US1736524A - Soaking-pit cover - Google Patents

Description

Nov. 19, 1929. 1.. ELLMAN SOAKING PIT COVER Filed Dec. 19. 1925 2 Sheets-Sheet 1 Nov. 19, 1929. L. ELLMAN 1,736,524

SOAKING PIT COVER Filed Dec. 19. 1925 2 Sheets-Sheet 2 Patented Nov. 19, 1929 UNITED STATES PATENT OFFICE LOUIS ELLMAN, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO M. H. DETRICK GOH- v PANY OF CHICAGO, ILLINOIS,

A CORPORATION OF ILLINOIS SOA KING-PIT COVER Application filed December 19, 1925. vSerial No. 76,863.

This invention has to do with refractory covers or closures for furnaces or heating chambers. It has particular reference to construction of removable covers such as are employed for closing soaking pits used for the heating of ingots, and the nature of the invention will be set out by reference to closures of that particular kind.

In the operation of soaking pits in rolling mills, it is necessary to remove and replace the pit cover many times a day for the removal of the ingots, usually one at a time, as they are to be fed to the rolls. The handling of the necessarily large and heavy covers incident to such removal a'nd replacement subjects them to extremely violent shocks and blows, particularly when the cover is lowered into contact with the top of the pit walls. The construction of covers able to withstand this very trying usage, and at the same time resist the deteriorating influences of the hot gases within the pits, has presented a very difficult problem. Heretofore, the type of construction most generally used has been one in which a heavy cast-steel frame is utilized to support a refractory lining built up of fire brick in the form of a dome or arch. Another form of construction sometimes employed is one in which the metal of the supporting frame is cast about the refractories which form the heat-resisting lining so that they constitute, in effect, an integral part of the structure. Both forms are Very expensive-to make, very heavy, and have a comparatively limited term of serviceability due to the fact that it is practically impossible to make effective repairs in them. The arched or domed covers, for example, require the most highly skilled masonry work in the first place, are dependent upon the maintenance of the absolute integrity of the archstructure throughout, and must be rebuilt completely upon the failure or Wearing out of even a limited area. In theform using the cast-in refractories satisfactory repairs can not be made, as the cast metal depended on to hold the refractories in place can not be removed and replaced. Moreover, in these constructions the violent shocks to which the frames are subjected in. the handling of the covers are transmitted to the refractories and of course tend to break and displace them. I

The general purpose of the present invention is the provision of improved construction for refractory covers or closures, such as is particularly. qualified to withstand the extremely hard usage occasioned by the handling of such closures in the customary manner, which is economical in construction in the first instance, and in which repairs may be made, in either limited or extended areas, with facility and at comparatively low expense.

An additional object is the provision of a construction for such covers which is particularly effective in providing a tight closure for preventing the escape of the hot gases and flame either through the closure itself or about the line of contact between the cover and the pit walls, and one which does not require the use of additional sealing material, such as sand, about the line of contact.

Some of the more specific objects of the invention are:

The provision of a construction which permits the employment of a frame fabricated from ordinary commercial rolled shapes, and thereby greatly lessensthe weight and the cost of thestructure, as compared with prior y The provision of a construction in which the refractories forming the heat-resisting lining are supported individuall and are not dependent upon one another or their security in thestructure, thus insuring the closure against sudden failure and permitting repairs to be made in any area without requiring extensive dismantling;

The provision'of a construction in which the refractory lining as a whole has a degree of movement independently-of the metallic frame, and .a desirable flexibility within it-- self, whereby expansion andcon'tract'ion are accommodated without imposing destructive strains on the refractories or the frame, and the refractories are safeguarded against the violent shocks to which the frame is subjected incident to the handling of the closure;

The provision of a construction which affords a relatively broad sealing area or zone between the refractory lining of the cover and the top of the pit walls and also a very close seal, without requiring the refractories to carry the weight of the cover when it is in place and without subjecting the metal frame members to destructive heating;

The provision of a construction in which it is possible to maintain the tightness of the seal by the repair and replacement of parts which become worn or broken, without requiring extensive dismantling or the discarding of any uninjured portion of the structure.

Other and further objects of the invention will be pointed out hereinafter, indicated in the appended claims, or obvious to one skilled in the art upon an understanding of the present disclosure. For the purpose of this application I have elected to show and describe herein one form in which the invention may be embodied in a cover for a soaking pit. It is to be understood, however, that this particular construction is here presented for purpose of illustration only, as I do not regard the invention as limited to this particular arrangement or this particular use, and hence the descriptive disclosure is not to be given any interpretation having the effect of limiting what I claim, short of the true and most comprehensive scope of the invention in the art.

