US2840046A - Metallic skewback beam - Google Patents

Description

June 24, 1958 E. w. POTTMEYER 2,840,046

METALLIC SKEWBACK BEAM Filed June 1, 1955 :5 Sheets-Sheet 1 FIG.I.

INVENTOR EDWARD W f POTTMEYER June 24, 1958 E, w. POTTMEYER 2,840,046

METALLIC SKEWBACK BEAM Filed June 1, 1955 3 Sheets-Sheet 3 u 28 2Q" INVENTOR 52 5 D 36 EDWARD W POTTMEYER as" 29" A United States Patent METALLIC SKEWBACK BEAM Edward W. Pottmeyer, Pittsburgh, Pa., assignor to 'Blaw- Knox Company, Pittsburgh, Pa., a corporation of Delaware Application June 1, 1955, Serial No. 512,454

1 Claim. (Cl. 122-6) This invention relates to a new skewback member made of metal, preferably ferrous metal, for use in openhearth furnaces or the like. More particularly, this invention pertains to a new unitary metallic skewback shape with compartmented cooling provision and structural beam strength for supporting the roof of such an open-hearth furnace or the like.

In an open-hearth steel-making furnace, for example, the framework and binding are made of structural steel members. Such framework and binding are usually protected by refractory walls, hearth and roof constructed inwardly of such structural steel, said refractory members defining the furnace space. A common practice in connection with such a roof is to arch it from front to back and to support the outermost course at the joint along the top of the front and back walls with a wedgeshaped refractory member termed a skewback, as illustrated in United States Patent No. 1,864,762. The strength limitations of a refractory skewback are known and a skewback structure steel channel was usually employed to back up such refractory skewbacks whenever there was a significant roof thrust upon the skewback. It was also a common practice to try to protect such refractory skewbacks where there was exposure thereof to the furnace heat, such as would occur in the span across a charging door and a frequent provision included a water-cooled ledge projecting from the door frame of the furnace. Even so, such refractory skewbacks constituted a relatively expensive refractory shape and remained subject to deterioration and replacement.

Further, attempts were made from time to time because of limitations of refractory skewbacks, to provide substitute metallic devices, two such disclosures being set forth in United States Patents Nos. 2,294,946 and 2,321,074. Such metallic devices, however, have not heretofore been able to resolve the skewback problem and were subject to expansion and contraction disadvantages, to the absence of or non-uniformity in temperature control, to deformation in some cases and to other problems.

In this invention, the disadvantages and deficiencies of prior refractory skewbacks and metallic devices, have been overcome. Thus, in my invention, a new metallic skewback is provided which is a unitary beam, preferably of steel, which may be fastened directly to the buckstays of an open-hearth furnace or the like or otherwise connected to the steel framework of such a furnace. Thereby, my new skewback beam avoids the use of the relatively expensive and fragile refractory skewback of prior practices and eliminates the need for a separate'skewback channel. Indeed, my new skewback represents an increased section modulus about a vertical neutral axis with resultant greater stiffness and rigidity even though the span between the furnace buckstays should be lengthened; and as against prior metallic devices, my invention is not only relatively simpler and easier to fabricate, but it achieves a new result in troublefree operation by comto deteriorate when exposed to furnace heat.

2,840,046 Patented June .24, 1 958 ice partmented cooling coupled with a uniformity of thermal character which not only makes my new skewback beam longer lived but also reduces the tendency of a skewback Still further, my new skewback is compatible with the adjoining refractory roof and wall structure so that neither exercise any detrimental effect upon the other because of the different temperatures and materials of which they are made.

Additionally, my new skewback beam may be used in furnaces employing an archless type of charging opening and without any water-cooled ledge on the door frame, since my new skewback beam is self-protecting.

