 rubles, and thus to have a net income of 14,500 rubles.

It is appropriate to mention here that, in the opinion of the plant manager I. A. Nonevich, the matter can be arranged still considerably better, especially in economic terms, by means of the following measures designed by him. First, he considers it disadvantageous to sell the prepared fat to outside parties, and proposes installing a soap-making apparatus for preparing soap, so as to supply with it first of all the large municipal laundry existing in Odessa, and to put the remainder on the market. Further, he finds it advantageous to install a glue-making apparatus for boiling glue from hooves, horns, etc., and from what remains in the process.

glue liquid. Thirdly, he proposes to reorganize and arrange in a more rational manner the sale of hides, skins, and horsehair, which are at present sold to outsiders in an unfinished state. Finally, drawing attention to the present unprofitability of the production of animal tallow, owing to the small demand for it and its low price, he considers irrational, from this point of view, the proposed destruction of the existing works at the irrigation fields of the municipal breeding piggery. He finds it more profitable, and even necessary, to resume operations with a view to consuming the tallow produced at the utilization plant.

It remains now to give information on the cost of the construction and equipment of the Odessa utilization plant. In this connection I have at my disposal: with regard to the cost of construction, an extract from the approved estimate for this construction; and with regard to the equipment, a copy of the approved estimate. I present these data, with appropriate abridgments, since I consider them very useful as references for persons practically interested in this matter.

The construction cost, according to the above-mentioned report, is determined by the following figures.

Item	Amount
Earth and masonry work	8564 rub. 80 kop.
Interior fittings	10865 rub. 42 kop.
Carpentry and joinery work	3029 rub. — kop.
Plastering work	1567 rub. 39 kop.
Miscellaneous work	439 rub. — kop.
Construction of the metal roof structure	7500 rub. — kop.
Total	31965 rub. 61 kop.
For scaffolding, bracing, removal and clearing of debris	639 rub. 39 kop.
For preparation of the design, estimate, detailed drawings, and supervision, 4%	1305 rub. — kop.
For maintenance of a foreman for 4 months	240 rub. — kop.
Grand total	34150 rub. — kop.

The cost of the mechanical equipment, according to the approved estimate, is calculated as follows.

1) Two Podéwils system utilization apparatuses No. V for processing whole animal carcasses, 3500 mm in length, 1500 mm in internal diameter, with a special large manhole for loading whole large carcasses and an ordinary manhole, with the necessary pipelines, fittings, and complete drive mechanism, with iron frame, platform, staircase, railings, and cast-iron columns, at 10,300 rub. each . . . . . . . 20,600 rub.

2) One utilization apparatus of the Podewils system, No. V, for treating animal carcasses in pieces of the same dimensions, with an ordinary manhole, with the same fittings and appurtenances . . . . . . . . . . . . . . . . . . . . . . . 7875 rub.

3) Three sheet-iron funnels for all Podewils apparatuses, lined with strip iron, with handles, at 95 rub. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285 rub.

4) Two water-pressure vessels of sheet iron, each 3000 mm high, with an internal diameter of 1500 mm, with fittings for steam heating and complete armature, at 1475 rub. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2950 rub.

5) Air pump, diameter 280 mm, piston stroke 140 mm, with an injection condenser (for the same) and complete driving mechanism . . . . . . . . . . . . . . . . 1300 rub.

6) Collecting vessel for hot condensation water, consisting of an iron cylinder, 800 mm in diameter and 1000 mm high, lined with angle iron . . . . . . . 175 rub.

7) Cooler for cooling the obtained fat, consisting of pipes with nipples for the pipelines bringing in and carrying off water . . . . . . . . . . . . . . . . 350 rub.

8) Gas separator for gases not subject to condensation, consisting of an iron cylinder 500 mm in diameter and 1000 mm high . . . . . . . . . . . . . . . 150 rub.

9) Transmission, total cost . . . . . . . . . . . . . . . . . . . . . . . . . 1975 rub.

