US2398386A - Bell for blast furnaces - Google Patents

Description

A. MOHR. JR., EITAL BELL FOR BLAST FURNACES Filed Oct. 9, 1943 Patented Apr. 16, 1946 UNITED STATES PATENT OFFICE BELL FOR BLAST FURNACES Albert Mohr, J r., and John P.-Grilli, Chicago, Ill.

Application October 9, 1943, Serial No. 505,639

- 4 Claims. (Cl. 214-36) In the charging equipment of an iron blast furnace it is necessary to provide two bells to prevent the escape of top gases from the furnace. These. bells are controlled so that only one hell is open at a time; that is, when one is open, the other is closed.

The top bell is designated as the small bell, and. is usually approximately from four to seven feet in diameter, depending upon the size of the furnace. The bell below the small bell is designated as the large bell, and has a diameter of approximately from thirteen to sixteen feet, depending upon the size of the furnace.

The present invention is more. particularly directed to the large bell. With allpresent large bells the flow and distribution of materials from the large bell into the furnace is subject to many variables. It is of paramount importance in the successful operation of the furnace, that the materials on the large bell flow into thefurnace at a uniform rate, and that the bell shall open equally around its entire circumstance; otherwise, the amount of materials will not be distributed uniformly, and this will preventthe furnace from attaining its best possible performance.

Such irregular distribution of 'the materials will cause the furnace to work hot on one side and cold on-the other side. At present the large bells are balanced after they are machined, but this balance is upset after the first few hours of operation. The reasons for the unbalancing of the large bell are the depositing of materials on the under side of the bell and the baking on of ore and other materials on the top side of the bell.

These materials do not deposit uniformly and are of different densities, and therefore throw the large bell out of balance, with the result that the large bell will be caused to open first on the side that the bell is heavy, thereby causing a greater amount of materials to be deposited in the furnace on that side:

Another condition which causes the non-uniform. distribution of the materials into the furnace is due to the fact that they bake on the top side of the bell, and they will slide off the bell on the cleaner side faster than on the baked section or side, thereby causing the large bell to swing. Thi condition is of such importance that in many plants the top surface of the large bell is cleaned many times a day, by using bars and snappers to remove the baked-on materials.

In the accompanying drawing diagrammatically illustrative of this invention:

Fig. 1 shows a portion of a hopper and a large bell in position to close the hopper.

Fig. 2 is a sectional view taken on line 2-.2, Fig. 1,, with parts omitted.

Fig. 3 is a fragmentary view of a portion of the hopper andlarge bell, showingjanother form of guiding means.

It is the usual practice in furnaces of this character to. suspend the large bell Ill from a bell rod H, which is approximately fifty feet long, and the bell is always centered in the furnacewhen the latter is cold. Howeven'when the furnace is in generation there is an ever changing'tempera ture distribution within the furnace, and there are times when the center of the. large bell Ill, and theecenter of the bellfrod H at its point of suspension, are not in the same perpendicular axes.

, This, of course, will cause the bell to swing, with the result that the bell will open on one side advance of the openingon the other side, and thereby cause unequal, distribution of materials in the furnace. i

It is one of the objects of the present invention to overcome these difficulties and objections, and to provide improved means for insuring that the large bell will lee-prevented from so swinging, but will be caused to open uniformly about its entire circumference, thereby insuring a uniform d'elivery cf thematerials into the furnace.

In carrying thisinventioninto use, the bell ill is shown connected to the rodll, preferably by means of a key l2, and this large bell co-operates with a hopper l3. Supported within this hopper, preferably by the wall thereof, are any suitable number of guide members 14 which may be secured in position in any suitable manner,

- and arepreferably of a wedge-shaped formation.

Carried by the bell Ill, preferably adjacent the circumferential edge thereof and outside of the bell, are additional guide members l5 which may be of any desired or suitable construction and configuration, and which may be secured in position in any suitable manner. It has been found, however, that the guides l 5 may be formed of rods or bars secured to the bell in any manner, such as by screwing one end of the rods into the bell. These guide members I 5 are arranged uprightly, one in proximity to each of the guide members I4, and as the bell is opened by lowering the same with respect to the hopper, the guides I 5 will cooperate with the guide I 4, and thereby maintain the bell against swinging, causing it to open evenly and to the same extent entirely around its circumference.

If desired, a plate or member l6 maybe provided to form a closure for the bell itself, and this plate may be supported and secured in position in furnace, and should the bell start to swing, the

guides l will strike the guides Land the bell will be maintained against any such swinging movement.

The'plate' lfi forming a closure at the bottom' of the hollow bell, will prevent materials depositing upon it, because it will always be hot and above the dew point of the gas leaving the stock of materials, as the influenceof the cold charge on the large bell will not keep this plate cold.

The materials on top of the large bell will not bake on the top surface thereof, because the plate or member It will prevent the gases in the furnace from passing over the bottom surface of the large bell.

Inthe form of the invention shown inFigure 3, the guiding means forthe bell consists of fins or members l9 secured to the outer face of the bell l0 adjacent the lower edge thereof, which, when the bell attempts toswing while opening, will contact-the wall of the hopper and prevent such attempted swinging movement. Any number of these members l9 may be provided, and are suitably spaced around thecircumference of the bell.

While the preferred forms of the invention have been herein shown and described, it is to be understood that various changes may be made in the details of construction and in the combination and arrangement of the several parts, within the scope of the claims, without departing from the spirit of this invention.

What is claimed as new iszj 1. A blast furnace bell and hopper, said bell adapted .to form a closure for the bottom of the hopper, means for supporting and for moving said bell into open andclosed positions with respect to r the. hopper, spaced Wedge-shaped'members secured to the inner face of the hopper adjacent the adapted to form a closure for the bottom of the hopper, means for supporting and for moving said bell into open and closed positions with respect to the hopper, spaced wedge-shaped members secured to the inner face of the hopper adjacent a the outlet end thereof, and upright guide bars secured to the bell and projecting thereabove, said guide bars co-operating with the respective wedge-shaped members to maintain the bell against tilting during its opening movement, there being a space between the guide bars and the respective wedge-shaped members, whereby to maintain the charge in the hopper from wedging between the bars and the guide members.

3. A blast furnace bell and hopper, said bell adapted to form a closure for the bottom of the hopper, means for supporting and for moving said bell into open and closed positions with respect to the hopper, spaced wedge-shaped members secured to the inner face of the hopper adjacent the outlet end thereof, upright guide bars secured to the bell and projecting thereabove, said guide bars co-operating with the, respective wedgeshaped members to maintain the bell against tilting during its opening movement, said bell being hollow, and a closure for the open bottom of the bell.

4. A blast furnace bell and hopper, said bell adaptedto form a closure for the bottom of the hopper, means for supporting and for moving said bell into open and closed positions with respect to the hopper, spaced wedge-shaped members secured to the inner face of thehopper adjacent the outlet end thereof, upright guide bars secured to the bell and projecting thereabove, said guide bars co-operating with the respective wedgeshaped members to maintain the bell against tilting during its opening movement, said bell being hollow, and a corrugated closure for the open bottom of the bell.

ALBERT MOHR, JR. JOHN P. GRILLI.

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