US2091979A - Annealing furnace - Google Patents

Description

Sept. 7, 1937. l.. c. HAMLINK ,2,091,979

ANNEALINQ FURNACE Filed June e. 1935 2 sheets-sheet 1 Sept. 7, 1937. L. c. HAMLINK A2,091,979

ANNEALING FURNAGE l Filed June e, 1935 2 sheets-sheet 2 Patented Sept. 7, 1937 UNITED` STATES PATENT OFFICE AN NEALING FURNACE Application June 6, 1935,*Serial/No. 25,250

6 Claims.

My invention particularly relates to annealing furnaces adapted for the heat treatment or annealing of metal plates, sheets, strips,`etc. in a controlled non-oxidizing atmosphere. It is thedesign of the invention tol provide a furnace of this nature which is easy to build and in which the heat treating operations maybe satisfactorily effected with a maximum of economy and the greatest convenience, together with a minimum of deterioration in operating equipment. Particularly,` the invention includes an improved heatradiating structure in which, by the circuitous circulation of the heating gases, fewer individual radiating units and, hence, fewer burners are re- 5 quired than in any other satisfactory furnace of this nature with which I am acquainted. Furthermore, my invention includes improved radiating units which are subject to far less deterieration in effective heating operations than any other radiating units with which I am acquainted.

' 'I'he annexed drawings and the following description set forth in detail certain means embodying my improved annealing furnace, such means constituting, however, but one of the various forms in which the principle of 'the invention may be illustrated.

In said annexed drawings: Figure 1 is a transverse vertical section of a ;0 form of my improved annealing furnace in which the radiating elements are formed of multiple interlocking units made from refractory material;

Figure 2 is a detached vertical section of one x5 of certain vertical panelled radiating units shown in'Figure 1, the unit being of tile construction, the section being taken in the pla'ne indicated by the line ZZ, Figure 3;

Figure 3 is a side elevation of the panelled unit l0 shown in'Figure 2;

Figure 4 is a pian section of the unit shown in Figures 2 and 3, the section being taken in the plane indicated by the line 4-4, Figure 3;

Figure 5 is a pian view of the unit shown in i6 Figure 3;

Figure 6 is a detached vertical section of one of certain anchoring units shown in Figure 1, the section being taken in the piane indicated by the line 6 4, Figure 7;

Figure 7 is a plan view of the anchoring unit shown in Figure 6;

Figure 8 is a detached vertical section of one oi certain horizontal partition units shown in g Figure 1, thesection being taken in the plane Ii indicated by the line 8 3, Figure 9;

(Cl. 26S-5) Figure 9 is a plan View and Figure 10 a side elevation of the partition unit shown in Figure 8;

Figure 11 is a longitudinal vertical section of one of the radiating elements shown in VFigure 1, but showing the radiating wall of the furnace partially in elevation, the view being taken in the planes indicated by the line i||l, Figures 1 and 12; and I Figure 12 is a fragmentary view of the furnace, partially in plan and partially in horizontal section, the view being taken in the plane indicated by the line I2|2, Figures 1 and 11.

Referring to the annexed drawings in which the same parts are indicated by the same respective numbers in the several views, my improved annealing furnace includes a cover 2, and a base i therefor having a foundation of insulating concrete 3 supported upon a steel plate 4. The plate 4 is supported upon longitudinal I- beams 5 reinforced by transverse beams'. A stock plate 9 is supported upon the top of the insulating base portion 3, and is vof an area greater than the area of the stock to be treated, and extends at its edges over'sectional troughs i0 preferably formed of refractory material and provided with sand seals I2, the stock plate 9 being formed with skirts il depending into the seals i2. The troughs I0 are seated in beds of cushion sand 41 disposed on end shoulders 3' of the insulating base 3. The cover 2 is formed with base plates I9 resting upon the shoulders 3' of the insulating base portion 3 and extended outwardly therefrom and having depending skirt portions 1 dipping into sand seais 8. Seals 8 are located in channels 8 abutting `the plates I9 at one upper edge and secured to the outer faces of the insulating shoulders and supported on the bottom by longitudinal I-beams i.

Upon the stock plate 9 the pack i3 of sheets is adapted tobe supported for the annealing operation, an inner cover il being provided which encloses the pack i3 and dips into the said seals i2 and is supported upon the bottom of the troughs ill. This inner cover .i4 permits more expeditious use. of the outer cover 2 and also makes unnecessary an absolutely gas-tight outer cover 2, as is well-known to those skilled in the art.

The main 'or outer cover 2 is adapted to be lifted from the insulating shoulders 3' of the base i `and replaced thereon, when necessary for effecting the placement and rem-oval of the pack I3, or when transferring the cover 2 to another upon the top of the roof i8 of the cover 2.

