US1617361A - Furnace resistor mounting - Google Patents

Description

.J. C. WOODSON FURNACE RESISTOR MOUNTING Feb; 15 1927.:

Filed Nov. 28, 1923 INVENTOR James G Woodson.

WITNESSES:

ATTORNEY Patented Feb. 15, 1927 U N I T ;1.

ENT OFFICE.

JAMES C. WOON, OB' EAST PTTSBUE, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTBIC & HAUFACTUBNG COMPANY, A COBPORATION OF PENNSYL- VANIA.

IUBNACE BEBTOR HOUNTING.

Application filed November 28, '1923. serial No. 877,!560.

invention relates to electrically heaturnaces and particularly to resistor mountings for electrically heated resistance furnaces. I The object of my invention is to provide a relativel simple resistor mounting for an electrica ly heated resistor furnace.

In practicin my invention, I provide a pluralty of re ractory heat-insulating walls e'nclosing a furnace chamber. In one or more of such rwalls I mount a. plurality of spaced sets of relatively thin, elon ated, metal members, of substantially T-s spe,

projecting into the furnace chamber. The' metal members of T-shape are spaced laterally in each ;set and relativel thin refractory plates or bars, having later& grooves in their inner surface, are held b the 'outer ends of aire of members of T-s ape. A reiatively eavy resistor 'member preformed to comprise a plurality of straight and substantially 'parallel-extending, end-connected convolutions is held by the grooved pletes whereby the convolutions extend substan- 95 tiall arallel .to the furnace wall and close ly jacent thereto;

'A substantially similar design is disclosed and claimed in condin application Serial No. 584,(320 of' A. I ei Electric & Manufacturing Company. As set 'forth in that application, refractory members of T-shape are supported by the "refractory walls of the furnace structure and, in order to dbtain suflicient strength,

the lateral area of the members of T sha e are made relatigely large and of such thic ness asto be substantially equal to the thickness of the refractory bricks or blocks emlo ed in buildin up the heat-insulating %nis g filed August* 30 28, 1922, and assigned to the Westinghouse -shape are of such thicknem that omprising the device embodying my inven- Fig. 2 is a. View, in perspectve, of a regctory grooved bar employed with the device embodying my invention,

Fig. 3 is a view, in perspective, of a devce embodying my invention,

Fig 4 is a view, in perspective, of a modified form of device embodying my invention and Fg. 5 is a View, in perspective, of a refracto bar employed with the modified form o metal supportingmember illustrated in Fig., 4.

An electric furnace, designated generally by the numeral 11, comprises an outer casing 12, of a suitable heat-insulating refractory material usually employed in the art. An inner lining 13 is composed of a plurality of bricks or blocks of a suitable high-temperature resisting material, a number of co-operating walls being provided, suitably spaced apart to form or enclose a furneoe chamber 14: of any suitable or desired -cony tour and dimensione.

The furnace structure is illustrated schematically only' as the' device embodying my invention may be employed with any similar type of furnace comprsing refractory walls occupyng a plurality of bricks or blocks in the inner lining. y A plurality of spaced sets of relatively thin and elon atd metal members 15, of substantially -shape, are rovided in one or more of the walls of the urnace structure 11. The members 15 are illustrated more particularly in Fig. 3 of the drawing, and comprise a relatively narrow, thin, and elongated main portion 16 and an integral flen portion 1 p thic ess of the main portion 16 is such ,that it me? be placed between two successive layers o 'bric s or blocks comprising the inner linin 13, the binding material usually provid being omitted wherethe member 15 of T-shape is located.

The members 15 in the respective sets are,

spaced apart a suitable distance, and rela tvely narrowbars 18, of a suitable refractory electric-insulating material, extend between spaced pairs of members 15.` Each ofthe members 18 is provided, in one face.

at one end thereof The tween the `members 18 suppo thereof, with a pluralty of spaced and laterally-extending grooves 19 and that face of the member 18 which is provided with the grooves 19 is normally located closely adjacent to a surface of the wall supporting the members 15. v

A resistor member 21 of relatively heavy metal, preformed to comprise a pluralit of straight and substantiallyparallel-exten ing convolutions, has parts of the individual convolutions located in the respective grooves 19 to extend therethrough and berted by the spaced sets of members 15, substantially as illustrated in Fig. 1 of the drawing.

