US1422481A - Electric vacuum apparatus - Google Patents

Description

IVI. SCHENKEL AND J. IUST.

ELECTRIC VACUUM APPARATUS.

APPL1CAT|011 F1150 Aus.12,1916. RENEwED AUG. 27.1920.

1,422,48 l Patented Juy 11, 1922.,

M. SCHENKEI. AND I. JUST.

ELECTRIC VACUUM APPARATUS.

` APPLICATION FILED AUG. 12| i916. RENEWED AUG- 27. I920. 1,422,481.

Patented July 11, 1922.

3 SHEETS-SHEET 2.

M. SCHENKEL AND l. JUST.

ELECTRIC VACUUM APPARATUS.

APPLICATION FILED AUG. I2| I9I6. IIEIIEwED Aue. 27,1920.

Patented July 1l, 1922.

3 SHEElS-SHEET 3.

UNITED STATES PATENT OFFICE.

MoRI'rz scHENxEL AND JOSEPH Js'r, or CHARLOTTENBURG, NEAR BERLIN, GERMANY, AssIGNoRs To sIEMENs-soHrJcxERT-WERKE G. M. is. H., or BERLIN, GERMANY, A coRroRATIoN or GERMANY.

ELECTRIC VACUUM APPARATUS.

Specification of Letters Patent.

Patented July 11, 1922.

Application led August 12, 1916, Serial No. 114,644. Renewed August 27, 1920. Serial No. 406,500.

To all whom t may coiwer'n:

Be it known that we, Moiirrz SGHENKEL and JOSEPH JUs'r, citizens of the (nrerman lEmpire, and residing at Charlottenburg,

near Berlin, Germany, have invented certain new and useful Improvements in Electric Vacuum Apparatus (for which we have applied for a patent in Germany, Serial No. S. 44,230, Aug. 13, 1915), of which the following is a specification.

Our invention relates to electric vacuum apparatus for large outputs or large currents, for example, metallic vapor rectifiers. It is the object of the invention to produce a vacuum apparatus of this character which owing to the new form and arrangement of the anodes may be easily manufactured, and which even in case of large output has'only comparatively small dimensions.

For this purpose according to the invention, in case several anodes are used, these anodes are arranged concentrically and they are for this purpose of annular shape, as is known in the art.

When Working with polyphase alternating current the individual anode may be connected either to only one phase or to several phases of the alternating current.l lInstead of making the anodes as complete rings they may be made as segments if desired, each anode constituting e. g. only half a rin-g and being separated from the next half ring by an insulating partition.

To these andother ends the invention consists in the construction, arrangement and combination of parts described hereinafter and pointed out in the claims. I

One illustrative Aembodiment of the invention and several modifications thereof are represented byv way of example in the accompanying drawings wherein Figure 1 is a sectional elevation which shows a form of the improved apparatus according to the invention. I

Figures 2 to 5 are likewise sectional elevations of several modifications of the apparatus.

Figure 3 shows a modified form of the means for fastening the cover as shown in Figure 3.

Figures 6 and 7 are respectively partial views and horizontal sections of the anode walls shown in Fig. 5. Referring to the drawing, the three-phase mercury vapor rectifier shown in Fig. 1. comprises annular anodes 1, 2 and 3 and the annular cathode 4. The latter is located at the bottom of' the vessel or container 5 of the rectifier, whilst the anodes are mounted on the cover G in known manner by means of insulated feeders 7, 8 and 9 which pass airtight through the cover. These feeders are preferably made hollow for supplying a cooling medium to the anodes. Anode chambers separated from one another can be made by means of tubular partitions 10, 11, 12. The vacuum vessel 5 which is preferably Vmade of circular cross section is enlarged below and has an annular slanting surface 13 located directly opposite the cathode. The vacuum vessel is provided, in addition, with a jacket 14 which encloses a space through which a cooling medium 15, e. g., a cooling liquid, flows. ln this manner a space which constitutes a condensing chamber is formed between the cooled wall 5, 13 of the vessel and the first partition 10 for the anodes. Most of the vapors rising from the cathode will be condensed at the slanting surface 13 and the remainder will substantially enter only into this condensing chamber and not into the anode chambers. The danger of a back current in the rectifier is diminished in the best and simplest manner. Admission of the cathode vapors to the anode chambers is also effectively prevented by making the diameter of the cathode ring larger than that of the outer anode 1.

