US2628088A - Refractory product - Google Patents

Description

Feb. 10, 1953 w, us ETAL 2,628,088

REFRACTORY PRODUCT Filed May 22 1950 2 SHEETS-SHEET 1 LESLIE WFQQ EW l HN D. ISA/10$ Feb. 10, 1953 w. AUSTIN EIAL 2,628,083

REFRACTORY PRODUCT Filed May 22, 1950 2 SHEETSSHEET 2 INVENTORS LESLIE W. AUSTIN the hearth.

Patented Feb. 10, 1953 UNITED STATES PATENT OFFICE.

REFRACTORY PRODUCT Application May 22, 1950, Serial No. 183,465 8 Claims. (crass-46) This invention relates to ports for metallurgical furnaces and more particularly to ports employed in metallurgical furnaces of the type generally referred to as soaking pits.

Soaking pits are employed for heating ferrous metal ingots and the like. They are usually comprised of a large box-like enclosure and can be fired in a'variety of ways the most common being bottom and side firing.

In the former or bottom method of firing the pit is heated by means of a burner port located in a central portion of the hearth, through which the flame is introduced. Ingots to be heated are charged on the hearth surrounding the burner port and are there soaked or heatedthrough,

preparatory to their being rolled into plates or .inthe several side walls of thepit and the exhaust gases are permitted to escape through an exhaust port positioned in a centralportion of A very important feature of this port which isv located in the central portion of thehearth, be it either in theform of an exhaust port for a side fired furnace or a burner port for a bottom fired furnace,;is the fact that it projects upwardly somewhat above thelevel of the hearth and is thereby subjected to the intense heat of the furnace which causes spalling and other failremoved by a crane or other similar hoisting device they are prone to swing about considerably and often strike against this port subjecting it to considerable physical abuse. H

In. the past, because of its prior construction which has been usually in the form of a masonry ring, the port has been subject to early deterioration and destruction due to its many joints and the bumpingof the ingots. Thejoints make the structure less compact, more subject ,to the spread of slag through to-the fiues below and lessresistant to spelling and whenthis structure becomes loose it is easilyv broken by a slight bump from an ingot.

Finally because of the early deterioration in the prior types of portsthey had to be replaced .or repaired several times during the life-f the remainder of the furnace lining. Replacement or repair of this hearth port is a costly opera tiondue, principally, to the factthat itnecessistates coolingwr shuttingidowni of the furnace,

they must be allowed to set and dry, after which they must be cured by the gradual application of heat. All of these steps necessitate a prolonged shut down period during which the furnace is inoperative.

To overcome these disadvantages it has heretofore been proposed to make a complete hearth port ring of a heavy cast steel or cast iron spider over which a plastic chrome material was rammed into place. This ring overcame thedisadvantage of workmen having to spend longer periods in building up a brick ring. It also eliminated the joints but had the disadvantage of utilizing two different materials, one of which has a tendency to shrinkand the other to expand. The metal spider not only tended to expand due to heat, but also derived expansion and growth due to oxidation together with scaling and a large volume increase. Since the plastic chrome was placed directly on this metal,

expansion would cause cracks to open up in the plastic channel which would allow more oxidation and would hasten the destruction ofthe ring or rosette. Accordingly, this type of rosette has not proved entirely satisfactory.

It is the primary objective of the present invention to provide a ring or rosette for soaking pits or the like which will be an improvement over those used in the past which had inherent assembled outside the furnace and then hoisted into position within the furnace, so that a minimum amount of timewill be lost in substituting a new ring for one which has become defective,

and with the result that the overall lengthof time during which a soaking pit is inoperative will be reduced.

Another object of the invention is to provide a rosette for a soaking pit hearth or the like which is adapted, to withstand considerable physical abuse and has high resistance to bumping by the ingots.

A further object of the invention is to provide a rosette for soaking pits which consists of a separate prefabricated, unitary structure for use with either a burner or exhaust opening and which may be entirely constructed outside the soaking pit at any time prior to the necessity for repairs and thereafter placed in operating position within the pit.

A still further object of the invention is to provide a rosette for a soaking pit hearth or the like wherein the refractory bricks comprising the ring or rosette are interlocked with one another so that their joints are compactly and effectively sealed to obviate the risk of slag spreading there through to the flues below.

Another object of the invention is to provide a rosette for a soaking pit or the like having a high resistance to spalling.

These and other objects are achieved by providing a rosette for the port openings of soaking pit hearths comprised of a plurality of refractory rings mounted one upon the other, at least one of said rings being comprised of a plurality of refractory segments which have tongue and groove portions whereby the individual segments of the said ring can be joined together, each of said segments having upstanding portions which engage groove portions in the ring mounted directly above the said segments,

each ring being further provided with vertical shafts which are in alignment with those of the ring mounted immediately therebelow and a metal annulus mounted in an annular groove in the underside portion of the lowermost refractory ring to which the lower extremities of tie rods thrust through said aligned vertical shafts may be threadedly connected in such a manner that when the upper extremities of the tie rods have been aflixed to a yoke, the said rosette may be hoisted into position within said soaking pit.

