US996582A - Static protector for vapor electric apparatus. - Google Patents

Description

J. L. R. HAYDEN. STATIC PROTECTOR FOB. VAPOR ELECTRIC APPARATUS.

Patented June 27, 1911.

Inventor: Joseph Le Ry Hayden,

UNITED- STATES PATENT orFioE.

JosnrH 1.. s. HAYDEN, or scnauncmnv, NEW roux, 'assicuoa so Gunman ELECTRIC commute A conronarxou or new Yo r.

' STATIC PROTECTOR FOB VAPOR ELECTRIC APPARATUS.

Specification of Letters Patent. Ihaten1:43-51 Jung 2 7, 191 1 Application filed January 5, was. Serial in); 20mm.

My present invention relates to vapor.

electric devices, and finds its mostuseful 0y alternating current.

It is one of the objects of my invention to protect the apparatus from deterioration during use, and to guard against the phe-] nomenon known as-arcmg in which one of the anodes of the apparatus temporarily becomes the cathode for a discharge from the companion anode. The various features of novelty reference to the following description taken in connection with the accompanying drawings in which,

fication.

my invention is applied is of a now well known ation serves as an anode. left-hand view is indicated at 3, while that in the right-hand view is partially concealed. The tubes 1 and 2 are connected by a tubular I bow-shaped member 4. From this member extends upwardly a relatively lar e chamber 5' which serves as a condensing c amber for the surplus mercury generated during the operation of the apparatus. Directly below the mouth of the condensing chamber 'there extend downwardly three pockets or tubes 6, 7 and 8, each of which is nearly filled with mercury. The central body of mercury contained in the'member 7 constitutes the.

cathode or negative electrode of'the' appaapplication to such of these devices asem -is occluded by the anodesand by the glass walls of the rectifier tube but, as soon as the much as my present invention is not concerned with the articular construction of the rectifier tube It will be unnecessary r-for' me to 1 go into further description thereot,

since the tube which I have illustrated is of a type well known in the art. a

- Tubes of the kind which I have described, although they are of the best-construction so far known, are subject to certain troubles during operation. This is especially the fact when they are used with excessively high voltages such for example as would be necessary when the rectifier is used to supply direct current to a series are light circuit of say '75 lights. In this case the effective alternating voltage across the main graphite anodes of the tube may amount to asmuch as 16,000 volts, while the peaks of the waves may reach a value probably not which characterize my invention have pointed. out in the appended claims. The invention itself, however,will be better understood by number of ways. Thus it may ha penthat a tube after running for a short ime fails .to give the required voltage on the direct i current circuit although the proper alternat- Figure 1 represents my invention as applied to a mercury arc rectifier tube of atype especially adapted for high voltage work. Figs. 2 and 3 are views of a modiing voltage is maintained across the anode terminals. This is the phenomenon which tcrvals to decrease until finally it is found to In the drawings, the rectifier tube to which be impossible to supply the normal current to the load. After this action has progressed for a time the current passes'through a minimum value and the rectifier goes out. Sometimes, especially on starting a tube, some'line disturbance may cause a static discharge froman anode lead to the glass wall of the rectifier so as puncture the same and ruin the tube. I

I will now explain what I believe to be the most probable cause of the deterioration of the tubes, but I wish it to be understood that I do not hold myself responsible for the accuracy of this theory.

Primarily I believe that the deterioration is due to gas obstructing the arc stream, which gas,before the rectifier tube. is started are is started, is driven ofi by the heat or other causes into the arc stream and. thus necessarily the most important factor in obstructs it.- I do not consider that heat is driving oif this gas. It is of courseunderstood that when the rectifier is running the anodes alternate in potential from ps1t1ve to ne ative. Whenpositive current flows there rom through the rectifier tube, while when they are of'negative POlfiI'ltY there is no current flowing. During these .half

periods when the anodes are of negative p0 tential there is I believe a discharge from the anode, then negatiVe of negat ively el'ectrified particles. The tendency 1s for the least stable portions of the anode to be, driven off andto some extent disintegrated. The gas absorbed or occluded in the anode is I probably the first driven off, while to some in the vicinity of the anode was filled with mercury vapor electrostatically charged. As soon as the anode reverses in polarity astrong electrostatic attraction is exerted upon the particles which thereuponare impelled toward or past the anode and strike elther the anode orthe anode support in the rear of the anode. This impact forms a vaporization center or cathode spot from which an arc may develop extending from that spot.

