US3890090A - Refractory furnace - Google Patents

Abstract

A refractory furnace having an upwardly opening chamber and an overhead cover providing an air curtain seal through a peripheral duct. An inlet leading into the duct registers, when the cover is positioned to close the chamber, with an outlet of a conduit leading from a remote source of pressurized air.

Description

United States Patent Sanderson June 17, 1975 [54] REFRACTORY FURNACE 3.623,?!4 ll/l97l Firmin 2 110/173 A 74 [76] inventor: Andrew G. Sanderson, I78 Patton 3'787'l72 m9 Sanderson 432/250 St., King City, Ontario, Canada [22] Filed: Nov. 14, 1973 Primary Examiner.lohn J. Camby [2!] Appl. No.: 415,671

Related US. Application Data [63] Continuation-in-part of Ser. No. 346,954, April 2, 7

1973, Pat. No. 3,787,l72. [5 1 ABSTRACT 52 us. c1 432/250; 110/173 A A refractory furnace having an p y Opening 511 1111. c1. F27d 1/02; F27d 1/18 chamber and an Overhead Cover Providing an air [58] Field of Search 432/247, 250; 34/242; Iain seal through a Peripheral An inlet leading M73 R, 173 A into the duct registers, when the cover is positioned to close the chamber, with an outlet of a conduit leading 5 Reierences Cited from a remote source of pressurized air.

UNITED STATES PATENTS 3,437,326 4/l969 Augustine et al. 432/250 5 Claims, 8 Drawing Figures REFRACTORY FURNACE This is a continuation in-part of U. S. Pat. application Ser. No. 346,954, filed Apr. 2, I973, now US. Pat. No. 3,787,172 issued Jan. ll, I974.

The present invention relates to a refractory furnace of the type using a cover or lid.

In certain large refractory furnaces. such as those used for heating steel ingots for rolling, the furnace chamber is closed by a top cover or lid. The refractory material of the cover must be held in a steel frame but the frame cannot rest directly on the walls of the furnace because it would deform. For this reason covers have been used which carry a downwardly projecting peripheral knife-edge steel rim which locates in a longitudinal groove in an upper edge of the walls, the groove being filled with sand to protect the steel rim from the heat. This construction is unsatisfactory because the sand tends to blow out of the grooves even under slight above-normal air pressure within the furnace. To meet this problem the steel rim has been replaced in some furnaces by an air curtain projected downwardly around the rim of the cover from a perforated cover circumscribing the cover. This air curtain cover also has a disadvantage in that, in the battery of furnaces, each cover must carry its own blower mechanism for supplying pressurized air. In either steel rim covers or air curtain covers the cover itself may be moved by a travelling crane or on rails external to the furnace and in either case may be held above the furnace chamber or raised on corner pillars outside the furnace walls.

It is an object of the present invention to provide a refractory furnace, using a cover having an air curtain seal, in which the pressurized air for the curtain is supplied from a remote source.

Example embodiments of the invention are shown in the accompanying drawings in which:

FIG. I is a perspective view of the upper portion of a refractory furnace with cover;

FIG. 2 is a perspective view, partly broken away, showing one upper corner of the furnace of FIG. 1;

FIG. 3 is an exploded perspective view of the cooperating pillar and cover fittings for the furnace of FIG. 1;

FIG. 4 is a view in cross-section taken along line 4-4 of FIG. 1;

FIG. 5 is a perspective view of the upper portion of a refractory furnace with an alternate embodiment of cover;

FIG. 6 is a perspective view partly broken away showing one upper corner of the furnace of FIG. 5;

FIG. 7 is a cross-sectional view taken along line 77 of FIG. 6; and

FIG. 8 is a cross-sectional view taken along line 88 of FIG. 6.

The embodiment shown in FIGS. 1 to 4 of the drawings consists ofa refractory furnace 10 comprising a refractory wall 12 enclosing an upwardly opening chamber 14 with a circumscribing, upwardly facing rim 16 which is flush with a deck 18. Chamber 14 is closed by a cover 20.

Cover 20 of refractory furnace I0 has a steel frame 22 which carries a refractory lining 24. A pair of parallel beams 26, one at each side of frame 22, are extended at each end to provide bearing means 28. A duct 30 circumscribes cover 20 on the underside of the cover facing rim 16 of refractory wall 12. Duct 30 is perforated throughout its length to provide a continuous row of apertures 32 facing rim 16. Each bearing means 28 has an inlet duct 34 opening from the underside of the foot and connecting with duct 30. As seen in FIG. 4 of the drawings, a divider baffle 36 is fixed in duct 30 facingduct 34. The underside of each bearing means 28 carries a foot 38 framing a vertical passage 40 and having an inverted trough 42 at its lower end.

