US2056070A - Heating furnace - Google Patents

Description

P. S. MENOUGH HEATING FURNACE Sept. 29, 1936.-

Filed NOV. l5, 1933 5 Sheets-Sheet l Sept. 29,1936. I p. s MENOUGH 2,056,070

HEAT ING FURNACE Filed NOV. l5, 1953 5 Sheets-Sheet 2 Hui-QW" /ZW//VOR i f Filed NOV. l5, 1933 5 Sheets-Sheet 3 Patented Sept. 29, 1936 UNETED STATES lPATENT ori-ICE HEATING FURNACE Pani s.,.Men0ugh, Pittsburgh, Pa. Application November 15., 1933, Serial No. 698,110

' 14 claims.,l (ci. 263-6) My invention relates generally to heating furnaces, and more particularly to heating furnaces used for metallurgical purposes" andY through which the material to be treated is conveyed at such a rate of travel, with reference to the length of the furnace chamber and the heat supplied, as to enable the articles to be properly heated by the time they shall have reached the delivery or The particular walking beam type of furnace; that is, a furnace wherein reciprocating members which co'- operate with either stationary supports or other reciprocating members are used for transporting p the material through the furnace.

Heretofore, considerable diiliculty has been eX` perienced in furnaces of this character inpro- ,viding satisfactory apparatus for transporting material through the furnace, which will not be deleteriously affected by the heat of the furnace. The temperatures in furnaces of this character range up to approximately 1950 F., and some- 1.' times higher, and consequently it is necessary to provide a structure embodying material supporting and moving means which will not be caused to warp or twist when subjected to such temperatures. In order to obviate this difficulty, it has ybeen heretofore proposed to use various alloys for the material supporting and moving apparatus, and particularly those portions'of such apparatus which are subjected to the'eXcessive temperatures of the furnace. Alloyv'materials are, of course, expensive and the use thereof Vin "such furnaces as are known appreciably increase the initial cost of the furnace.

By my invention, I provide a furnace structurev of the character above referred to, wherein thev amount of alloy required is reduced -to a minimum, and the initial cost of which is low as compared with that of other similar satisfactory structures. I

In accordance with my invention,.I provide a structure wherein the furnace bottom is made up of a plurality of longitudinally extending sections, at least one of which is reciprocable in a longitudinally extending direction. These sections are preferably made of refractory material, andl consequently the problem o-f preventing warping or twisting thereof is completely eliminated. In View of the fact that there is movement of the various sections relative to each other, it is necessary to provide adequate clearance therebetween. If the openings between the various sec-v sections so as to provide a vertically tortuous passage or slot therebetween.

In accordance with my invention, I further pro-1" vide novel means carried by the material supporting sections on which the material rests during its 5 passage through the furnace, and which is so arranged as to afford adequate support for the material at all timesand prevent bending thereof.Y The material engaging means which I provide are so arranged as to cooperate withthe secl0 tions on which they are mounted in such'manner as'to render it unnecessary to secure them thereon. They are adapted to merely rest onY the tops of th-e sectionsof the furnace bottom forming the material moving mechanism.

By my invention, I further provide Vnovel means whereby the furnace bottom Vmay be sealed; and whereby any scale and the like which falls through the openings in the furnace bottom may l be readily collected and disposed of.

Another feature of myv invention resides in the provision of a walking beam type of heating furnace which is adapted to transport tubes or rounds therethrough. Heretofore, it has been deemed impractical to use a walking beam type of furnace for the normalizing of tubes or rounds, in view of the fact that it is necessary tocontinually or periodically rotate or roll tubes in order to prevent one side from getting an excess amount of heat. Various types of furnaces have been heretofore used in the heating of tubes or rounds, and wherein the tubes or rounds have been rolled or turned either continually or periodically in order to obtain uniform heating. However, walking beam types of furnaces have never been used for this purpose as their use has been deemed impracticable. This turning or` rolling of the tubes while they are being'heat treated is most essential. If 'the tubes are not heated uniformly, warping of the tubes will result.