An electromagnet comprising the conical pole-piece 17 and the winding 18 is arranged in the upwardly projecting bottom 16 of the vacuum vessel. This electromagnet is mounted on a plate 19 which serves as base plate for the entire apparatus and is screwed to the bottom 16 of the vessel. The electromagnet is thus completely separated from the interior of the vacuum apparatus proper. As indicated by dotted lines in the drawing a substantially radially directed magnetic field will be produced between the one polepiece 17 and the annular pole-piece 20- mounted on the bottom 16. When the magnet is energized by direct current the arc is then compelled to rotate, and in this manner the entire surface of the cathode is used uniformly. The density of the current may be selected so great that the base of the arc o'vers a very large area on the surface of the cathode and possibly moves over the entire surface of the cathode. This isffacilitated when, as shown in Fig. 1, the vessel 2l for the cathode liquid is constricted towards the top, so that the upper part of the cathode 4 forms only a narrow ring. The vessel 21 may be composed of a fireproof insulating material or of metal, e.` g., iron.

In order to prevent the surface of the cathode from cooling too severely, rings 22 of suitable insulation are preferably arranged at the two sides of the upper part of the cathode vessel, e. g., in the form shown in Fig. 1 at the constricted parts of the vessel. These rings may be madeof two or more arts so that they may be more readily assembled. In order to prevent an arc from striking bottom 16 of the vacuum vessel, in the apparatus shown in Fig. 1 the bottom is covered with an insulating conical cap 23. Under certain circumstances it is preferable to subdivide this cap also, and to make it of as many concentric parts as there are anode chambers. Fig. 1 shows how this cap 23 may be made hollow and `provided with projecting ribs 24, 25, 26 which project into the anode chambers. These ribs render it more difficult for the cathode vapors to rise into the anode chambers. In order to render it impossible for condensed vapor to collect between the ribs 24, 25, 26 these are provided with perforations 48 of such a form that the liquid can readily flow back to the cathode 4. If the chamber in the cap 23 is also cooled by a-cooling medium 15 the admission of the 'cathode vapors is prevented still more effectively by the condensation which occurs at the ribs. v

AThe cathode need not necessarily be shaped in the form of a rin as shown in Fig. 1, but it may have the form of a disk and be located in the middle of the vacuum vessel. The annular form has the advantage, however, that the condensing chamber can be located at the outer wall of the vacuum vessel 5, as indicated in Fig. 1. Instead of a mercury cathode a glow cathode consisting of either one or several parts may, of course, be employed. Also, if desired, the cathode may comprise several concentric partial cathodes or several parts of rings. If the current load is to be equal for all the anodes, the anode section can be diminished as the diameter of the anodes increases, as indicated in Fig. 1, so that the cross-section ofthe anode is inversely proportional to the diameter.

In Fig. 1 the feeders of the anodes are insulated from the metal cover 6 of the vacuum vessel, whilst in Figs. 2, 3, 4 and 5 other modes of attachment and insulation of the feeders are shown.

In the apparatus shown in Fig. 2 the cover of the vacuum vessel is subdivided into two parts 27 and 28 insulated from one another and from the vacuum vessel 5, and each of these parts has one ofthe two anodes l and 2 electrically connected with it. The feeders to the` anodes can therefore be directly connected from the outside to the parts of the cover. The insulators 29, 30 which insulate the parts of the cover from one another and from the vacuum vessel must therefore be suitable for the working voltage existing l between the individual parts.

In the apparatus shown in Fig. 3 the cover 6 itself is made of insulating material, e. g., porcelain, and is preferably provided with ribs 31 for rendering it sufficiently rigid and capable of standing the atmospheric pressure. As regards leading the anode feeders through the cover attention need be paid merely to making joints which are as perfectly airtight as possible. The cover is preferably pressed onto the flange 48 of the vacuum vessel 5 by means of screws 32 uniformly distributed round the cover at its periphery. In order to obtain a gentle pressure and an uniform distribution of pressure round the edge of the cover and thus to prevent the cover cracking it is preferable either to insert yielding washers -33 of wood, lead, presspahn or the like between the cover and the screws, as shown in this figure, or to transmit the pressure of the screws to the cover by way of springs 34, as shown in Fig. 3a. Fig. 3 also shows how the supply pipe 35 and the escape pipe 36 for the cooling liquid for the bottom 16 of the vacuum Vessel can be led through the core of the magnet.

