US2422571A - Furnace wall construction - Google Patents

Description

June 17, 1947., s; N. LEVY EI'AL 2,422,571

' FulinAcE WALL CONSTRUCTION Filed Dec. 22, 1942 s Sheets- Sheet 1 June 17, 1947. 5, N1 LEVY HAL 2,422,571

FURNACE WALL CONSTRUCTION Filed Dec. 22, 1942 3 Sheets-Sheet 2 June 17, 1947. s. N. LEVY ETAL 2',422,57'1- FURNACE WALL CONSTRUCTION Filed Dec. 22, 1942 3 Sheets-Sheet 3 Patented June 17,1947

FURNACE WALL CONSEIIZIEHJC IZIQNv SylianN Eevyand Williams B: Iz'evt";

Wilmington, Deli AhplicatiomDecemherZZ, 1942,,senam0. 69,838!

Gfaiinsa This invention relates to' metal heatingt fur.- naces, and" more particularly to furnaces. ofthe muffle typ such asrepresentecf the one dis closed in our priorUiiited States lietters Patent; No. 2,277,595, dated March 24,1942.

The present invention more especially relates to improvements iirthe" construction" of the fiont wallofthe furnacein which the entrance to the muffle is located; whereby" replacement of? one or' more of" a series of refractory face tiles". framing the mine entrance; and replacement'off a refrac=- tory'tile which" is disposed" in an'cti forms part" of the: ceiling? of a short" entry or passageway ex*--- tending through the front' wall of the furnace tethe -open endof the mufife; are made possible; without dismantlihg'therfurnace.

Another feature of the present invention re sides in the elimination of distbrtibnihithflt pertiozr of" the front plate oi the shell ofthe furnace: which is disposed directly above the tile- :fi-arned entry to the mufiie; and were-n lies behind the" path of" it vertically slidabi'e door open-- ating' in a plane immediately adi-acent the plane of the front" faceof the furnace; for" closingthe enhancetothemuffie;

Anyappreciable amount of warping; bulging or other distortion occurring that portion of the front plate of the fixmace-l3 iirg= dire any ab ove the muifle entry will cause a jamming ofthe door, or will necessitate the provision of sufficient free" play" between the door and" the face plate of the furnace as will cause excessive heat losses thrmigh the clearancethus provided; in" view of which; oneof" the object's of the present; ihve'n tion is to* provide a separate expandable anti contractable plate as a component? section of the front plateaof'thefllrnace'; above themufiie-entry, and to" retain this expansion plate in the plane of" said face' plate: in a: manner" to permitex-=- pansionand contraction thereof, in said plane thereby ohvi'atingt said distortion and preventing consequent? jamming of the door; without creat i'n'g any heart-loss clearance betweem the door and theface piatez Another object] of the invention is" to" provide a unique arrangement: of a" series of. face tiles which coil'ectiv'elyframe the; mufife entrance in ther front wall of" the fiirnacee whereby, upon removal of the aforesaid expansion section of the face plate of the furnace; repiacement of one or" more of the flaming" the" may he re'adi'l'y accompiishedi.

AYIUtHGFObjECfi of theinvention is to provide in" the ceiling? of the, entry" to the mufiia and 1U tionkofthepresent invention:

Fig: 2" is a face view' of the. furnace with the: door, and portions of the door=guiries removed? Fig; 3; is a; detached perspective view of. the expansion plate normally,- di'sposed' above the mufile doorway:

Fig. 4 is a detached" p'erspective of" the: anchor bar. for the lower'portion of the" expan= sion plateshowrrinFi'g. 3

Fig; 5 is; an assembled" perspective view"of-" the refractory t'iie' framing; of the" muflie c'roorwaizzj Fig: 6 is 'a; detachedp'erspectivefviewofthe arch" tile-ofthe mufiieentry ceilingyand.

Fig; 7, is a; fragmentary sectional: Viewof" a: detailo'fthe invention:

A's shown; irr the drawings; the: furnace comprises an outer'metalli'cshell which includesar maihcylindrical barrel" or-bodyportion' 2-, a front or'faceplate 3; andaback platel l'.