In the furnace which I provide, the tubes or rounds are transported through the furnace by the walking beams and the walking beams are so designed as to cause the tubes to periodically roll thereon in order to turn the tubes and obtain uniform heating or cooling of the tubes. Furthermore, in the structure which I provide, the hot gases may circulate between .the walking beams and under the tubes. This also tends toward uniform heating.

@ther advantages of my invention will be apparent to those skilled in the art as the nature of my invention is particularly understood. It consists in the novel construction, combination, and arrange-ment of 'parts hereinafter more fully described, illustrated and claimed.

In the drawings, I have shown a preferred embodiment of my invention and a modification thereof. It will be understood, however, that I do not intend to be limited to the structures shown Lto permit material to be discharged therefrom =of the ordinary type walking beam furnace inso- 7.5L. furnace comprises one series of Ylongitudinally in the drawings, as my invention may be otherwise embodied. In the drawings, my invention is shown as applied to an ordinary normalizing furnace. It will be understood, however, that my invention is equally applicable to other types of heating furnaces, fo-r instance, pack heating furnaces.

In the drawings- Figure l is a longitudinal sectional View taken through two different horizontal planes of the furnace which I provide;

Figure 2 is a vertical sectional view of a portion of the furnace shown in Figure 1 taken adjacent and looking toward one of the vertically movable sections;

Figure 3 is a view similar to vFigure 2vbut taken adjacent and looking toward one of the horizontally movable sections of the furnace;

Figure 4 is a fragmentary elevational view of a. portion of the mechanism for moving the horizontally reciprocating sections of the furnace bottom;

Figure 5 is a fragmentary plan view of the vertically and horizontally reciprocable sections of the furnace bottom;

Figure 6 is a fragmentary transverse sectional View showing the reciprocating sections-fand a portion of the apparatus for moving them;

Figure '7 is a side elevationalview of Va portion of the apparatus for reciprocating ythe longitudinally` movable sections;

Figure 8 is a transverse sectionnthroughY the. furnace shown in Figure 1, the furnace bottom` engaging lngerassuch as shown in Figure 9,

adapted to carryv a plurality of tubes tied together by spacing bars.

As shown in the drawings, the furnace structure proper comprises sidewalls 2, end walls 3, a

ltop wall 4, and a bottom wall indicated generally by the reference character 5. An opening. 6 is provided at one end ofthe furnace to permit material to be placed therein. A discharge open- V ing 'I is provided at the `other end of the furnace after its passage therethrough. The furnace structure may be of any desired width or length depending upon the use to which it is to be put and the size of the materials to be heated. v

The material is placed in the furnace and is carried therethrough by means of the reciprocable sections of the furnacebottom. These reciprocable sections may be termed beams herein,-

as they function in a manner similar to the beams far as the movement of the material through the furnace is concerned. These reciprocable sections, however, are not comparable to the ordinary beams in the usual type of walking beam furnace in any other respects. Their provisionv is highly desirable and results in a furnace far superior to the types of furnaces now known. The furnace bottom structure or walking beam structurefor conveying the material through the fing forward through the furnace.

Figure 10 is a fragmentary side elevational viewV` extending sections 8 which are supported for vertical reciprocatory motion, and a second series of longitudinally extending sections 9 which are supported for horizontal longitudinal reciprocatory movement. The operation of these series of sections or walking beams is so coordinated that the vertically movable sections 8 are in their lowermost position during the period that the longitudinally movable beams are mov- During this period,the` material is supported by the longitudinally movable sections and is carried forward thereby, the vertically movable sections in their. lowermost position being below and out of contact with the material. After the forward stroke of the longitudinally movable sections has taken place, the vertically movable sections are raised by appropriate mechanism to be hereinafter briefly described, and the material lifted from the longitudinally movable sections 9 and v supported thereby. During the period that the material passing through the furnace is supported by the vertically movable sections, the horizontally movable sections are moved rearwardly so as to be readyto receive and again carry forward-the material when the vertically movable beams are again lowered. In this manner the material is carried through the furnace in a stepby-step manner, the horizontally movable sections carrying the material forward through the furnace and the vertically movable sections supporting the material during the period that the horizontally movable sections are being returned to a position to again advance the material through the furnace.