Other objects and features of the invention will be apparent from a consideration of the following detailed description taken in conjunction with the accompanying drawings, wherein:

Figure 1 is a central, vertical section of a metallurgical furnace or soaking pit wherein a burner port is located in the hearth and it further illustrates the general construction thereof and the application thereto of the rosette embodied in the present invention;

Figure 2 is a perspective view of the partially dismantled rosette shown in Figure 1.

Figure 3 is a perspective view of a modified form of the rosette, shown in Figure 1;

Figure 4 is another sectional View of the rosette shown in Figure 1 to which a yoke has been attached for the purpose of transporting the same into position within the soaking pit;

Figure 5 is a sectional view of another modified form of the rosette;

Figure 6 is a sectional view of the rosette shown in Figure 3.

With further reference to the drawings and particularly Figure 1. a metallurgical furnace or soaking pit is shown as comprising a hearth ID surrounded by a vertical wall H and adapted to be closed at its top by a removable cover not --0f gas or other fuel entering through a. pipe M which is directed upwardly and. centrally of the burner opening. A refractory rosette or ring l5 embraces the port opening and projects upwardly into the soaking pit to the most advantageous height. A plurality of ingots [6 are located about the port and its associated rosette.

This rosette combines with the burner opening to produce the desired shape in the port opening for inducing the proper flow of gas and air into the furnace and obtaining efhcient admixture and combustion thereof.

It is evident therefore that this member or rosette must be so constructed that it will be able to withstand intense heat and the severe physical abuse resulting from charging the furnace with the ingots.

In the preferred embodiment of the invention this rosette is comprised of two refractory rings H and I3, one of which is superposed upon the other. Each of these rings in turn may be comprised of a plurality of p-remolded, interfitting, arcuate, refractory segments 20, having tongue and groove ends or sections 2| and 22, respectively, whereby the aforesaid refractory segments in each individual ring may be securely joined together to form a single compact ring.

The refractory segments of the bottom ring 8? are also provided with an upstanding portion 3 located in substantially the central portion of the top surface of each segment, which serves as a tongue engaging the hollowed out or grooved portions 24 on the underside of each refractory segment which make up the upper ring or rosette 18, thereby providing means for locking the upper ring 18 to the lower ring [1.

By utilizing the aforesaid tongue and groove joints for the ends of the refractory segments in each ring, as well as between the rings themselves all the various elements of the rosette are securely locked together to form a single compact and unitary whole.

In order that provision may be made for hoisting this unit into the pit a metal annulus 25. may be positioned within an annular groove formed by the hollowed out portions 21 on the underside of each refractory brick of the lower ring [1, which hollowed out portions are in open communication with one another when the segments of this ring are assembled together.

By providing vertical shafts 28, in the upper ring [8 which are in opencommunication with similar shafts 29 in the lower ring Il, means are provided, whereby tie rods 30 may be thrust therethrough and thre-aded'ly secured at their lower extremities to the annulus 25. A yoke unit 3| may then be fastened to the upper extremities of the tie rods for hoisting the entire ring into the soaking pit.

Once the rosette has been moved into position in the port opening I2 the tie rods 30 may be unscrewed from steel annulus 25, and then lifted completely out of the rosette by means of the yoke. If this is done the only metal remaining in the rosette then is the metal annulus 25. Since this ring is relatively small in comparison with the rosette as a whole and, since it is mounted within the lower ring I! in such a way that it has suflicient room for expansion, any expansion or oxidation thereof will cause little or no pressure upon the refractory ring 11.

In the event facilities are not available for assembling the rosette as a unit outside the soaking pit, the various refractorysegments having preformed tongue and groove portions may be individually lowered into the soaking pit, where they can "be simply-joined together: to form a rosette by masons working in the pits. Since preformed tongue and roove segments are used the working time of the masons in the pit will obviously be reduced.

As shown in Figures 3, and 6, the lower refractory ring I! may be provided with an upper set back portion 40 along thatpart of its outer periphery which projects above the hearth In. The purpose of this is to reduce the outer circumference of that part of the rosette which projects above the hearth, thereby providing more room within the'soaking pit for the ingots so that their danger of strikingthe rosette is lessened. .The upper ring I8 is accordingly'also constructed with a smaller outer periphery to coincide with the reduced periphery of ring l1.

The'inner peripheries of rings l1 and I8, however, remain constant so that the inner contour of the rosette asa wholewill be uniform and the most favorable for evenly distributing the flame from the burner port into the soaking pit.

Since that portion of the rosette which projects above the level of the hearth is the part of the rosette, which is most subject to deterioration and destruction by contact with the ingots, it may be reinforced by a metal ring 4| as shown in Figure 5. When such a reinforcing metal ring is used in conjunction with the upper refractory ring l8, ring I8 is made in the form of a single, non-sectionalized refractory piece with the reinforcing ring cast therein.