10) Pipelines with armature, total cost . . . . . . . . . . . . . . . . . 2550 rub.

11) Insulation of three Podewils apparatuses and steam pipelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 480 rub.

12) Wrenches and various tools . . . . . . . . . . . . . . . . . . . . 185 rub.

13) Installation of all machine equipment and its trial run, as well as familiarizing the workers with production, travel expenses for the fitter, transport of his tools, drawings, and other expenses . . . . . . . . . . . . . 2250 rub.

14) Auxiliary workers for installation . . . . . . . . . . . . . . . . . 1360 rub.

15) Slaughterhouse, sectional and loading:

two safety winches, each with a load capacity of 1250 kilograms, with automatic brake, other fittings, and a steel cable about 40 m long;

4 movable trolleys for transporting meat along a suspended track;

4 small hoists for removing hides;

2 collecting vessels for blood and wash water, placed in the floor of the sectional room, with pipes for emptying and conveying the blood with wash water into the apparatuses;

2 wall-mounted washing basins, cast-iron enameled, with taps and with drainage.

The total cost of equipping these premises is 2,500 rubles.

16) Storehouse:

a lifting device from the apparatus room for hoisting animal meal into the storehouse;

3 tipping iron carts, each with a capacity of 200 liters;

an “Excelsior” mill for grinding animal meal, with a drive and a spare pair of millstones;

a device for lowering sacks of animal meal from the storehouse onto carts, with a braking device and a winch.

Total cost of the storehouse equipment . . . 2,900 rubles.

17) Installation of the slaughterhouse, section room, loading room, and storehouse . . . . . . . . . . . . . . . . . . . . . . 300 rubles.

18) Construction of foundations for the apparatus:

under the knees of the Podewils apparatuses,

Item	Area	Cost
total about	6.4 sq. m
under the mill	1.2 sq. m
under the air pump	2.0 sq. m
under the water-pressure vessels	2.2 sq. m
under the winches and gas separators	1.7 sq. m
Total about	13.5 sq. m	450 rubles

Total full cost of the machinery equipment . . . 48,635 rubles.

Thus, the construction of the plant cost in all 34,150 rubles; the equipment, 48,635 rubles; and the total initial cost of the plant was 82,785 rubles. This expenditure, it must be said, appears extremely high.

In any case, using this figure, let us verify the economic profitability of this institution.

If we take as a basis the available figures for the first 9 months of the plant’s existence, it turns out that gross income may be reckoned at 18,400 rubles. The total expenditure for the whole year is 14,604 rubles. Thus the net income, not counting interest on capital and amortization, will be 3,796 rubles for the year. Thus, in the first year, the utilization plant more than covered its operating expenses. For the following years we shall take as a basis those figures which, in the opinion of the plant manager, may be expected in 1906 and 1907. Let us take as the profitability figure the arithmetical mean between 21,000 rubles and 27,500 rubles, i.e. 24,250 rubles; likewise, for expenses, the mean between 14,000 rubles and 13,000 rubles, i.e. 13,500 rubles. Then the net annual income, without deduction of interest and amortization, will be 10,750 rubles. If we consider that the interest on the expended capital of 82,758 rubles and the amortization together amount to 10%, i.e. 8,276 rubles.

Then the net profit will be 2,474 rubles. On the sum of 82,785 rubles this amounts to about 3% per annum, i.e., a respectable monetary income for the municipal treasury, given the very high initial expenditures, as was indicated, quite apart from the sanitary benefits that the rendering plant provides the city through its operation.

