US3389899A - Blast furnace bell - Google Patents

Description

United States Patent O 3,389,899 BLAST FURNACE BELL Lowery J. McFarland, Crown Point, Ind., assignor to United States Steel Corporation, a corporation of Delaware Filed Oct. 5, 1965, Ser. No. 493,176 1 Claim. (Cl. 266-27) ABSTRACT OF THE DISCLOSURE An abrasion :resisting blast furnace bell. The bell includes a central cylindrical member, a horizontal platform extending outwardly therefrom, and a frustum shaped ring on the outer periphery of the platform. Charge material is accumulated on the platform adjacent the central cylindrical member.

This invention relates to -means for extending the life of the bells of iron-producing blast furnaces, to preclude the need for their replacement prior to furnace shutdown for general furnace rebuilding. This is accomplished by structural innovations which reduce bell abrasion incident to the flow of said charging material thereover, which innovations largely center about the provision of a cone-shaped cap of charge material to provide a wear free sliding surface for discharge of incoming charge.

In order to prevent the escape of yblast furnace gases during top charging of solid raw materials, the furnace tops are conventionally provided with a pair of hoppers, one above the other. The hopper bottoms are closed with apex-up cone shaped members, known as bells, which in the closed position afford a gas tight seal, in conjunction with suitable furnace structure, much after the fashion of an inverted poppet valve. These are opened in sequence, to permit descent of charge material successively from the upper hopper, to the lower hopper, and thence into the furnace proper. The cone structures aid proper charge distribution.

The aforementioned abrasion problem has been greatly aggravated, in recent years, by the change from relatively soft to extremely hard charge materials. Thus the soft fine iron ore has been largely replaced with a briquetted, hard iron bearing pellet as made from extremely hard taconite ore. The fluxing material, formerly relatively soft limestone, has, in many instances been largely replaced with hard burned uX-bearing sinter as made lby heating and agglomerating blast furnace dust, iron ore lines, Huxing components, etc. The coke has been upgraded to a hardness that will support the hard masses of sinter and 4briquettes above described, which intermixed therewith must not permit its excessive crushing.

The effect of these hardened ingredients to quickly abrade the cone surfaces, resulting in untimely replacement, has been to resort to high abrasion-resistant metals, to replace the cast steel ordinarily employed, with resulting cost increase. The instant invention provides a more economical solution.

In operation, the upper hopper receives from a lift car, not shown, successive loads of the various ingredients going to make up a furnace charge. In the interest of proper mixing of charge ingredients, it is the practice to open the upper bell after each car load is received, and

feed the material into the lower and larger hopper for accumulation of a proper mix of ingredients. Accordingly, the small upper bell is actuated more frequently than the large lower bell, with increased tendency for abrasive deterioration in the small bell. For this reason the invention will be described particularly in conjunction with a small bell installation.

FIGURE'l is a vertical section of a small bell of the invention, and related furnace structure, taken on the center line of the furnace, the bell portion being taken along the lines I-I of FIGURE 2; and

FIGURE 2 is a plan view of the bell of FIGURE l.

An upper portion of blast furnace 1, of generally circular cross section, has sealing edge 2 adapted to mate with the outer surface of frustum shaped ring 3 of bell, generally designated B. The bell maybe raised and lowered by means of cylindrical bell rod 4 which slidably surrounds large bell actuating rod 5.

The bell may be constructed in two generally symmetrical halves, for ease of installation.

A half of ring 3 is welded, at its inner periphery, to a multiplicity of ribs 6 and a horizontal -base plate 7. A semicylindrical member y8, concentrically located at the center of ring 3 extends upwardly from the bottom of 4ribs 6, through plate 7, and is welded to semi-cylindrical collar 9. A multiplicity of gussets 10 are spaced around mem-ber 8, directly under and welded .to collar 9.

A complete bell is formed by joining two halves, as detailed above, by means of a multiplicity of bolts 11, bolted through face plates 12.

Bell B is vertically suspended from rod 4 by means of collar 9 reposing on shoulder 13, at the lower end of rod 4.

The outer periphery of ring 3 is provided with abrasive resistant surfacing 14, in conventional manner.

In operation, plate 7 provides a shelf upon which portions of incoming charge C repose in conical shape, thus providing the new bell with the same general shape as the former bells, but with a surface which is wear proof. Expensive abrasive resistantI materials are limited to a small portion of the cone, at ring 3.

While a particular embodiment of the invention has been presented in some detail, this is to be understood as being for the purpose of facilitating ready practice of the invention, and not as limiting it. l

I claim:

1. An abrasion resisting blast furnace bell comprising a cylindrical central Amember attached to a bell rod, a horizontal platform extending outwardly from said cylindrical member at its lower extremity, said platform having `attached at its periphery a frustum shaped ring adapted to engage the bell sealing edge of a blast furnace, and charge -material for-ming an abrasion resisting conical surface supported on said platform.

References Cited UNITED STATES PATENTS 2,194,971 3/ 1940 Crockard 214-36 3,116,842 1/1964 Mohr 266--27 X 3,2713 10 9/1966 Hanna 266-27 I. SPENCER OVERHOLSER, Primary Examiner. WILLIAM J. STEPHENSON, Examiner.

E. MAR, Assistant Examiner.

UNITED STATES PATENT OFFICE `GERTIFICA'IIE] OF CORRECTION Patent NO. 3,389,899 June 25, 1968 Lowery J. McFrland It is certified that error appears in the above identified patent and that said Letters Patent ere hereby corrected as shown below:

Column 1, line 25, "said" should read solid Signed and sealed this 11th day of November 1969.

SEAL) mest:

Idward M. Fletcher, Jr. WILLIAM E. SCHUYLER, JR.

Lttesting Officer Commissioner of Patents

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