around through the rectifier tube to the op.- posite anode which obviously is then of positive potential. This action which is known as arcing may occur with .more or less frequency and obviously in a time disintegrates the anodes, destroys the vacuum, and

so ruins the tube. To"overoome these and other difficulties, I surround the anodespace,

by an electrically conducting shell, of copper for example, such as indicated 1n Fig. 1 at 9 and 10. The shell9 is represented in cross section to show more clearly the relation of the parts, while the shell 10 is represented in full view.- Each of the shells is electrically connected as by flexible wires 11 and 12 with the corresponding anode leads. The shells may of course assume a variety of shapes though for the present purpose I have found good results .by making the shell in the form ofabell. Thisbell may rest upon a glass rod 13 surrounding the lead wire 14 and extend down below the lower end of the anodeand be flared outward as indicated. This bell I call a static protector.-' It is separated from the glass by an air space as indicated and may be held in position by any'suitable means as for example, by adjustable spacingscrews 15 of some non-conducting material such as fiber. In order that the presence of the static protector may not cause the anode space to become too hot I provide the proeoasea tector with numerous perforations in order as shown in Figs. 2 and 3 in which the protector 16 is of imperforate; sheet metal practically open at the top except for the skeleton cross pieces 17. e .The open top of this keeps down the temperature of the anode space.

, It will be understood that the protector,

protector. permits eflicient ventilation and by reason of'its electrical connection to the leading in conductorpof the anode, is at all times at the same potential as the anode itself. This being the fact, there is no tendency for the. particles within the space circumscribed b the protector to be attracted in one direction or the other because every pointwithin said space is, by .well known electrical laws,.at the same potential. The dissipation of matter from the anodes, and the arc-provoking action of. the anodes on the surrounding vapor are thus prevented. I

Moreover,fstaticdischarges from the anode leads are no longer able to" puncture the glass walls of the tube. I 1 I Bythe above theory I explain the re markable results which I have achieved by the use of the static protector, though Iwish it understood that this explanation even if accurate, is at best incomplete. Regardless, however, of what the true explanation may be, the beneficial effects of my invention may be obtained without reference to any theory of operation. I have found that with the use of my invention, rectifier tubes, which withoutthe static protector were absolutely useless in. practice, could for the second time 1. In a vapor arc apparatus, the combination of an exhaustedenvelop, electrodes therefor one at least of which is of vaporizable material, and means for rendering the entire space about a given electrode of the same potential as the electrode itself.

2. The combination. with a rectifier tube, electrodes for the'tube. one at least of which is vaporizable material, and a good conducting shell surrounding one of the electrodes and electricallyconnected thereto the rim of said shell extending beyond the end of said electrode.

3. The combination of av .rectifier tube, electrodes therefor one at least of which is of vaporizable material, and means for doing by the use of the equalizing the potential of the rounding one of the electrodes.

. 4. In a vapor arc apparatus, the combination of anexhausted envelop, electrodes therefor one at least of which is of vaporizable material, and a static stress equalizer for one at least of said electrodes whereby the space about said electrode is made of the same potential as the electrode itself.

5. The combination of a rectifier tube, electrodes therefor one at least of which is of vaporizable material, a good conducting space surshell surrounding oneof said electrodes, and

an electrical connection between said shell andthe supply lead for said electrode.

6. The combination of an evacuated tube, electrodes therefor one at least of which is of vaporizable material, and a shell of high conductivity outside of said tube and surrounding oneof said electrodes and electrically. connected thereto said shell extending beyond said electrode. t

The combination of a vacuum arc tube, an electrode therefor, and a flared shell of high conductivity surrounding 'said electrode and electrically connected to it, said shell extending at least as far as the free end of the electrode.

8. The combination of a vacuum are tube provided with electrodesone of which consists of easily vaporizable metal, andmeans for rendering the space surrounding one at least of said electrodes of the same potential as the electrode itself, said space having its the points 1n which are of substantially the same potential.

11. In a vapor are electric apparatus, the combination of an exhausted envelop, a plurality of anodes, a cooperating vaporizable.

cathode and a shell. consisting of a good electrical conductor surrounding each of said anodes outside of said envelop and electrically connected to said anodes.

12. In an alternating current va or electrio apparatus, the combination 0 an exhausted envelop, a cathode, cooperating anodes and means at the anodes for preventing an. abnormal lag of the starting of the arcs with respect to the phase of the impressed electromotive force.-

In witness whereof, I have hereunto set my hand thisftth day of January, 1906.

JOSEPH L. R. HAYDEN.

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