It will be understood that my -invention is not limited to furnaces having walking beam structuresof the character above described, as it may be embodied in structures utilizing an entirely different type of movement. It may be embodied in structures wherein a single series of movable beams or sections are employed, which are movable both in a longitudinally extending direction and a vertically extending direction, the material being supported on stationary supports or sections during the return stroke of the series of movable lbeams or sections.

Each .reciprocable section 8 and 9y is preferably made of refractory material and they are located in close proximity to each other in order to cut down the size of the longitudinally extending slots therebetween to thereby cut down the heat loss and to prevent any influx of cold air into the furnace.

Each longitudinally movable section 9 is carried by angles I0 and secured thereto. Each angle II) is carried by a longitudinally extending web II carried by a trough or tray I2. Angle irons ,I3 may be provided on either side of the web I I kto give it su'icient rigidity to support the section 9.and the material carried thereby. Each tray or trough I 2 extends longitudinally throughoutv the length of the furnace and is provided with rails I4 adapted to cooperate with wheels I5 carried by a cross shaft I6 supported in bearings in curved bars I'I which are connected together throughout the length of the furnace by spacer bars I8. The wheels I5 are adapted to cooperate with and move along rails I9 formed of channels suitably connected together by means of bolts 2i! and spacing sleeves 2I The rails I9 may be suitably mounted on transversely extending pedestals or piers 22.

Extension arms 25 are provided and suitably connected to the longitudinally movable sections 9. Y These extension arms are each provided withY a rack Z6 adapted to cooperate with a gear 21 carried by a shaft 2B driven by a suitable motor `29 through appropriate gear reducing mechanism 3u Through the-mechanism above described, the longitudinally movable sections will be reciprocated longitudinally forwardly and rearwardly through the furnace.

The vertically movable sections 8 are suitably mounted on and secured to angles 35. Each angle is rigidly co-nnected to and supported by a plurality of posts or pins 36. ries a rack 3l' adapted to cooperate with a segmental gear 3S driven by a shaft 39 driven by a metered@ through gear reducing mechanism 4| and other suitable driving connections. These driving connections are shown in the drawings, but it is deemed unnecessary to describe them in detail.

Each vertically reciprocable beam 8 carries a plurality of material engaging fingers L15, and each horizontally reciprocablc section or beam 9 carries a plurality of similar material engaging fingers 4S. These material engaging fingers are spaced longitudinally of the furnace along the beams or sections 8 orV 9 and the material engaging fingers @-5 and i6 overlap each other transversely of the furnace but are spaced relative `to each other longitudinally of the furnace.

Yadjacent the material engaging surfaces thereof by bars 33. These bars t9 have pointed upper surfacesv 5@ which are substantially in the same plane as the material engaging surfaces of the I fingers and aid in supporting the material.

As will be readily understood from the above description, the material engaging fingers are unsecured to the beams or sections 8 and 9, but nevertheless will remain in position thereon by K reason of the manner in which they are mounted subjected in the furnace.

thereon. This permits the material engaging surfaces of the transporting mechanism to be readily replaced in the event that they become distorted or disintegrated in any manner by reason of the high temperatures to which they are Furthermore, by reason of the arrangement of the fingers, adequate support is given to the material at all times during its passage through the furnace.

In furnace structures of this character, it is highly desirable to eliminate any substantially straight vertical slots or passageways through the bottom of the furnace. Such substantially straight vertical slots, if allowed to exist, will cause black streaks to form on the material immediately above such slots or passageways.

