US3123029A - Cover for soaking pits - Google Patents

Description

March 1964 w. A. MORTON &

COVER FOR SOAKING PITS Filed Sept. 6, 1960 I 3 Sheets-Sheet Fig.2.

INVENTOR. William A. Morton his ATTORNEYS COVER FOR SOAKING PITS Filed Sept. 6, 1960 3 Sheets-Sheet 2 JNVENTOR. William A. Morfon his ATTORNEYS March 3, 1964 Filed Sept. 6, 1960 W. A. MORTON COVER FOR SOAKING PITS Fiq. 5.

3 Sheets-Sheet 3 IN V EN TOR.

William A. Morton his ATTORNEYS.

United States Patent O 3,123,029 COVER FOR SOAKNG PITS William A. Morton, Mount Lebanon Township, Allegheny County, Pa., assignor to Loftus Engineering Corporation, Pttshurgh, Pa., a Corporation of Maryland Filed Sept. 6, 1960, Ser. No. 54,310 1 claim. (Cl. 110-173) The present invention relates generally to removable covers for top loading furnaces which customarily employ a sand seal between the top of the furnace walls and the cover when in closed position. Such seal is necessarily fractured by opening movement of the cover and must be renewed when the cover is returned to closed position. More specifically, the present invention resides in improvements in cover Construction, mounting and seal maintenarce.

One frequently employed design of top charging furnace is the soaking pits employed in steel mills which receive and reheat the ingots, as stripped from the molds, preparatory to rolling. Customarily a plurality or' such furnaces are provided in order to maintain a continuous supply of uniformly heated ingots for rolling, and due to the high temperatures to which the ingots are subjected, such furnaces and covers are fully insulated. The covers are, therefore, strongly constructed and are of considerable weight. Customarily the means employed to remove such covers comprises individual wheeled carriages moving upon fixed tracks at the sides of said pits or furnaces. Such carriages are customarily provided with means which first lift the cover free of the furnace opening and then move the cover longitudinally relative to the furnace opening for charging the ingots into the furnace and thereafter reverse the movements of the carriage and cover to close the furnace opening. Snch wheeled carriages are not only expensive to manufacture but require large amounts of electrical energy to operate them.

Conventional covers for pit furnaces have a series of alloy seal blades extending around the periphery of the refractory cover. The refractory portion of the cover is supported by a steel frame to which the seal blades are attached. The pit walls either support sand troughs or have troughs formed in the top of the walls. The seal between the cover and pit proper is broken when the cover is lifted and restored when the cover is again lowered when in proper register with the sand troughs.

After the conventional cover is first lifted free above the pit walls it is moved horizontally to expose the heated ingots that they may be removed from the furnace. In so doing the alloy seal blades on that portion of the cover which must travel over the open furnace are exposed to the direct heat of the furnace, which in steel heating practice is in excess of the temperature that the alloy seals will withstand. The result is that these alloys seal lades are sometimes very quickly destroyed. One of the objects of this invention as may be noted from the description of the operation is to eliminates the end alloy seal blades to reduce maintenance, and so supporting the sand on the end pit walls of the urnace opening and shaping the underside of the refractory portion of the cover that scaling of the gases within the furnace is effected each time the cover is closed.

Another object of the present invention is to provide a simplified form of mounting for the cover, whereby movement only in a single horizontal plane provides for removal and replacement of the cover.

Another object of the invention is to provide a new and improved form of cover having refractory surfaces effectin g the seal about the ends of the cover.

A further object of the invention is to provide a novel i the members 9.

3,l23,029 Patented Mar. 3, 1964 form of sand seal about the cover which requires only infrequent replacement and a convenient means for effecting such renewal.

These and other objects' of the invention will be made apparent from the following description and the drawing forming a part thereof, wherein:

FIG, l shows a plan view of two such carriages and covers mounted side by side, with the cover of one furnace in closed position and the other cover removed for charging the furnace;

FIG. 2 shows a section taken on lines II-II of FIG. l, illustrating a transverse sectional view of the cover and the furnace opening;

FG. 3 shows a longitudinal section through the cover and furnace opening taken on lines III-III of FIG. 1;

FIG. 4 shows a side levation of the cover and carriage; and

FIG. 5 shows a longitudinal section through the cover and furnace opening, as in FIG. 3, but with the cover in partially open position.