The partitions between the anodes can be attached in various ways. In Fig. l their top ends are provided with flanges 37, by which they are held by corresponding flanges 38 of the leading-in bushings. Fig. 4 shows how these flanges 37 of the partitions can be brought into engagement by means of step joints, the anode chambers being completely se arated by a roof of insulating material rom the cover 6. The joints between the flanges 37 are filled with asbestos or like lireproof and yielding insu lating material. The inner tubular partition 12 is provided with a roof 39 for the same urpose. It is also preferable to provide t e outer cylindrical partition 10 with a iiange 4() which rests on the top of the vacuum vessel itself. it is necessary to insulate the anode chambers from the cover G for avoiding arcs between the anodes and the cover.

- ln order to still hold the outer partition in position an elastic support 41 may be provided for its lower rim as is shown in Fig. 1, this support being fixed to the vacuum vessel. Also the inner partitions l1 and 12 may be provided with supports 42 which extend to the next outer partition and rest on a rim 43 on this latter partition as is shown in Figs. 1. and 8. Any suitable number of supports preferably three or six .nay be provided on the circumference of the cylindrical partition.

However, it is not absolutely necessary to utilize all modes of securing the partitions in one apparatus as is shown in Fig. 1. Quite often it may be desired in consideration of the simplifying of the construction to omit the additional supports 41, 42, 43, in cases where the upper portions of the partitions are arranged as shown in Figs. 1 or 4. Furthermore, in order to facilitate the mounting of the `device the partitions may be mechanically separated from the cover and may only be supported by supports 41, 42, 43 as shownl in Figs. 2 and 3. According to the arrangement .in Fig. 2 the outer cylinder 10 rests with its flange 40 on the upper rim of the vessel; in the arrangement according to Fig. 5 cylinder 10 is used Without vthe upper flange. but is held in place vertically solely by the supports 41 and 42 and laterally against the wall ofthe vacuumy vessel by a preferably elastic layer 44 on its outside edges. The bottom support 41 may be elastic. so that the partitions between the anodes can yield somewhat downwards when the cover 6 is put into position. Consequently fracture of the partitions by screwing the cover down is prevented and a tight joint under the cover can be made with certainty.

Figs. 5 to 7 show how the cylindrical partitions can be placed on the insulating cap 23 of the vacuum vessel. In order that the partitions may be elastically supported the cap 23 may rest elastically on its support or it may be otherwise mounted elastically In order that the one artition may be mounted elastically indepen ently of the others, as is frequently desirable the cap 23 may be subdivided, as mentioned above so that each part carries only one partition. For this purpose the partitions are preferably mounted on the bottom support by means of leaf springs 46 of small height adapted to the circular form of the support. In order to enable the arc to pass without hindrance through the partitions the latter are provided with archway-shaped apertures 45. Fig. 6 clearly shows these apertures 45 and the feet 46 of the partitions resting on the leaf springs 46.- As Fig. 7 shows in bottom plan view` the feet 46 ofthe partitions are arranged staggered in order to obviate as much as possible any undesirable increase in the resistance otl'ered to the arc.

Fig. 5 also shows the employment of a metal cover as Well as a porcelain cover 47 which closes the anode chambers and insulates the anodes from the metal cover. The porcelain cover 47 can be placed directly on the cylindrical partitions. The mode of supporting these partitions from below, for example as shown in Figs. 2 3 and 5, has the advantage that it is ossible to assemble the apparatus more rea ily, as the cover with the anodes is placed in position only after the partitions have beenl mounted:

1. In an electric vacuum apparatus the combination with a container and a cathode therein, of a plurality of concentric annular anodes mountedv in the container and having different annular diameters and insulating partitions separating said anodes from each other.

2. In an electric vacuum apparatus the combination with a container and a cathode therein of a plurality of concentric annular anodes mounted in the container and insulating partitions separating the anodes from one another and from the Wall of the container.