' projections 5@ which cooperate with the faces 5I Each post 36 carto provide a torto'us passageway' or slot through An arrangement of Furnaces of this character .are generally pro-` vided with a furnace bottom which is made up of a layer of refractory brick and a layer of heat insulating material therebelow.' The heat insulating material is, of course, for the purpose of preventing loss of heatthrough the furnace bottom. In addition to the provision of a layer of heat insulating material below the refractory material, it is necessary to provide sealing means to seal the furnace .against the escape of hot gases or the ingress of cold air around the moving parts extendingY upwardly through the furnace bottom. In the furnace which I provide, this is accomplished in an entirely novel and considerably less expensive manner. Each base plate on which the sections 8 are mounted is provided with downwardly extending flanges BB. 'Ihese flanges eX- tend longitudinally of the furnace and are adapted to overlie an-d extend downwardly into adjacent trays I2, the side walls Si of each tray being located between the downwardly projecting flanges .andthe posts 36 carrying the sections 8.

Each tray i2 is provided with heat insulating material 62, such as .silocelf, into which the fianges 6D extend for the purpose of effectively sealing the bottom structure of the furnace against the escape of hot gases, or the ingress of cold air or the loss o-f heat by conduction. As will be readily seen, in a structure .such as that which I provide it is unnecessary to provide the furnace bottom with a lay-er of heat insulating material, as the heat insulating material carried by the trays I2 serves the double purpose of sealing the furnacerand preventing heat loss by conduction.

Each tray I2 is provided with end walls 62. At least one o-f the end walls 62 of each tray l2 is removable sc'as to permit the removal of the trays lengthwise of the furnace.v It is highly d-esirable that these trays be removable as it facilitates the removal of scale and the like which falls therein through the slots in the furnace bottom. It will be readily seen that the furnace bottom structure is of such character as tol-not retain the scale which drops from the material being carried' through, and the scale will drop through the slots in the furnace bottom and into the trays from which it may be removed.

In removingv the trays l2 lengthwise of the furnace, the longitudinally reciprocable sections El' will also be removed as the sections or beams 9 are carried bythe trays, as described above. This facilitates inspection of the material engaging fingers 46 and the replacement thereof, and also forms a passageway or passageways through the furnace so that a person may enter the furnace and readily examine and replace the material engaging fingers 45 carried by the vertically reciprocable sections 8.

In Figures 9, 10, and 11, I have shown a walking beam furnace structure which is peculiarly appli# cable to the heating of tubesror rounds or the like. In this embodiment, the material engaging means carried by the vertically movable sections is in the form of a plurality of bars 'lo having longitudinally upstanding portions 'i' i. The lower portion of each bar 'l0 carries forks i2 adapted to rest on the substantially V-shaped portions 'I3 of the .sections 8. By providing a forkedbar 'ill of this character, the bars may be placed on the thereto. -The material engaging surfaces 16 of the bars 1B are sloped at an angle to the horie` zontal toward the discharge end of the furnace.

The end of each bar l0 closest the discharge end horizontally movable sections is also in theform of a plurality of bars 70 having longitudinally upstanding portions 1I. The lowerportion of each bar 1D carries forks 12 adapted to rest on the substantially Veshaped portion 13 of the beam or sectionS. The material engaging surfaces' 16' of the bars 1Q' are substantially horizontal.

In the embodiment shown in the drawings, the

stroke of the horizontally movable beams or sections will be of such length as to place the tubes or rounds at the forward end of the stroke in such position as to be engaged by the bars 'l' adjacent the rear ends thereof. The tubes will then be caused to roll by gravity along the surlvertically reciprocable sections or beams 8 and 9,

and that they may be so positioned that the horizontally movable beams or sections will posi-l tion the tubes carried thereby on the rear of each bar 'l0 carried by the vertically reciprocable sec- Vtions or beams 8, as they are raised to receive tions 9 adjacent the rear ends thereof,vand that the tubes ar-e then rolled along Ythe surfaces of the bars 'l0 carried by the sections 9 until they reach the abutments 14 at the forward ends thereof.

In walking beam furnaces wherein there are a series of horizontally reciprocable beams or sections .and va second series of vertically reciprocable beams or sections, the bars 10 or equivalent means may be placed on either series of beams or on both. In furnaces where only one series of movable beams is` provided, the bars 10 or equivalent means may be placed on either the stationary.

supports or the series of reciprocating beams, or on both. Furthermore, in furnaces where only a single reciprocating section or beam is provided, the bars 10 or their equivalents may be placed on either the reciprocable section or the stationary supports, or both.

