US1861213A - Electric furnace with cooling means - Google Patents

Description

May 31, 1932. A. E. GREENE LECTRIC FURNACE WITH CQOLING MEANS Filed April '7. 1951 INVENTOR ATTO R N EYS Patented May 31, 1932 PATENT oF'1-"1cs ALBERT E. GREENE, 01 MEDINA; WASHINGTON ELECTRIC FURNACE WITH CObLING MEANS Application filed pi-11 7, 1931. Serial No. 528,823.

My present invention relates to improve-' ments in the mechanical construction of electric .furnace shells and electric furnace refractory supporting structures, particularly the door and roof structures.

In electric arc furnaces built with cylindrical shells, and with door ways to the chamber within, the arch brick forming the top of the door way is subject to' extreme heat from the arcs and to wear and to the effect of heating and cooling so that it is one part of the linln which wears out more quickly than others. %)ne object of 'my present invention is an improved arch cooler construction to increase the life of this part of the refractory lining. H

. Electric arc furnaces are usually provided with removable roofs which either rest on the top of the shell and brick wall, or rest on the top of the wall inside the shell. These roof rings are usually made by bending. a

steel channel section with the flanges in so as to form a support for the brick arch structure, or else the rings are made up of angles and plates forming a similar ring structure.

In certain cases water cooling pipes have been mounted inside this ring structure. One object of my invention is an improved ring structure comprising an outer ring. plate with a pipe welded to it at the bottom on the ina side forming. a combined cooler and arch suport. 1

p These and other details of my invention will be better-understood by reference to the annexed drawings, in which Fig. 1 is a plan view of a furnace embodying my invention,-.

. showing the roof cut away in part. Fig.2 i-s asectional elevation of the furnace of Fig. 1 through the center line A Fig, 3 is an elevatlon view partly in section of one embodiment of my invention, the section being taken about along a line corresponding to the line B B of Fig. 1 to cut away the front flange of the channel forming the bottom of the cooling cavity above the arch.

- Referring to these figures, thefurnace shell consists of a bottom head 1 to which is Welded a cylindrical plate 2 forming the shell proper, and to which in turn is welded a reinforcing channel 3 atthe' top of the shell plate 2. The

shell is lined with a hearth 4 and walls 5, eX- tending up to the line 6. A door way 7 into the furnace chamber is formed by arch brick 8 above the doorway resting on side brick 9. The door way is closed by a refractory lined door 10 which fits against a plate 11 which in turn fits against the structural members 12 at the bottom and 13 at the top welded to the shell. The top member in these illustrations is a channel section. It has a web 1 1 and inner flange 15 and outer flange 16. The front view of the door structure in Fig. 3 shows the curved surface of this channelat 14 just above the arch brick; The weld at the top of the inner flange is indicated at 17 and a cover plate 18'may be seen in Figs."2 and 3. The channel is Welded to the shell plate 2 and the inner flange of this channel is welded to plate 2 at 19 and 20. The water cavity is formed, by welding the top plate 18 to the top of the channel flange 15 and to the inside of the shell plate 2. An opening'is provided at'the lower, part of the cooling cavity thus formed at both sides of the cavity asindicated by the pipes 21 and 22 which serve for circulation of cooling water.

This forms a very simple and substantial and eflicient construction. The channel reinforces the shell at the door way. It also forms the cooling cavity with the necessity of only a single piece of plate, like that at 18 in addition to the channel and shell plate. The fiat. inner surface of the channel forms a surface for a second arch'23 to abut over the'door way arch brick 8 and provides for protection of the shell in'case the archbrick of the door way is allowed to become worn away.

It is understood that my construction is not limited to the use of the channel member or "to the shape of cooling cavity indicated but that I'may build this structure up in other ways and accomplish the purpos'eofniy in-- vention without getting away from the essentials thereof.

The construction of the roof structure will 95 now be described. I have shown the roof ring of my present invention made of a steel plate 24 formed with slightly less outside diameter than the inside diameter of the shell plate 2. This plate 24fornis a complete ring and the ends ai'e welded together at some convenient. place. Inside this ring 24 and at the bottom. of it an iron pipe is welded to it so as to be approximately flush on the bottom with the bottom of the plate 24. The welding need not be completely around the ring but is preferably above the pipe as well as on the lower part as indicated at and 26. This pipe forms a complete circle inside the plate exchamber. They are supported by means of K the pipe and by refractory material indicated at 31 forming. a skw back. This may be brick or it may be rammed-in refractory material. The roof ring and refractory held in it rest inside the furnace shell on the to of the refractory chamberwall.

y improved roof ring not only is simpler to construct but also avoids the burning away of the ring structure as when the ring has an inwardly extending flange instead of the pipe. Furthermore, in case of wear of the wall' brick till they become excessively thin, even if the pipe is exposed directly to the heat within, the water cooling protects it and prevents damage.

What I claim is: I 1.In anelectric furnace having a plate metal shell with a curved surface through which is a door way into a refractory lined chamber within, a cooler for the brick work above the door way, said cooler comprising .a weld-sealed water cavity between the shell plate and the refractory material inside the shell above the door way, and inlet and outlet openings for water cooling this cavity.

2. In an electric furnace having a cylindrical plate shell, a door way arch cooler comprising a water cavity between the inside of the curved shell plate and another plate 'mem*-. ber forming'with the curved plate a sector of a circle and having top and bottom plates all welded together to be water tight and having openings for water circulation through the cavity thus formed.

' 3. In a cylindrical electric furnace shell having a door opening, a refractory lining within and a door way through said lining to the chamber within, an arch above 'said door way, and a cooler for the top. of said arch comprising a curvedplate member conforming to the top of said arch, an inner plate member forming a sector shaped opening between it and the shell above the arch plate, and a top member for the water cavity thus formed, said member being welded together and having water circulation means.

4. In an electric furnace shell, having a refractory linin and door way therein, sur, mou'ntedby a rick arch, a door arch cooler formed by a bent channel member arched over the to of the brick arch and having a,

porting the brick arch and for'cooling the furnace structure.

In testimony whereof I aflix my signature.

ALBERT E. GREENE.

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