US2452931A

US2452931A - Annealing box

Info

Publication number: US2452931A
Application number: US616108A
Authority: US
Inventors: Morris L Jacob
Original assignee: PITTSBURGH ANNEALING BOX CO
Current assignee: PITTSBURGH ANNEALING BOX CO
Priority date: 1945-09-13
Filing date: 1945-09-13
Publication date: 1948-11-02
Anticipated expiration: 1965-11-02

Description

- Nov. 2, 1948. M. l.. JACOB 2,452,931

ANNEALING BOX Filied Sept. 15, 1945 2 Sheets-Sheet 2 INVENTOR.v

Patented Nov. 2, 1948 UNITED STATES ANNEALINGBOX M y l Morris L. Jacob, Pittsburgh, Pa., assigner to Pittsburgh -Annealing Box Company, Pittsburgh, Pa., a corporation ofPcnnsylvania i Application September 13, 1945, Serial No. 616,108

6 Claims. l (Cl. 263-49) This invention relates generally to annealing boxes for receiving steel to be annealed in open fired annealing furnaces and more particularly` to fabricated annealing boxes havingwa clamped and sealed lid.

Upwardly open cast steel annealing boxes having lid or closure members are commonly employed to contain steel while'being annealed in an open fired `annealing furnace. a similar oxygen absorbing agent is frequently placed in the box with steel, the lid is then placed thereon and the box is loaded into the open.

/red annealing furnace. `The annealing furnace may be provided with burners in the end walls, side walls or in the roof` of the furnace chamber and the ames ordinarily impinge directly on the annealing boxes loaded into the furnace. These annealing furnaces are iired` for predetermined periods of time and at different controlled temperatures ranging from 1300 F. to l900 depending upon the character of the steel to be annealed, the degree of annealing desired and load or charge in the annealing furnace.

Repeated use of cast steel annealing boxes under ring conditions of this character cause them to develop ssures and deep cracks in a short time, making them unfit for further use. Again, the cast steel boxes and their lids may bulge or -become otherwise distorted, preventing them from properly sealing the steel within the box which makes them unfit for further use. The development of these and other defects prevent the cast steel boxes from being used more than twenty to thirty times before they have to be scrapped.

Another disadvantage of the cast steel annealing boxesresides inthefact that their side and end walls are heavily constructed and must be tapered 4to permit their removal from the mold in which they` are poured.` "Ihis construction reduces `the capacity of the load receiving chamber or thebox, f

The principal object of this invention is the provision of a fabricated annealing box which is not subjected to the disadvantages of the cast steel box and is capable of being used for six times as many as the cast steel boxes.

@Another object isthe provision of a fabricated annealing box that is constructed to prevent warpage or distortion upon repeated use.

Another object `is the provision of a fabricated annealing `box that is flexibly reinforced to permit itto expand and retract without warping or becoming distorted.

Another object is the provision of a fabricated annealing box havinglateral reeniorcing means arranged to prevent the box from bulging intermediate of its ends and also arranged to clamp y and retain the lidin sealed position.

`another object is the provision of -a reenforced Charcoal or 2 annealing boxproviding a. perimetral` sand seal for the lid of the box.` i

Another object is the provisionof an 'anneal ing box formed from steelplateand having a perimetral trough `shaped reenforcing member for containing sand for the seal and also 'ar--` ranged to receive `clamping `means i for holding the lid tightly in place and furtherVaid-.in preventing the box from bulging laterally intermediate ofits ends. 1""` V Another object is the provision ofia` novel lid and sand seal for an annealingubox. f l Another object isthe provision of an annealing box fabricated fromsteel plate which is capable ofwithstanding repeatedluse at high temperature annealing. i i f Another object is the provision of a fabricated annealing `box which provides an annealing chamber of maximum capacity for the over all size as compared to that of the caststeel'ibox. i i bfi Another Objectis the provision of a fabricated plate annealing box simple in construction 'and economical to manufacture.` i 1 i Other objects and `advantages appear from the following description and claims. i 1 1. Practical emodiments illustrating the vprinciples of this inventionare: shown in the` accompanying drawings wherein: I

Fig. l is a plan View of the fabricated annealing box with a` portion of thelid broken away.`

Fig. 2 `is a side elevation of` thefabricated an'- nealing box shown in Fig. 1. i i i Fig. 3 is a sectional viewof the fabricatedanehealing box shown in Fig. 1. i i l Fig. 4 is a perspective View ofthe underside of the lid." 1 `1 i y i y Fig. 5 is a plan view ofthe lidglocking batten and reeniorcing member. l y I Fig. 6 is a modified form of'thelidand hatten locking structure. y H