In the drawing forming a part of this specification,

Fig. 1 is a longitudinal sectional elevation of a soaking pit cover shown in position on top of the pit walls and in association with a portion of the handling crane or carriage;

Fig. 2 is a transverse sectional elevation of the cover on substantially line 2-2 of Fig. 1; r

ig. 3 is a detail showing, in perspective, one of the frame shoes;

Fig. 4 is a top view of the cover; and

Fig. 5 is a sectional detail, on a somewhat larger scale, taken on line 5-5 of Fig. 4.

Describedgenerally, one construction con templated by my invention comprises a suit; able metallic frame which may be built up from ordinary commercial rolled shapes. This frame affords suspension members upon which refractory tile are suspended in a pendulous fashion such that the refractories are supported individually and independently of one another and have an extent of individual mobility, whereby they can adjust themselves within the structure and thus maintain a desirable close contact with one another effective to prevent the leakage of gases from the heating chamber. The frame is arranged for support in any suitable fashion on the handling or transporting crane or carriage, whereby it maybe moved into and out of position closing the mouth or opening of the heating chamber, the walls of which it is adapted to overlap a substantial distance in order to provide an effective closure and also to allow for the chipping or breaking off of internal corner portions of the walls, as frequently occurs from blows from the articles being lowered into or lifted out of the chamber. The support of the refractories on the frame is such that they may be removed from selected areas without requiring extensive dismantling of the structure, and may be replaced with others, so

that any injured area of the refractory linin the event of injury, so that the integrity of the seal may-be maintained. The suspended refractories are free from and movable independently of these shoe members so that as the cover is lowered to bring the latter in contact with the pit walls, the resulting shock will not be transmitted to the refractories.

The nature of the invention may be un derstood more specifically by reference to the illustrative embodiment in the drawing, in which, let it be understood, the reference characters 10 designate the walls of the soaking pit or heating chamber with which the removable closure is associated and adapted to be handled by a suitable operating mechanism, a portion of which is illustrated by the crane or carriage arm '11. comprises a frame made up of the marginal The cover members 12 of rolled channel shapes connected in rectangular disposal by the usset plates 14. Between the side mem ers extend the suspension beams 15 which carry the freely supported arch bars 16. A girder 17 spans the frame and affords a means of maintaining the same on the handling carriage. The arch bars 16 are hung on the suspension beams 15 and are free to shift longitudinally of the latter. They have lateral flanges along their lower edges to constitute supports for the refractory tile 18, which are provided with T-shaped slots of dimensions such as to accommodate the flanged arch bars with suitable clearance to allow a considerable freedom of movement. The arch bars are of such length that there is sufiicient room between the ends of those carried on adjacent suspension beams to allow for the removal of refractories between them. In these spaces are suspended the refractories 18, which are carried individually on T-shaped bridge hangers 19 which have flanged lower portions for engaging the tile and overhanging head portions adapted to find support on the tops of the tile carried on-the adjacent arch bars.

The horizontal dimensions of the structure are adequate to allow for a substantial overlapping of the tile over the top of the chamber walls about the chamber opening. The dimensions and locations of the arch bars and the suspension beams are such that the tile will depend for a considerable portion of their height below the lower flanges of the frame members 12. As a means for providing lateral support for the marginal refractories so as to. hold all the suspended tile in proper close lateral contact with one another, and for affording the necessary support of the frame on the pit walls, I provide the marginal shoe members 20. These are made of suitable material, such as cast-iron, having the requisite strength to carry the intended load and the necessary heat-resisting qualities to withstand the temperatures to which they are subjected at the sealing zone. One of these shoe members is illustrated in per-- spective in Fig. 3. It has an upright portion so 20 terminating at the bottom in an external flange 20 and an internal flange 20. Substantially midway of the height of the body portion is an outwardly directed flange 20 extending at a right angle from the body por- 3 tion. Reinforcing webs 20 afi'ord additional support for the flange 20 On its upper side this flange is formed with the spaced-apart ribs 20 and-with the elevated seats 20 The outer side of the body 20 is likewise provided 4 with spacing ribs 20. The attaching flange 20 is piereced with bolt holes 20 for the re- --ception of the bolts. 21, whereby the shoe members are secured to the lower flanges of the frame members 12. These shoe members are secured to the frame members in series, end to end, with proper small expansion spaces between them, the bolts making it possible to remove any of the shoes with fa cility. The raised seat portions 20 and the spacing ribs E20 and 20 contact the bottom of the lower flange and the inner side of the web of the frame member and afford air circulating spaces or channels between the shoe and the frame member. The dimensions of the shoe members are such that they extend a slight distance 'below the lower ends of the refractories 18 and afford a supporting rim adapted to seat on the top of the chamber Walls and maintain the refractories slightly 69 spaced from them. The dimensions of the frame are such as to leave a clearance between the suspended refractories and the inner sides of the shoe members, and these spaces are filled with slabs or split brick 22 of refracr tory material of proper width to hold all of not necessary or desirable to provide compressible expansion joints in the structure, as the effectiveness of the closure requires very close contact between the component refractories, and such expansion as occurs in them is accommodated by the joints between the tile. Vhile'thus holding the suspended refractories under the desired lateral com pression, the edging of split brick 22 allows a desirable mobility of. the suspended refractories vertically relative to the frame. As a consequence, when the structure is lowered, frequently with severe violence, into its position over the chamber mouth, the impact is received by the shoe members and transmitted to the frame without permitting the suspended refractories to receive either a direct blow by contact with the chamber walls or a concussion transmitted directly to them from the frame. The shoe members prevent the refractories contacting the chamber walls, and the mobility of the members upon which they are suspended, together with their own freedom of support, permit them to give relative to the frame and thusabsorb the shock without likelihood of fracture. The shoe members form a tight seal with the top of the chamber walls, and due to the nature of the material of which they are formed, as well as to the arrangement for dissipating heat from them through the webs 20 and ribs 20 and 20 are able to withstand the temperatures to which they are subjected without appreciable deterioration. In the event a shoe is injured by ,the cutting action of the furnace gases or broken by a blow, it may be removed very quickly and replaced with another at slight cost. It usually occurs, as when the furnace is of the regenerative type or is heated by injected fuel, that there is quite high pressure within it. This renders it important. that the refractory structure be very tight and the seal very close. The slotted bolt holes 20 permit a .variation in the positioning of the shoe members to accommodate variations in the width of the tile and enable the shoe members to be secured in the proper adjustment, to hold the tile in close lateral abutment. The extensive overlapping of the refractory cover structure over the chamber walls, as is afforded by the present construction, contributes to the tightness of the seal by minimizing the access of the flame and hot gases to the shoe members. Y

