US2749107A - Insulated water-cooled furnace members - Google Patents

Description

June 1956 J. w. coRRlsToN.

INSULATED WATER-*COOLED FURNACE MEMBERS Filed April 24. 1952 2 Sheets-Sheet l JOH/V w/z so/y (owe/5 70% BY fl ///S A T TOP/VHO June 5, 1956 J. w. CORRISTON INSULATED WATER-COOLED FURNACE MEMBERS 2 Sheets-Sheet 2 Filed April 24. 1952 INVENTOR. Joly/Y IV/150A (OPE/570 WM INSULATED WATER-COOLED FURNACE MEMBERS .iohn Wilson Corriston, Springfield, Pa.

Application April 24, 1952, Serial No. 284,079

14 tllaims. (Cl. 263-6) The present invention relates to heating furnaces such as are commonly employed in the metallurgical industries and is concerned primarily with the water-cooled pipes which function as skid rails or stock supports in such furnaces.

At the present time, it is common practice in the steel and other metal industries to move stock in the form of billets, slabs and the like through a furnace for heat treatment purposes. Skid rails and stock supports are ordinarily provided for the purpose of supporting the work as it is moved through the furnace. Due to the high temperatures which obtain in such furnaces, it has been the practice to employ Water-cooled tubes as the work supporting elements. Moreover, during recent years, because of-high fuel and repaircosts, it has been recognized as 'desirable'to insulate these tubes of pipes by applying a lining or covering of refractory material thereover. In the patent to J. W. Corriston, Number 2,022,649 dated December 3, .1935, there is illustrated and decribed an arrangement whereby a plastic refractory is applied and held in position on such water-cooled pipes by the studs which are full Welded directly to the pipe and outstand therefrom. In addition, the covering of high heat-and slag resistant insulation acts to protect the surface of the piping from deterioration from-the hot and corrosive gases of the furnace.

The present invention, has in Vii-3W, as its foremost objective the provision of a novel and improved structural arrangement for securing these studs in effective position by which the piping is further protected by enclosing the same in an impervious metal sheathing.

In accordance with present day practice, such stud is individually and fully welded in position on .the water- 'cooled pipe. When it is considered that in many instancesthesepipes are already installed in finished rfurnaces it is evident that there is great delay and loss of valuable production time, as ell as much difficulty, experienced, in welding these studs'in theirprcpcr positions.

With the foregoing conditions in mind, the present invention has in view, as another important objective, the provision of a'heatin'g furnace of the character indicated in which a Water-cooled pipe has secured thereto one or more intermediate units, each of which carries a plurality of studs.

Another object of the invention is'to provide, in a heating furnace of the type noted, a multiple stud unit which is shaped to conform '"tolthe contour of the pipe to which it is applied and which is se'cure'd to the pipe in any prefen'edm'anner as bytack welding at appropriate points.

In carrying out the above noted idea in a practical embodiment, the intermediate multiple stud units are provided in complemental semicircular pairs With'each-pair being adapted to encompass any' particular pipe section.

Still another object of the invention ist'o provide an intermediate multi-stud unit of the type aforesaid which is prefabricated by securing the stud members in posi- 2,749,107 Patented June 5, 1956 tion thereon in any preferred manner such as by full welding. This prefabrication may be carried out at any convenient location; and, after it is accomplished, the prefabricated multiple stud units may be readily applied to water-cooled pipes which have already been installed in a furnace.

With the base plate of each multiple stud unit, having a contour substantially conforming to the curvature of the pipe to which it is applied, good heat transfer is definitely assured. This heat transfer includes radiation, convection, and conduction. It may be that some areas of poor contact, or air gaps will be created; but, for the main part, there is sufficient close relation to insure of good heat transfer by radiation, which however is supplemented by the areas of tack weldingand the additional transfer across the air gaps by convection.

From the foregoing .it is apparent that the multi-stud units are provided as elements separate from the pipe about which they are applied. Under-conditions of actual usage, changes in temperature within any furnace may cause the base plates of the multi-stud units to expand or contract at a rate different from comparable changes in the pipe. Thus another highly important object is to provide, in a metallurgical heating furnace of the type noted, an arrangement whereby the multi-stud units are secured in position about the pipes in such a manner as to accommodate such expansion and contraction.

