US1046081A - Vapor electric apparatus. - Google Patents

Description

G. A. KRAUS &' R. D. MAILEY.

VAPOR ELECTRIC APPARATUS.

APPLICATION FILED AUG. 27, 1909. 1,046,081. Patented Dec. 3, 1912.

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CHABLESA. KHAUS, F NEWTON HIGHLANDS,

AND BOY .D. BAILEY, OI LYNN,

MASSACHUSETTS.

VAPOR ELECTRIC APPARATUS.

Application fled August To all whom it may concern:

Be it known that we, CHARLES A. Kris na and Ror D. MAILEY, citizens of the United States, and residents of Newton Highlands and Lynn, in the counties of Middlesex and Essex and State of Massachusetts, have invented new and useful Improvements in Vaor Electric Apparatus, of which the folowing is a specification.

Our invention relates to the construction of vapor electric apparatus and has for its object the provision of structural features which shall insure elliciency and durability and capacity for preserving continuity of operative conditions while carrying electrical currents larger than have heretofore been considered feasible in such apparatus Particularly, these improvements relate to the construction and attachment of the electrodes and electrode leads which constitute essential factors in vapor electric apparatus.

Asa typical example of vapor electric apparatus we take for purposes of description a va or rectifier in which the characteristic mem rs are a container, .hermetically sealed so as to include highly rarefied mercury vapor, at least two anodes and one cathode, and leads for these electrodes which pass through the walls of the container.

While it has been roposed to em loy metal as the material or containers 0 vaor electric ap aratus, so far as we are inormed, the on y practically effective apparatus of this class heretofore used, have employed glass as the material of which the container is composed. It is diflicult, indeed commerciall impracticable, to construct a rectifier of arge capacity while employing a glass container; breakage in handling and transportation of such instruments, even those of the capacities considered practical, has proved a prolific source of loss; a glass container for such an instrument as a rectifier is by its nature and under the conditions of operation a delicate apparatus, since its interior is exhausted to very low pressure and contains also a body of liquid mercury which, under the vacuum conditions, is

liable to break the container unless the apparatus be handled very carefully. Moreover, owing to the difiiculty of sealing electrode leads of large dimensions through the glass walls of a lass container, it has not been found feasib e, so far as our experience and observation go, to construct efiicient Specification of Letters Patent.

27, 1909. serial No. 514,808.

glass rectifiers capable of converting cur'rerit Patented Dec. 3, 1912.

substantially greater than amperes. The chief difliculty which has embarrassed constructors of metal contained rectifiers' and kindred ap aratus is, inherent in the construction of the elect-rode leads and connections. Obviously current must be led to the electrode within the container through connections which are effectively insulated and which at the same time do not impair the essential hermetic closure of the container. So faras we are informed, the only technically effective solution suggested to meet this difficulty has been to ead the current through columns of mercury at atmospheric height, -and those who are familiar with the demands of industrial and commercial conditions will recognize the practical disadvantages of such an arrangement; moreover, we believe it to be doubtful ifthe necessary vacuum to be maintained in a recti- I fier can be successfully preserved when a system of mercury sealed leads is employed.

The necessity for effective gas-tight insulating joints for the electrode leads employed by the usual container has been recognized as, for instance, in Austrian Letters Patent No. 19,023, issued Jan. 25, 1905, to )ooper Hewitt Electric Company, and U. S. Patent No. 760,483, dated May 24, 1904, to Van Recklinghausen, in which, however, the only suggestlons as to practice are either a mercury seal between a metal bottom and a glass top of a vapor electric container, or non-conductin bushings which are described as made tight in a metal lid which is either ground into the neck of the container or united therewith in some other manner, the detailed or specific manner of making gas-tight joints being otherwise left to the imagination. We have demonstrated to our own satisfaction that mercury seals, ground joints and cemented joints are incapable of producing effective practical results, and the subject matter of this specification relates particularly to the construction of electrode lead connections in combination with a metal container which dition essential to the operation of the apparatus; broadly speaking, these joints consist of metallic members and a refractory insulating member either wholly or superficially vitreous so as to be-gas-tight, the insulating member adhering to the metallic members by means of a flux vitreous in its character which fuses at a relatively moderate temperature and which should possess, moreover, when heated, the effect of dissolving the oxid of the metal Which composes the metal member and of Wetting and ad hering to the metal with the greatest intimacy. A composition or compositions of matter well adapted for use as the nonmetallic members of such joints and also sundry peculiarities of the joints themselves, form the subjects matter of applications for Letters Patent of the United States Serial Nos. 514,858 and 514,859, filed on or about August 27, 1909, which will be briefly described in connection with the subjoined specification in which is explained an example of vapor electric apparatus constructed according to and containing the inventions and improvements claimed herein.

In the drawing hereto annexed there is shown an example of vapor electric apparatus which embodies our inventions.

In this drawing A is a metal container cylindrical in form and constructed of cold rolled sheet steel. The sides, top and bottom of this cylinder should be as thin as is consistent with the strength required to sustain external atmospheric pressure, thus the total weight of the rectifier may be reduced, its manufacture facilitated and the radiation of heat from its body active except where it may be intentionally checked by heat insulating contrivances if such are found desirable. At the top of the container there are secured tubular extensions B, B, B, all of which are preferably composed of cold drawn steel tubing. The top, sides and bottom and also the tubular extensions are fitted together and then welded by means such as the oxyacetylene flame. Previous to the final fitting together of these parts a lining M composed of refractory insulating material, such as porcelain or glazed lavite, is introduced into the con-- tainer. This lining furnishes a suitable well.

