but which the potentials of the anodic peaks were measured is, in this case, not the same for different temperatures. Conversely, when a saturated calomel electrode is used at constant temperature, the results of the studies are to some extent distorted by the thermoelectric EMF that arises. Therefore, in the experimental part of the work all values of the anodic-peak potentials were not given on the potential scale, but were treated relative to the half-wave potential at the same temperature, which also made it possible for us to eliminate the distorting influence of thermodiffusion potentials and to obtain satisfactory agreement between the experimental data and the calculations.

References

1. S. N. Karbainova, A. G. Stromberg, Yu. A. Karbainov. Electrochemistry, 10, 1409, 1971.
2. S. N. Karbainova, A. G. Stromberg. Electrochemistry, 10, 1488, 1971.
3. S. N. Karbainova. Collection of Works of Young Scientists. Chemistry and Chemical Technology. Tomsk, 1973, 19.
4. Yu. A. Karbainov, S. N. Karbainova, A. G. Stromberg. Electrochemistry, 2, 220, 1973.
5. A. G. Stromberg, S. N. Karbainova, Yu. A. Karbainov. “Factory Laboratory,” 3, 257, 1970.

STUDY OF THE INFLUENCE OF AN ELECTRIC FIELD ON HEAT TRANSFER AND HYDRAULIC RESISTANCE IN A FLOW

I. P. Chashchin, V. P. Ignatov

Heat transfer occupies a leading place in industry; therefore, questions related to the intensification of heat-transfer processes are at the center of attention of many researchers.

Along with traditional methods of heat-transfer intensification, such as turbulizing inserts, finning, etc., methods of intensifying heat transfer by electric fields are being proposed.

A number of authors indicate that electric fields are a powerful factor in heat- and mass-transfer processes.

We have carried out studies to investigate the influence of nonuni-

uniform electric field on the heat transfer and hydrodynamics of the flow.

The studies were carried out on a setup whose main element was a vertical tube-in-tube heat exchanger. Heat transfer took place from water vapor condensing in the inner tube to air flowing laminarly in the annular space. The electric field was produced on wire electrodes 0.2 mm in diameter, placed in the air flow parallel to the grounded heat-releasing surface. A VTM I/10 rectifier served as the high-voltage source.

In order to reduce the influence of the conditions at which the flow entered the apparatus on the heat transfer and hydrodynamics of the flow, the experimental data were recorded in the stabilized section \((\ell/d_{\mathrm{eqv}} > 50)\).

Temperature measurements were made using chromel-copel thermocouples connected to a Shch-63 potentiometer. The flow rate of the air entering the heat exchanger was measured with an RG-40 gas meter. Hydraulic resistances were measured with an inclined manometer.

The influence on heat transfer and hydraulic resistance of the magnitude of the applied voltage, the number of electrodes, and their length was investigated.

The series of experiments differed in the air flow rate \((Re\) varied up to 2300), the magnitude of the applied voltage \((E = 0 \div 8\ \text{kV})\), the number \((n = 1, 2, 3)\), and the length of the electrodes \((200 \div 560\ \text{mm})\). The electrodes were installed either in the inlet section of the apparatus or in the stabilized section.

The results of the experiments showed that when the electrodes were installed in any of the indicated sections of the apparatus and when the electrodes were made to corona by applying voltage to them, an increase was observed in the heat-transfer coefficient and in the hydraulic resistance of the flow.

When the electrodes were installed in the inlet section, the relative heat-transfer coefficient was \(\alpha_{\mathrm{el}}/\alpha_{0} = 1.48\), and the relative hydraulic losses were \(\Delta P_{\mathrm{el}}/\Delta P_{0} = 1.36\). When the electrodes were installed in the stabilized section, \(\alpha_{\mathrm{el}}/\alpha_{0} = 1.58\) and \(\Delta P_{\mathrm{el}}/\Delta P_{0} = 1.40\). The comparisons are given for three electrodes 564 mm long and \(Re = 600\).

When the electrodes were installed in the inlet section of the apparatus, it was observed—

an increase in heat transfer on the stabilized section by 12%, and in hydraulic resistance by 9%, was obtained.

With an increase in the number of corona electrodes of constant length on the stabilized section from one to three, the heat-transfer coefficient increased from 18% for one electrode to 58% for three electrodes; the hydraulic resistances correspondingly increased from 10% to 40%.

With an increase in the length of the electrodes, the intensifying effect of the electric field on heat transfer and hydraulic resistance also increases.

The results of the experiments show that increasing the corona surface promotes greater intensification of heat transfer.

The intensifying effect of the electric field is observed within a definite voltage interval. The lower limit of the voltage applied to the electrodes is characterized by the appearance of corona discharge. The upper limit is the transition of the corona discharge to breakdown; in this case the voltage drops.

Taking into account the low consumption of electrical energy supplied to the electrodes, the indicated method of heat-transfer intensification can be applied in certain characteristic processes.

STUDY OF THE MECHANISM AND KINETICS OF THE PROCESSES OF DISCHARGE–IONIZATION OF ARSENIC ON SOLID ELECTRODES

N. A. Veits, A. A. Kaplin, A. G. Stromberg

The aim of the work was to determine the kinetic parameters of the processes of discharge ($\alpha$, $K_{S_2}$) and ionization ($\beta$, $K_{S_1}$) of arsenic in a hydrochloric-acid medium on solid electrodes, and to determine the composition of the complexes predominating in solution and directly discharging on the electrode. For the calculation, relations were used that follow from the equations for the potentials of the cathodic /1/ and anodic /2/ peaks in a complex-forming medium.

Graphite, platinum, and gold electrodes were used as indicator electrodes. The reference electrode was a saturated calomel electrode.

The transfer coefficients of the process of discharge ($\alpha$) of arsenic were determined from the dependence of the potentials of the cathodic peaks ($\varphi_{p,k}$) on