As shown in Figure 11, a plurality of tubes 80 may be tied together by a spacer bar 8| and transported through the furnace together. Where a plurality of such tubes or rounds are tied together and carried through the furnace, they will roll along the inclined material engaging .surfaces 13 of the bars 10 forming the material engaging and supporting means.

It will be readily seen that a structure such as that shown in Figures 9 to 11, inclusive, is highly desirable for the heating of tubes or rounds, and met the tubes or rounds maybe rotated at pre- Th-e material engaging means carried by thesections 8 without Asecuring or fastening '-them determined intervals to prevent warping. A structure of this character permits rapid travel through the furnace without any increase in speed or stroke of the moving mechanism. y

In the foregoing specification, I have described my invention as relating generally to heating furnaces, and more particularly to heating furnaces used for metallurgical purposes. My invention is not limited to heating furnaces for metallurgical purposes but relates to heating furnaces of any characterl whatsoever wherein the material to be treated is conveyed through the furnace at vsuch a rate of travel as to enable thev material to be properly heated and treated by the time it reaches the delivery or discharge end of the furnace. It is equally applicable to glass annealing leers, as well as metallurgical furnaces, and the term heating furnace as used in the specification and claims hereof includes annealing leers and the like, as well as metallurgical furnaces.

While I have shown and described a preferred embodiment and a modification of one of the features of my invention, it will be understood that I do not intend to be limited thereby, but that the invention may be otherwise embodied Within the scope of the appended claims.

I claim:

1. In a continuous heating furnace, a furnace bottom structure comprising a series of spaced longitudinally extending sections formed of refractory material, and a second series of spaced longitudinally extending sections, means for reciprocating one of said series of sections in a longitudinally extending direction through said furnace, the other of said series of sections being adaptedV to support the material passing through said furnace during the rearward stroke of said reciprocable sections, and a plurality of transversely extending material engaging fingers mounted on at least one of said sections.

2i. In a continuous heating furnace, a furnace bottom structure comprising a series of spaced longitudinally extending sections formed of refractory material, and a second series of spaced longitudinally extending sections, means for reciprocating one of said series of sections in a longitudinally extending direction through said furnace, the other of said series of sections being adapted to support the material passing through said furnace during the rearward stroke of said reciprocable sections, and a plurality of transversely extending material engaging fingers resting von and unsecured to at least one of said sections. Y

3. In a continuous heating furnace, a furnace bottom structure comprising a series of spaced longitudinally extending sections formed of refractory material, and a second series of spaced longitudinally extending sections, means for reciprocating one of said series of sections in a 1ongitudinally extending direction through said furnace, the other of said series of sections being adapted to support the material passing through said furnace during the rearward stroke of said reciprocable sections, and a plurality of spaced transversely extending material engaging fingers mounted on each of said sections and arranged in horizontally overlapping relationship.

4. In a continuous heating furnace, a furnace bottom structure comprising a series of spaced longitudinally extending sections formed of refractory material, and a second series of spaced longitudinally extending sections formed of refractory material and arranged in alternating relationship relative to said first series of sections, means for reciprocating said first series of sections in a vertically extending direction, and means for reciprocating said second series of sections in a longitudinally extending direction, and a plurality of spaced transversely extending material engaging fingers mounted on each of said sections.

5. In a continuous heating furnace, means for moving material through the furnace comprising a series of spaced longitudinally extending beams, means for reciprocating said beams in a longitudinally extending direction, a plurality of transversely extending material engaging and supporting fingers carried by at least one of said beams, said fingers being spaced longitudinally of the furnace, and means arranged between said spaced beams for supporting the material during the return stroke of said beams.