Another advantage of utilizing a reinforcing metal ring in the upper refractory ring l8 lies in the fact that when the upper portion or upper ring of the rosette present within the soaking pit has become damaged it will be a simple matter to replace it without moving or destroying the still good and useful lowermost refractory ring IT. This is brought about by the fact that tie rods 45 can be either Welded or threadedly fastened to ring 4| and a yoke unit affixed to the tie rods 45 for hoisting the new ring IB into position over ring H. In this way a completely new upper unit or ring can then be quickly lowered into the soaking pit to replace the damaged or destroyed upper ring. Alternatively, metal ring 4|, and also tie rods 45 when the latter are welded on, are wrapped or coated with a material which is combustible or volatile when heated under the conditions of use, such as cloth, paper, tar, wax, etc. The removal or destruction of the wrapping or coating material in use has the advantageous effect of providing a free space which will perm-it oxidation or expansion of the metal ring, and rods, in use without causing disruption of the refractory piece. Metal ring 4| can also be constructed as a ring broken, or open, at one place whereby the ends can expand toward or past each other.

Ring l8 with its reinforcing metal ring or band 4| also has an annular depression on its underside, which serves a a groove into which tongues 23 on refractory ring I! fit. As in the case of tie rods 30 once the new ring l8 has been lowered into place the tie rods 45 may then be removed.

The rosette of the instant invention has been described only with reference to a soaking pit which is bottom fired. However, it is obvious that it could be also utilized in a soaking pit which is side fired since in the latter case there would be no change in the structure of the rosette. The only change would be that the burner port shown in Figure 1 would serve as an exhaust opening and further openings would be provided in the ertieai va-11 lower ring by tongue and groove jointsnot in alignment with the jointsin the upper ringor by utilizing a sectionalized lower'ring' andfa solid upper ring or vice versa, through 'joints'in'the rosette are eliminated together with the; risk of having slag seep thereth'rough to"the"flues below. 1

Furthermore by utilizing tongue1 andg'roove joints as the means for strengthening and solidifying the rosette instead-of other means 'the proper inner contour of the rosette can' be maintained for spreading the flame and for obtaining maximum radiation to the ingots, when t is used as a burner port. Other arrangements of tongue and* groove joints may be used as Well as those described and shown in the drawings and it is also within the contemplation of the invention to construct the rosette in the form of a single ring made up of a plurality of refractory segments united together by means of tongue and groove joints.

In the claims the word ring includes not only refractory layers made in the form of a circle, but also those which may be made in the form of a rectangle, square, triangle, etc.

Various changes and modifications may be made in the invention without departing from the spirit and scope thereof and accordingly it is not to be limited except by the appended claims.

What is claimed is:

1. The improvement in rosettes for the port opening of a soaking pit hearth comprising the combination of a plurality of refractory rings, placed one upon the other, each of said rings being comprised of a plurality of refractory segments, each one of which has tongue and groove portions, whereby the individual segments and the rings formed by said segments can be joined together as a removable unit, certain of said segments in one ring being further provided with vertical shafts, which are in alignment with similar shafts located in the ring immediately therebelow, and a metal annulus mounted in an annular groove in the underside portion of the lowermost refractory ring to which the lower extremities of tie rods thrust through said aligned vertical shafts may be threadedly connected in such a manner that when the upper extremities of the tie rods have been aiiixed to a yoke, the said rosette may be hoisted into position within said soaking pit.

2. The improvement in rosettes for soaking pit hearths comprising the combination of a plurality of refractory rings mounted one upon the other, the lowermost ring being comprised of a plurality of refractory segments which have tongue and groove portions whereby the individual segments of said ring can be joined together, said segments also having upstanding portions engaging roove portions in the refractory ring mounted directly above the said segments, a reinforcing metal ring located within said uppermost refractory ring, each refractory ring being further provided with vertical shafts which are in alignment with those of the ring mounted immediately therebelow and a metal annulus mounted in an annular groove in the underside portion of the lowermost refractory ring to which the lower extremities of tie rods thrust through said aligned vertical shafts may be threadedly connected in such a manner that when the upper extremities of said tie rods have been affixed to a yoke, the said rosette may be hoisted into position within said soaking pit.

3. The improvement in rosettes for soaking pit hearths comprising the combination of a plurality .01?v refractory rings mounted one upon the other,

. ring located within the uppermost refractory ring,

means for affixing said metal ring in said uppermost refractory ring to a hoisting unit, and means for affixing the entire plurality of refractory rings comprising said rosette to a second hoisting unit, said metal ring and said means for affixing said metal ring to a hoisting unit being coated with a material removable by heat.

LESLIE W. AUSTIN. JOHN D. ISAACS.

REFERENCES CITED I'he followlng references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 86,796 Absterdam Feb. 9, 1869 898,348 Fieldhouse Sept. 8, 1908 1,068,259 Mesick July 22, 1913 1,406,746 McCullough Feb. 14, 1922 1,417,959 Walther May 30, 1922 1,696,876 Bacon Dec. 25, 1928 1,832,873 Milner Nov..24, 1931 1,843,175 Sears Feb. 2, 1932 1,873,549 Cofiey Aug. 23, 1932 2,124,888 Morton et al July 26, 1938 2,297,696 Elder et a1 Oct. 6, 1942

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