Referring now in detail to the drawing wherein like reference characters refer to like parts, the soaking pits 1 are of generally conventional Construction having side walls 2 and end walls 3. A plurality of such pits are usually arranged side by side. The tops of the pit side and end walls about the pit opening are inclined downwardly relative to the horizontal, in the direction of cover opening movement. A slope of /2" per foot has been found to be satisfactory. At each side of each pit opening is provided a suitable track means, such as 4, disposed in a horizontal plane.

Mounted on track means 4, is the cover indicated generally by the reference character 5. This cover may be of any suitable Construction and is shown as having a structural frame comprised of spaced side members 6 connected by end members 7 and 8. The side members 6 are braced intermediate their ends by transverse structural members such as 9 extending between and connected to the members 6. The members 9 terminate above the lowermost edge of the members 6 as shown in FIG. 3 of the drawing. These members 9 may also be braced by the intermediate longitudinal structural members 10, which preferably are of substantially the same depth as Depending from the members 9 and 10, and filling the space between the side members 6 and end members 7 and 8 is a suitable refractory member such as 11. Member 11 in combination with members 6 and 7 cooperates with the sand seals herenafter discussed to seal off the top opening of the soaking pit.

As shown in FIGS. 2 and 3, the refractory member 11 depends below end member 8 and preferably termiuates flush with the bottom plane of end member 7. The side members 6 of the cover depend below the bottom face of refractory member 11 to provide side seals as hereinafter discussed. The bottom face 19 of refractory member il, as shown in FIG. 3, is disposed in substantially parallel spaced relation to the sloping top faces of the soaking pit side and end walls. End wall Sa at its top face is provided with an inner inclined portion 12, an upwardly and outwardly inclined portion 13 and a horizontal portion 14. The refractory member 11 also has an inclined portion 15 disposed substantially parallel to and in spaced relation to said end wall portion 13. End wall 3 is provided with an inclined top face 16, downwardly inclined portion 17 and a horizontal face 18. As indicated by FIG. 2, each pit side wall 2 has a top face 20 which is provided with a longitudinally extending recess 21 within which the lower ends of cover side members 6 depend. Preferably the lower ends of members 6 are provided with a downwardly converging portion Ga.

As shown by the drawing, the cover 5 is provided with a pair of longitudinally spaced suitable axles 22 which extend beyond both cover side members 6. Mounted on the outer ends of said axles 22 are suitable fianged supporting wheels 2251 which bear upon the track 4. AXles 22 are journaled in suitable bearings 220 mounted on members 6. Since the track means 4 are disposed in a horizontal plane, the cover 7 will move in a horizontal plane from closed to open position. As indicated on FIG. 1 of the drawing, the cover is actuated by any suitable means conventionally indicated as motor 23 and gear reducer 24 upon a support such as plate 25. The gear reducer 24 is provided with a shaft 2412 upon whose outer end is a suitable driving gear 26 engaged with a driven gear 27 Secured to the aXle 22. As shown in FIG. 1, each track means is provided with a suitable stop means 28 limiting movement of the cover into closed position and a similar stop 29 limiting movement of the cover 5 into opened position. The motor 23 is driven by any suitable electrical means (not shown) and preferably each track 4 is provided with a suitably wired limit switch (not shown) for cutting off power to the motor 23 prior to engagement between the cover supporting wheels 22a and said stop means.

As previously described, the track 4 upon which the cover 5 moves is disposed in a horizontal plane and the bottom face of the refractory member 11 of the cover which overlies the top faces of the pit opening is disposed in parallel spaced relation to said pit opening top faces. At 'the sides of the pit opening, the recesses 21 in the pit side walls are filled with sand through which moves the cover side member portions 611. This arrangement provides an adequate sand seal at the sides of the cover.

Each top face portion 16, 17 and 13 of pit end wall 3 and each top face portion 12, 13 and 14 of pit end wall 311 are provided with a coating of granular refractory material S', which may be sand or other suitable material. The initial thickness of coating is not less than the spacing between said end wall top face portions and the corresponding parallel faces of the cover refractory member 11, when the cover is in closed position. By this means a complete seal is provided between the adjacent bottom face of the cover and the coated top faces of the pit end walls by contact between the engaging refractory surfaces thereof when the cover moves into closed position.

Referring now to the use of the invention, the cover 5 has reciprocal movement between closed and open positions upon the wheels 22:: moving over the track means 4 whose wheel supporting surfaces are in a horizontal plane. By reason of the covver having linear movement in a horizontal plane over a pit opening whose top surfaces are in a plane downwardly inclined from the horizontal and in the direction of opening movement of the cover, the bottom surface of the cover refractory member 11 has a movement of translation both horizontally and vertically relative to the plane of the inclined top surfaces of the pit opening.

