US2749108A - Billet heating furnace - Google Patents

Description

June 5, 1956 F. o. Hass 2,749,108

BILLET HEATING FURNACE Filed Aug. 2o, 1952 INVENTOR. FREDERICK O. HESS ATTORN EY.

BILLET HEATINGrFURNACE YiFrederic'O."Hess, Philadelphia, V'"Pa., assignor to 'Selas JCorporation. of.Amerca,- Pliladelphia, Pa., a corporaftionof Pennsylvania Application August20, 1952, Serial No. 305,458

'5 Claims. i(Cl.-263-6) .The present invention relates to furnaces, and more .particularly to, furnaces through which .metaLbodies such Vasingots and billets are moved one after another to be heated.

`.It is an object of the .present invention to provide ya furnace .in which the objects to-be heated are carried therethroughon an overhead -conveyor. VItis afurther objectof the inventionto provide `a furnace having a `plurality of .openings :or doors in .the .bottom through ,whichvthe objects beingheated can be removed if they l 'drop "from 'the conveyor.

`The.inven`tion includes a v'furnace having a chamber thatis directly `fired by.apluralityof burners. The-roof of the chamberhas .a slot .extending lengthwise thereof through which conveying mechanism extends to support Vthe work so that it maybe heatedevenly on all sides.

'From time to-time ythe work pieces .may drop from Vthe conveyorand obstruct the'furnacechamber. The floor .of the chamber is ytherefore vprovided with .or made of a plurality of doors that can be opened individually so that the workpieces thereon may easily be.rernoved.

The various features of novelty whichcharacterize my vinventionare pointed out Wi'thparticularity in the claims annexed to land forming apart of .this specification. For better understanding of the invention, however, .its advanges and specific objects attained with its use, `reference 'should be had to the 4accompanying drawings and descriptive vmatter in which l have villustrated .and described a preferred embodiment of the invention.

IVln the'drawings:

Figure l is a section View taken throughthe furnace on line 1-'1 ofFigure'Z; and

Figure'Z is .a transverse section of therfurnace.

Referring to the drawings, there are shown a pair of foundation .beams l extending longitudinally .of the furnace. Attached to these beams at spaced ,points are vertically extending-supports 2 uponwhich'structure forming :a 'furnacevchamber .is mounted. This chamberis built inilaccordance withordinary. furnace 'practice and-includes f 'a'meta'l backing ,sheet 4,around.the'-sitlesfand top thereof. This backing serves .to .supporta furnace linin-gof suitfable refractory Vmaterial 5 of .a thickness and composiftion to 0withstand .the vtemperature fof the furnace. 'The ltop of fthe furnace rstructure is yThung '..from the supports `2 iby means-of braces 6 weldedtheretolwhich lextend -in- Mardly from each side thereof. The ffurnace can be heated by any suitable burners but is preferably heated by burners of the type which produce radiant heat such as those disclosed in Furczyk Patent 2,561,793, issued on July 24, 1951. These burners each include a ceramic block 7 which is embedded in and forms part of the furnace wall. Each block is provided on its face in the furnace chamber with a cup-shaped depression 8 into the base of which extends a distributor 9. Air and gas under suitable pressure are supplied through the distributor from which it is discharged in a plurality of radially directed jets that burn along the surface of the cup 8 to heat the same to incandescence. Radiant heat from 2,749,108 Fatented June a5, 1956 thereup, '-as well as vhot ,products .of ``combustion, fheat the walls -of the'furnace chamber to:incandescence and transfer 'heat tto the work AEach of these "burners is supplied individually through a pipe Vllfanditheburners -in eachrow may be'connected to amanifold 1'2. The -supplyvof fuel toeach burner can 'be-'adjusted individually by a valve l. As :shown therein, vthe .burners :are

` staggered on opposite zsides tof the f furnace `chamber, so

that the work is heated evenly throughoutiits entire .area .as it'is being-moved longitudinallyzthroughthechamber.

