US2436024A - Annealing furnace - Google Patents

Description

Feb. 17, 1948. L.. E. SMITH 2,435,024

' lNNEALIIG FURNACE Filed Jan. 2o, 1942 e sheets-sheet 1 atroz/Ma' @3b. L E, SMH-H ANNEALING FURNACE Filed Jan. 20, 1942 6 Sheets-Sheet 2 Iva we@ for Feb. '17, 194s@ L, E; SMWH 2,436,024l

* ANNEALING FURNACE Filed Jan. 2o', 1942 e sheets-sheets Feb. 17, 1948*. L E SMH-H ANNEALING FURNACE Filed Jan. 20, 1942 G Sheets-Sheet 4 me/Who@ Feb. 17, 1948. v .YEV, sMn-H v 2,436,024

ANNEALING FURNACE I Filed Jan. 20, 1942 6 Sheets-Sheet 5 l. :JrvuQ/YVYOL eender feige@ 5m a' 5.25/

Feb. 17, 194s. L E SMITH l.

ANNEALING runnen 6 Sheets-Sheet 6 Filed Jan. 20, 1942 mama ret. 11. 194s 2,436,024 y UNITED srA'ras PATENT ortica ANNEALING FURNACE Leander Eugene Smith, Kokomo, Ind., assigner to Continental Steel Corporation, Kokomo, Ind., a corporation of Indiana Application January 20, 1942, Serial No. 427,505

s claims. (ci. zes-4s) This invention relates to annealing furnaces,

particularly for annealing sheets, although capable of use for annealing other material, for example, wire, and hence not so limited. The invention more especially pertains to that type of annealing furnace wherein after the sheets or charge of other materials arey piled on the hearth, an inner cover formed of good heat conducting metal is placed over the sheets to enclose same, vfollowing which the outer cover, or the furnace proper is placed over the inner cover, with both covers supported on the base or bottom of the furnace. and sealed from the ingress or infiltration of air bysand, oil, or equivalent, the covers being spaced to provide `a heat. ing and combustion chamber in such space.

Following the application of heat, for'sufllcient a period of time to anneal the charge, the outer cover is removed and replaced with relation to another inner cover which latter encloses a second charge piled on a second base, after which the heat is similarly applied to the innerl cover of the second charge, while the first charge, from Vincreases the rapidity of heating of the inner cover, and which also applies the heat in a uniform manner so as to effect uniform heating of the batch or charge of material.

A further object of the invention is to provide means for applying heat to the inner cover by maintaining a zone of ring with the name enveloping and literally hugging the inside wall of the outer cover.

Still further the invention aims to provide heating means for the inner cover which intercepts the flame and thereby not only directs or deects same so as to -cause the flame to follow a acts to -direct or'deflect and spread the flame against the inside wall of the outer cover, and also provides an increase of heat by radiation.

The invention further resides in means for holding the corrugated baie plate or tile in position and to provide means on the inside wall of the outer cover, which cooperates with the baille plate or tileto form a heat passage that deilects the heat so as to cause the flame to always maintain a position close to the inside wall of the cover.

The invention still further aims to control the heat supplied to the inner cove'r by providing a damper mechanism which is responsive. to the gas supply.

The invention has still other and further objectives which will be later set forth and of themselves manifested in the course of the following description.

In the drawings:

Fig. 1 is a vertical sectional view taken transversely through the central portion of a furnace constructed in accordance with the present invention;

path close to the inside wall of the outer imping- Fig. 5 is an elevation partly broken away, and

partly in section, of one of the bolts or fasteners employed to secure the refractory tile in position; Fig. 6 is a top plan view of the corrugated or undulating refractory baille plates, showing the t mode of connecting the sections;

Fig. 7 is a front elevation of Fig. 6, partly broken away, of one of the baille sections;

Fig. 8 is a fragmentary perspective view of the inner face of the side wall of the outer cover;

Fig. 9 is a view similar to Fig. 5 of a modified form of bolt or fastener;

Fig. 10 is a fragmentary view of the top of the outer cover; and v Fig. 11 is a fragmentary perspective view of the damper control.

In proceeding in accordance with the present invention and referring more particularly to Fig.

1, l designates the hearth of the furnace which is formed of refractory material and is provided with a trough 2, which surrounds and receives as indicated at 3.

4other forms.

Therefore dependent upon the 'shape of the inner cover I, the trough 2 is shaped to corre-V spond thereto so as to receive the entire bot tom portion of the inner cover and thereby seal same against the ingress or infiltration of air.