Other objects and advantages of this invention will be apparent from the following description and from the accompanying drawings, which are illustrative only, in which Figure 1 is a view in front elevation of a charging opening section of an open-hearth furnace utilizing one. embodiment of my new skewback beam;

Figure 2. is a view in section taken along line IIII of Figure 1;

Figure 3 is a plan view of the structure shown in Figures 1 and 2 with arched roof portions being omitted for clarity of presentation;

Figure 4 is a view in rear elevation, with parts broken away, of the embodiment of my new metallic skewback beam which is also illustrated in Figures 1 to 3;

Figure 5 is an end view taken along line AA of Figure 5;

Figure 6 is a view taken along line BB of Figure 4;

Figure 7 is a view taken along line C-C of Figure 4;

Figure 8 is a view taken along line D-D of Figure 4;

Figure 9 is a view in rear elevation, with parts broken away, of a modified embodiment of my new metallic skewback beam;

Figure 10 is an end view taken along line X-X of Figure 9;

Figure 11 is a view in section taken along line XI-XI of Figure 9;

' Figure 12 is a view in rear elevation of a still further modification of an embodiment of my new metallic skewback beam; and

Figure 13 is a View in section taken along line XIII- XIII of Figure 12.

Referring to the drawings, Figures 1, 2 and 3 illustrate a portion of an open-hearth furnace employing one embodiment of my invention. Therein, structural framework of such a furnace will usually include buckstays 10, each of which may comprise spaced posts 11 of steel with structural steel channels 12 respectively aflixed thereto in opposed spaced relation, such buckstays being joined laterally and transversely in most cases by other structural members to complete the structural steel binding for such a furnace. A doorframe 13 is positioned between adjacent buckstays 10 at the front of the furnace, said doorframe having a water-cooled lintel 14 and watercooled legs 15. The legs or jambs 15 and lintel 14 of doorframe 13 define a charging door opening 16 which normally is closed by a furnace charging door 17. A sill 18 resting on furnace breastwork 19 forms the-lower portion of the door opening 16.

A new skewback beam 26 of this invention in the illustrated embodiment being described is provided with studs 21 welded or otherwise afiixed to the back of beam 20. Studs 21 may extend through the middle of each buckstay 10 between the channels 12 and through a retainer plate 22 drawn tightly against the outer flanges of the channels 12 of the respective buckstays 10 by nuts 23 engaging the outer threaded ends of the studs 21.

The underside of my new skewback beam 20 may be supported on each side of door opening 16 by refractory furnacewall 24. A plurality of my new skewback beams front edge of a refractory furnace roof 25 which in the illustrated embodiment is a ribbed roof having ribs 26 which may also receive at least partial support at the front ends thereof by" abutting. the front or slanting face 28 of my new skewback beams 20. A similar series of skewback'beams 20 may extend across the back of the open-hearth furnace, which is only partly illustrated in Figures 1 to 3, to correspondingly support the lower back edge of the roof 25. on the other hand, conventional skewbacks may be utilized in part of such furnace where roof or other stresses are less severe.

In the embodiment of my new skewback beam 20 illustrated in Figures 1 to 8, inclusive, the new device is preferablyfabricated from steel plate and strip and the parts thereof affixed together as by Welding. Thus, skewback beam 20 has an outer shell 27 of relatively uniform thickness which is triangular in cross section and preferably may take the form of a right angle triangle. The mode of bending, shaping and welding to fabricate such new skewback beams from steel plate and strip will be readily apparent to those to whom thisinve'ntion is disclosed. Hence, shell 27 has a front or skewback face 28, a bottom or base.29 and a back 30. The front angle or corner 31 is preferably curved whereas the top angle 32 and back angle 33 may be rounded or sharp as desired. In the embodiment illustrated in Figures 1 to 8, the back corner 33 is a relatively sharp right angle whereas the top corner where the front wall'28 and back wall 30 join is a rounded curve produced in the fabrication and shaping thereof.

The relatively uniform thickness at least of walls 28 and 29 assists in the avoidance of thermal differentials in the course of the functioning of my new skewback beams 20. The ends of shell 27 are closed by end plates 34 so that cooling fluid, usually water, may be circulated through the interior of shell 27.to protect my new skewback beam' from being burned away during the operation of a furnace or the like where extreme heat is encountered.

I have also discovered that my new skewback requires compartmentation. This, in skewback beam 20, a lower compartment 35 protects the highly exposed area in the region of front corner 31 and bottomrwall 29 while an upper compartment 36 which may be somewhat larger dissipates heat received through the balance of the shell 27. Compartment 35 is separated from compartment 36 by a solid partition 37 made of steel plate strip of appropriate dimensions, the partition 37 being welded around its edges to fix it in place in the beam 20.