The development of the matter of decontaminating slaughterhouse waste in Western Europe at the present time, under the influence of the growth of cities and the accompanying growth in the centralization of slaughterhouse and knacker’s-yard operations, as well as under the influence of public demands for the sanitary improvement of cities, is proceeding at an accelerated pace. Russian cities are inevitably following the same path. The municipal administrations of larger cities, for hygienic reasons, usually concentrate in their own hands the slaughter of livestock; they also often assume, for the same reasons, though less willingly, the removal and the associated partial utilization of animal carcasses. The duty to care for the sanitary improvement of the city, including its cleansing of all kinds of waste, in this case confronts municipal administrations with no easy task. The increasing quantity of slaughterhouse waste and confiscated material makes their removal, followed by burial, ever more difficult and costly, while at the same time providing no guarantee of decontamination; at the same time, primitive methods of dealing with the carcasses of fallen animals are unhygienic and imperfect with respect to utilization, and infected carcasses are excluded altogether from utilization, causing only expenses for removal and burial. At the same time, the ever-growing demands of rational public hygiene emphasize the imperfection and unreliability of the simplest methods of decontamination, and have particular right to emphasize this when applied to institutions of public significance. Thus, for municipal administrations, alongside other questions of urban sanitation, there arises the important and difficult question of a rational method for decontaminating slaughterhouse waste, confiscated material, and animal carcasses, and of the possibility of utilizing the valuable parts of this material in a manner irreproachable from the hygienic point of view. Municipal administrations, of necessity, turn to the example of the cities of Western Europe and seek the solution of the problem in technical inventions, in the construction, in place of old knacker’s establishments, of rendering plants, and in equipping slaughterhouses with the same rendering institutions or devices for the destruction of waste. These technical devices, at the present time, after a series of trials and improvements, make it possible in the most reliable manner to decontaminate slaughterhouse—

slaughterhouse wastes of all kinds and, moreover, simultaneously with decontamination, to utilize all the valuable parts of such wastes. Thus, technology provides a path toward a rational solution to this question of urban sanitation.

The methods for the destruction and decontamination of that kind of solid refuse of urban life represented by slaughterhouse wastes, confiscated products, and animal carcasses constitute a branch of sanitary engineering that has been little touched upon in Russian technical literature. Meanwhile, an exposition of it is important not only for the completeness of a scientific survey of the methods of urban sanitation, which constitute the task of sanitary engineering as a science, but also in the interests of the matter itself. First of all, the existing methods of destroying and decontaminating slaughterhouse wastes, like all technical inventions, despite all the merits that do credit to their inventors, cannot lay claim to perfection. The path of their development is far from complete, and such development is even necessary in the sense of further improving the design of the apparatus, and especially in the sense of simplifying this design and reducing the cost of the installations. The spread and development of this branch of urban improvement depend most seriously on this latter circumstance. Therefore, a printed presentation of information relating to the destruction and decontamination of slaughterhouse wastes may attract the attention of specialists to this field of technology and promote technical progress in the apparatus and methods of treatment. On the other hand, it is the duty of those engaged in technical science, which is concerned with the sanitary improvement of cities, to place at the disposal of persons interested in questions of urban sanitation—in particular, municipal officials—material on this question of urban technology, new to most, that is fairly complete and systematically presented; to contribute to the popularization of this question among them; to help put a new and useful undertaking into practice; and, in its practical implementation, to make it possible to understand consciously the technical and economic aspects of the matter. These aims I had in mind in collecting, systematizing, and presenting the material that is offered to the attention of readers in the form of the present work.

All the data set forth above concerning modern technology for the destruction, decontamination, and utilization of slaughterhouse wastes, confiscated products, and animal carcasses, in connection with information on how the matter is organized in certain existing institutions, lead to the following conclusions.

Modern technical installations make possible the complete,

complete and safe decontamination of all wastes of animal origin, slaughterhouse wastes, confiscated materials, and animal carcasses, including infected ones, without removal beyond the limits of populated places, at the place where these wastes are obtained or in special institutions.

Technical methods of decontamination give incomparably more reliable results in the sanitary sense than the method of removal and burial, although replacing this customary method with them is more often decided by economic considerations.

In institutions producing a small quantity of animal wastes, the most suitable means of replacing removal is the destruction of wastes by incineration; in large institutions, the more advantageous principal means of replacing removal is thermal processing and utilization of wastes, accompanied by sterilization.