Various other more detailedobjects and advantages of the invention .such as arise in connection with carrying out the above .noted ideas ina practical embodimentwill, in part, become apparent,-:and, in part, be hereinafter stated as the description of the invention proceeds.

The'invention, therefore, comprises a water-cooled pipe that is included in aheating furnace ofthe typeemployed mthe'metallurgical industries and which-pipe has applied thereto a plastic refractory lining which is maintainedlin position by intermediate :multi-stud units which are prefabricated and have base plates that conform .to the curvature of the pipe. These multi-stud units aretack welded to the water-cooled pipe, and-in some instances in sucha manner as to accommodate differences in the'rate' of expansion or contraction of the base plates as compared to thepipe.

For a' full andmore'complete understanding o'f'the' invention, reference maybe had to the foll'oviing'description and accompanying drawings wherein:

Figure '1 is a perspective view of a portion of a heating furnace including skid rails which are covered with'a r'evfractory lining in' accordance with the precepts of this invention.

Figure'Z is a sectional view taken on an enlarged scale through one of the water-cooled skid rails and showing the multi-stud units in exploded relation.

Figure 3 is another enlarged detailed section through one of the skid-rails showing the rnulti-stud units-in e'ifective position and with the refractory lining applied-thereover.

Figure 4 is a view partially'in a section andpartially in elevation taken normal to the showing of Figure 3.

Figure 5 is a detailed transverse 'section through one modification; and

Figure '6 is a similansectio'n through another modifi cation.

Referring now to the drawings wherein like reference characters denote corresponding parts and, first, more particularly to 'Figure l a portion of a heatingfurnace is thereillustrated. It is to be understood that this heating .furnace is of the type commonly employed in the steel or comparable metallurgical-industries for the purpose of :heating stock in the form of billets of slabs-whereby it is adapted to subsequent forming processes;

The furnace includes a horizontal wall and a vertical wall 11. Extending upwardly through openings formed in the horizontal wall 10 are a plurality of vertical pipes 12 which project into the interior of the furnace. The upper ends of the pipes 12 support a pair of horizontal skid rails 13. Moreover, the pipes 12 communicate with the hollow skid rails 13 so that a cooling medium such as water may circulate therethrough. Those portions of the vertical pipes 12 which are located within the interior of the furnace are covered with a refractory lining. This is also true of the skid rails 13 and cross members 14. In accordance with the present invention, this refractory lining is of the plastic type having a chrome base. The present invention is concerned primarily with the structural arrangement provided for the purpose of accommodating this chrome refractory.

Referring now, more particularly to Figure 2, each skid rail 13 is shown as including a rib 15 of generally circular cross section which is formed therewith or attached thereto at the top, as shown in Figure 1. The work which is represented by a billet 16 contacts the exposed surfaces of the ribs 15 as it rides over the skid rails.

A pair of complemental multi-stud units are illustrated in Figure 2 and are referred to in their entirety by the reference characters A and B. These multi-stud units are substantial duplicates and only one of them is described in detail as that is believed to be sufficient for the purposes of the specification.

The multi-stud unit A comprises a base plate 17 which is generally semicylindrical in formation and has an inner curved surface 18 which is shaped to substantially conform to the outer contour of the skid rail 13. This base plate 17 has an extent slightly less than one hundred and eighty degrees because of the presence of the rib 15. Outstanding from the outer surface 19 of the base plate 17 are a plurality of metallic studs 20. Each of these studs 20 is formed with a ring-like rib 21 intermediate its ends to improve the holding effects on the chrome refractory which is applied thereover and to improve the efficiency of heat transfer from the refractory. The studs 20 are substantially all alike and the inner end of each stud may be secured to the outer surface 19 of the base plate 17 in any preferred manner, although the invention has particularly in mind the full welding of the inner end of each stud to the base plate, the welded joint being indicated at 22. It is essential that this weld be complete and thermally effective, in order to give full metallic contact and maximum heat transfer from stud 20 to plate 17.