A vertical battle 38 is preferably also provided extending between partition 37 and bottom wall 29. Preferably vertical bafile 38 is nearerfront wall 28 and front corner 31 than its back wall 30. The ends 39 of baffie 38 terminate so that a circulation passage 40 exists between such ends 39 and the respectively adjacent end plates 34 in compartment 35. Thereby, compartment 35 is divided into a forward section 35a and a rearward section 35b.

An internally threaded inlet fitting 41 may be welded to top corner 32 in registry with an opening through shell 27 leading into a pipe 42 extending downwardly through an opening therefor in partition 37. A nozzle 43 may be connected to the lower end of pipe 42 to discharge cooling water from a point approximately midway between end plates 34 into section 35a. may have constricted ends 44 to jet such cooling water and increase its velocity of flow from the middle of section 35a in compartment35 to the ends thereof where such water passes through the passages 40 and returns via section 35!) of compartment 35 to an outlet pipe 45. Pipe 45 extends between an outlet opening in partition 37andan outlet opening through shell 27 in top corner Nozzle 43 r 32 where an internally threaded outlet fitting 46 is welded to shell 27.

In one operation, a separate stream of cooling water thereby enters compartment 35 through fitting 41 and leaves compartment 35 through fitting 46 after being forced to flow at relatively good velocity, particularly through the more exposed section 35a of compartment 35. In such operation, further, compartment 35 is entirely filled at all times with such moving cooling water. Normally, inlet '41 will be connected to the regular plant 'or mill water line.

If desired, the inlet and outlet pipes 42 and 45 respectively may be connected to an independent source of cooling fluid separate from the plant water line so that any desired extent of cooling in compartment 35 may be achieved, or means may be utilized to provide the extent of or to vary cooling as desired, particularly across the inside of the region of front corner 31 and of bottom wall 29.

Moreover, all such cooling will be relatively uniform and will not subject my new skewback beam to cracking or deterioration in that thermal paths through the metal of my new skewback beam are relatively uniform and readily accessible at all exposed areas to the cooling fluid. As an adidtional consequence, a refractory roof, like roof 25, will tend to receive uniform support without likelihood of cracking or spallingthcreof due to excessive expansion and contraction differentials.

Such uniform thermal regulation of my new skewback beam, like beam 20, is further provided in that compartment 36 is also cooled in service in a manner which may be similar to the cooling provided for compartment 35. 7 Thus, compartment 36, in the embodiment shown, is made into a lower section 360 and an upper section 36d by a horizontal guide plate 47. Horizontal guide plate 47 extends between the inside of front wall 28 and the inside of back wall 30, as shown in Figures 2 and 5 to 8. Guide plate 47 may be in two parts with the inner ends 48 thereof spaced apart sutficiently for the passage of pipes 42, 45 and an inlet pipe 49 for cooling water intended for compartment 36. The outer ends 50 .of guide plate 47 are spaced from the respectively adjacent end plates 34 to form passages 51 between lower compartment section 36c and upper compartment section 36d.

An inlet fitting 52, which is internally threaded, is fastened to top corner 32 in registry with an opening through shell 27 for communication with the upper end of pipe 49. The lower end of pipe 49 is connected to and communicates with the interior of a nozzle 53 which is similar in construction and operation to nozzle 43. Hence, as cooling water is jetted by the ends 54 of nozzles 53 toward end plates 34 in section 36c, the cooling water cools compartment 360 and passes upwardly through the passages 51 into section 36d and toward an outlet defined by internally threaded outlet fitting 55 welded to an opening through shell 27.

In the course of such an operation, some cooling water may enter section 360 from section 36d through the space between ends 48 in the manner of a partial recirculation due to the jetting action that may be induced if constricted ends 54 are used on nozzle 53. Again, during operation of beam 20, cooling water entirely fills all parts of compartment 36. The source of cooling fluid for compartment 36 may be the same source as for compartment 35, such as a manifold water supply pipe 56, or the sources may be independent if desired. Similarly, the outlet cooling fluid flows from the respective compartments may pass into a common manifold 57 or go to separate outlet facilities.

