USRE24606E - robinson r - Google Patents

Description

Feb. 24, '1959 G. ROBINSON Re. 24,606

" \REPLACEABLE2 SUPPORT F'OR REFRACTORY LINING OFF'URNACE DOORS original Fiied sept. 28,1949 y 2' sheets-sheet 1 l l' i* Y f .74h 20 2'1 A17 14h L11 21 20 a 1 fly. s.

50 l l @dem l 4|- l I 14 14a z5 55 :4b 25 12 y lNVENTOl? Geo/'ge L. Robinson Feb. 24, 1959 Re. 24,606

REPLACEABLE SUPPORT FOR REFRACTORY LINING 0F FURNACE DOORSl G. L. ROBINSON 2 Sheets-Sheet 2 original Filed sept. 28, 1949 United States Patent() I REPLACEABLE SUPPORT FOR REFRACTORY f LINING OF FURNACE DOORS George L. Robinson, Pittsburgh, Pa., assignor, by mesne assignments, to Blaw-Knox Company, Pittsburgh, Pa., a corporationof Delaware Original No. 2,673,533, dated March 30, 1954, Serial No. Y

. 118,336, September 28, 1949. Application for reissue l November 14, 1956, Serial No. 622,233

8 Claims. (Cl. 110-173) Matter enclosed in heavy brackets [1 appears in the original patent but forms no part of this reissue specilicalion; matter printed in italics indicates the additions made by reissue.

This invention relates to replaceable supports, that is, anchor members for the refractory lining of furnace doors. More particularly, it pertains to a socket and replaceable anchor stud combination for plastic refractory lined furnace doors such as those used on open-hearth furnaces.

It is customary to line water-cooled furnace doors with a plastic refractory cast in the hollow recess of the door, and to secure the lining to the door by means of metal studs projecting from the face of the door and embedded in the refractory, the studs being secured to the face of the door by some means. The refractory lining and the studs are consumed or eroded away by action of the hot furnace gases, and require replacement after about one to three months of service. The furnace vdoor `itself may last about four to ve years before it must be replaced. YA typical steel mill may have about ten to 'twelve furnaces, each with live doors. If these doors require relining at about six week intervals, it is evident that about nine'or ten of these doors may have to be relined each week. It is apparent, therefore, that a new construction and manner of fastening anchor studs which increases the ease and economy of re-studding and re-lining a furnace door is important.

Various means for securing such studs to the door have been suggested and used. Assuming such studs have the same material and spacing, they are believed to give comparable performance during the time the door is on the furnace. However, they are not as satisfactory as the replaceable supports of this invention insofar as ease and cost of replacement are concerned. Thus, the most common practice is to Weld one end of the stud to the face of the recess in` the door. When such ardoor is to be relined theresidual ends of the consumed studs must be burned or clipped olf at the door face. Such preparation for the welding on of new studs, as well as the welding itself, is expensive. Other fastenings for studs, not requiring welding, have also been suggested. Some of these involve holding a rearward extension of 'the stud in the hollow water-cooled body of the door, and are not'only relatively high in c ost but impose restrictions on the door construction to accommodate thek desired stud spacing. Others, such 4as nutspermanently welded to the face of the door into which studs with threaded ends are screwed, have proved impractical due to the difficulty of removing the studend of the burned-down stud from the nut. None of the prior devices has Ybeen wholly satisfactory and some better solution to the problem has long been desired.

' The instant invention overcomes these diiiiculties in that the anchor members are readily replaceable despite any bending 'or movement in the structure of the door which lmay occur in operation. Further, the retaining and anchoring members which are made in accordance Re. 24,606 Reissued Feb. 24, 1959 'ice ' employing the combination of this invention;

Figure '2 is a vertical cross sectional view taken along line II-II of Figure 1 and showing a portion of a plastic refractory lining in place;

Figure 3 is a horizontal cross sectional view taken along line III-III of Figure 1; Y f

Figure 4 is a view in front elevation of a preferred embodiment of this invention;` y

Figure 5 is a view in side elevation ofthe preferred embodiment of Figure 4 taken along line V--V of Figure 4 through the retaining member;

Figure 6 is a plan view of the preferred embodiment shown in Figure 4;

Figure 7 is a view in front elevation of a modified embodiment of this invention;

Figure 8 is a view in elevation of the modified embodiment shown in Figure 7 taken along line VIII--VIII of Figure 7 through the retaining member; and ,g

Figure 9 is a plan view of the modified embodiment shown in Figure 7.

