US1248497A - Vapor electric apparatus. - Google Patents

Description

R. P. JACKSON.

VAPOR ELECTRIC APPARATUS.

APPLICATION FILED APR. 6, T914.

Patented 1000. 4, 1917.

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iTdPQ ELECTRIC APPARATUS.

specification of Letters Patent.

' Patented ta, a, ttt',

Application filed April 6, 1914!. Serial No. eaaeoa.

To all whom it may concern:

Be it known that T, RAY P. citizen of the United States, and a resldent of Edgewood Park, in the county of Allegheny and State of Pennsylvania, have mvented a new and useful Improvement in Vapor Electric Apparatus, of which the following is a specification.

My invention relates to vacuum electric apparatus and more specifically to the structure of the wall of such apparatus in the neighborhood of the electrodes.

The object of my invention is to prevent puncturing the wall of a container, short circuits between the electrodes, and the -ac cumulation of gas at certain points.

The accompanying drawing is a view, partially in elevation and partiall in section, of a vapor arc rectifier embo ying my invention,

A containing receptacle 1 of glass or other insulating material is provided with suitable anodes 2 and with cathodes 3. The method of operation of devices of this character is well known in the art and needs no detailed description. Suffice to say, alternating current is applied to the two anodes, a suitable electromotive force is applied to the cathodes 3, the latter are caused to coalesce and separate with the formation of a small arc therebetween. Current then flows alternately from the anodes 2 to the cathode that is negative with respect to the starting arc. Each anode is supported and shielded as follows: In the upper part of th container wall a rentrant portion t is formed to support a bulb member 5 at its inner end. The anode 2 is carried by the outer end 6 of the bulb member 5 and is constructed of any suitable refractory mate rial, such, for example, as carbon or iron Tn order to prevent, so far as possible, the

formation of direct arcs between the two anodes, the bulb member 5 is extended inwardly, as shown at 7, and provided with a lateral outlet opening 8. The lateral openings of the two anode shields face in opposite directions in order to form a tortuous path between the anodes. A tubular member 12 of insulating material is suitably supported in the neck of the reentrant member 4 and provided with notches 13 at its inner end. During operation, the rectifier bulb is s bm ged n an insulating cooling fluid,

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In the operation of devices of this character, there are three distinct defects which tend to develop and which overcome by my invention. In the first lace, a phenomenon known as fading velops. This manifests itself as a continuously rising resistance in the path of the vapor arc during the life of the rectifier and is caused, apparently, by the presence of gas in the arc. path, especially in the neighborhood of the anodes. Such free gas particles as may be within the container are drawn to the anodes by electrostatic attraction and occlude therein when the device is not in use. When it is started into operation, the gas particles are given 0d and apparently form a high-resistance cloud or blanket near the anode. Secondly,- in spite of the tortuouspath provided, an arc will frequently form from one anode to the other, causing excessive heating and the speedy destruction of the device. This are appears to be set up by the breaking down of the ne a tive electrode reluctance of one of the anodes by the impinging thereupon of a particle of metal vapor. During a half cycle, while the anode is positive, it imparts a positive electrostatic charge to any vapor particles that may be in its neighborhood, owing to current flow through the conducting arc path. In the succeeding half cycle, when the anode is of negative polarity and the are path is comparatively nonconducting in nature, the positively charged conducting particles are influenced by electrostatic attraction and are drawn directly against the body of the anode, causing the aforementioned breaking down of the negative electrode reluctance of the electrode. In the last place, it is found that, when an anode is positive in polarity, its electrostatic action is much more pronounced than when it is negative in polarity. In consequence, negatively charged gaseous particles are drawn to the outer surface of any member that surrounds the anode, such, for example, as the member 4. When any slight over voltage is set up in the system, such as a switching strain or equently de readil space etween the mem ers 4 and 5 with an ordinary silvering solution, such as is used for forming the backing of mirrors. Upon removing such a solution, a dense, closely r adherent deposit of metal will be left. This film is in electrical connection with the anode stem 10 at the point 11 so that it is always of the same polarity and substantially of the same potential as the anode 2. The presence of this conducting film causes the anode to be immersed in a field entirely free from electrostatic stress, as is well known in the art, and, consequently, there [will be comparatively little tendency for charged gaseous or vapor particles to be drawn to an anode, a great majority of those which enter the bulb 5 being drawn toward the wall thereof. 1 thus, to a great extent, obviate the above mentioned defects.