`Referring to the drawing, the `annealing'box lll is fabricated from steel plate.` If the box'isto contain steel and is` to be `subjected `to `temperatures up to1650or F; the steel platefemployedito make the box is preferably `made fromlow car'.- bon steel. If higher temperatures are`required, such as 1650o F. to 1900 F. 10W alloy high ,tensile strength steel plate is preferred for the constructionofthebox.` i i i The bottom Il and theside walls I2 of the l-box are formed fromlone plate bysharplyibending them at right angles along the bottom edges to produce ashort radius oriillet` therebymaking Th'e perimetral sand seal trough I6 which is formed by the perimetral reenforcing member il is preferably made from a heavier plate than that from which the box is constructed. Thisplate is formed into an angle bar having a short'horizontally disposed flange i8 and a longer flange 2.5i.

The right angle of the bar4 is sharply formed to provide a short radius or small fillet.

Four sections of the angle bars are cut toprovide the side and end sections of the perimetral reenforced member I'lwhich extend beyond the dimensions of the box I!! to the extent of the shortgflangel andthe ends are morticedso that they will fit when secured to the box.r Owing to the fact that the plate employed to construct the box may be seven-.eighths of an inch'in thickness they Vmay not be perfectly smooth. It therefore maybe desirable to fit the edges of the short flanges I8 to the outer surfaces of the box. Particular care is made to properly place the top edge of the long flange 20 above thetop edges 2l of kthe side and end wallsof the box. The edgeof the flanges 20 sh'ould be slightly less than `the thicknessof the Acover 22 above the ,top edges ZI ofthe box. This may be accomplished by tack welding the edge of the shortflangesl to the box `andfwhenfall of the sections are properly fitted andtacked in position both sides 4of the flanges I8 are securely welded tothe side and end walls of the box as indicatedv at 23, thereby perably spaced about afoot and onefhalf apart alongthe side'and end walls of the box. i

Before the side angle bars `are tack welded to the box, `a series of. oppositely disposed square notches 29 .are cut out of the long flanges ll spaced intervals depending'upon the length of the annealing box. These notches aretted with upwardly .extending lugs 25. of the same thickness of the flange 2U, Each of these lugs 25 extend above the upper edge of the flange 20 and are provided with a transverse opening 26. The lugs 25are` welded along the adjacent edgesurface on both sides of the flange 28 as indicated at 2l'. This construction provides a strong joint between the lugs 25 and the flanges 20. Whenthe angle bar f' sections are securedvto the box, the oppositely disposed lugs-on each side thereof are in alignment Yand are arranged to receive the tie bar battens-28 as shown in` Fig. 5. Each tie bar batten is preferablyy made of the samegauge steel' plate as the angle bars and they'are approximately one and one-half as wide as the lugs 25. Each batten 28 has la slotted opening 35 adjacent the ends thereof for receiving the upwardly projecting lugs 25. The openings 3U provide sufficient clearance to permit the Ybatteri to be dropped over the lugs when the completed box is being closed.

The lid 22 is shown inverted in Fig. 4.' This is preferably made from a plate having the same thickness as'` the box. The four .corners` are notched a sucient depth to permit the flanges 3i to be turned toward the underside of the lid and welded along the inner and outer beveled seams at each corner, as indicated at 32, to produce a continuous perimetralange preferably depending at an angle greater than 25 from the horizontal and arranged to be contained within the perimetral sand seal I as shown in Fig. 3. It will be noted that the bend forming the flange is spaced outwardly from the upper Vedge 2l of the side and end walls of the box to insure true and flat sealing surfaces between the under side of the lid 22 and the top perimetral edge 2l of the box. y

The sand seal trough I6 is practically filled with sand when the lid Ais lowered by the hoisting lugs 33 on to the box and the angular depending flange 3| moves the sand inwardly and upwardly to fill the void. More sand is then applied to the trough to ll the same. Tight packing of this sand seal may beV accomplished by thinl tampers employed to work th'e sand ybetweenv the long flange 2t of the trough and the flange 3| ofthe lid.