The main outer cover 2 includes side walls I6 and end walls I1 and a roof I8, all of refractory material, there being welded or otherwise suitably secured upon and adjacent the outer peripheral edges of the base plates I9 the lower anges of horizontally-disposed channels 29 which are secured to the lower parts of outer metal casings 49 abutting the outer faces of walls I6 and I1.

The horizontal channels 20 have welded to their upper flanges vertical I-beams 22 reinforced by horizontal I-beams 23. This supporting and enclosing structure is reinforced by lower gusset plates 2| secured to the base plates I9 and to the inner faces of the metal casings 49.

The roof I8 is of arched construction having a lower brick arch I82 and an upper insulating member I8', preferably of asbestos, the roof I8 being conned by upper exterior longitudinal channels 25 welded to the vertical I-beams 22, 2.0 and transverse I-beams 26 secured to the channels "25 and supporting a metal plate 43 above the arch II!2 and insulating member I 8.

Referring to the accompanying drawings, I utilize for effecting annealing operations a heat- 25 radiating structure of refractory tile units 30, 3|, and 32, Figures 1 to 10, interlocked together, a's hereinafter fully described, and forming, when ssembled, in combination with the radiating aces duits 21 for the passage of the heating gases which are fired into the conduits from burners 28. The actual radiating units are those designated 30 and 3|, of which-units 30 are vertically disposed at a spaced inner distance from the radiating wall faces I6' and are interlocked with vertically-spaced horizontal partition units 3|, the latter being supported at their outer ends in the walls I6 and interlocking at their bottom faces with the units 32 which are anchoring units and are seated within the interior ofv the walls I 6; The chamber between the inner radiating faces I6' of the walls I6 and the outer faces of the vertical radiating units 30 forms, by reason ofthe spaced horizontal partition units 3|, a 45 tortuous passage 21 for the movement of the heating gases repeatedly between the end walls I1, as clearly shown in Figure l1, it being noted that alternately at the ends ofthe partitions 3|,

openings -212 are provided whereby the gases can 50 pass, adjacently the end walls I1, from between two adjacent horizontal partitions 3|, to the space between the next higher adjacent horizontal partitions 3|. In order that more intense heating may be provided intermediate the ends 55 of the furnace than at the extreme end portions thereof, the walls I6 are thickened intermediate their ends, as clearly indicated in Figure 12, so as to restrict the intermediate area of the passage 21, and thus speed up the gas velocity. in 60 this intermediate area.

For purposes of illustration, I have shown a length of conduit 21 which is substantially four times the length of the furnace, the burning gases entering the conduit 21 at the bottom and 5 passing from the conduit 21 at the top into a flue 29 passing through the roof I8. One of the conduits 21 is provided at each side of the furnace, and heating gases are furnished to the conduits 21 repeatedly, and adjacent one end of each sec- 70 tion of the conduit 21, as clearly seen in Figure 11, there being thus provided four burners 28 for each conduit 21, two burners at 'each end thereof arranged in vertically-staggered relation to the burners at the other end.

75 The refractory units 30, 3|. 32 are interlocked I 6' of the furnace walls I6, tortuous con-- into a complete radiating assembly by the following means: The vertical unit 30 is of rectangular formation and comprises a peripheral portion 34 and a comparatively thin panelled body portion 33, thus being in eiect a saucershaped tile. clearly shown in Figures 2 and 3. This unit 30 is formed with an exteriorly-extending tongue 35 upon three of its sides and with a groove 36 upon the fourth side. This groove 36 interlocks with the tongue 35 upon the adjacent side of one of the horizontally-adjacent tiles 30, thus to form of one tier of the tiles 30 a closed wall facing the interior of the heating chamber 24 of the furnace. The tongue 35 on the other two sides of the unit 30 interlock with grooves 31 formed respectively upon the adjacent upper and lowerhorizontal partition units 3| and adjacent one end thereof, as clearly shown'in Figure' 1. These partition units 3| are rectangular unpanelled tile of uniform thickness throughout. The units 3| are also formed in their lower faces, and adjacent the outer ends thereof, with grooves 38 which interlock with tongues 4I formed upon the top of the anchoring tile 32. For the purpose of interlocking adjacent partition tiles 3|, the latter are formed with tongues 40 extending from one end, and on the opposite end are formed with complementary grooves 39.

In order to reduce the heat transfer at the ends of the furnace, solid tile 30 are used adjacent each of the end bends of the tortuous conduit 21, instead of the panelled tile 30, as clearly indicated in Figure`12.

