US1839502A - Fluid electrode electric discharge device - Google Patents

Description

jafil- 1932- R. RUDENBERG ET AL 1,839,502

FLUID ELECTRODE ELECTRIC DISCHARGE DEVICE Filed March 2, 1926 WITNESSES: INVENTOR w BY ,ATORE Patented Jan. 5, 1932 UNITED STATES PATENTQOFFICE REINHOLD RUDENBERG, OF IBERLIN-GBUNEWALD, AND RUDOLF G. BERTHOLD, OF

BERLIN-SIEMENSSTADT. AND KARL DONA'I' AND WERNER ESPE, OF BERLIN- CHARLOTTENBURG, GERMANY, ASSIGNORS TO WESTINGHOUSE ELECTRIC 8a MANU- FACTURING COMPANY, OF NEW YORK, N. Y.,-A CORPORATION FLUID ELECTRODE ELECTRIC DISCHARGE DEVICE Application filed March 2, 1926, Serial No. 91,755, and in Germany May 22 1925.

izes very quickly at the point where the arc touches the cathode, and returns along the walls of the container in fluid form after condensation. It is known that such devices have a predetermined voltage drop, depending upon the voltage drop in the fluid cathode,

or the cathode drop, a loss of voltage which varies with the distance between the anode and the cathode, and the anode drop. The voltage drop in the rectifier, however, means 29 a loss in the transformation ofthe energy in the device.

According to our invention, the loss of voltage in the container is reduced by adding metals or their compounds to the fluid cathode, whereby the electron emission of the cathode is increased. The increase in the electron emission is a consequence of the decreased loss of voltage, or the decreased work of emission, when the electrons leave the 30 fluid electrode and enter the discharge chamher.

All of the metals of the first and second groups of the periodic system, that is, the alkali metals and the alkali earth metals, or their compounds, have been found particularly adapted for this purpose. Such metals are, for example, barium, strontium, potassium, magnesium, caesium, and rubidium. Especially the last two metals, caesium and rubidium, are very well adapted for use as additions to a mercury cathode. The materials may be added'to the mercury in pure metallic form so that they will form an amalgam with the mercury.

It is also possible, however, to add compounds of these metals to the fluid cathode.

Obviously, the added materials may com-.

prise any desired number of different metals. The relative amount of the added material is preferably so chosen that the emissivity of even exceed the normal temperature in the condensing chamber. In order to make complete condensation possible, in such a case, and to obtain a good return flow of the condensate into the cathode chamber, it has been found preferable to utilize special means for maintaining the temperature of the condensation chamber and of the cathode higher than-is the case in the usual uncooled discharge device. Special heating means may be provided which will heat the condensation chamber and the cathode, and the discharge device may also be surrounded by a heatinsulating material which prevents a too rapid radiation of the heat produced within the container.

Our invention consists in the details of construction and combinations hereinafter more particularly described and claimed and illustrated in the accompanying drawing, the single figure of which is an elevational view, partly in section, showing a preferred con- I struction illustrating the application of our invention to a rectifier.

In theiillustrated embodiment of our invention, a glass container 1 of a mercuryvapor rectifier is of the usual shape, and is provided with anode arms 2, the mercury cathode 3 being amalgamated with one of the above-mentioned metals of the first and second groups. In order to make possible a certain condensation,-on the one hand, and a maintenance of the heated state of the metal compound, on the other hand, the glass vessel is surrounded by a heat-insulating cover member 4, and a heating means, in the form of a spiral wire 5, is provided directly on the container 1. Y

The admixture of metals of the first and second groups to the fluid cathode has also the advantage that the mixtures are resent in the metal vapor between the cat ode and anode. Consequently, the exciting potential of this metal vapor is reduced, and thus the loss of'voltage in the rectifier is still further decreased. It is possible, therefore, in such devices, to make the distance between the cathode and the anodes larger than ordinarily. This has the further advantage that the safety against back fire is increased. For example, as shown in the drawing, the anode arms 2 can be made materially longer than usual. Consequently, the path for back fires is increased by double the amount by which the anode arms are lengthened.

Our new apparatus may also be utilized in discharge devices which have no definite cathodes, as in devices serving for the passage of alternating currents.

We claim as our invention:

In combination with a vapor electric device comprising an electrode composed of a liquid amalgam of mercury and material from the group comprising the first and second groups of the periodic table of elements, two solid electrodes, and means adapted to reduce the rate of heat outflow from said device, except in the vicinity of said solid electrodes. 7

In testimony whereof we aifix our signatures.

REINHOLD RUDENBE'RG. RUDOLF G. BERTHOLD. KARL DONAT.

WERNER ESPE.

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