The preferred embodiment of this invention illustrated in enlarged view in Figures 4 to 6 inclusive is applied to the furnace door shown in Figures l to 3 inclusive. This furnace door is the subject of United States patent application Serial No. 613,073 filed August 28,` 1945, in the name of Edward W. Pottmeyer, now Patent No. 2,547,229. Although the door of the said application Serial No. 613,073 is particularly useful in the practice of the instant invention, the instant invention may also readily be used with both solid and full panel type furnace doors.

In Figures 1 to 3, such a furnace door 10 has an inner wall 11, the inner side 12 of which comprises the face of the door against which a plasticrefractory lining 13 is periodically cast as each relining .is performed. A hollow peripheral ange 14 extends around the outside of the door-10. VThese anges have inner sides 15 set at a vslight angleto each other to form a dovetail fit withplastic lining 13. Wall 11 also has a rear or outer surface 16 against which water-cooling means are ap plied. These waterfcooling means comprise a serieskof vertical channels 17 which intercommunicate with each other and with vertical anges 14a through the horizontal flanges 14h of the hollow peripheral ange. Pipe nipples 18 Welded to the top of door 10 respectively form an inlet and an outlet to the coolingrwater passages through door 1G. A vent nipple 19 is lalso provided for door 10 with access to the water cooling passages therein.

-Washout plugs 20 are threaded into tapped holes in blocks 21, which tapped holes communicate with thecooling water passages in door10 at the bottom `of the' vertical rails 14a of flange 14. A lifting yoke 22 and lugs 23 for conventional, counterbalance cables affordV a conventional arrangement for the raising and lowering of door 10. v Y 'I Rings 24 and 25 are in registry and together form an observation port-throughdoor 10 including the central channel 17. A cover 26 normally rests against ring 24-and closes the port. Cover 26 is operated by means of a chain 27 in a conventional manner. i

In the preferred embodiment a plurality of retaining 3 v members' 30 is welded in a predetermined Ypattern to surface `12. This pattern may be varied so long as it furnishes the required support for a plastic refractory lining to be cast against surface 12 and the respective inner sides-1S. Each retaining member 30 is in the form of a socket of a material like sheet steel bent into the form of a longitudinal arch having a longitudinal central portion 31vspacedaway from surface 12. This. spacing is obtained by the divergence of two straps shown as side portions 32 extending toward surface 12 so that lthe innermost-'side edges thereof may be welded to metal wall 11. A U-shaped recess 33 is cut or punched through central portion 31 for a substantial portion of the length thereof downwardly from the top edge ,34 of socket 30.

Since central portion 31 and sides32 are each relatively plane, the space between recess 33 and the lower part of portion 31 and surface 12 is relatively trapezoidal in configuration.

As a consequence, an anchoring membersuch as a stud 35 having an outwardly flared or countersunk base f3.6 of greater diameter than the width of recess 33,- can be held tightly against surface- 12 by sliding it with body 36a substantially between recess 33 and surface 12. The base 36 of stud 35 is of a diameter which readily passes through recess 33 between the sides thereof so that it extends normal to wall 11 into the space tol be occupied by alining 13. In practice, stud 35 is a rivetwith a c ountersunk head, which head acts as base 36. In the formation as by bending of socket 30, the slope of sides 32 is generally similar to the aring of the sides of base 36. Thus, as shown in Figure 6, the inner edge 37 normally bears against base 36 to insure a proper t between stud 35 and socket 30 there being enough give, which may be termed elasticity or resiliency or flexibility, in the metal of the arched socket, for example, to enable it to hold the stud 35 tightly against surface 12 when the stud is knocked into place as will be understood fully by those in the art to whom this invention is disclosed.