Specially constructed furnaces for incinerating wastes, destructors or cremators, produce rapid and irreproachable decontamination of wastes, but, requiring considerable expenditures for their construction and operation, at the same time fruitlessly destroy a number of valuable materials contained in the wastes.

The actual wastes of slaughterhouses—the contents of the stomach and intestines, intestinal mucus, drained blood, etc.—in modern installations are processed into a fully sterile powder for fertilization, although for the present, with considerable difficulties, not entirely faultlessly as regards the external side of the process, and usually without economic benefit.

The confiscated materials remaining at slaughterhouses, meat wastes, and blood may, with the aid of modern apparatus, undergo complete sterilization and be processed into fat, glue, feed or fertilizer cake, if their quantity, without prolonged storage, is sufficient for independent processing. The same apparatus can sterilize and process into the same products the carcasses of fallen and slaughtered animals, including infected ones, separately or together with confiscated materials and meat (and sometimes other) wastes of slaughterhouses.

Apparatuses for the sterilization and processing of confiscated materials and carcasses are quite numerous, but they are similar in their basic idea and in the process of thermal treatment. The newest and most advanced of them, the so-called universal utilization apparatuses, carry out the entire process of sterilization and processing, up to the receipt of finished products that are impeccable in the sanitary sense, within a single, hermetically closed system, with immediate

removal, decontamination, or destruction of all useless liquid and gaseous products of production.

The most tested, widespread, and, apparently, most perfected and reliable utilization apparatuses are the systems of Otto-Hartmann and Podewils. Although there are theoretical grounds for considering the first system to have been developed more coherently and completely, the results of practical operation, insofar as they are known, do not yet provide grounds for speaking of any noticeable advantages of one system over the other.

The utilization of confiscated materials, meat waste, and animal carcasses, when the institutions intended for this purpose are properly and economically arranged and when the enterprise is conducted rationally, usually not only covers the costs of construction and operation, but also yields a net income. However, contrary to the frequently encountered thoughtless and incorrect evaluation of this matter exclusively from the point of view of the income produced, it must be remembered and emphasized that a utilization plant is a sanitary-technical institution, not an industrial one; that its chief advantage consists in the sanitary benefit it brings to urban improvement. If even small deficits occur in the operation of such institutions, they are always repaid many times over by the sanitary advantages obtained by the city.

Utilization plants, when properly arranged, with modern technical equipment and rational operation, are so well provided for with respect to the sanitary cleanliness of their processes that it is permissible to establish such plants, for the joint sterilization and utilization of slaughterhouse waste and animal carcasses, within the limits of populated places and, for convenience, in the immediate vicinity of slaughterhouses.

But in order for a plant to have a real right to be considered modern and properly organized, a whole series of conditions relating to its arrangement, equipment, and operation—conditions both hygienic and technical—must be fulfilled. These conditions have been indicated and justified in their proper place, but it is never harmful to repeat them. These are, first of all: the correct choice of site; the proper placement and rational external and internal arrangement of the building and of the separate rooms, especially those intended for receiving and processing the material; well-functioning double ventilation; an abundant water supply; good sewerage. Further, what is needed is the proper selection and installation of apparatuses; ensuring their impermeability during operation; the immediate and faultless removal of vapors and gases, with their condensation and incineration; the presence

spare apparatuses and parts, as well as a destructor, in case of a temporary interruption in the operation of the apparatuses; the maintenance of the apparatuses in full working order and the transition to more advanced types, should the latter appear and production grow. Then—and this is one of the most important conditions, determining many others—there is need for an extremely careful selection of the institution’s manager, the selection of the working personnel, and the placing of the latter under such conditions as would ensure devotion to the work, founded on an awareness of its public importance.