The end portions *of the respective re-` sistor members 21 are bent at substantially right angles to the plane of the convolutions and may extend through suitable insulating bushings 22 provided in the respective walls of the Jfurnace structure.

In mounting the individual resistor members 21 in their proper operative positions in the furnace structure, they are moved in a direction substantially at right angles to the plane of the convolutions and of the adjacent furnace wall so that the end portions will extend through the bushing 22 and the individual convolutions will be held temporarily by the operator in substantially their proper operative positions. The .bars 18 may then be placed in their proper operative positions with a part of each convolution located in a groove 19, the bars 18 being temporarily located out of contact with the co-o rating supporting members 15 and move into their proper operative positions longtudinally `of !the convolutions.

As the resstor member 21 e'xpands and contracts duringthe normal operation of the furn'ace, it is necessary `to provide means to revent movement of the members 18 away rom the sup orting members 15, and I provide' relative y small key members 23 that are located on the 'respective sides of the members 18 and extend through suitable openings 24 in the members 15, closely adjacent to the flange portion 17.

In Fig., 4, I have illustrated a modified form of metal member 25 that is rovided with a single opening adjacent t e 'oute'r end through which extends a loc pin 26 that is easily and quickly remove therefrom. v

A refractory bar 27, having plurality of laterally-extending grooves 19 in one sur-- -ace thereof, is provided with longitudinally exteding gro'oves 28 in that face o posite to the grooved face at each end of the bar. The longitudinal extent of the grooves 28 ia suflicient to rmit of inserting and remov ing the hol ing iocated in thegrooves 28 of the two mem bers2'? operetiveiy euge any ose of members pin 26 which has its and When the modification of the metal sup porting member, illustrated in Fig. 4-, is em plo ed, the method of assembly is slightly diirent from that described when member 15 is employed in that, after the resistor member 21 has been placed temporarily closely adjacent to one of the walls, the respectve bars 27 may be placed in their proper o erative positions by being moved toward t e surface of the wall it being understood that the ins 26 have n removed 'from their normaFoperative positions in the members 25.' After the bars 27 have been placed in their proper operative positions closely adjacent to the co-operating' furnace wall and supported by, and extending between, the members 15, the holding or locking pins 26 may be dropped into their proper operative positions, thereby preventing any lateral movement of the bars 27 away from the su porting members 15.

As urnaces of the type referred to in this a'p lication are intended to o rate at relative y high temperatures, I emp oy metal members 15 or 25 that are made of a metal that does not `otidize at such relatively high temperatures and I may em loy nichrome or some similar material for t is pur As the distance between pairs o members 15 in the ree tive sets thereof cannot be made very ar e, on account of the strength of the mem rs 18 and 27, the weight that each member 15 must support is' relativel small and, as the overhang thereof or t e distance which it rojects into the furnace chamber may be mase relatively small the thickness of the main ortion 16 may made relatively very sma thereby permitting, as was hereinbefore stated, the

nsertion of this member in place of the binding material provided to hold the adjacent layers of bricks or blocks together.

The device embodying my invention thus permits of coverin 'a much greater portion of the furnace wa s with a resistor member than would be the case' if the sup rting members of T-shape were made of re atively thich* refraetory material, as has heretofore been the case., As the rooved refractory bars may be made relatvely narrow, substantially all of the resistor member 21 is left bare and in direct heat-radiatig relation within the iurnace -chamber t ereby preventin any. pocketing of the' eat and possible ama e to the resistor.

erious m ifications and changes may be made without departing from the spirit and acope ot the' invention, and I desire., therefore, that only such limitationa shall be steizal T-shape, and of substantialiy nonmeans operatively associated with each memox a and projecting therefrom, a notched refracsaid bars laterally t` ereof.

tory bar, of electric-insulating material ex- In testimony whereof, I have hereunto 5 tending between each pair of metal memsubscribe& my name this 20th day of Novembers, s. resistor member su porte& by said ber; 1923.

`notehed refl-&story bars an being substantially self supporting therebetweem, and JAMES C. WOODSON.,

e material, supported by said wall ber of 1'-shape for fireventing movement of 10

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