The partition 37 taken with the shell 27 of my new skewback beam provides for a relatively smaller weight of metal, with a relatively greater section modulus about a vertical axis. Thereby, a skewback beam, like beam 20, may be utilized to increase the permissible span between buckstays and would also permit wider charging door openings. In addition, such a relatively more rigid beam, like my newv beam 20, gives greater trouble-free operation from any tendency to deflect horizontally and impair the fitting between a doorframe, like doorframe 13, and the back face 30 of beam 20. Elements like baflle 38 and guide plate 47 in my new construction augment the stiffness and rigidity provided by my new skewback beam.

Further, my new skewback beam provides materially longer life and greater strength in service with complete self-protection of my new skewback beam. The separate compartments 35 and 36 in my new skewback beams also permit operation of one or the other compartments, in the event of a failure of the cooling fluid supplied to the remaining compartment, for at least a sutficient period to restore the cut-ofl cooling fluid supply with the result that furnace operation may be able to continue without having to shut down in the midst of a furnace heat.

A modification of my invention is illustrated in Figures 9 to 11, inclusive, wherein parts thereof generally similar in structure and functioning are provided with the same reference numerals with the addition of a prime factor thereto. In skewback beam provision is made for the inlet and outlet of cooling fluid respectively to compartments 35 and 36' through back wall which may be more convenient for certain types of furnace piping layouts. In addition, bathe 38 has spaced inner ends 38a between which pipe 42' passes perpendicular to back wall 30' to supply nozzle 43 with cooling water for discharge into section a of compartment 35. In the case of compartment 35', the cooling fluid exits through fitting 46' at the opposite end of compartment 35' from fitting 41'. Further, above top corner 32', beam 20' is provided with an integral hanger strip 58 with holes 59 therein for afiixation to a transverse structural member on the structural binding. Rearwardly extending side plates 60, which may form a continuation of end plates 34, are also punched to enable beam 20f to be aflixed to the sides of the adjoining backstays where beam 20 is to be used.

A still further modification of this invention is illustrated in Figures 12 and 13 wherein parts having the same general structure and function are provided with the same reference numerals as those applied respectively in Figures 1 to 8, with the addition of a double prime factor thereto. In the modification of Figures 12 and 13, a structural beam 61, which may' be provided with lugs 62 for the hanging thereof from the steel superstructure of a furnace or the like, has the lower portion thereof constructed as a new skewback beam 20" with a lower compartment 35" and an upper compartment 36". Circulation of cooling water through each of those compartments is obtained Without the employment of nozzles by having water flow through the respectively independent compartments from one end to the other for cooling purposes. The water or cooling fluid for each compartment may be either from a common source or from distinct sources. As shown, the flow in the compartments 35" and 36" is in the same direction but, if desired, the flow of cooling fluid through those respective compartments may be in opposite directions.

Various modifications may be made in the details of my new skewback beam construction without departing from the spirit of this invention or the scope of the appended claim.

I claim:

In a fabricated metal skewback beam, in combination,

an elongated hollow shell being substantially in the form of a right angle triangle in section, said shell having the front and bottom walls thereof of relatively uniform thickness with at least the lower front angle of convex curvature along the joint between the front and bottom walls thereof, the front wall of said shell being upwardly and rearwardly inclined, a solid partition fastened to the front and back walls and'dividing the interior of said shell into upper and lower compartments extending across the thickness of said section, each such compartment having a'separate set of inlet and outlet openings communicating therewith through said shell, said openings being adapted for the flow of a cooling liquid for the separate and respective cooling of said compartments, a baflie positioned at least in said lower compartment, said bafile being positioned generally along and rearwardly of the inside of said front angle to provide forward and rear circulatory sections in said lower compartment communicating with each other, the circulatory section nearer said front angle in said lowercornpartrnent being of lesser cross-sectional area than the cross-sectional area of said other circulatory section in said lower compartment, and nozzle means communicating with the inlet opening to said lower compartment to discharge incoming cooling liquid into the circulatory section between said baflle and said front angle.

References Cited in the file of this patent UNITED STATES PATENTS 1,275,943 Knox Aug. 13, 1918 1,529,193 Lewis Mar. 10, 1925 1,915,398 Bedell June 27, 1933 2,321,074 Fon Dersmith June 8, 1943 2,552,142. Braun May 8, 1951

Images