It will be understood that the multi-stud units A and B will be prefabricated at any convenient location. They are then applied over the skid rail 13 in the manner depicted in Figures 3 and 4. After being so positioned, the base plates 17 are tack welded along their upper edges to the rib 15 as indicated at 23 and along their lower edges to the skid rail 13 as indicated at 24. This tack welding serves to securely anchor the units A and B in position over the skid rail 13. The chrome refractory which is represented at 25 is now applied in a plastic condition over the units in the manner illustrated in Figures 3 and 4 to a thickness which is determined by the length of the studs 20. After this refractory has dried and set, the skid rails will be in position to accommodate the work pieces 16.

It will be understood that the vertical pipes 12 are covered with pairs of complemental semicylindrical' multistud units in exactly the same way above described with the possible exception that the base plates will have an extent more closely approaching a semicircle due to the fact that the ribs 15 are not included in the vertical pipes. Instead of being tack welded to the pipe 12, the base plates 17 may have their edges in abutting relation at either one or both of the seams with the joint being rendered permanent by a butt weld 25.

The studs 20 serve dual functions, in the first instance they actually secure and anchor the refractory lining 25 in position and in the second instance they actually protect and prolong the life of the lining itself by conducting heat away from the lining and transferring it to the cooling medium. In order to perform this latter function, there must be good heat transfer between the studs 20 and the skid rail 13. This heat transfer is provided by the high degree of metallic contact through the welded joints of the studs 20 to the plates 17. The heat then dissipates rapidly throughout said plates, the aggregate surface area of which is greater than the aggregate end areas of the attached studs at their points of attachment.

In consequence of the above, the highly heated stud is prevented from being rapidly burned or oxidized away from the heat of the furnace, since its heat is dissipated into a relatively large area of formed plate which, in turn, transfers its heat to a comparable area of relatively cold pipe surface, and thence to the cooling liquid within.

Referring now more particularly to Figure 5, the rib 15 of the skid rail 13 is shown as being provided with a pair of outwardly extending flanges or lips 26 which are spaced from the rail 13 a distance corresponding to the thickness of the base plates 17. In this embodiment, the tack welds 23 are not used and the upper edges of the plates 17 are simply inserted beneath these lips 17. They are tack welded at the bottom as indicated at 24. Thus, an expansion joint at the upper edge of each plate 17 is provided.

In Figure 6 the pipe 12 is shown as having a connecting strip 27 of T cross section secured longitudinally therealong. This strip 27 presents the flanges or legs 28 within which the edges of the plates 17 are inserted. The opposite edges of this plate may be in abutting relation as illustrated and butt welded together as shown at 27. Thus there is an expansion joint for each plate 17 at the strip 27.

In both Figures 5 and 6, the edges of the plates are never fully inserted beneath the lips 26 or 28. Thus there is always a space between the edge of the plate 17 and the rib 15 or the leg of the T strip 27 as the case may be. It is this space that accommodates expansion of the plate relative to the pipe 12 or skid rail 13.

While preferred specific embodiments of the invention are hereinbefore set forth, it is to be clearly understood that the invention is not to be limited to the exact constructions, mechanisms, and devices illustrated and described, because various modifications of these details may be provided in putting the invention into practice within the purview of the appended claims.

What is claimed is:

I. In a heating furnace, a water-cooled tubular work support, an intermediate multi-stud unit applied to said work support, and, a plastic refractory lining applied over said multi-stud unit, said unit lying in direct contact with said work support to effect a transfer of heat away from the refractory to prolong the life thereof.

2. In a heating furnace, a water-cooled tubular work support having an outer cylindrical surface, a multi-stud unit including a base plate having an inner curved surface conforming in curvature to the outer surface of said support, said multi-stud unit being secured in position over said support in direct contact therewith to effect an efiicient transfer of heat, and a refractory lining carried by said multi-stud unit, the studs of said unit extending through the refractory lining with the ends thereof flush with the surface of said lining.

3. In a heating furnace, a water-cooled skid rail having an outer cylindrical surface that is interrupted at the top by a work supporting rib, a pair of complemental multistud units applied about said skid rail and tack welded to said rib at the top, and a refractory lining carried by said units, said units lying in direct contact with said work support to effect a transfer of heat away from the refractory to prolong the life thereof.

4. A multi-stud unit adapted for application to a watercooled tubular support in a heating furnace, said unit comprising a semi-cylindrical base plate for circumscribing said support in direct surface contact therewith to efliect an efficient heat transfer, and a plurality of studs, carried by, and outstanding from said base plate.