Various advantages of the construction have been referred to above. In addition thereto, it is pointed out that the construction of the frame from commercial rolled shapes is much more economical than the provision of a cast frame of the types heretofore employed, and such a frame is likewise considerably lighter than the cast ones. In the event of any serious injury to one of the frame members in the fabricated structure, it may be removed and replaced without requiring the scrapping of the entire structure, as is necessary when a cast frame is used. These highly important advantages of the fabricated frame are rendered available by my invention through the provisions made for protecting the steel members from injurious heat. It will be observed that they do not have contact with the refractories, are liberally spaced from the sealing zone, are exposed fully to the air, and are afforded extensive surface exposure and ventilation between them and the shoe members. As a consequence it has been found that even when the shoe members are red hot, the rolled steel frame members show no signs of deterioration, even after an extended period of use. Due to frequent removal and replacement of the cover over the heating chamber, the refractories necessarily are subjected to rather extreme and sudden changes in temperature. Due to their individual mobility and the flexibility of the structure as a Whole, injury from such changes is minimized and the opening of leaks prevented. Under proper supervision the refractories may be assembled in the structure, or the necessary replacements made, by ordinary unskilled labor, instead 1 of requiring the highly expert and expensive masonry work requisite 1n the building of the arched or dome shape structure heretofore employed. Hence it will be observed that the invention accomplishes great saving in original cost, provides a closure which is susceptible of maintenance repairs and hence has a prolonged term of utility, which accommodates the making of repairs very quickly and thus avoids loss from prolonged outage of the furnace, and which provides a most'effective, tight and easily handled movable closure. These several advantages make possible an even greater saving and efliciency in plant operation as they permit the building of covers much larger than is now feasible and hence permit the use of larger pits and heating chambers.

\Vhat I claim is:

1. A movable closure for fire chambers comprising a circumscribing frame, suspension members supported on the frame and courses of refractories suspended on the suspension members and encompassed by the frame. i

2. A closure for fire chambers comprising a fabricated steel frame, cast members se' cured to the frame to form spacing supports for seating on the chamber wall, and refractories su ported in the frame and retained laterally by said cast members to form a fire resisting closure.

3. A movable closure for fire chambers comprising a fabricated steel frame, refractories suspended therein to form a heat resisting closure adapted to overlap the chamber wall, and supporting members for seating on the chamber wall to support the frame and refractories out of contact therewith, said supporting members spacing the refractories laterally from the steel frame members.

4. A movable closure for fire chambers comprising a fabricated steel frame, refractories movably anchored therein and projecting beyond the furnace side of the frame to form a refractory cover, and cast members secured to the frame and extending about said projecting portion of the refractory cover.

5. A closure for fire chambers comprising a fabricated steel frame, refractories movably anchored therein to form a fire resisting clo sure, and cast foot members removably secured to the.frame to seat on the chamber wall, said foot members retaining the refractories out of contact with the frame.

6. In a soaking pit cover, a movable frame, a plurality of refractory tile suspended from the frame by their upper ends, and an edging of refractory material carried on the frame for supporting the tile in lateral abutment.