Because of the arch shape of retaining member 30, it is` open at the top and at the bottom as' shown' in Figure 5. Any refractory or other material which may accumulate around base 36 within socket 30 during use is readily removable either when the stub en d of stud 35 is removed or thereafter. Such stub ends can readily be removed by knocking them up by hammer blows and out of their respective sockets 30. Any other material between socket 30 and wall 11 can be dislodged by further blows or by poking the material out with a chisel. Thereafter, new studs 35 may be knocked into place by moving them downwardly in recess 33 generally parallel to wall 11. Although the rearmost portion off the sockets 30 is illustrated as surface 12, such socketsv may, if desired, be provided with back platesof their own which back plates can then be welded to wall 11 toform the combination of thisv invention. Further, although the recesses 33 are illustrated as being U-shaped in vertical position, various departures from such shape and orientation may be made in particular'ca'ses;

' It is evident that socket blanks can be stamped outor otherwise cut and recessed and bent very quickly and inexpensively. Such sockets would then be welded in a predetermined pattern to the particular furnace door to be used. In the case of full panel type doors using box-type panels with vertical spaces between or in the event there are observation openings for the refractory lining through the back of the door and through a wall portion corresponding to wall 1l, suitableblanking o'fE can be used to ll such spaces; during the casting operation while the refractory lining is still plastic. Subsequently', such blanking off pieces may readily be removed. In using a furnace door of the type illustrated in the aforesaid application Serial No. 613,073, the pattern for the sockets 30 need not make any allowance for the immediate presence of water cooling means directly in 4 back of the respective 'socket on the other side kof wall 11. Thus, as shown in Figure 3, sockets 30 may be directly in front of a channel 1'7 or directly in front of the space between adjacent such channels or directly in front of the flange of a channel afxed to surface 16.

As the lining 13 is consumed or eroded away, the studs 35 also progressively burn away. However, the studs are not completely consumed since a short stub end will remain even though the lining around vit is completely consumed. It has been found in tests of the improved stud and fastening of this invention that no fusing of such stub end to its anchor socket,such as socket 30, occurs on such exposure although the exposure may be prolonged for a substantial period of time. And despite such exposure, the stub end is still easily removable and the socket remains in good condition indefinitely for the reception of new studs when the door is to be relined. Such severe exposure Lis not usual because furnace doors are usually relined before metal plate l11 is exposed, but it occasionally occurs. Thus, it is a-further important advantage of this invention that the time of relining is not critical in relation to the functioning of the device of this invention.

When such a door is to be relined, an unskilled workman can readily hammer the old studs 35 out of the sockets 30 and similarlydislodge any hardened plastic or other material which may have collected around base 36 in socket 30. Such dislodgrnent is facilitated by the open bottom of socket 30 permitting the material to fall free where it can be swept away. The insertion of new vstuds 35 is then readily accomplished by sliding them into place with the aid of such hammer blows as may be required. A rigid pattern of new anchor members is thus quickly obtained for the new lining which can then be cast.

In Figures 7 to 9 inclusive, a modified socket 4 0 is shown substantially in the form of one-half of a conical washer. A recess 41 is provided by the opening in such Washer which recess accommodates astud 42 which is identical with stud 35.- The rearwardly extending edge of socket 40 is welded to a wall surface such as wall 11 and functions substantially as socket 30 functions except that socket 40 has no bottom opening for the convenient dislodgment of caked or accumulated material.Y Moreover, socket 40 offers somewhatless support totheanchor members than docs the preferredl embodiment socket 30.

The particular shape and orientation of ythe retaining members and of the recesses therein and of the locking space defined thereby for a generally corresponding cross section of the cooperating anchor members arematters which may be widely varied and Astill be within the spirit of this invention as defined by the scope of the appended v claims.

the width of said body, said base having a length movable between said face and said portion to hold the-remainder of said stud extending through said recess normal to said face tofanchor said refractory.

2. In a plastic refractory lined furnace ldoor, in com; bination, a wall having a face against which refractory `is placed, a pluralityof sockets perm'iner'itl'y fastened to said face, each of said sockets having a central portion closely parallel to but spaced from said face andv side portions extending between said central p'ortionand said face, said central portion having a recess therein, stud for each of said sockets, each `stud having a body arid a base, said body having a width less than thewdth of said base, said recess having a width less than the width of said base but greater than the width of said body, said base having a length approximating the distance between said central portion and said face, said stud being slidable parallel to said face with its axis perpendicular thereto and into said recess with said base between said central portion adjacent said recess and said face to hold the remainder of said stud extending through said recess and normal to said face to anchor said refractory.