There is, finally, one more general condition necessary for the genuinely purposeful operation of utilization plants. The point is that the utilization of the better part of slaughterhouse waste and animal carcasses, under certain local conditions, is an operation so profitable that abroad we not infrequently encounter cases in which utilization plants are established by private individuals and companies. It is possible that among us as well there will be attempts at the private exploitation of such materials on a broad scale, especially in the larger cities. Still more probable are cases of leasing utilization institutions built by the city. Notwithstanding all the desirability among us of private initiative in general, it is necessary to treat it with great caution in enterprises of a sanitary-technical character, and especially in such a difficult and delicate matter as the rendering harmless (the principal thing is rendering harmless) and processing of slaughterhouse waste. The demand for high profitability, at any cost, from sanitary-technical enterprises has not infrequently paralyzed the initiative of the municipal administrations themselves in the development of such enterprises, or has set them on a false path. It is clear what may be expected in the present case from the self-interested aspirations of private entrepreneurs. Therefore, the fundamental condition for the proper organization of the exploitation of utilization plants must be considered to be that they should necessarily be under the direct management of the municipal administrations. The latter must never forget that the chief purpose of utilization plants is the rendering harmless of animal material and, by this means, the protection of urban soil from contamination, and only thereafter the utilization of this material; that, in general, these institutions are not industrial, but sanitary-technical. I cannot better conclude my thought than by repeating the opinion, already cited once, of the Senate of the city of Hamburg on this matter: “Experience has shown us that the retention in the hands of the city of the business of utilizing animal carcasses, especially from the standpoint of careful supervision, should be preferred to a lease system of maintenance. New views on this

...on the subject rightly emphasize that, in these enterprises, the principal attention must be directed to the rapid and reliable destruction of waste and to hygienic improvements in the processing of business. These requirements are, of course, contradicted by leased maintenance, since it is aimed solely at profit. Only the direct management by public administration guarantees the careful preservation of sanitary measures and may be considered to meet all the successes of technology in this field.”

This authoritative opinion excellently expresses the actual goal of all elements of the sanitary-technical improvement of cities in general, and the only correct attitude of municipal administrations toward them.

TABLE OF CONTENTS

Preface.

I. Residues and refuse from slaughterhouses and objects of rendering establishments . . . 1.

II. Quantity of residues and refuse from slaughterhouses . . . 4.

III. Processing of slaughterhouse residues (general concepts) . . . 7.

IV. General concepts of the decontamination of refuse from slaughterhouses and animal carcasses . . . 13.

V. Destruction of refuse from slaughterhouses and animal carcasses . . . 19.

VI. General concepts of the decontamination of refuse from slaughterhouses and animal carcasses by means of utilization . . . 26.

VII. Arrangement and general equipment of the buildings and premises of a rendering plant . . . 30.

VIII. Processing of slaughterhouse refuse . . . 39.

IX. Sterilization and processing of condemned material and animal carcasses in tallow-rendering boilers and in digesters . . . 50.

X. Sterilization and processing of condemned material and carcasses in disinfectors . . . 60.

XI. Sterilization and processing of condemned material and carcasses in universal rendering apparatuses . . . 78.

XII. Products of the processing of condemned material and animal carcasses . . . 116.

XIII. Information on the economic results of processing condemned material and animal carcasses . . . 122.

XIV. Information on the development of the decontamination and utilization of condemned material and animal carcasses in the city of Odessa . . . 136.

XV. Layout and internal arrangement of the Odessa city rendering plant . . . 139.

XVI. Mechanical equipment of the Odessa plant and the processing procedure . . . 142.

XVII. Information on the products of operation and the economic aspect of the work at the Odessa plant . . . 151.

Conclusion . . . 158.

List of drawings and illustrations.

Materials.