6. In a continuous heating furnace, means for moving material through the furnace comprising a series of spaced longitudinally extending beams, means for reciprocating said beams in a longitudinally extending direction, a plurality of transversely extending material engaging and supporting fingers carried by at least one of said beams, said fingers being spaced longitudinally of the furnace, means arranged between said spaced beams for supporting the material during the return stroke of said beams, and a plurality of transversely extending material engaging and supporting fingers carried by said means, said fingers being spaced longitudinally of the furnace and being arranged in alternating relationship relative to the material supporting fingers carried by said beams '7. In a continuous heating furnace, a furnace bottom structure comprising a series of spaced longitudinally extending sections formed of refractory material, the adjacent faces of said sections being arranged to provide a vertically tortuous slot between adjacent sections.

8. In a continuous heating furnace, a furnace bottom structure comprising a series of spaced longitudinally extending sections formed of refractory material, and a second Series of spaced longitudinally extending sections, and means for reciprocating one of said series of sections in a longitudinally extending direction through said furnace, the other of said series of sections beingY adapted to support the material passing through the furnace during the rearward stroke of said reciprocable sections, adjacent faces of adjacent sections being arranged to provide a vertically tortuous slot therebetween.

9. In a continuous heating furnace, a furnace bottom structure comprising a series o-f spaced longitudinally extending sections formed of refractory material, and a second series of spaced longitudinally extending sections formed of refractory material and arranged in alternating relationship relative to said first series of sections, means for reciprocating said first series of sections in a verticallyV extending direction, and means for reciprocating said second series of sections in a longitudinally extending direction, adjacent faces of adjacent sections being arranged to provide a vertically tortuous slot therebetween.

10. In a continuous heating furnace, a furnace bottom structure comprising a plurality of longitudinally extending supports, means for reciprocating at least one of said supports in a longitudinally extending direction, a tray positioned below said reciprocating support containing heat insulating material, and means .depending downwardly from one of said supports and adapted to extend into said heat insulating material, whereby the furnace bottom is sealed against the exit of hot gases or ingress of cold air around said reciprocatory section.

11. In a continuous heating furnace, a furnace bottom structure comprising a plurality of longitudinally extending supports, means for reciprocating at least one of said supports in a longitudinally extending direction, at least one of said remaining supports being adapted to support the material during at least a part of one stroke of said reciprocating support, a tray positioned below said reciprocating support containing heat insulating material, and means depending downwardly from one of said supports, and adapted to extend into said heat insulating material, whereby the furnace bottom is sealed against the exit of hot gases or ingress of cold air around said reciprocatory section and against heat loss through the furnace bottom.

l2. In a continuous heating furnace, a furnace bottom structure comprising a series of spaced longitudinally extending sections, and a second series `of spaced longitudinally extending sections, means for reciprocating one of said 'series of sections in a longitudinally extending direction through said furnace, the other of said series of sections being adapted to support the materiall passing through the furnace during the rearward stroke of said reciprocable sections, and a plurality of trays having therein heat insulating material positioned below said longitudinally reciprocable sectcions, the other of said series of sections having downwardly depending longitudinally extending flanges adapted to extend into said heat insulating material, whereby the furnace botto-rn is sealed against heat loss by convection or conduction.

13. In a continuous heating furnace, means for moving material through the furnace comprising a series of longitudinally extending supports, means for reciprocating said series of supports in a longitudinally extending direction, a second series of supports arranged in alternating relationship relative to said first mentioned series of supports, and adapted to support the material during at least a part of one stroke of said reciprocating supports, each of one series of supports having downwardly extending anges thereon, and longitudinally extending trays positioned below the other series of supports adapted to cooperate with said flanges to seal the furnace.

14. In a continuous heating furnace, a furnace bottom structure comprising a series of spaced longitudinally extending sections formed of refractory material, and a second series of spaced longitudinally extending sections, means for reciprocating one of said series of sections in a longitudinally extending direction through said furnace, the other o-f said series of sections being adapted to support the material passing through the furnace during the rearward stroke of said reciprocable sections, and means for supporting each of said longitudinally reciprocable sections including a tray positioned therebelow.

PAUL S. MENOUGH.

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