After the lid` 22 has'been positioned by a crane 5 or suitable hoist the' tie bar battens 2G are dropped over their corresponding lugs 2,5 and low angle wedges 35 aredriven byva kSledge into the openingsZS, thereby tightly kclamping thelid22 on the upper edge 2 I of the box. I y The loaded annealingbox is then transported tothe annealing furnace and redfor a predetermined period of time under controlled temperature conditions. 'Ordinarily the open fired furnace is shut off at the end of the firing` period and the furnace load is permittedto slowly `cool. Whencooled to below oxidizing temperature, the furnace is opened and the annealing boxes may then `be removed and unloaded. VThis process' is known as a complete annealing cycle. However, the firing schedule may require on and off firing periods during which time the temperature is raised to av predetermined amount and then per-y mitted to drop. u

Theshort flange i8 lbeing normal to the side and end walls of they box provides reenforcing around the perimeter of the box. The tie bar clamping battens Zlare equally spaced and when tightly clamped by thewedge blocks 34 provide further reenforcement preventing the fabricated plate box from warping or otherwise distorting when subjected to repeated use; whereas the cast steel box may be used for twenty to thirty times', the fabricated box Vcomprising this invention has been used one hundred to one hundred and thirty times when red at 155-0.F. .Since the box is constructed from plate material it may be straightened and reconditioned after one hundred and thirty annealing cycles and theyhave been used for ythirty to fty .times at temperatures of from 1659" F. to1700 F. without failure. The success cf this box vis believed to be due to its construction as well as to the fact that platerniate'rial isemployed to fabricate `the same.

` The clamping stress placed on the tiebar bat.- l

tens is believed to aid their being capable ,of retaining the box in shape after so many annealing cycle uses. The long anges 2U are alsoy be# lieved to flex during the expansion and contraction of the metal due to `alternate heatingard cooling. This resilien-ceis believedto represent an important object of this invention. 'After long use these boxes may become vdise torted and warped. Owing to the.. fact that they are made of platernaterial,` they may be readily straightened and reused withoutthe formation of cracksand fissures Which is impossible with the caststeel annealing boxes.` This is also believed tobe an important improvement in this arti., In the modifiedl form of this invention shown in Fig. 6, the lugs 25 are replaced by the lugs 40 and 4| which are constructed in pairs and are welded to the outer or inner face of the long flange 2D and the lug 40 is provided with a short ange 42 Whereas the opposite lug 4I of the pair is similar to the lug 25. The lugs d and li may be welded to the outer surface of the flange 20 as shown. The tie bar batten 28 is provided with the slotted opening 43 sufficiently large to permit it to be threaded over the flanged head 42 and the opening 36 at the other end of the batteri may then be dropped down over the lug 4I andlocked by the Wedge block 34 as before. Thus, only one wedge block need be used to tightly clamp the lid 22 in place.

The lid 44 of Fig. 6 may be used with either type of tie bar batten lock. This lid is merely a flat plate which closely fits the inner perimetral surface of the long anges 20 adjacent the upper edge, A properly positioned perimetral depending iiange 45 is welded on both marginal edges to the under side of the lid .44 so as to be centrally positioned and deeply inserted into sand retained by the perimetral trough i 5 to properly produce a sand seal.

When the lid Mi is used with either form of lug locking structure, the tie rod battens 28 prevent the box walls from bulging and the at lid 44 prevents them from buckling. Thus, the movement of the metal due to expansion and contraction is limited in both directions by flat metal parts which is an important object of this invention.

I claim:

1. In an annealing box the combination of, a box having a bottom with side and end walls to provide a chamber and a top rim disposed in a single plane, a perimetral` reenforcing member having two flanges, one flange being disposed normal to the walls of the box and secured to the outer surface below the rim, the other iiange extending upwardly to form a perimetral trough with Walls of the box, upwardly projecting lugs extending above the rim and secured at oppositely disposed positions in said other flange, a lid covering the rim of the box and disposed'between said lugs, a at batteri bar having openings adjacent its ends to receive the upwardly projecting lugs, and means to removably secure the batten to the lugs to tightly `clamp the lid on the! box rim and retain the opposed walls of the box against distortion due to heat. l

2. The structure of claim 1 characterized in that said lugs are inserted in and secured to the said other flange of the reenforcing member.

3. The structure of claim 1 characterized in that said means comprises a wedge arranged to be driven in a hole through the lug to forcibly hold the lid against the rim of the box.

4. The structure of claim 1 which also includes a series of spaced triangular brace members secured to the under side of said one flange of the reenforcing member and the box Walls.

5. The structure of claim 1 which also includes a perimetral flange on the lid spaced from the rim and depending into the trough.

5. In an annealing box the combination of an upwardly open box having a bottom with side and end walls to provide a chamber anda at rim disposed in a single plane, a lid engaging said rim to close the box, upwardly projecting lugs extending above the rim and secured at oppositely disposed portions on the sides of the box, a batten bar having openings adjacent its ends to receive the upwardly projecting lugs, and means to removably securethe batten to the lugs to tightly clamp the lid on the box rim and retain the opposed walls of the box against distortion due to heat.`

MORRIS L. JACOB.

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

UNITED STATES `ieATEirrs Number