3. In an electric vacuum apparatus, the combination with a container and a cathode therein, of a plurality of concentric annular anodes mounted in the container, insulating partitions separating the anodes from one another a-nd from the Wall of the container, and means for cooling the part of the Wall of the container surrounding the outermost of said partitions for forming the space located between the wall of thel container and the outermost partition into a condensing chamber.

4. In an electric vacuum apparatus the combination with a container, an annular cathode and a plurality of concentric annular anodes mounted therein of insulating partitions separating the anodes from one another and from the Wall of the container and an object located directly above the cathode constituting a condensing surface and means for cooling this object.

In an electric vacuum apparatus, the combination with a container and a cathode therein, of a plurality of concentric annular anodes mounted in the container, insulating partitions separating the anodes from one another and from the wall of t-he container, said container being suitably shaped to bring its lateral wall portions substantially into vertical alinement with the cathode, the part of the Wall of the container located directly above the'cathode constituting a condensing surface, and means for cooling the condensing surface.

6. In an electric vacuum apparatus, the combination with a container and an annular cathode therein, of aplurality of concentric annular' anodes mounted in the container, insulating partitions separating the anodes from one another' and from the Wall of the containerand forming anode chambers, and a cooling screen located at the lower ends of the anode chambers.

7. In an electricv vacuum apparatus, the combination of a container, a cathode and a plurality of concentric annular anodes mounted in the container, insulating partitions separating the anodes from` one another and forming anode chambers, and cooling means located in the anode chambers..

8. In an electric vacuum apparatus, the combination of a container, a cathode and a. plurality of concentric annular anodes mounted in the container, insulating partitions separating the anodes from one another and forming anode chambers, and a cooling screen having projecting parts entering into the anode chambers.

9. In an electric vacuum apparatus, the combination of a container, a cathode and a plurality of concentric annular anodes therein, insulating partitions separating the anodes from one another and forming anode chambers, and a cooling screen having projecting parts entering into the anode chambers said projecting parts of the screen being perforated at their base. v

10. In an electric vacuum apparatus, the combination With a container having a cover and a cathode in the container, of a plurality of concentric annular anodes mounted in the container, and insulating partitions, separating the anodes from one another and from the Wall of the container, mounted on the cover.

11. In an electric vacuum apparatus, the combination with a container having a detachable cover and a cathode in the container, of a plurality of concentric annular anodes mounted in the container, and insulating partitions separating the anodes from a plurality of concentric annular anodes mounted in the container, and insulating partitions separating the anodes from one another and from the wall of the container, said partitions being supported by eac-h other, except the outermost, which is carried by said container.

13. In an electric vacuum apparatus, the combination with a container having a cover, and a cathode in the container, of aplurality' of concentric annular anodes mounted in the container, and insulating partitions separating the anodes from'one another and from the Wall of the container and means for mounting said partitions elastically in t-he container.

14:. In an electric vacuum apparatus, the combination with a container and a plurality of concentric annular anodes therein, of a cathode vessel containing a cathode liquid, the sides of the cathode vessel being covered with a heat insulating material, for the purpose of raising the temperature of the active surface of the cathode.

15. In an electric vacuum apparatus, the combination With a container, and a plurality of concentric annular anodes of an upwardly constricted cathode vessel in the container, said vessel being filled with a cathode liquid up to the constricted part thereof.

16. In an electric vacuum apparatus, the combination with a container, a plurality of concentric annular anodes, and a cathode vessel containing a cathode liquid therein of means for producing a magnetic eld over the surface of the cathode, for compelling an arc formed between the. anode and the cathode to rotate.

17. In an electric vacuum apparatus, the combination with a container and a plurality of concentric annular anodes, of a cathodein the container, the operative surface of the cathode being of sufficiently small size to cause the base of the arc to cover said entire surface at a current load below the maximum for which the apparatus is designed.

18. In an electric vacuum apparatus, the combination with a container and a cathode therein, of a plurality of concentric annular anodes mounted in the container, the crosssectional area of each anode being inversely proportional to ,the annular diameter thereof.

MORITZ SCI-IENKEL. JOSEPH JST.

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