Flush with each" of the opposite" ends of thebarrel 2 is a ring 5, which prefrahly' i's composed of angle irorr having: one" flange welde'd' or otherwise permanently secured to "the inside sur face offthei barrel 2' andthe' second flange drilled and* tapped at: relatively spaced point around the circumference of the barrel 2 for the reception of counter-sunk screws 66, in the present instance; by which the front and rear" plates 3- andl are rigidly securedtothebarrel2i Within the shell- I, the furnace includes one or more layers" or envelopes of heat insulating material; as disclosed irr ouraforesaid prior patent. &

Enclosed within the insulating" shell I is the combustion chamber Hl== of the furnace, which: is: preferably formed of pre-moulded unit's (if-high: test refractory material, suchas-=silicon carbide, silli'manite or' suitableequivalent, fitteod and secured together in substantially the same mamneras disclosed in the afbresaid prior-patent;

The pre-moulded unit i oh the combustiom.

chamber I0" include flame tiles, by: rib".- bons of flame are directed tangentially against the inner wall of the circular combustion. chamher" [0, instaggered-reiatibm to each:v other longitformihgpart of" the front wallof the mac tudihally of Said-a chamber, to provide th xnecesa The envelope 1 may be formed, in part, of ma- 7 terial moulded directly within the furnace, between the shell I and the combustion chamber In, or the envelope may be composed in part of pr'e-moulded units fitted around the combustion chamber, with the portions of the envelope which lie directly adjacent the flame tubes, flame blocks, and exhaust tubes ll, moulded directly in the furnace, between relatively spaced pre-moulded units, to provide a solid compact mass of insulation around the combustion chamber and said tubes.

The combustion chamber includes a front wall 13 and a back wall l4, each of which is provided with a rectangular opening l5, which are adapted to receive and support the opposite ends respectively of the muffle lB.. The mufile is of substantially rectangular cross section arranged with its longitudinal axis substantially coincident with the longitudinal axis of the furnace, as disclosed in the aforesaid patent.

Access to the muflle I6 is afforded through a short entry or passageway ll formed in the front wall of the furnace, between the front plate 3 of the furnace shell I and the front plate [3 of the combustion chamber Ill. r f

The muffle entrance ll is framed by a series 23 of refractory tiles, as shown in Fig. 5. The series of facing tiles 2!] comprises a central bottom tile 20a, right and left lower corner tile 20b, 20b, upper right and, left. corner tile 2ilc, 20c, central side tile 20d, 20d, and an upper central or keystone tile 206, as shown in Fig. 5 and in Fig. 2.

The assembled series 20 of tile present a complete rectangular facing for the. muffle entrance fl and collectively form a substantially rectangular opening 2! of the same shape and size as the mufile entry ll, said opening constituting a part of said entry. r r a The assembled series 26 collectively form a rectangular facing pad 22, defined by a, marginal edge 23, which projects through a correspondingly shaped opening 24 formed in the front plate 3 of the furnace. Each tile of the series '23 is provided with a locking flange'25 extending'laterally from the marginal edge 23 of the facing pad 22, behind the marginal edges of the opening 24, whereby the frame formed of the series-28 of tile units is held in position in the front wall of the furnace, said units being .imbeddedin the heat-insulating material constituting the front wall of the furnace, between the front plate 3 thereof and the front plate l3 of the combustion chamber Ill. 7

Also imbedded in the insulating-material, and forming the ceiling of the entry ll, is an arch block or tile 39, formed of pro-moulded insulating refractory material. This arch block 33 extends from the rear face of the frame units 230, 2:30 and 206 to the front face of the front wall E3 of the combustion chamber lb.-

Imbedded in the insulating material 7, immediately above the facing units 200, ZUcandZBe is'a bar- 3!. As shown in Fig. Z the opening 24 in the front plate 3 extends upwardly from the uppermost of the facing tiles 23 to the peripheral edge of the outer shell 2 of the furnace. That portionof the opening 24 lying between the upper' facing' units 280', 23c and 2% and the peripheral edge of the furnace is normally closed by an expansive plate 32, which is secured adjacent its lower edge, by screws 33, 33, to the bar 3!, said plate 32, adjacent said peripheral edge of the furnace, being secured, to the angle iron 5 by screws 34, 34. The opposite ends of the bar 3i are respectively secured to the face plate 3 by screws 35, 35.

The opening 2| in the facing frame 29 of the muffie entry fl is adapted to be closed by the door All of the furnace. The door 43 is provided with laterally extending flanges 4| which are slidably mounted in guide-ways 42 located at opposite sides respectively of the opening .24 in the front plate 3. v

The bottomof the door 40, when the, door is closed, is adapted to. rest on a'sill 43, said sill and said guide-ways 42 being securedto the front plate 3 in anysuitable manner, as by weld- 111g, V e I I As shown in Fig. l,.the .depth of the rabbeted recess bordering the assembled facing. units 26, which is formed by the angle of the marginal faces 23 and front faces of. the flanges 25 of the units of theseries 20, is greater than the thickness of thefront plate 3 and the supplement 32, whereby the front face 220i "the-framing. 26 projects slightly beyond the front. face of the front plate 3 and supplement 32, whereby the:

rear face 44 of the door may be brought into sealing contact with the frontface 2-2 of the frame 20, to prevent escape of heat from themterior of the furnace. i Y

