US1051036A - Electric-resistance melting-furnace. - Google Patents

Description

UruTE-D sTAirEs PATENT oFFioEJ AUoUs'i` voELKER, or BEUEL, NEAR BONN, GERMANY.

ELECTRIC-RESISTANCE MELTIG-FURNAE.

specification of Letters Patent.. Patented Jan. 21, 1913.

pplication filed February 18, 1911. Serial No. 609,468.

TQ all whom t may concern Be it known that I, AUGUST VonLKnn, a subject of the King of Prussia, German Emperor, lresiding at 77a' Siegburgerstrasse, Beuel, near Bonn, in the `Empire of Germany, have invented a new and useful Electric-Resistance'Melting-Furnace, of which the following is a specification.

Quartz melting furnaces are known, consisting of a carbon core in the shape of a rod, which is in closed on the central part of its length by a concentrically arranged tubular shell, leaving an annular space aroundA said core, and which willxin consequence of an electric current sent through it, fuse the arenaceous quartz filling out said annular space progressively from the inside to lthe outside. these melting' furnaces consisty in lit being possible, indeed, to make the outer portions of the quartz body produced in the annular space, cohere, Iand even to create on it a thin glaze-like fused film of the shell generally7 made ofl carbon surrounding the .central heating core; it is, however, not possibleito lso thoroughly fuse the interior of the quartz charge so that. a product is obtained of a uniform structure throughout, although it is of the'greatest importance forthe subse# quent treatment of the quartz body and the quality of the articles made therefrom,

My invention relates to improvements 'in such lelectric furnaces, whereby 'the said `One `improvement consists in connecting the 'outer shell at one endby means of a conductor in series with the inner core pass- Ving through the shell.

Another improvement consists in longitudinally adjustable connections on both the s'hell and the core for the conductor between j vthe shell and the core at the said one end and for the current cables at the other end.

A-third improvement consists inthe longitudinaladjustment of the' core relatively to .the shell. Then the electric current will first longitudinally pass through the shell and then by means of the conductor through the core. Thereby it is obtained, that,-al;

though at first,` that is at the commencement of the furnace, the outside o f the working shell Ywill be heated, even if not up' to the :melting temperature of the quartz, and with `it the adjoining vportion of thequartz charge,the.current will, according the duration of the passageof the cur- -The drawbacks of` rent and the progress of the fusion; gradually pass, besides in a longitudinal, lalso in a radial direction from the shell tothe core thro-ugh the charge becoming conductive in consequence of the fusion, so that a final product of homogeneous structure is obtained. This process may bel regulated by gradually shiftingthe points of connection on the `shell and' the core as thereby the re- 65 sistances and also .the heating effect may be varied.

lt is true, electric melting furnaces `are known, `ir which a Crucible-like melting chamber, closed below, is employed as series resistance for 'a centrally arrangedv live heating core in contact with the bottom. But with such arrangement it is intended to keep the walls of the Crucible cold and save thev latter', by increasing the 'heating of the 75 tional form of the vinvention forming the subject matter of the present application is exemplified. It must be understood, that the invention shall not be limited to this one constructional form only.

It consists of a furnace bodyia supportl ed on trunnions turning on stands l), and 1s lined with insulating material. Into said body a is fitted a carbon tube c in such a manner that it projects `at both ends from the furnace. closed by suitable disks (not shown) Aof in' sulating material and providedwith a central hole. Where so preferred, of course in otherwords they may be provide shoulders adapted to bear against the annular end faces ofthe. tube c, 'so that they may be Vinserted and detached Y easily. Through the central holesof these two' disks.