The batch or stack of sheets or other chargeof material is initially placed upon the sand filled portion B of the hearth, following which the inner cover 4 is applied in the position shown in Fig. 1.

The superstructure of the furnace, which will be referred to as the furnace proper, is removable from the base structure, which latter includes the hearth, and has a supplemental trough 6 provided below, and in surrounding relation to the trough 2. to likewise receive a sealing material. The furnace proper has an arched top 8, ends 9' and sides 9 formed of tile or refractory material, and held in place by a suitable metal casing indicated generally at I0. The bottom of the casing has a depending web II secured thereto, which is received within the trough 6 so as to form an air seal, as in the instance of the seal of the trough 2.

Any suitable crane or grapple engaging member I2, is connected to the top of the furnace proper, which constitutes the outer cover, so that the latter may be removed and replaced upon a second base corresponding in structure to that just described. to heat a second batch or charge of material while the rst batch or charge of material is cooling with the inner cover enveloping same to thereby prevent the ingress of air to the batch, as shown in Fig. 1.

passages or chambers. and are corrugated or of undulating formation, so as to provide an increased heat radiating area which confronts the inner cover l.

For the purpose of securing the baifiles in position, bolts having rectangular heads 28, as

` shown in Fig. are employed, the latter being In the instance of a furnace of rectangular form such as herein illustrated the two opposite sides only are equipped with burners or heat generators which extend substantially throughout the length thereof. I'he sides 9 have their inner walls formador faced with either refractory and/or refractory insulation material in brick or tile monolithic construction, and similar lower tiles Il, which coniointly form the inner faces of the side walls of the outer cover.

The tiles I4 are formed with substantially vertical lower faces I5;' outwardly curved or bulged intermediate portions I6, which merge at II into outwardly bulged upper portions I8, so that the heat from the burners will be directed inwardly of the tiles by the bulged portions I6 and I8.

Vertically disposed spaced pilasters I4' are formed on the sides 9, and have beveled sides which deflect and spread the heat and increase radiation. The pilasters are located on opposite sides of the burners, and serve to provide a series of vertical alleys for the heat, and to also support or reinforce the walls.

The bottoms of the walls of the furnace proper are chambered as indicated at I9, to receive insulation 20, upon which latter slabs 2l and 23 formed of insulating material, are disposed, the

'latter forming the bottom or floor of the heat 'l walls of the heat supplying passages, or chambers 2l, while' vertically disposed baiiles or plates 2B, are provided to form the innerwalls of such composed of inner sections 21, and outer sections 28, the sections being preferably welded in end to end relation as indicated at 29. Since the sections 2l are disposed in a zone subjected loy and has a rectangular head 2B' similar to ghe lsxead 26 of the form of the bolt depicted in 1g.

In Figs. 3 and 4, a modified form of side walls is disclosed, and wherein the bulge of the portions I6' is more pronounced and extend outwardly from the vertical faces I6' to a greater degree, than in Fig. l. Further there are straight portions Il' which extend upwardly from the portions I6' and which terminate in straight inclined upper portions I0', which deflect the heat inwardly. that depicted in Fig. 1.

The burners, generally Vindicated at 3l, are of any suitable type and are disposed within housings 32 formed of refractory material. A iighting hole 33 for the burners is provided, as depicted in' Figs. 3 and 8. A Aseries of lower abutments or projections lb, are formed on the tiles I4, and also upper abutments or projections I6b, to Vengage the upper and lower sides respectively of the bullies. the abutments Ib and I6b, forming seats against which the outer faces of the bailles engage, and are held seated by the heads of the bolts 26 or 26 which extend through the tiles Il, and securely engage the inner faces of the bailles, upon tightening of the nuts 30 of the bolts.

-'1'he top 8, of theouter cover and the top of the metal casing. is, as shown in Figs. l and l0. formed with a series of ilues 3l, which are controlled by dampers 35 that are connected to chains 36. The chains are suspended from arms 31 that are rigidly connected to a shaft'38, suitably journaled on the top of the metal casing I0.

An arm 39 is rigidly connected centrally of its ends to an end of the shaft 38, and has a series of perforations for selective connection to the upper end of a rod 4I, which latter is actuated by an automatic control valve mechanism, not shown. This mechanism is responsive to the amount of gas supplied to the burners. Thus, if the gas supply is high, the dampers are fully opened, and if the supply is low the dampers are partially closed, Consequently the opening and closing of the dampers is proportional to the amount of gas supplied to the burners.