As shown in'Fig. 1, atmosphere gases are permitted to escapefrom theinterior cf. the mufile through a vent, formed partly in the ceiling arch block 30 and partly in.the heat insulating material forming; the front .wall of the, furnace, above said ceiling block, said vent being provided H with a horizontal extensionAli-terminating adjacent one of the exhaust flues ll, whereby the flame escaping from the combustion chamber til will ignite the atmosphere gases .escapingfrom the interior of the muflie I6 through the vent As-shownin Fig. 7, the screws 34 whichv secure the supplementary expansion'plate 32 to the bar 3!, and to the angle iron 5, are of the countersunk type and pass through openings 37, formed in the plate 32, which are larger in diameter than As the furnace isbrought to predetermined operatingtemperature, any tendency of the supplementary plate 32. to buckle,;and thereby effect jammingqo-f the door 40 at such time as the door may be open subsequent to the furnace being brought to-operating temperature. is obviated by the enlarged openings 41 for the screws 35' permitting a certain amount of relative expansionand contraction of theplate 32-, in the plane of the face plate 3, said enlarged openings permitting th plate 32 to shift. slightly without binding on the screws 34 and thuspreventing buckling of theplate between said screws, relative elongation of the screws 34,-as a result of the heating of the furnace; compensating forv a oer.- tain small amount of expansion in the thickness of th plate 32, which contributes. to the freedom of said plate during itsexpansion andcontraction and thus aids in the prevention of its buckling.

asaagnz'i Also; as shown inEigslrelativelyismallamount of: clearance: is: provided between. the marginal edges: of the plate 32; the: edges of" the; adjacent portion'szof' the: front plate 3 and the upper edge 2:3: of: the. framing: to permit expansion of: the piate: without binding: and. bucklmg Ifiatuamrtime, itshouldzbenecessanyto: replace anyofr the upper facing tilesJZflC 2R0 or' 20c; one or: thexothen of the side. tiles.- 2lldt may be moved laterallyinthe; directiorr of one of'the: arrows a, 2,.into'lthe opening kl, after whichgendthe removal or lonsening of the expansion. plate 32', one. or the. other or; both of the corner tiles. 20c, 20c. maybe movedi downwardly: andi inwardly,. as indicatedby the" arrows b; brinFigz. Displacement of either of the corner tiles 200 will permit removal. offthe center upper tile 20c, in the direction of the arrow 0. With the upper facing tiles 20c, 20c and 20eremoved; the-ceiling tile may also be removed, by moving. it forwardly and out through the opening provided by the removal of said upper facingtile, as showninFigs. 2 and 5.

The upper central the it? is of wedge shape and acts as a keystone to, lock the other facing tiles in" firm relation to each:v other, during, any expansion and, contraction! that, may occur irnthe series=of facing tile 26,,the weight-of the'keystone tile Zlle; at. all times, tending to. exert a. lacking pressure on th other tilesz of the: series; in: the eventthat any shrinking QI',1010S6I1BSS of. themdividual tiles may occur..

It, is also? possible to, remove the lower facing tiles 20a, 23b, 201) by raising the center bottom tile 20a, as indicated by the arrow d, until its bottom edge clears the upper edges of the corner tiles 2%, 28b, after which said corner tiles may be moved out of place in the direction of the arrows e, e.

Replacement of the tiles may be effected in the reverse order to that just described in regard to the removal of the various tiles.

Also, the lower corner tiles 28b, fill) may be removed after the removal of the two side tiles ill-d, 2001 by removing the corner tiles 20b, 2'01) upwardly and inwardly into the opening 2| as indicated by the arrows f, i.

From the foregoing description, it will be clear that, by providing for free expansion and contraction of that portion of the front plate of the furnace directly above the entrance to the mufile, where the greatest amount of heat is concentrated, particularly when the door is partly open, no buckling of the face plate will occur to cause jamming of the door as it is raised and lowered to afford access to the interior of the muffle.

It will also be clear from the foregoing that, should any of the facing tile of the framing around the mufil entry become cracked or broken, or should the ceiling tile of said entry collapse, replacements may be readily made without disturbing any but the most conveniently removable parts of the front wall of the furnace.