these disks may be set off on the periphery,

`a comparatively thin carbonior graphite rod 106 Y d is passed and the space between said rod,

the inside of the shellc and said two disks istilled with arenaceous or other raw quartz. The two ends of the carbon bodies al and c carrydisplaceable contact rings f1, f2 and e1, 110

e2 respectively made of the same material. Terminals g1, 1 are provided on the contact' They are therefore more or less un- 80 The ends of the tube c are with .rings e1, fl/at the lower end for -introducing l -the current to and'letting it out from the shell tube 'c orthe heating lcore d respectively, while similar terminals g2, i2 are providedon the contact rings e2,-.f2 'at the upper end and-.al bar la, is 'provided for connecting v the yterminals g2, .2 at various heights by y enters at e1 intotheshell c, flows through' "mcans'ofa series of holes and for serving as Viii/conductor, 1t conducting the' current from gft/tod. f

While the furnace is-working the current 'the latter'and the bridge bar h into. the

.core d. and `fromthe core d into the conduc tor connected to the.terminal 1.- At first' c' and igher temperature of core the charge, whilethe quartz along the inside shell c will coherev andcake.- lVi'th the pro-V gressing fusing of the 'charge thesame will become conductive, in consequence o f which 'the'j current willno more flow through the bodies c and d in .a longitudinal direction only,bu't will also passin --a radial direction through the charge, purify it and fuse it in alfomogeneous manner. The resistance of the carbonbodiesc, d varying-with'thedura# `tion et the passage of the current-andthe- `.30

progressingl fusion, may be compensated or also .an intentional 'variation oflthese re-f sistances may,jfor the purpose of Aobtaininga. more rapid Afusion 'and urifcationof cer,-`

' 'tain parts of the quartz ch 35.

arge, be produced by changing the position of theI admission and outlet terminals il, i2 'and g1, g2 re; spectively by .displacing the contact 'rings v f2 and 91,62 von their respective carbon bodies d and c, so-that the length of the pathofthe current. land the heating effect o-iithe parts' ofz the charge penetrated may be easily regulated.

'I claim: 1. An electric melting furnace, in which a thin live .resistance heating core' 1s concentrically surrounded at a given'distance 'by a 4tubular shell for between the core and the shell, the' said inliig a 'space for the char e' tubular 'shell connected by afcoiiductor as a'.

5ol' core, whereby the current entering at one series resistancein 'series with the'heating end (if said' 'shell will flow longitudinally through 'the same,`.then'pass into' said conductor connecting the shell with the core and' finally come out atfthefother end of the core the tube at one end and connected with an inlet -lating 'material providedl withcentral holes,

at both ends of. said tube, a thin carbon rod guided in the holes of said twocovers and projecting therefrom at both ends, whereby an annular space for the charge is formed between said' rod, the insidebf said tube and said twocovers, a contact ring ad'ustable on terminal, a -similar contact ring adjustable on the tube at the other end and conductivel connected with a bridge bar provided with,

holes, any adjustable contact ring on the correspondingend of the carbon rod and conductivelyconnecte'd with said bridge .bar and ladjustabley thereto by means of said holes, i

and an' adjustable contact ring at Athe other l 'e'nd offsaid carbon' rod connected to a`cond 'uctor leading-olf the current. d0 "3.1A1i 'electric melting furnace consisting l .of a furnace lbody supported on trunnions turningon stands, and lined with insulating material, a 'carbon tube in said body project. ing at 'both ends,l two removable covers of insulating material provided with central holes at both ends of said tube, a thin car- 'bon rod guided in the holes of said two covers -and projecting therefrom at both ends, whereby an'annular space for the charge is formed between sa'id'rod, the inside of said' tube and said two covers; a-'contact ring adjustable on the tube-'at one end and connected with an in'let terminaba similar contact ring adjustable on the tube at'the other end 95 and conductively connected withav bridge bar provided with holes, an adjustable contact ring. on the corresponding end yof the carbon Lrod and conductively connected with said bridge bar and adjustable thereto by means of said'holes, and an adjustable contactring lat the other end of said .carbon rod connected to aconductor leading off the current. a In testimony whereof I hereto aix my 105 signature ini the presence of two witnesses.-

. AUGUST VQELKER; s In presence o-f- N IKoLAUs Mmmm, Louis VANDORY.

Images