Trough 42 of foot 38 is constructed to nest on the upper ridge 44 of a pedestal 46 also having a vertical passage 48 which connects with passage 40 in foot 38. A gasket 50, fixed by bolts 52 to pedestal 46, is interposed between trough 42 of foot 38 and ridge 44 of the pedestal.

Each pedestal 46 is fixed by bolts 54 to a fixed base such as a pair of spaced, back-to-back l-beams 56 in deck 18. An air duct 58 leading from a remote source of pressurized air (not shown) branches into lateral ducts 60 beneath deck 18 which connect with pedestals 46 and lead into passages 48 of the pedestals.

In the operation of the embodiment of FIGS. 1 to 4, chamber 14 of refractory furnace 10 is charged and cover 20 is moved over the furnace by suitable means such as a rail carriage straddling the cover. When cover 20 has been located above furnace 10 it is lowered to have troughs 42 of feet 38 nest with ridge 44 of pedestal 46, with gasket 50 between the trough and the ridge. To provide the seal for cover 20, air is forced continuously through duct 58 to pass through each duct 60 and connected passages 48 and 40 to inlet duct 34 and perforated duct 30 where it emerges under pressure from apertures 32 to form an air curtain 62 directed against rim 16 of refractory wall 12.

In the alternate embodiment shown in FIGS. 5 to 8 of the drawings refractory furnace 10 has a cover closing chamber 14. Cover 70 has a steel frame 72 which carries a refractory lining 74 and a carrying beam 76. A duct 78 circumscribes cover 70 and this duct is perforated throughout its length to provide a continuous row of apertures 80 facing rim 16 of refractory wall 12. An inlet 81 contains a passage 82 which leads laterally into duct 80 from an opening defined by a terminal ring 84.

An upstanding conduit 86 is located outside refractory wall 12 and terminates at its upper end in an outlet 88 containing a passage 89 which leads laterally to an opening defined by a ring 90. Ring 84 is externally bevelled and ring 90 is internally bevelled to couple with ring 84. Ring 90 is mounted on an accordian mount 92. A pair of inlets 81 are provided, one located on each of opposed sides of cover 70 which are parallel to the direction of travel 94 of the cover when closing chamber 14 of furnace 10. Inlets 81 couple with a pair of outlets 88.

In the operation of the embodiment of FIGS. 5 to 8, cover 70 is moved in the direction of arrows 94 to close chamber 14. As cover 70, approaches the end of its travel ring 84 meets ring 90 with accordian mount 92 absorbing any shock. An air curtain 96 is then provided (see FIG. 8) by introducing air pressure through duct 86 to duct 78 and downwardly through apertures 80 against rim I6. Cover 70 may be moved into a closing position by any suitable means such as an overhead travelling crane gripping beam 76 or by rails supporting rollers journalled laterally on the cover.

I claim:

1. A refractory furnace comprising:

A refractory wall enclosing an upwardly opening chamber;

an overhead cover for the chamber comprising a frame carrying refractory material, a peripheral duct fixed to the frame and having at least one inlet leading into the duct, and air curtain outlet apertures opening towards the refractory wall;

conduit means located outside the refractory wall and connectable with a remote source of pressurized air, the conduit means having an outlet; and

the inlet of the cover being constructed and arranged to register with the outlet of the conduit means when the cover is positioned to close the chamber 2. A refractory furnace as claimed in claim 1 in which the inlet opens laterally from the duct.

3. A refractory furnace as claimed in claim 2 in which the inlet and outlet terminate in a pair of elements comprising disengagable coupling means.

4. A refractory furnace as claimed in claim 3 in which one of the elements is resilient in the direction of coupling.

5. A refractory furnace as claimed in claim 4 in which the cover is rectangular and the peripheral duct has a pair of inlets one located on each of those two opposed sides of the cover which are parallel to the direction of movement of the cover when the chamber is being closed by the cover.

* i t II!

Claims (5)

1. A refractory furnace comprising: A refractory wall enclosing an upwardly opening chamber; an overhead cover for the chamber comprising a frame carrying refractory material, a peripheral duct fixed to the frame and having at least one inlet leading into the duct, and air curtain outlet apertures opening towards the refractory wall; conduit means located outside the refractory wall and connectable with a remote source of pressurized air, the conduit means having an outlet; and the inlet of the cover being constructed and arranged to register with the outlet of the conduit Means when the cover is positioned to close the chamber.

2. A refractory furnace as claimed in claim 1 in which the inlet opens laterally from the duct.

3. A refractory furnace as claimed in claim 2 in which the inlet and outlet terminate in a pair of elements comprising disengagable coupling means.

4. A refractory furnace as claimed in claim 3 in which one of the elements is resilient in the direction of coupling.

5. A refractory furnace as claimed in claim 4 in which the cover is rectangular and the peripheral duct has a pair of inlets one located on each of those two opposed sides of the cover which are parallel to the direction of movement of the cover when the chamber is being closed by the cover.

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