`If desired, suitable automatic :controls can be provided to regulate the furnaceternperature The top ofthe chamber vis `provided vwith :a-eentrally .extending slot -14 alongthe .upperedgesxof `whichfare :Io-

cated water cooled 'passages `15. These'passages'arefsupplied'with cooling water at .oneend bypipes I6, andthe Vcooling water is Vremoved at the'oppositefend of thefurnace.

The .bottom or door of the furnace -comprises'a iplurality of doors which can be opened 'togive accesstofthe furnace chamber. -Eachofthesedoors includes a metal frame in'fonniof a casting 17 that isJfilled with a Ysuitable refractorymaterial '18, and lwhiclrextends from the low`er edge of voneside wall to the lower edge of the lother. The frame -17 is pivoted at -19on api-vot that lisparallel to the side walls,'so that'the doors -c'an be tilted YVfrom their fullline to their-dotted line positions in -Figure r1 and .thereby permit removal lof --ingots or billets when such is necessary. Each-casting-isgprovided -w-ith Tan=arm 21 extending `to the right, -as shown in v'Figure 4l of the drawing, and to -which is vattached-'a counterweight 22 that is heavyenough normall-yrto-h'oldtheidoorin closed position. IThis counterweight may be supplementedwith a spring if desired. yIn ksortie cases it -may'be desirable to lockthe doors in=their closed .position. This :is -accomplished by aflatchplate 23 extendingfrom the left side of casting 17, which 'plate *is engaged by -a latch '24 that ris -pivotedon Vthe yright side yof the furnacevframe "The upper end of .the rod is rvfastened to a carrier L9 that 'is .provided with Vrollers [31 which-engage -the -filanges of a track 32. rlhis track `extends lengthwise Aof ythe Jfurnace and is supported by crosspieces 33 which-arcattachedto'the upper ends of the vertical supports 2. :Each of the billet carriers is provided with a yheat seal to 'preventloss df heat`thro'ug'hfthe roof or" the'lfurnace which `includes a ishield' through which 'the rod .'27 extends. `rPhe Vrod l-is *provided 'with a 'collar I'35 i'n order to keep the shield 3:4 from falling below va 'predetermined point 'Whe'n the #carriers are tout 1 d'f the ffurnace. Skid plates 35 extend along the upper surface of the channels 15 for the shield to ride along as the carrier is moving a billet through the furnace.

The ends of the furnace chamber are closed by doors similar to the one shown at 37 in Figure 2. The door is guided for vertical movement and is opened by lowering it below the oor level. The door is raised and lowered by counterweighted cables 38 that pass over pulleys 39 attached to the furnace supported structure.

Prior to the time the billets 26 are heated, a ring 2S or some similar supporting device is fastened to the top thereof as by welding. The billets are then placed on the hooks of the carriers 27 and are ready to be heated. Periodically, the door 37 is opened and a carrier is rolled along the track to move a billet into the furnace. As the billets progress through the furnace, they are heated to a forging or extrusion temperature in the neighborhood of 2250 F. This heat is produced by the burners predominately in the form of radiant heat, but also by hot products of combustion. Ordinarily, the cups of the burners of this type are heated to a temperature in the neighborhood of 2800 F., and the furnace chamber itself will be a few hundred degrees lower or in the neighborhood of 2500 F. With a temperature gradient of this type, a billet of alloy steel 6.35 inches in diameter and 28 inches long weighing 250 pounds can be brought up to a forging temperature in 2J:- minutcs or less. The radiant heat produced by the furnace will heat the bi.- lets evenly throughout their volume, so that by the time they are removed from the other end of the furnace, they can be placed directly in a forging or extrusion press. The fuel-air ratio supplied to the burners is controlled so that there is normally a neutral atmosphere of products of combustion in the furnace chamber, and thus there is practically no scale formed on the billets during the heating process.