The disclosure of the invention is that preferred. but it is to be expressly understood that the same is susceptible to all changes, modifications and the 'like as fall within its scope and spirit, announced by the following claims.

Otherwise the structure is similar to What is claimed is:

1. In an annealing furnace of the type having a charge-receiving hearth, a removable inner cover for the charge, and a removable outer cover spaced from the inner cover to form a heating and combustion chamber therewith; a series of burners carried by theouter cover, and extending at right anglesk to the side-wallj'f the latter, a lining for the outer cover formi'/g one Wall of a heat conducting passage for the gases and having a substantially straight portion disposed above the burners and further having an inwardly bulged portion and an upper portion extending vertically upward from said inwardly bulged portion, a bottom for the passage located beneath the burners, and a vertically disposed corrugated baille forming the other wall of the passage disposed between the burners and the inner cover and spaced from each thereof, and having its upper end spaced below the upper inclined portion of the rst-named wall of the passage.

2. In an annealing furnace, a series of burners, a body having means forming one wall of a heat supplying passage and having a substantially straight portion disposed above the burners and further having an inwardly bulged portion and an upper portioninclined inwardly and upwardly from the bulged portion, a, bottom for the passage located beneath the burners, and a vertically disposed corrugated baille forming the other wall of the passage and having its upper end spaced below the upperinclined portion of the rst named Wall of the passage.

3. In an annealing furnace, a base for supp0rt v ing a charge to be heat treated, a cover having an open bottom mounted on said base and having side and end walls and a top provided with an outlet, the side walls of the cover having a plural' ity of spaced inwardly facing recesses therein adjacent the lower edges thereof, a baiiie carried by the cover in 'spaced relation to the rear walls defining said recesses and having its upper edge terminating spaced from the upper walls dening said recesses so as to provide a heat conducting passage therebetween, and a plurality of spaced burners, one each in each of said recesses, projecting through the side walls of the cover adjacent the lower end of the baille and at right angles to the latter for directing a flame thereagainst, whereby heat from the burners will ow upwardly through the heat conducting passage between the upper edge of the baffle and the upper wall of the recess and then upwardly along the face of the side wall of the cover-above the recesses and toward and through the outlet in the top of the cover.

4. In an annealing furnace, a base for supporting a charge to be heat treated, a cover having a. top-wall. side walls, end walls and an open bottom mounted on said base, said top wall having a damper controlled outlet therethrough, the side` walls of the cover each having an inwardly facing recess formed therein adjacent its lower edge, a burner in each of said recesses, and a vertically extending baille disposed in each of said recessesv in spaced relation to the wall dening the back of the recess and having 'its upper edge terminating spaced from the wall deilning the top of the recess so as to provide a heat conducting passage therebetween, said baiiies each having their outer side faces in vertical alinement with the inner side face of the side wall above the adjacent recess, whereby the heat from said burners is directed against the inner faces of the baies and then upwardly through the heat conducting passage between the upper edge of the baiile and the top wall of the recess along the face of the side wall of the cover above the recesses and toward and through said outlet.

5. In an annealing furnace, a base for supporting a charge to be heat treated, a cover mounted on said base having a top wall, side walls, end walls, and an open bottom, said top wall having a damper controlled outlet therethrough, said cover having at least one of its side walls providedl with aninwardly facing recess adjacent itsy lower edge, a baffle carried by. the side wall in spaced relation to the Wall defining the back of the recess and having its upper edge terminating spaced from the wall defining the upper end of the recess -so as to provide a. passage for the flow of hot gases therebetween, said baille having its inner side face alined with the inner side face of the side wall of the cover above the recess, and a burner in said recess for directing hot gases against the outer side face of the bafile so as to be deflected upwardly thereby and through the passage defined between the upper edge of the baille and the upper end of the recess and then upwardly along the inner side face of the side wall of the cover toward and through the damper controlled outlet in said top wall.

LEANDER EUGENE SMITH.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date' Re. 15,000 Stafford Dec. 7, 1920 1,247,015 Roth Nov. 20, 1917 1,599,165 Clark Sept. 7, 1926 1,734,871 Morse -..c Nov. 5, 1929 2,024,024 Carpenter Dec. 10, 1935. 2,089,843 Wilson Aug. l0, 1937 2,194,977 Hoak' Mar. 26, 1940 2,217,363 l Hoak Oct. 29, 1940 2,276,971 Hoak Mar. 17, 1942 i FOREIGN PATENTS Number Country Date 468,653 Germany Nov. 16, 1928

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