LIST

OF DRAWINGS AND ILLUSTRATIONS

Drawing 1. Destructor of the Kori system.
Drawing 2. Destructor of the Freyer system.
Drawing 3. Destructor of the Horsfall system.
Drawings 4 and 5. Doors of destructors.
Drawings 6 and 7. Fixed grates of destructors.
Drawing 8. Movable grates of destructors.
Drawing 9. Support for movable grates.
Drawing 10. Injector of the Horsfall system.
Drawing 11. Injector of the Kerting system.
Drawing 12. Manure poudrette factory at the Munich slaughterhouse.
Drawing 13. Disinfector of the Delacroix system.
Drawing 14. Kafil-disinfector of the Rietschel and Henneberg system.
Drawing 15. Plan of a utilization installation with the Rietschel and Henneberg apparatus.
Drawings 15a and b. Utilization apparatus of the Delacroix–Voevodsky system with a regenerative furnace for burning refuse.
Drawing 16. Drying apparatus of the Otto system.
Drawings 17 and 18. Drying apparatus of the Rietschel and Henneberg system.
Drawing 19. Kafil-disinfector of Rietschel and Henneberg with drying device.
Drawing 20. Extraction apparatus of the Hartmann system (vertical).
Drawing 21. Extraction apparatus of the Hartmann system (horizontal).
Drawing 22. Drum of the Podewils utilization apparatus. (Side view).
Drawing 23. Utilization apparatus of the Podewils system. (Section).
Drawing 24. Same, general view with part of the machine room.
Drawing 25. Tilting drum of the Podewils system.
Fig. 25a. General view of part of the apparatus room at the utilization plant of the city of Dresden.
Drawings 26–28. Utilization chamber at the slaughterhouses of the city of Yuryev.
Drawing 29. Utilization apparatus of the Hartmann system.
Drawing 30. Sterilizer of the utilization apparatus of the Otto system.
Drawing 31. General arrangement of the parts of the utilization apparatus of the Otto system.

Drawing 32. Loading the Otte apparatus with whole carcasses.

Drawing 33. Utilization apparatus of the Otte–Hartmann system.

Drawing 33a. Diagram for feeding the boiler with condensate water in the Otte–Hartmann system.

Drawing 34. Plan of a utilization plant according to the Otte–Hartmann system in Düsseldorf.

Drawing 35–36. Utilization plant according to the Otte–Hartmann system at the Berlin slaughterhouse.

Drawing 37. Sterilizer of the utilization apparatus of the Tejero system.

Drawing 38. Sterilizer of the utilization apparatus of the Hart system.

Drawing 39. Utilization apparatus of the Pfrocher system.

Drawing 40. Utilization apparatus of the Wilke system.

Drawing 41. Utilization apparatus of the Goltzhausen system.

Drawing 42. Odessa municipal utilization plant, plan of the first floor.

Drawing 43. The same, plan of the second floor.

Drawing 44. Initial design of the Odessa utilization plant.

MATERIALS

Belov, A. Industrial processing of slaughter waste and refuse from slaughterhouses. Moscow, 1892.

Id. Technical and sanitary survey of slaughterhouses. 1901.

Voevodsky, E. G. Destruction, by means of utilization, of refuse and impurities from slaughterhouses. St. Petersburg, 1891.

Id. The arrangement of rational slaughterhouses and methods for removing and destroying refuse. St. Petersburg, 1893.

Id. Project for a plant for the removal of contagious and fallen animals. St. Petersburg, 1898.

Dr. Haecke. Handbuch des Abdeckereiwesens. Berlin, 1906.

Dr. Haefcke. Die technische Verwertung von tierischen Kadaver. 1899.

Hartmann, R. Kadaververnichtungs und Verwertungsapparat syst. Rud. A. Hartmann. (Prospectus).

Report of the Moscow City Administration on the construction at the municipal slaughterhouses of a horse-slaughterhouse and utilization plant. 1902.

Zuev, V. I. Removal of solid household refuse. Odessa, 1900.

Kelvin, L. Refuse-incineration furnaces (destructors) of the Horsfall system. 1902.

Neishtube, S. T. Utilization of the carcasses of fallen animals, slaughterhouse refuse, and all kinds of animal products. St. Petersburg, 1891.

Smolensky, P. O. Slaughterhouses and cattle-drive yards. 1902.

The improved Podewils system for processing infected carcasses and slaughterhouse refuse. Published by the joint-stock company Arthur Koppel in St. Petersburg.

Fischer, R. Die Beseitigung, Vernichtung und Verarbeitung der Schlachtabfälle. Stuttgart, 1905.