.. for the reception of the liquid mercury cathode H. The other and further peculiarities and functions of this lining will be explained hereinbelow. This lining, in structure and functional relationships with other portions of the apparatus forms the subject matter of an application for patent Serial No. 569,694, filed by us on or about June 30, 1910, and are consequently not made'the subject of claim herein.

The anodes E and F are composed of solid metal, preferably iron or steel, and are se-- cured to the electrode leads E and F; the

lead E consists of a metal rod, while the lead F for the purposes to be alluded to consists of a tube of metal. The electrode leads are welded so as to form a completely tight joint as at D with the iron or steel bonnet D.- These bonnets are preferably cylindrical and of the same diameter as the tubular extension B; the extensions B are provided with conical flaring ends B and the bonnets D with similar conical flaring ends D.

The sealing joint is made between the tubular extensions B and the bonnets D in the following manner: The metal members being heated, a vitreous flux is fused upon the surface of the conical extensions B, D, in such manner as to coat them thoroughly; this flux is preferably composed of borax which may have incorporated in composition with it, sodium glass and also ferric oxid. Borax alone has the property of dissolving the oxids which form upon the surface of the metal, and of wetting and adhering to the metal itself, but the composition above described has not only this property but is moreover more intimate in its adherence to iron or steel and possesses mechanical strength in a large degree. An insulating ring C which may be composed of glass or other refractory insulating material, such for instance, as the semivitreous substance known as lavite, is placed between the conical extensions B and D, the joints thereof being fused by means.of the flux applied as above stated. If the insulating ring C is composed of material in any degree porous it should first be thoroughly coated or glazed with a refractory film which is thoroughly gas-tight. Thus united, the tubular extensions B, the insulating rings C and the bonnets D, constitute hoods between which .and the electrode leads E, F and G a space intervenes. Leads J, F, G, and all portions of the electrodes E and F, except the active ends, should be incased in a refractory insulating covering E F and G, lest they form arcs or shortcircuits undesirably. These insulating coverings may in some cases be made to adhere by fusion directly to the metal surfaces to be protected; the vitreous composition, composed of about 60% soda glass, 25% borax and 12% ferric oxid, has been found eminently suitable to this purpose. The coating G of the lead G should-be carried well below the surface of the mercury cathode H. The anode E shown in the drawing is smaller than the anode F, and approaches more closely to the cathode H, and this anode E, according to a system of electrical distribution invented by us, which forms the subject matter of' an application for United States patent filed by us on or about August 27, 1909, and serially numbered 514,907, may be employed in a merely auxiliary Capacity so that the current condicontainer at low temperatures, and'the prestions therein are not such as to heat the sure in the container thereby eventually beanode unduly. On the other hand, ifas comes too high for advantageous operation. may well be the case the anode F operates By pumping out at high temperaturesthe under conditions which produce large delivery of these gases is greatly accelerated quantities of heat, it is well to adopt proand the gas exuding from the metal Walls visions for regulating its temperature. In can be effectively removed. I

the drawing the anode F and its lead F are The mode of construction above described shown as tubular; the tubular lead F eX- enables the manufacturer of such apparatus tends out through the insulating hood to to employ effectively permanently sealed inthe atmosphere. A small quantity of mersulated electrode leads of large size and cacury H is disposed in the bottom of the pacity and to maintain these electrode leads anode tube or in the hollow anode bulb, and efi'ec'tively insulated so that the proper funcby its evaporation and subsequent condensations of the vapor electric apparatus may be tion upon the walls of the tubular lead F performed consistently with the employwill regulate the temperature of the anode ment of a metal container which is obviously F. (The tubular anode and provisions for better qualified to resist theemergencies of regulating its temperature form the subject transportation and use than any of the glass matter of an application for patent, Serial or porcelain containers heretofore suggest- No. 5)69,698, filed by us on or about June 30, ed and employed. 1910. I I

In the construction of a rectifier such as Letters Patent is:

above described, after the electrodes have In a vapor electric apparatus, a metallic been introduced and the insulating joints container, an electrode therein, a metallic perfected, the rectifier is heated and mainelectrode lead, a tubular hood projecting tained at a temperature in the neighborfrom the container and comprising two hood of 500 C. and exhausted until a metallic portions, one integral with the conproper vacuum is secured. Devices for eX tainer wall, the other integral with the elechausting the rectifier, for introducing mertrode lead, and an annulus of insulating malVhat we claim and desire to secure by cury, and for sealing the rectifier are not terial between and sealed hermetically to I herein shown. The mercury 1s boiled out in the two metallic portions of the tubular the rectifier to remove traces ofgas, or the hood, the lead spaced on all sides from the rectifier may be put into electrical operation inner surface of the tubular hood.

for the same purpose; after being finally Signed by us at Boston, Massachusetts sealed the rectifier is allowed to cool and is this 23rd day of August 1909.

ready for use. It is highly desirable to CHARLES A. KRAUS. pump out such a rectifier at a high tempera- ROY D. MAILEY. ture for the reason that appreciable quanti- \Vitnesses:

ties of gases are held in the metal walls and GILBERT N. LEWIs,

these gases are slowly given off into the ROBERT CUSHMAN.

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