We claim:

1. A furnace comprising a substantially vertical front wall provided with a through passage affording access to the interior of said furnace, a face plate of predetermined thickness on the exterior of said wall and provided with an opening of greater width than said passage with th'e inner edges of said opening extending horizontally beneath said passage and vertically at opposite sides respectively thereof a substantial distance above the passage to the top edge of said face plate, a separate plate section of substantially iii) th'ezsam thi'ckness as said face plate. and of normadly lesser width than said opening located in said? opening: above said: passage in the plane of facev plate; securing: screws of greater overall length thanv the thickness ofv said plate section passing through said plate section to-secure said platezsection said position within said opening, said screws. including counter-sunk heads seated in counter-sunk openings formed insaid plate section and: threaded shanks of predetermined diameter passing through plainbores of relatively larger" diameter: formedin said plate section in axial alignment respectively with said countersunk openings; and: meanshaving threaded bores embedded in said wall to receive the threaded shanks: oi saidi screws to secure said plate; section in: position;

2-1. A furnaceicomprising a substantially vertical frontwa-ll" provided with a through passage affording access: to theinterior of saidfurnace, a face plate of predetermined thickness on the-exteriorof sai'd wall and provided with an opening of greater width: than saidpassage with the inner edges of said opening extending horizontally benea$h said passageand vertically at opposite sides respectively thereof a substantial distance above the passageto thetopedge of said faceplate, a separate plate section of substantially the same thickness as said face plateandof normallylesser width than said opening located in said opening abcvesaidi passage in-the planeof said face plate, securing: screws- 0f greater overall length than the thickness of said plate section passing through said plate section to secure said plate section in said position within said opening, said screws including counter-sunk heads seated in countersunk openings formed in said plate section and threaded shanks of predetermined diameter passing through plain bores of relatively larger diameter formed in said plate section in axial alignment respectively with said counter-sunk openings, horizontal bars embedded in said wall and extending across said opening behind said separate plate section, means for securing said bars to said front plate at opposite sides respectively of said opening, said bars having threaded bores for receiving the threaded shanks of said screws for securing said separate plate section in position.

3. A furnace comprising a front wall provided with 9, through-passage affording access to the interior of the furnace, a face plate on the exterior of said wall provided with a rectangular opening affording access to said passage, a sectional frame around said passage and formed of a series of units each including a flange extending behind the marginal edge of said openin and a face projecting through said opening to at least the exterior surface of said plate, said units being embedded in said wall behind said plate, said series including corner units and intermediate units therebetween with abutting edges of the two upper corner units and the top intermediate unit being formed on angles converging toward the horizontal axis of said passage to lock the units of said series in place automatically during contraction and expansion thereof, and a separate section forming part of said face plate adjacent the upper marginal edge of said opening adapted to be removed from said wall to facilitate replacement of said upper units.

l. A furnace comprising a front wall provided with a through-passage affording access to the interior of the furnace, a face plate on the exterior of said wall provided with a rectangular opening affording access to said passage, a sectional frame around said passage and formed of a series of units each including a flange extending behind the marginal edge of said opening and a face projecting through said opening to at least the exterior surface of said plate, said units being embedded in said wall behind said plate, said series including corner units and intermediate units therebetween with abutting edges of the two upper corner units and the top intermediate unit being formed on angles converging toward the horizontal axis of said passage to lock the units of said series in place automatically during contraction and expansion thereof, a ceiling unit in said wall behind said upper units and formin the top of said passage, and a separate section forming part of said face plate adjacent the upper marginal edge of said opening adapted to be removed from said wall to facilitate replacement of said upper and said ceiling units.

5. A furnace comprising a front wall provided With a through-passage affording access to the interior of the furnace, a face plate on the exterior of said wall provided with a rectangular opening afiording access to said passage, a sectional frame around said passage and formed of a series of units each includin a flange extending behind the marginal edge of said opening and a face projecting through'said opening to at least the exterior surface of said plate, said units being embedded in said Wall behind said plate, said series including corner units and intermediate units therebetween with abutting edges of the two upper corner units and the top intermediate unit being formed on angles converging toward the horizontal axis of said passage to lock the units of said series in place automatically during contraction and expansion thereof, a separate section forming part of said face plate adjacent the upper marginal edge of said opening adapted to be removed from said wall to facilitate replacement of said upper units, a, bar embedded in said wall above the upper edges of said upper units, and means securing said section to said bar adjacent the lower marginal edge of said section to secure said lower marginal edge in overlapping relation to the flanges of said upper units.

SYLVAN N. LEVY. WM. B. LEVY.

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

UNITED STATES PATENTS Number Name Date 1,393,647 Spillane Oct. 11, 1921 2,254,900 Lessman Sept. 2, 1941 1,665,555 Liptak Apr. 10, 1928 1,534,548 Slade Apr. 21, 1925 659,941 Swindell Oct. 16, 1900 784,737 Foote Mar. 14, 1905 1,481,014 Kerr Jan. 15, 1924 2,270,484 Wallerius Jan. 20, 1942

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