From time to time defective welds will be formed between the supporting members 26 and the billets 26. A billet having one of these defective welds will frequently fall from the conveyor, and will block the passage through the furnace chamber if provision is not made for removing these billets. Since the bottom ot' the furnace consists of a plurality of doors that are counterbalanced to a closed position they will open individually when a billet falls on them. The billet is thereby quickly removed from the furnace without losing a great amount of heat from the chamber and without interrupting the heating process of the remaining billets. lf the latches 24 are being used, it is only necessary for the operator to release the latch of the door upon which the fallen billet is resting in order for it to be removed.

From the above, it will be seen that l have provided a furnace through which billets are conveyed by an overhead structure one after the other as they are being heated. The furnace oor consists of a plurality of doors through which individual billets can be removed, if for some reason they should fall from the conveying mechanism. The billets can be moved directly through the furnace on a production line basis to a point upon which work is performed on them.

While in accordance with the provisions of the statutes, I have illustrated and described the best form of embodiment of my invention now known to me it will be apparent to those skilled in the art that changes may be made in the form of the apparatus disclosed without departing from the spirit and scope of the invention as set forth in the appended claims, and that in some cases certain features of my invention may be used to advantage without a corresponding use of other features.

What is claimed is:

l. In a furnace system, the combination of structure forming an elongated furnace chamber having side walls, a roof and a oor said roof being provided with a slot extending lengthwise thereof and through which is adapted to extend a conveyor to carry billets to be heated in said chamber, said oor being formed of a plurality of sections extending between the lower edges of each side wall, means to mount each section for movement between a first position in which it closes the space between said side walls and a second position in which said space is open, and means to bias said sections normally to their first position, said oor sections moving to their second position against the action of the biasing means to discharge billets dropped by the conveyor.

2. ln a furnace system, the combination of structure 'forming an elongated chamber having side walls and a roof, said roof being provided with a slot extending ccntrally thereof from one end to the other, a plurality of burners located in said side walls to supply heat to said chamber, a oor for said chamber being formed of a plurality of doors extending between the lower edges of said side walls, means to mount said doors for pivotal movement around an axis below and parallel to one of said side walls, and latch means operative to hold said doors in closed position extending between said side walls.

3. A furnace comprising vertical supports, structure mounted on said supports forming an elevated furnace chamber substantially rectangular in section, said structure forming side Walls, burners for heating said chamber mounted in said side walls, said structure also including means forming a roof for said chamber with the roof having a slot running lengthwise thereof from end to end through which a conveying mechanism for carrying work to be heated is adapted to extend, and said structure including means forming a bottom for said chamber consisting of a plurality of sections, pivot means to support each of said sections for swinging movement parallel to one of said sides whereby when work is dropped from the conveying mechanism it can be removed trom the chamber through one of said sections, and means to bias each section normally to its closed position against the lower edges of said sides.

4. The combination of claim 3 including means to latch positively each of said sections in its closed position.

5. Apparatus for heating billets comprising structure forming the side walls and roof of an elongated furnace chamber, said roof being provided with a slot extending from one end to the other thereof, a plurality of doors forming the oor of said chamber, each door engaging the lower edge of each of said sides, means to mount each door below one of said sides and for pivotal movement around an axis parallel to said side, means to maintain each of said doors in its normal closed position, and a door at each end of said chamber through which dork to be heated can be moved as it is carried by mechanism that is adapted to extend through said slot.

References Cited in the file of this patent UNITED STATES PATENTS 836,679 Garred Nov, 27, 1906 1,773,049 Lobley Aug. 12, 1930 1,858,434 Colby May 17, 1932 1,586,599 Bohler June 1, 1936 2,062,642 Darrah Dec. 1, 1936 2,224,460 Mortenson Dec. 10 ,1940 2,269,827 Mendoza Jan. 13, 1942 2,272,966 Dany Feb. 10, 1942 2,478,964 Cooper et al Aug. 16, 1949

Images