US1352040A - Electric furnace - Google Patents

Description

F. VON SCHLEGELL AND W, B. LEMS.

ELECTRIC FURNACE.

APPLICATION HLED APR. 4. i919.

F. VON SCHLEGELL AND W. B. LEWIS.

ELECTRIC FURNACE. Aiwucmon mm APR. 4. 1919 Patented Sept. 7 1920.

2 SHEETS-SHEET 2.

QTHWED STATES ()FFICE.

IF'ITLLIADE LEW.

fJIEiIUAGO,

cation oi Letter-is Sept; 7, 1920.

compare- 'ro"ecting casing refractory she contact whereby a substan:

Y i th hoe"; enerated in ,aid

tricai resistance, will be ciiatiox; said casing 1nd mounted on the e furnace aiso to ccntaet, she re the irorn. flowing out .Mnrnace of the 0 provide, in 00111- icai contact of the ore wit surrounding the tap will 'be aping description, taken accompanying CiI'ZWW t of the inven- ULQVZtiOH of an electric irnace oi: the gg type showing the 0001- ront and contact in position;

is sectional view taken on the .1 ration of the contact seine r moved irom the furnace,

ViGW of the water cooled L more in detail to the drawings, esignates an electric furnace comprisbody 11, the upper wortion 12 of which a cyiinihicai shape While the lower porion thereof is of conical design, the sides 01 said lower portion tapering downwardly inwardly toward the vertical axis of said furnace. The roof of the furnace is at 1' The entir funace is prefere nounteci in an upright position on a hm lity of rockers 15, whereby said furnace may he tiited in order to pour the contents thereof out hrough the tap hole 16 after each he: operation s preclude ali possi- J1 .L. body or the on of the shell which covers the area of c rent 4,. l he furnace surrounding; the tap or is preferably cut away and in ieof a water cooled front for the 5 1:1 "n e is provided. This water cooled front comprises a hollow water jacket 19 n the form of an annulus which preferably completely surrounds the tap hole, the lower po on of said annuius extending beneath h spout 17 of the furnace and being em ed within the refractory material thereediately adjacent to and in contact re breast lining of the furnace, as more clearly in Fig. The water provided with an outwardly eX- flange :20, which completely surthe same and by means of which bolted or otherwise secured to Cfil'ltedges of the shell 18 of the This water jacket l9 is provided ilet 21 and an outlet 22, the outlet ghtly lar er than the inlet so that quickly oc ted in the water acket in'erme 5 inlet and outle is baffle plate 23 t 1 V to insure passage of the water, ted into the jacket through the inlet 0 521., downwardly therefrom and around the .ap hol nd then upwardly and outwardly rhe outlet 22, thus preventing the m passing; directly through the on of the jacket from. said inlet It is preferred to provide the each sl d of the batlle plate 23 open if si'ich as shown at 24-. in pnwide communication between or of the jacket and the atmosof the furnace whereby be generated within the re operation of the furnace, adiiy escape, thus reducing to a. min )SSll)lll. J:\ .Of an explosion by I pressure within the jacket i. .e noted from j foregoing that tocntiz'e front of the furnace surroundingg,

: tap hole is cooled at all times, the holaulus through which the water passes inlet to the outlet thereof being directly in. contact with the re- .i'ial of the front, thus serving y lengthen the life of such mans well lrnown, the arch of r"- jacket of which is in direct contact with the arch and, in fact, the entire area of the furnace front which surrounds the tap hole, the lower portion of said jacket being embedded in the refractory material immediately below the tap hole and adjacent to and in contact with the breast lining. Thus it will be noted that these portions of the furnace are protected and cooled, as a result of which the burningaway thereof, due to the intense heat within the furnace, is greatly reduced.

Around the lower QC go of the water jacket 19 there is provided an outwardly project-- ing semi-circular shaped flange to which may be secured in any suitable manner a supporting shell 26 for the spout 17. This shell 26 is provided at its outer end with a flange 2? which is curved over the outer end of the spout to thereby protect the same.

