US1588214A - Production of gas by electrolysis - Google Patents

Description

June 8 1926.

R. L. WALSH PRODUCTION OF GAS BY ELECTROLYSIS Filed June 29. 1921 2 Sheets-Sheet 1 June 8', 1926. 1,588,214

R. L. WALSH PRODUCTION OF GAS BY ELECTROLYSIS Filed June 29. 1921 2 Sheets-Sheet 2 .JzgLE..-

Patented June 8, 1926.

UNITED STATES ROBERT L. WALSH, OF SACRAMENTO, CALIFORNIA.

PRODUCTION OF GAS BY ELECTROLYSIS.

Application filed June 28, 1921.

This invention relates to the production of gas by electrolysis of av chemical compound in liquid form or in solution.

While this is the broad application of the inventive idea, it is contemplated specifically as applied to the production ofhydrogen and oxygen by decomposition of water.

The primary object in view is to increase the gas output of any given electrolytic cell of this type and thereby render it more efii- 'cient.

Heretofore, the efficiency of electrolytic cells has been reduced by polarization of the electrodes. The accumulation of gas bubbles on the electrodes has increased the resistance of the circuit to such an extent that the current density has been lowered very materially. Since the rate of evolution of gas is proportional to the current density, this reduction in amperage has meant choking of the cell and lowering of the gas output.

The necessity of preventing polarization has long been realized, the object being to permit continuous and uninterrupted activity of the cell. It has been proposed to depolarize primary and secondary batteries and various types of electrolytic cells by mechanically removing the film of gas bubbles from the electrode faces as fast as it forms. Such treatment has been intended to keep the resistance down to a minimum and thereby prevent interruption of electrolytic action. That is evidently the extent of purpose in each instance.

I propose to advance a step further in the art by efiecting depolarization and at the same time increasing the current density positively and through a wide range for the express purpose of multiplying the output of gas. I am not aware of any prior method which involves positive manipulation of the current density. Therefore, the result sought, which is multiplied output, seems to be entirely new.

An ultimate object of the invention is to provide a gas producing apparatus of compact form and small size, capable of installation on a field truck, which is capable of generating the gas output which now requires the use of an enormous stationary plant.

Other objects of the invention may ap- Serial No. 481,311.

ing means.

In Figure 1 of the drawing, one form of apparatus for carrying out the new method of electrolysis is disclosed. I do not want to be restricted to the use of this particular apparatus, however. The requirements of practice may necessitate the adoption of some other apparatus. suggested in Figure 2.

Referring to Figure 1, the cell in this instance includes a fluid-tight casing 5 which is intended to be stationarily mounted. Since no novelty resides in the specific construction of electrodes or the supporting means therefor, these details will be described only in broad terms. The anodes 6 are electrically connected with the bus bar 7 whereas the cathodes 8 are connected electrically with the bus bar 9. The bus bars 7 and 9 are properly insulated and are connected in circuit with a source of current. such as the generator 10. which is conventionally represented. The current density may be varied at will by means of a rheostat 11 connected in the circuit. In accord- Another form is 'ance with the usual practice, sheets 12 of asbestos or other suitable material separate the anodes" from adjoining cathodes to prevent mixing of the gaseous constituents of the electrolyte during'evolution. A series of tubes 13 and 14 respectively are provided for conducting off the oxygen and hydrogen separately from the anodes and cathodes.

In this instance depolarization is accomplished by producing relative motion be; tween the electrolyte and the electrodes by agitating the electrolyte. For this purpose an agitating vane 15 is mounted within the cell casing upon a rotatable shaft 16. This shaft is journaled in a bearing 17 disposed in the cover of the casing. The bearing is insulated from the bus bars in convenient manner. The shaft may be driven by any suitable prime mover such as an electric motor (not shown).

The apparatus just described, while intended primarily for use in the production of hydrogen and oxygen by electrolysis of water, can be used in the generation of other gases by decomposition of compounds containing the same. I

Before describing the operation of the apparatus in carrying out the method for the production of any particular gas, or gases, the mechanical construction of a modified form of apparatus will be disclosed. This modification is illustrated diagrammatically in Figure 2. In this instance, the electrolytic cell 18 is pivoted by trunnions 19 for oscillation by means of a motor or other convenient prime mover (not shown) through the medium of cam 20.' Relatiye motion between electrolyte and electrodes may be accomplished in this alternative manner without having to extend a moving part through the cell casing, as is required in the apparatus of Figure 1. Also, instead of the simple electric generator and rheostat shown in Figure 1, the current may be supplied and regulated in the modified ap aratus by the regulating booster set 21.

s an example of the way in which the method may be carried out in either form of apparatus disclosed, or in some other suitable apparatus, the electrolysis of water will be considered. First, however, the old method upon which the present invention is an improvement will be discussed for the purpose of comparison with the theoretical results obtainable and with the improved method and its results.

It is only necessary to consider a single cell in the example. Multiplication of the number of cells merely represents propor tional multiplication-of the current factors, output, etc. One like that shown in Figure 1, when operating as a caustic soda cell (10% solution) without depolarization and with a current density of 400 amperes and an E. M. F. of 2.5 volts, gives a gas output of 5.2 to 7 cubic feet per kilowatt hour. Theoretically, this same cell should give 9.3

fore, the theoretical results are not obtain- I able under those conditions.

I have found, however, that, by mechanically depolarizing the cell and at the same time increasing the current density, much more satisfactory results will be obtained. For instance, with a Voltage of 3.0 and an amperage of 800, 12 to 15 cubic feet of gas will be produced per kilowatt hour. In fact, I have discovered that multiplication of the current density to ten times that possible in a polarized cell results in the production of approximately ten times the gas output, when depolarization is performed simultaneously with such increase of the amperage.

- From the foregoing, it should be apparent that, by the employment of my improved method, one cell can give the output of ten cells as heretofore worked. That means that a series of cells necessary for a certain desired gas output will occupy onetenth of the space usually required. This advantage is certainly most important when the installation of gas producing cells in small buildings, or rooms, and in trucks or railroad cars, is considered. Numerous other advantages, such as reduced cost of apparatus for a given project, reduction in thepersonnel required to operate the apparatus, etc., should also be evident to persons working in this art.

What is claimed is:

The method of producing gas by decomposition of a chemical compound which consists in applying an electric current to the compound through a plurality of electrodes to release the gaseous constituent, simultaneously washing the surfaces of the electrodes to depolarize the same, and re ulating the current density of the electriccircuit.

In testimony whereofl afiix my signature.

ROBERT L. WALSH.

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