The flues 29 from the passages 21 communicate with the interiors of pipes 42 which extend upwardly through the roof I8, and which are rwelded to the cover plate 43 and dip at their lower ends into sand seals 44 provided in, and adjacent one end of, the cover I8. For controlling the vacuum in the radiating element and inducing suitable draft, I provide inspirators 45 projecting into the ues 29 through the brick walls I6.

De-oxidizing gases are supplied to the interior of the inner cover I4 by means of tubes 46 passed through the insulating base 3 and the troughs I0. A tube 50 is provided for pyrometer leads 48 which are passed into the pack I3 and connect with thermo-couples 48.

What I claim is:

1. Heating means for an annealing furnace vconsisting of the combination with a furnace side wall and adjacent portions of the two furnace end walls, of a series of vertically-spaced horizontal refractory tile supported by and extended from said side wall, vertical tile interlocked with said horizontal tile and disposed intermediate the extended ends f the respective vertically-adjacent.horizontal tile, the upper and lower horizontal tile forming la top and a base, respectively, for the heating means, the intermediate-horizontal tile being formed with end openings, said openings being arranged alternately at opposite ends of the horizontal tile so as to form a tortuous conduit for the travel of the heating medium between the bottom and the top of the heating means.

2. An annealing furnace comprisinga base provided with a stock plate, a removable cover for the base and forming therewith a treatingchamber disposed above the stock plate, a heating element positioned interiorily of the .cover and consisting of communicating conduit sections extended repeatedly from end to end of the cover aooimo and at successively different levels thereof to form a tortuous conduit between the bottom and top of the cover, a waste ilue for said conduit. and a plurality of burners communicating with the conduit at each end of the cover and at respectively dii'lerent levels thereof, the burners at one cover end being arranged in staggered relation' to those at the other cover end.v

3. An 'annealing furnace comprising a base provided with'a stock plate, a removable cover for the base having end and side walls and arooi, heating elements disposed upon opposite sides of the cover and arranged interiorly of. the side -walls thereof, said elements each consisting 4of relatively vertical communicating conduit sections forming tortuous conduits runnin's repeatedly back and forth along said side walls and extending between the bottom and the top of the latter, said side walls intermediate their ends being extended inwardly within the respective conduits to constrict the cross-sectional area ofthe latter, awaste ilue communicating with each conduit, and a plurality voi burners for 'each conduit which communicate with the conduit at diilerent 5 levels.

4. An annealing furnace comprising a stocb supporting, base. a reino able cover for the base having a side wail and a root forming an interior treating chamber, a heating adjacently interiorlyof said side wall and comprised of a plurality of superposed horizontal conduit sections, each section intermediate the top and bottom sections communicating at one end with an adiacently lower section and at the,

i other end with an adiacently higher section. thus forming a tortuous conduit running vertically oi the cover, burners tiring into the conduit adjacent the respective areas where the two sections of adjacent pairs of sections communicate with 0 each other, another burner tiring into one end of the conduit, and a waste ilue leading from the other end of the conduit. l t 5. An annealing furnace comprising a stocksupporting base, a removable cover for the base 5 having a treating chamber, oppositely-disposed disposed heating elements element positionedheating elements positioned interiorly of the cover and located laterally of the treating chamsaid heating elements plurality of superposcd horizontal conduit sections having communicating 'passages forming. a

top-o! lthe cover, each two vertically adjacent scctions communicating at one end, a` plurality of verticallyaligned burners iiring into the conduits through the ends of the cover and into the conduit areas where the respective two sections of the adjacent pairs oi'. conduit sections communicate with each other, other burners nri'ng into one end o! the respective conduits, and waste d ues leading from the other ends of the respective conduits.:

6. Anannealing supporting base, having endand side walls and a roof, oppositelypositioned adjacently interiorly of said side walls and deiining an interior treating chamber, said heating elements each comprised of a plurality of superposed horizontal conduit sections, each -two vertically-adjacent furnace comprising a stocksections running between said end walls. each section intermediate the top and bottom sections communicating at one end with an adiacently lower section and at the other end with an adjacently higher section, thus forming a tortuous conduit running vertically oi' the cover, the side walls of the cover intermediate their ends being extended inwardly within the respective conduits to constrict the crosstional area of the latter, said heating elements including walls facing the treating chamber and extending from end to end thereof and which are thicker at their ends than in the intermediate portions thereof, burners ilring into the conduits areas where the'two sections oi adjacent pairs of sections communicate with each other, other burners' ilring into one end o t the respective conduits. and `awaste nue leading from the other end of each conduit.-

LAZENBY C. HAMLINK- a removable cover for the base each comprised of a ltortuous conduit leading from the bottom to the adjacent the respective

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