US2189635A - Electric discharge device - Google Patents

Description

Feb. 6, 1940. KLEMPERER 2,189,635

ELECTRIC DISCHARGE DEVICE Filed Jan. 13, 1958 WITNESSES: INVENTOR (57 #005 flem oererf ATTORNEY Patented Feb. 6, 1940 UNITED STATES ELECTRIC DKSCHARGE DEVICE Hans Klcmperer, Pittsburgh, Pa, assignor to Westinghouse Electric & Manufacturing Company, East Pittsburg Pennsylvania 11, Pa, a corporation .of

Application January 13, 1938, Serial No. 34,834.

2 Glaims.

My invention relates to vapor electric discharge devices and more particularly to means for controlling the flow of vapor in such devices incident to its operation.

It is well known to those skilled'in the art that a considerable quantity of mercury vapor is developed at the cathode in excess of that required for carrying out the electrical processes. Re-

versals of current, for example, restriking during the non-conducting half cycle and other allied phenomena may have an adverse effect upon the proper discharge of such devices.

According to my invention, the general purpose is to provide means for increasing the current carrying capacity of such discharge devices'without an appreciable increase in the are voltage. Briefly, I divide a portion of an evacuated container into a multiplicity of separatechambers with radial openings, by securing to the inside Walls of the container a plurality of annular I plates. The division of the principal container into smaller chambers affords easy access for mercury vapor. The ionized mercury vapor, according to my belief, assumes more or less of an uncontrolled path due to the sudden blast of mercury vapor from the cathode upon the for mation of an are between the make-alive electrode and the cathode of such devices. By providing a deflector somewhere near the cathode spot, it is contended that the stream of vapor may be directed into the separate chambers where reflection of the vapor atoms from the container wall to regions near the anode may be substantially eliminated. Moreover, the mercury vapor expands in the condensing chambers before striking the container walls. By obstructing the free path of the ionized vapor, the life of these vapor particles is considerably reduced which otherwise may have a damaging efiect if kept in an active state for too long a time before becoming deionized.

It is believed that such a construction reduces vapor pressure in the container, increases the cooling area and especially helps to accommodate the mercury vapor by giving it an opportunity to expand before striking the cont iner Walls. Such a construction would, be, in particular, suit-' is for such applications requiring heavy duty for one or more cycles only andaiter duty a long time is available for the cooling down process.

t therefore, an object of my invention to provide means for deflecting a vapor stream emanating from a cathode spot into separate chamhere Where condensation and deionization is effected. I

Another object of my invention is to prevent inverse arcing or reversals in the operation of vapor dischargedevices of this character.

A specific object of my invention is to provide an improved'construction of an electric discharge 5 device for effectively disposing of metallic vapor within the container of such] devices incident to its operation. I I 7 .Still further, it is anobject ofiny invention to provide means for-increasing the current carrying capacity of arc discharge devices of this type without increasing the probabilities of backfire.

Other objects and advantages of my inventionwillbe apparent from the following detailed description taken in conjunction with the accompanying drawing in which the single figure is a I sectional View of a vapor discharge device embodying my invention.

Referring more specifically to the drawing, my invention is shown applied to a metal tank rec- 20 tifier 3 comprising a main tank portion 5 having an anode "i suspended from the top. portion of the main tank 5 and a cathode ll of vaporizable reconstruction material, preferably mercury, disposed in the bottom of the main tank 5. A makealive electrode ii havinga tip of" high resistance material in permanent contact with the cathode 9. Mounted on the make-alive electrode ii is a deflecting plate l3, preferably made of steel. A plurality of annular plates 55 having radial openings it are mechanically secured to. the walls E1 of the metal tank 5, preferably, near the lower portion thereof. The plates it thus mounted, form a plurality of chambers it wherein mercury vapor enters and condenses as I shall hereinafter point out in greater detail. I prefer to slope the annular plates i5 somewhat downwardly toward the deflecting plate is mounted on the make-alive electrode ii to render them more effective in entrapping the mercury vapor swept along with a rectifying arc that is being maintained between the cathode 9 and the anode I.

The walls ll of the metal tank. 5 may be cooled by circulating a liquid through a water jacket 2! located about the main tank 5. Since the deflecting plate i3 protects striking of the lower portion of the anode l againstthe vapor stream, it is common practice to substantially surround. the sides of the anode l by a suitable insulator23, although it is to be understood that this does not form part of my invention.

In the operation of the device, an auxiliary arc is first initiated between the make-alive e1ectrode H and the cathode 9' by passing a current through the former from some suitable source 25 such as a grid-controlled device, thus liberating electrons and evaporating mercury. By impressing an electric field between the anode T and the cathode 9, so that the anode 1 is positive with respect to the cathode 9, the arc will transfer to the anode 7 and the electrons liberated at thecathode 9 will travel along the lines of force towards the anode 1. However, the main arc is deflected somewhat towards the walls I! of the metal tank 5 by the deflecting plate i 3 on the make-alive electrode H. A stream of heated mercury vapor carried along with. the arc is deflected towards the tank walls I! instead of spreading in all conceivable directions. As a result, the mercury vapor is efiectively guided and directed away from the anode 1 in such manner that the anode I is not subjected to the vapor blast.

The areas or chambers l9 formed by the annular plates i 5 provide sufiicient condensing surface for the mercury vapor, which, upon entering the plurality of chambers I9, expands before condensing on the walls I! of the container 5 or on the walls of the annular plates 1 5. Without the condensing chambers IS, the free path of the ionized vapor atoms might produce a damaging effect by keeping the ions alive long enough so that their reflection from the tank walls I! towards the anode I would not be blocked.

Although I provide a deflecting plate i3 above the make-alive electrode H to control the direction of the stream of mercury vapor, all other deionizing means between the cathode 9 and the anode l which may increase the arc drop could be eliminated.

While I have shown and described certain specific embodiments of my invention, it will be apparent that changes and modifications can be made therein without departing from the true spirit or scope of the accompanying claims.

I claim as my invention:

1. A vapor-electric device comprising an evacuated metallic vessel, a vaporizable cathode in said vessel, an anode cooperating with said cathode, a make-alive electrode in permanent contact with said cathode, a plurality of annular plates secured to the side walls of said vessel to provide a plurality of substantially separate condensing chambers, said plates having openings to provide a substantially unobstructed path between said anode and cathode, a substantially conical baille adjacent the cathode surface to direct vapor rising from said cathode into said 1 condensing chambers, and means for cooling said condensing chambers.

2. A vapor-electric device comprising an evacuated metallic vessel, a vaporizing cathode in the bottom of said vessel, an anode cooperating with said cathode, a substantially centrally located make-alive electrode in permanent contact with said cathode, a plurality of annular plates secured to the side walls of said vessel to divide the vessel into a plurality of substantially separate condensing chambers, said plates having aligned central openings providing a substantially unobstructed arc passage between said anode and cathode, an upwardly diverging baiile mounted on said make-alive electrode for diverting the cathode vapor from said are passage into said condensing chambers, and means for cooling said condensing chambers.

HANS KLEMPERER.

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