When the cover 5 is in fully closed position as indicated in FIG. 3 of the drawing, the bottom face 19 of the cover refractory member 11 is in parallel spaced relation to each of the top faces of the pit end walls 3 and 3:1. The coatings of sand upon inclined surface 12 of pit wall 311 and the inclined surface 16 of pit wall 3' are in scaling engagement with the adjacent surfaces of the face 19 of the cover refractory member 11. Since all portions of the bottom surface 19 of refractory member 11 have only linear movement in a horizontal plane to the left of FIG. 3, during opening movement, those portions of said bottom surface 19 in contact with the inclined sand coatings upon inclined pit wall top surfaces 12 and 16 have a movement of translation away from and not parallel thereto. Thus there is no tendency for surface 19 to drag sand from said wall top surfaces 12 and 16 about the pit opening. However, since the top surface 18 of pit wall 3 is disposed in a horizontal plane and the adjacent portion of cover bottom surface 19 is in parallel spaced relation thereto, such latter surface will have a linear movement to the left and in contact with the sand coating upon said wall top surface 13. At the same time all portions of the bottom surface 19 of cover member 11 in contact with the sand coatings on surface 17 of pit wall 3 and surface 13 of pit wall 3:1, will simultaneously move to the left and a point along the cover which when in closed position is in sealing relation with the granular seal supported on the furnace now gradually is raised above the sand coatings or seals upon surfaces 12, 21 and 16. The angle of inclination of surfaces 13 and 717 and the coacting surfaces 15a and 15 is preferably greater than the angle of repose of the sand, and sand pushed against surfaces 13 and 17 when the cover is closed will fall by gravity to the normal angle of repose and during the closing movement of the cover will act as a friction cushion for the closing action and the sand will again be pushed vertically into the, spaces between surfaces la and 17 and 13 and 15 to re-establish the seal.

During successive opening and closing movements of the cover 5 some sand from the seal at the ends of the a cover may be entirely displaced from the top surfaces of the pit end wall 3 and 3a. Such sand may be readly replaced through the sand filling openings 3@ at the rear and inserting sand into said openings. At the front end of the cover the sand seal may be readly established by inserting sand upon the wall surface 14, by a wor'kman standing upon the adjacent platform 32.

Having thus described the invention in its presently` preferred form, it will be understood that the details of Construction shown are for purposes of illustration and not limitation. Thus those skilled in the art may modify the details of the invention without departing from the invention as defined by the scope of the appended claim.

I claim: In a furnace having two upwardly extendng end walls and two side walls whose tops define a substantially rectangular furnace opening,

(a) the top of each said end walls comprising a shelflike surface, with the shelf-like surface of one end wall disposed at a higher elevation than that of the other,

(b) a layer of granular refractory scaling material on i each said end wall shelf-like surface,

(c) the top of each said side walls having an inclined groove therein extending between the shelf-like surfaces of said end walls,

(d) a granular refractory sealing material in said grooves, r

(e) substantially horizontal track means extending longitudinally of the opposite sides of said opening,

, (f) a substantially rectangular cover mounted on wheels for reciprocal linear movement on said track means to cover and uncover said furnace opening,

(g) said cover having surfaces at its opposite ends for severally mating with said shelf-like end wall surfaces and the scaling material thereon, and

(h) the opposite sides of said cover having longitudnally extending depending members from one end to the other longitudinally of the door for severally engaging the scaling material in said inclined grooves,

said depending members being inclined' relative to the track and parallel to sai-d inclined grooves.

References Cited in the file of this patent UNITED STATES PATENTS 1,044,093 Smythe Nov. 12, 1912 1,074,509 Leask Sept. 30, 1913 1,499,801 Bond July 1, 1924 l,656,963 Stevens et al Jan. 24, 1928 2,039,761 Weniger May 5, 1936 2,17S,668 Longenecker Nov. 7, 1939 2189280 Croft Feb. 6, 1940 2,881,942 Allbright et al. Apr. 14, 1959 UNITED STATES PATENT OFFICE CERTIFICATE l CRRECTION Patent No. 3,123,029 March 3 1964 William A. Morton It is he'z'eby Certified that error appears in the above number-ed patent req'iring correction and that the said Letters Patent should read as corrected below.

Column 4 line 24 after "rear" insert of the cover i above wall 3 by removing the stopper 31 Signed and sealed this 14th. day of July l94 (SEAL) Attest:

EST ON G. J OHNSON EDWARD J BRENNER Attesting officer Commissioner of Patents

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