3. In a plastic refractory lined furnace door, in combination, a wall having a surface against which refractory is placed, a retaining member having a central portion closely parallel to but spaced from said surface and side portions extending between the sides of said central portion and said surface, the edges of said side portions adjoining said surface being permanently axed to said wall at said surface, said central portion having an end spaced from said surface, said central portion further having a recess forming a slot extending to said end, a stud having a body and base, said base being wider than said body and said recess, said recess being wider than said body, said base removably tting between said central portion, said side portions and said surface to hold the remainder of said stud extending through said recess normal to said surface to anchor said refractory.

4. In a plastic refractory lined furnace door, in cornbination, a wall having a surface against which refractory is placed, a plurality of sheet metal sockets and metal stud anchors for said refractory, each socket being welded to said wall at said surface, said socket having a central portion closely parallel to but spaced from said surface and side portions extending between said central portion and said surface, said central portion having upper and lower edges spaced from said surface and a recess forming a slot extending downwardly from said upper edge,V a stud for each socket having la body and base, said base being wider than said body and said recess, said base further having a length generally equal to the distance between said central portion and said surface, said recess being wider than said body, said base being slidable parallel to said surface and between said central portion and said surface to hold the remainder of said stud extending through said recess normal to said surface to anchor said refractory.

5. In a furnace door having a wall with a face against which refractory is placed to line said door, in combination, a stud mounting socket having at least one edge permanently fastened to said face, said socket having a raised portion close to but spaced from said face, said portion having a recess therein affording access to the space between said portion and said face, said last-mentioned space having an unobstructed width greater than the width of said recess, said recess further having an unobstructed entry portion, said socket extending to each side of said recess to overlie said space to each such side.

6. In a furnace door having a wall with a face against which refractory is placed to line said door, in combination, a stud mounting retaining member structure comprising a pair of respectively spaced sides having opposed edges, said opposed edges of said sides being spaced from said face and from each other for at least a part of their length to define a recess therebetween parallel to said face, there being an unobstructed opening extending transversely of said sides in the space between said sides and said face, and a welded connection for each of said sides to said wall and from which said sides arch toward said recess.

7. In a studded furnace door of the water-cooled type having a back plate with a reentrant portion defining a recess for the reception of a monolithic lining of refractory material, a stud mounting structure comprising a pair of metal straps spaced from each other to dene a notch with coplanar stud mounting edges respectively spaced from and parallel to said back plate, there being an unobstructed opening extending transversely of said straps in the space between the straps and said back plate, and a welded connection at one end of each of said straps to said plate and about which a length of the strap may resiliently flex.

8. In a studded furnace door of the water-cooled type having a back plate with a reentrant portion defining a recess for the reception of a monolithic lining of refractory material, a stud mounting structure comprising a pair of metal straps spaced from each other to provide a space therebetween with coplanar stud mounting edges respectively spaced from and parallel to said back plate, there being an unobstructed opening extending transversely of said straps in the space between the straps and said back plate, a welded connection at one end of each of said straps to said plate and about which a length of the strap may resiliently flex, and a stud projecting through said space and having an enlarged end of frusta-conical shape, said enlarged end having an axial length longer than the opening of said straps from said back plate whereby adjacent edges of said straps will engage with and be fiexed outwardly by the frusta-conical surface of said enlarged end upon movement of said stud to a position in which it pro-jects through said space.

References Cited in the tile of this patent or the original patent UNITED STATES PATENTS 282,846 Cole Aug. 7, 1883 488,851 Stock Dec. 27, 1892 614,177 McBride Nov. 15, 1898 739,326 Leonard Sept. 22, 1903 1,127,596 Crabiel Feb. 9, 1915 1,588,566 Wisrner June 15, 1926 1,951,115 Wonsowicz Mar. 13, 1934 1,953,856 Heyrnan Apr. 3, 1934 2,037,018 Hall Apr. 14, 1936 2,063,261 Mees Dec. 8, 1936 2,103,106 Yurkovitch Dec. 21, 1937 2,124,425 McAfoos July 19, 1938 2,127,973 Isett Aug. 23, 1938 2,325,945 Fuchs Aug. 3, 1943 2,395,757 Peters Feb. 26, 1946 2,477,161 Ausland et al. July 26, 1949 2,513,626 Corriston July 4, 1950

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