7 In a soaking pit cover, a cast metal shoe having a body portion affording a supporting member at its lower end and a laterally projecting attaching flange and spacing ribs on said flange and body portion affording intervening ventilating channels.

8. A pit cover comprising aframe, carriage mechanism supporting the same for horizontal traveling movement, suspension members carried on the frame and extending in the direction of its travel, refractories suspended on the suspension members in courses running longitudinally of the latter to form a refractory closure for the pit mouth, and abutments for the refractories at the ends of the courses.

9. .A pit cover comprising a traveling frame, suspension members carried on the frame, courses of refractories suspended on the suspension members, and heat-resistant members on the frame holding the refractories of different courses in lateral abutment.

10. A pit cover comprising a frame mounted for horizontal travel over the pit walls, suspension members carried by the frame, refractories suspended in collaterally arranged courses on the suspension members and depending below the frame over the pit walls and means carried on the frame and cooperating therewith to hold refractories of different courses in lateral abutment.

11. The combination with a pit furnace, of a frame movable horizontally over thepit walls, suspension members [carried on the frame, refractories removably suspended on the suspension members in courses and depending below the frame to form a cover for the pit, and means for supporting the cover on the pit walls with the refractories out of contact therewith, said means cooperating with the frame to afford the refractories lat eral retention.

12. A soaking pit cover comprising a movable frame, tile-supporting members within the frame, refractories suspended on the tilesupporting members to form a continuous closure and marginal members carried by the frame for seating against the pit walls, said marginal members affording the marginal refractories lateral support at their outer sides.

13. A pit cover comprising a movable frame, refractories suspended on the frame in lateral abutment to form a continuous closure, said refractories having portions 'depending below the lower margin of the frame, foot members secured to and extending downwardly from the frame, and refractories supported by said foot members in lateral abutment. with the marginal suspended refractories.

14. In a pit cover comprising a movable frame, suspension members movably supported by the frame, refractories suspended on said suspension members and depending below the lower margin of the frame, and marginal members held'by the frame to constrain the refractories in lateral abutment with one another, said marginal members extending downwardly from the frame to afford supports whereon the cover is supported on the pit walls.

15. A pit cover comprising a movable frame, suspension members movably supported in the frame, refractories movably suspended on the suspension members and depending below the lower margin of the frame to form a heat-resistant cover, and foot members of heat resisting material attached to the frame and. extending to a plane below the lower ends of the refractories to form a sealing rim for seating on the pit walls about the cover.

16. A pit cover comprising a movable frame, refractories suspended from t e frame by their upper ends to form a heat resisting closure, foot members carried by the frame laterally of the marginal refractories, and refractory material supported by said foot members in lateral abutment with the marginal refractories.

17 A pit cover comprising a frame, refractories suspended on the frame by their upper ends and depending below the lower margin thereof, foot members attached to the frame and having ledge portions depending below the refractories, and edging materlal supported on said ledge portions in lateral supporting cooperation with the marginal refractories.

18. A"movable closure for fire chambers comprising a fabricated steel frame, refractories movably anchored therein and projecting beyond the furnace side of the frame to form a closure, and members attached to the frame at margins of the closure and extending beyond the furnace side thereof to form a sealing rim for seating on the furnace walls.

19. A movable furnace cover comprising, in combination, a plurality of refractories suspended in lateral contact with one another to form a cover, a metallic frame having portions surrounding said cover and holding the refractories in lateral abutment with one another, certain of the refractories being withdrawable outwardly from the cover to afford room for removal of other refractories therefrom, and carriage mechanism for shifting the frame and cover bodily.

20. A furnace closure comprising, in combination, a frame including oppositely disposed frame members connected together, refractories suspended on the frame to form a heat-resistant cover, said refractories having portions between the frame members and portions extending beyond the frame members, and marginal members mounted on the frame members and retaining the refractories out of contact with the frame members, said marginal members. formed to afford spaces for circulation of air between them and the frame members.

21. A closure for furnace chambers coinprising, in combination, a plurality of refractories arranged in lateral contact with one another to form a heat-resistant cover, a fabricated steel frame encompassing the cover and affording support for the refractories, cast iron foot members mounted on the frame in series extending along the margins of the cover and cooperating to form a continuous sealing rim for contact wlth the furnace'walls.

22. A heating chamber cover comprlsmg, in combination, a metallic frame including side members connected by end members, carriage mechanism whereby said frame may be shifted horizontally above the furnace. chamber, refractories removably suspended on the frame and extending downwardly beyond the same in lateral abutment with one another to form a refractory top closure for the furnace chamber, and members depending from the frame and engaging the outer faces of the refractories at both the side and end margins of said closure to hold the refractories in abutment with one another.

In testimony whereof l have hereunto signed my name.

LOUIS ELLMAN.

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