5. A multi-stud unit adapted for application to a watercooled tubular support in a heating furnace, said unit comprising a semi-cylindrical base plate having an inner curved surface shaped to conform to the outer contour of said support in direct surface contact therewith to effect an efiicient heat transfer, and a plurality of studs outstanding from said base plate with the inner end of each stud being full welded to the base plate.

6. A multi-stud unit adapted for application to a watercooled tubular support in a heating furnace, said unit comprising a semi-cylindrical base plate for circumscribing said support in direct surface contact therewith to effect an efficient heat transfer, and a plurality of studs outstanding from said base plate with each stud having an intermediate ring-like rib.

7. A multi-stud unit adapted for application to a watercooled tubular support in a heating furnace, said unit comprising a semi-cylindrical base plate having an inner curved surface shaped to conform to the outer contour of said support in direct surface contact therewith to effect an efiicient heat transfer, a plurality of studs outstanding from each base plate in spaced relation, and with the inner end of each stud Welded to said base plate, and a ring-like rib intermediate to the ends of each stud.

8. In a heating furnace, a water-cooled skid rail having an outer cylindrical surface interrupted by a work engaging rib at the top, a pair of complemental multi-stud units tack welded to said skid rail, each of said multistud units comprising a semi-cylindrical base plate having an inner surface conforming in shape to the outer surface of said skid rail for making direct surface contact therewith to etfect an efiicient heat transfer, a plurality of studs outstanding from the outer surface of said base plate with each stud having its inner end welded to said base plate, a ring-like rib on each stud intermediate to the ends thereof, and a plastic refractory lining applied over said studs and held in position thereby.

9. In a heating furnace, a water-cooled pipe having an outer cylindrical surface, a pair of complemental multistud units applied about said pipe, each of said units including a base plate in surface contact with said pipe and with one edge of one base plate butt welded to the confronting edge of the other base plate, means at the other edges of said base plates for anchoring them to said pipe, and a refractory lining carried by said units.

10. In a heating furnace, a water-cooled pipe having an outer cylindrical surface, a pair of complemental multistud units applied about said pipe, each of said units including a base plate in surface contact with said pipe and with the edges of one base plate butt welded to the edges of the other base plate, and a refractory lining carried by said units.

11. In a heating furnace, a water-cooled skid rail having an outer cylindrical surface that is interrupted at the top by a work supporting rib, a pair of complemental multi-stud units applied about said skid rail, an expansion joint between an edge of each of said units and said rib, means for securing the other edges of said uints to said skid rail, and a refractory lining carried by said units.

12. In a heating furnace, a Water-cooled skid rail having an outer cylindrical surface that is interrupted at the top by a work supporting rib, a lip outstanding from each side of said rib and spaced from said cylindrical surface, a pair of complemental multi-stud units each having a base plate with an edge inserted beneath one of said lips, means for anchoring the other edge of each plate to said skid rail, and a refractory lining carried by said units.

13. in a heating furnace, a water-cooled pipe having an outer cylindrical surface, a pair of complemental multistud units applied about said pipe, each of said units including a base plate in surface contact with said pipe, at strip of T cross section secured to said pipe and extending longitudinally therealong, said strip presenting an outwardly extending lip at each side thereof, each of said plates having an edge inserted beneath one of said lips, means for anchoring the other edge of each base plate to said pipe, and a refractory lining carried by said units.

14. In a heating furnace, a water-cooled pipe having an outer cylindrical surface, a pair of complemental multistud units applied about said pipe, each of said units including a base plate in surface contact with said pipe and with one edge of one base plate butt welded to the confronting edge of the other base plate, and a strip of T cross section attached to said pipe for securing the other edges of said plates to said pipe by expansion joints, and a refractory lining carried by said units.

References Cited in the file of this patent UNITED STATES PATENTS 2,022,649 Corriston Dec. 3, 1935 2,142,542 Wallach Jan. 3, 1949 2,482,878 Schmidt Sept. 27, 1949 2,563,883 Strickland, Jr Aug. 14, 1951 FOREIGN PATENTS 467,553 Great Britain June 18, 1937 OTHER REFERENCES Page 336 of Trinks Industrial Furnaces, vol. 1, 4th edition, Copyright 1951. This text is published by John Wiley and Sons, Inc., New York, N. Y.

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