The flange 27 adjacent the pouring area of the outer end of the spout is preferably cut away as at 28, in order that the metal, as

the same is poured from the furnace, may not contact with the metal of the shell. If desired, this curved over flange 27 may be formed integral with the spout supporting shell :26 or it may be constructed separately and secured thereto by means of bolts or other fastening elements, as shown/in the drawings.

The improved contact, which forms a very important part of the present improvements, is shown. in the drawings at 29, said contact being provided with two pairs of opposite flanges 30 and 31, preferably provided with a. plurality of bolt holes common to the bolt holes 32 provided in the flange of the water jacket 19 near the lower end thereof. By means of these flanges and 31 and the holes for the fastening means just described, the contact 29 may be securely and rigidly attached to the water front of the furnace immediately beneath the spout 1'7 thereof, as shown more clearly in Fig. 2 of the drawings. From these points of attachment the contact extends downwardly for. a short distance over the outer surface (if-the furnace and their inwardly and upwardly into the melting chamber thereof, said contact being preferably hollow from a suitablepoint adjaccnt the portion of the Contact which lies atmosphere exterior-1y of the furnace, as above described, thereby precluding all possibilities of the cooling water causingan eX- plosion within the furnace as occasionally results in the use of water cooled bottom contacts of the type heretofore commonly employed.

.l'lolted to the shell 15% of the furnace and. extending outwardly therefrom around the lower portion of the contact -29 is what may be termed a contact bowl l0, preferably constructed of sheet metal. T his bowl-shaped member s0 is spaced away from the contact 29 and provides a support for the refractory lining ll which is placed in said bowl and which fills the space between the same and the contact, as shown clearly in 2. lt will be noted from the drawings that the contact is attached to the water front adjacent the cylindri -al portion of the furnace and that it extends downwardly from such' point of attachment and into the melting chamber of the furnace through the conical portion thereof. This, in the absence of some provision. such as the bowl 4+0 and the lining 41, would, it will be noted, leave the portion of the contact where the same is curved ini ardly into the wall of the furnace unprotected. in providing the bowl i0 and lining ll this portion of the contact is not only protected with refractory material, but

the escape of metal from the furnace through the bottom thereof around the contact is provided against, as well as the escape of any of the contact metal should the same be in a molten state. Furthermore, in providing this lining 41 on the exterior of the furnace for the )rotection of the contact, said lining may be made of such thickness that a large portion of the heat produced in and around the contact, due to electrical resistance, may radiate outwardly through said lining. thus aiding materially in cooling the contact. The space between th upper edge of the bowl 4d) and the adjacent surface of the contact is preferabl covered by means of a suitable plate i2 secured to the bowl in any suitable manner.

By means of the bolts 43 and asher ts the cable yoke or bus bar 45 is rigidly tached to the outer face of the upturned head 36 of the contact. At 46 the cables or electrical conductors are shown, the same being attached-db any suitable manner to the outer ends of the cable yolre.

In attaching the Water cooled front, contact and bowl to the shell of a furnace, it is preferred to use bolts in order that said parts may be quickly removed, should repairs or replacement become necessary. It

is obvious that these parts, owing to their construction, may be mounted in position on practically any'of the electric furnaces of the tilting type now in use by merely cut ting the shell of the furnace away, as has already been indicated, and providing a suitable opening through the wall below the tap hole for the insertion of the contact.

While the contact has been herein de scribed and illustrated as located in the wall of the furnace immediately below the tap hole thereof, and as entering the melting chamber of the furnace at a point intermediate said tap holennd the vertical axis of said furnace, it is obvious that said con tact may be positioned at various other locations in the furnace other words, the exact location of the contact is immaterial so long as the same enters the melting chamber at such a point that the metal thereof, should the same be in a molten state, will not be poured out through the tap hole upon a tilting of the furnace as in a pouring operation.