Furthermore, in the operation of my 'device, charged gas particles are driven up into the condensing chamber, between the two anodes, by the cathode blast and there tend to exert a harmful electrostatic influonce. The shielding member on the inside of the re e'ntrant portion 4 collects and tends to neutralize these gas particles, at the same time, shielding the protective coating on the outside of the bulb 5 and leaving said coating free to operate upon the space immediately surrounding the anode. A single shield around an anode "located as in applicants device, would soon be loaded up with gas particles, coming to both sides thereof, but, by employing a double or composite shield, as shown, much greater gas-collecting capacity may be developed in a given space. I am aware of United States Patent No. 996582 to Joseph L. R. Hayden but consider my device a marked improvement thereover in the following particulars: It would, be quite difiicult to insert a metallic shield of the type disclosed by Hayden in the restricted annular space between the members 4 and 5. Furthermore, such a shield when so inserted, would not be as efiective as is mine because it would necessarily be much farther away from the respective walls and, as is well known in the operation of devices of this character, the

force of electrostatic attraction varies inversely with the square of the distance between the respective portions. Accordingly,

-' as es my conducting member, in very close proximity to the wall, exerts a marked electrostatic force therethrough. In addition, a

conducting shield of the type disclosed by bulb at the inner end of the reentrant portion, an electrode mounted in the end of said bulb, and a closely adherent conducting member on the inner surface of the regniiigant portion and the outer surface of the .2. In vapor electric apparatus, the combination with an evacuated container composed of insulating material and having a reentrant portion, of an outwardly extending bulb at the inner end of the reentrant portion, an electrode mounted in the end of said bulb, and a closely adherent conducting member on the outer surface of the bulb.

3. In vacuum electric apparatus, the combination with an-evacuated container composed of insulating material and having a reentrant portion, of an outwardly extending bulb at the inner end of the rentrant portion, an electrode mounted in the end of said bulb and a closely adherent conducting member on the inner surface of the reentrant portion and the outer surface of the bulb and electrically connected to the electrode.

4. In vapor electric apparatus, the combination with a vacuum container composed of insulating material and having a re'e'ntrant portion, of an outwardly extending bulb at the inner end of the rentrant portion, an electrode mounted in the end of said bulb, and a closely adherent conducting member on the outer surface of the bulb that is electrically connected to the electrode.

5. In vacuum electric apparatus, the combination with an evacuated container composed of insulating material and having a rentrant portion, of an outwardly extending bulb at the inner end of the reentrant portion, an electrode mounted in the end of said bulb, and a closly adherent metallic film on the inner surface of the reentrant portion and the outer surface of the bulb.

6. In a vacuum electric apparatus, the combination with an evacuated container composed of insulating material and having a reentrant portion, of an outwardly integer .metallic film on the inner surface of the recntrant portion and the outer surface of the bulb that is electrically connected to said electrode.

7. In a vapor arc rectifier, the combination with a container composed of insulating material and having a reentrant portion, of an outwardly extending bulb at the inner end of the reentrant portion and an anode mounted in the end of the bulb, and a deposit of silver on the outer surface of the bulb in electrical connection with the anode stem.

8. The combination with a vapor rectifier provided With a condensing chamber and with an anode, of means for collecting electrostatically charged particles from said chamber and additional means for collecting electrostatically charged particles from the neighborhood of said anode.

9. The combination with a vapor rectifier provided with a condensing chamber and with an anode adjacent thereto, of a compound electrostatically charged shield, one portion of which is arranged to collect charged gas particles from said chamber and the other portion of which is arranged to collect gas particles from the neighborhood of said anode, each ofsaid portions shielding the other from the electrostatic action in its field of operation.

In testimony whereof, I have hereunto subscribed my name this 31st day of Man, 1914.

RAY P. JACKSON.

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