Schwarz. Bau, Einrichtung und Betrieb öffentlicher Schlacht-und Viehhöfe. Berlin, 1898.

Brockhaus and Efron Encyclopedic Dictionary.

Erismann, F. F. Course of hygiene.

Table 17.

Drawing 31. General arrangement of the parts of the Otte system apparatus.

(1/150 natural size).

Drawing 33. Utilization apparatus of the Otte–Hartmann system.

(1/75 natural size).

Fig. 33. Diagram of feeding the boiler with condensate water. Table 18

In place of an Otto–Hartmann.

Fig. 34. Plan of the rendering plant in Dresden.

Table 19.

Fig. 35. Utilization plant at the Bezenchuk slaughterhouse.

Cross section.

Fig. 36. Plan.

Table 21.

Fig. 38. Sterilizer of the Hartmann utilization apparatus.

Drawing 41. Utilization apparatus of the Holthaus system.

(1/75 natural size.)

Table 20.

Drawing 37. Sterilizer of the Tegero apparatus.

(1/75 natural size.)

Drawing 39. Utilization apparatus of the Pfrüchner system.

(1/100 natural size.)

Drawing 40. Utilization apparatus of the Wilke system.

(1/100 natural size.)

Special rendering plant.

Fig. 43. Plan of the second floor.

Fig. 44. Plan of the first floor.

Second floor

1. Staircase for the external [[unclear: hoist/lift]] for raising animal carcasses.
2. Place for disinfection and decontamination of anthrax-infected carcasses.
3. Place for unloading the [[unclear: raw material/carcasses]].
4. Place for receiving healthy hides, collected [[unclear: in the corresponding room]].
5. Place for receiving infected hides, with an autoclave.
6. Laboratory room for [[unclear: transferring carcasses]] to the internal elevator.
7. Place for the hoisting machine.
8. Laboratory room for [[unclear: transferring carcasses]] to the internal elevator.

First floor

1. Beckmann apparatus for continuous cooking.
2. Beckmann apparatus for [[unclear: processing/cooking]] carcasses.
3. Trolley.
4. Scales.
5. Mixer for mixing meal.
6. [[unclear: Oil/fat transfer]] to the inner room.
7. Steam engine and [[unclear: crusher/mill]].
8. Three oil separators.
9. Centrifuge for degreasing.
10. Centrifuge.
11. Air pumps.
12. Receiver for fat.
13. Reservoir for tallow.
14. Pouring device for fat delivered by the centrifuge.

Drawing 44. Design of a utilization plant at the slaughterhouse of the city of Odessa. ([[unclear: parenthetical note]]; see the explanatory description placed in No. 6.)

Scale: 1:200.

[Architectural plan and sectional drawing with lettered equipment labels.]

Legend

A.A. — 2 apparatuses [[unclear: for rendering/processing]]
B.B. — 2 apparatuses [[unclear: continuation cut off]]
C.C. — 2 [[unclear: water]] [[unclear: continuation cut off]]
D — air [[unclear: continuation cut off]]
E — [[unclear: word]]
F — [[unclear: word]]
G — [[unclear: word]]
H.H. — 4 collectors [[unclear: continuation cut off]]
J.J. — 2 [[unclear: word]]
K.K. — 5 [[unclear: word]]
L — [[unclear: word]]

Drawings

Table 23.

A A — 2 Poddubny-system apparatuses with large boilers for treating whole infected carcasses.

B B — 2 Poddubny-system apparatuses for treating carcasses in parts.

C C — 2 water-pressure apparatuses for heating the washing liquid.

D — air pump with a moisture-absorbing condenser.

E — mill for grinding cooked meat meal.

F — lifting winch in the mechanism.

G — collecting vessel for clean condensation water.

H H — 4 collecting vessels for blood and washing waters.

J J — 2 lifting winches.

K K — 5 movable winches for transporting carcasses.

L — winch for lowering [[unclear: sacks or wagons]] with meal.