It is also obvious that the construction herein illustrated and described is susceptible to many changes and modifications within the spirit of the invention, and it is not, therefore, desired nor intended to limit said invention to the particular embodiment shown except where limitations ap pear in. the appended claims.

What we claim is 1. The combinationwith an electric furnace having a melting chamber and a tap hole, of an electrical contact for said furnace projecting through the wall thereof below said taphole into said melting chamher, the out n end of said contact being up turned and provided with a cooling chamber above the inwardly projecting portion of said contact.

2. A contact for electric furnaces comprising a substantially horizontally estending portion adapted to project into the melting chamber of the furnace through the wall thereof, and an upturned portion at the outer end of said contact adapted to be cured to said wall adjacent the outer surface thereof, said upturned portion being provided with a. cooling chamber which eatends above the plane of said horizontal portion.

3. in an electric furnace, a. metallic bottom contact, and means for cooling the same, said cooling means being located above metal of the contact.

a. The combination with an electric furnace, of a. contact thercforattached to tne outer surface thereof below the tap hole, said contact extending from its point of attachment downwardly and then inwardly and upwardly through the wall of said furnace into the melting chamber thereof.

5. The combination with an electric fur, nace, of a contact therefor attached to the outer surface thereof below the tap hole, said contact extending from its point of attachment downwardly and then inwardly all without departing from the spirit of the invention. In"

through the wall of said conical. portion into the melting chamber of said furnace, a bowl shaped member secured to the outer surface of said conical portion and extending outwardly therefrom below said contact and refractory material filling the space between said contact and said member.

18. in an electric furnace, bottom contact, a portion of which. projects exteriorly of the furnace Wall and a thin casing of re, fractory material covering said portion.

19. 11 an electric furnace, a bottom contact, and a thin casing of refractory material therefor mounted exteriorly of said furnace, said casing covering said contact 'at its point of entrance into the Wall of said furnace and extending upi'vardly from such point to a plane substantially coincident with the horizontal plane containing the inner end of said contact.

20. The combination with a tilting electric furnace having a melting chamber. a tap hole and an inclined channel extending from the bottom of said chamber to said tap hole, the bottom of said channel being substan-- tially horizontal When said furnace has reached its limit of tilt as in a pouring operation, of a bottom contact for said furnace extending through the wall thereof and entering the melting chamber through the bottom of said channel whereby substa tially no portion of the metal of said contact is displaced during a tilting of the furnace, should said contact be in a molten state at the time of tilting.

2-1. The combination With tilting electric furnace having a tap hole and a melting chamber, a portion of the bottom of which between said tap hole and the vertical axis of the furnace remains below said tap hole throughout the tilting of the furnace, of bottom contact for said furnace extending through the Wall thereof and entering said chamber Within said portion.

22. The combination with a tilting electrio furnace having a tap ho e and a meltingchamber, a portion of the bottom. of'which between said tap hole and the vertical axis of the furnace remains below said tap hole throughout the tilting of the fi-u'nacc, of a bottom contact for said furnace extending through the wall thereof and ei'itering said chamber within said portion, and a cooling; chamber exterior of the thu-nace and formed tached to the outer surface of vid'ed with a cool] immediatel beneath the noun thcreoi sa l contact extending melting chamber from such. point of at tachment through the adjacent wall of th furnace and entering said chamber point which normal j below the outer of contact.

The combination with at furnace, of a bottom contact th tachcd to the outer surface sai immediately beneath the "pouri I thereof, said contact extending into melting; chamber from such point of at inent through the adjacent "Wall furnace and entering said cherub of said conta 261 The combination with a trio furnace, of a contact therefor to project through the wall of ti to the contents thereof, and a coo her for said contact mounted the furnace and above the point at said contact enters said furnace.

27. lhe con'ibination with a trio furnace, of a contact their to project through the Wall of to the contents thercoha coolh for said contact mounted exterio furnace and above the point at contact enterssaid furnace, and a re pocket for the portion of said contact v lies exteriori v of said furnace Wher i age of the metal of said con latter be in a molt In testimony wise" our names.

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