US2388941A - Blast furnace charging bell - Google Patents

Description

Nov. 13, 1945.

G. WEHR BLAST FURNACE CHARGING BELL Filed Dec. 22, 1944 '2 sh t -sheet, 1

INVENTOR jib-L .1-

A'ITORNEY Nov. 13, 1945. G. WEHR BLAST FURNACE CHARGING BELL 2 Sheets-Shet 2 Filed Dec. 22, 1944 INVENTOR BY ma.

ATTORNEY Patented Nov. 13, 1945 :UNITED STATES PATENT OFFICE Application December 22, 1944, Serial No. 569,330

4 Claims. (01. 266-27) This invention relates to blast furnace charging mechanism and more particularly to a ventilating system for preventing the accumulation of explosive gas mixtures in the charging chamber.

Blast furnaces are charged at the top, there.

being a large'charging bell constituting th base of the charging chamber and a small bell consmall chargin bell is opened the inrushing air I will produce an explosiv mixture which may be ignited by a spark produced from charging of a metal object through the upper bell.

It is among the objects of the present invention to maintain atmospheric pressure when the charging bell are closed and prevent the accumulation of explosive mixtures in the charging' chamber at the time the small bell is lowered by continuously venting the charging chamber to the atmosphere when the lower bell is closed. a

It is a further object of the invention to provide means for coordinating the charging chamber vent with the movements of the large charging bell.

These and other objects of the invention will become moreapparent from a consideration of the accompanying drawings constituting a part hereof, in which like reference characters designate like parts, and in which Fig. 1 is a vertical cross-sectional view of the top of a blast furnace diagrammatically illustrating the bell operating and charging chamber ventilating mechanism embodying the principles of this invention; and

Fig. 2 is a similar view of a modified form of ventilating mechanism and control therefor.

With reference to Fig. 1 of the drawings, the numeral i designates the top of the blast furnace housing, 2 the side walls of a charging chamber, 3 the top wall of the charging chamber which supports a hopper 4 controlled by a small hell 5 to periodically feed measured charges of ore, limestone and coke into the charging chamber. The mechanism for operating the bell 5 is not shown. A large charging bell 6 constitutes the bottom of the charging chamber and is supported by a rod 1 extending through the hollow shank 8 of the-small bell 5, rod 1 being pivoted at 9 to a lever It fulcrumed at III and operated by a cable I! which is actuated by an operating cylinder 13. A ventilating stack It extends from the top wall 3 or the charging chamber and is provided,'with a valve l5 at the top thereof which seats against an annular flange l8 when closed, it being shown in the open position with the vent holes ll establishing com munication of the vent stack and charging chamber with the atmosphere. Valve 86 is connected by a link iii to a counterweighted lever is that is fulcrumed at 20 to a bracket 2i mounted on the vent stack It, the lever l9 being further connected by a link 22 to the bell operating lever ill at 23; Movement of lever It) produces corresponding movement of the counterweighted lever l9 so that when the large charging bell 6 is lowered, valve I5 is likewise lowered against it seat It to seal the charging chamber, thus preventing the escape of the blast furnace gases through the vent stack M. When the large hell 6 is closed by lifting the same, vent valve I5 is raised to the position to vent the charging chamber to the atmosphere through openings ll to maintain atmospheric pressure when both bells are closed. Upon subsequent lowering of the small charging bell 5,'there can be no explosion as there is no explosive gas mixture in the charging chamber.

In the form of the invention shown in Fig. 2, the counterweighted venting lever I9 is operated independently of the bell operating lever iii by means of a drum 25 that is operated by a motor 26, a cable 2! wound on the drum 25 being connected to valve operating lever I 9 at 28. The motor 25 is controlled by a starter 29 connected to a master switch 30 which has conduit connections, 3|, 32, 33 and 3t with switches am, 32a, 33a and 34a, respectively. In operation, when the operating cylinder l3 lowers the large bell 6, the lever ill will efiect closing contact of switch cm which starts motor 26 to drop valve IS on its seat. When lever l9 effects contact of switch 3 3a, motor 26 will stop. When the hell 6 is raised, contact or switch 3la is broken and when switch 32a is closed motor 26 will be energized to actuate lever iii to raise valve l5, and

- when switch 34a is closed motor 26 will be deenergized. By means of the switch controlled motor operated valve IS the charging chamber will be vented at all times when bell 6 is in closed position, and will close the vent to prevent the escape of the blast furnace gas when the charging bell 6 is lowered to open position.

It is evident from the foregoing description of the invention that no explosive gas mixtures will accumulate or be available in the charging chamber when the charge is dumped by the opening of the small charging bell and no gas can escape from the furnace through the charging chamber when the large bell is lowered to open position. Also. by relieving the gas pressure in the charging chamber, escaping gas and flue dust is eliminated at the top of the furnace which has been a hazard to workmen and detrimental to operating parts.

Although several embodiments of the invention have been illustrated and described, it will be evident to those skilled in the art that various modifications may be made in the details of construction without departing from the principles herein set forth.

I claim:

1. In a blast furnace, a charging chamber'having a small bell in-the top for charging said chamber and a large bell in the bottom for discharging said chamber, a vent for said chamber communicating with the atmosphere to at all times maintain atmospheric pressure between I the bells when both are in their closed position,

the bell is in open position and open said vent when the bell is in closed position.

2. In a blast furnace, a charging chamber having a small bell in the top for charging said chamber and a large bell in the bottom for discharging said chamber, a vent for said chamber communicating with the atmosphere to at all times maintain atmospheric pressure between the bells when both are in their closed position, said vent comprising a conduit extending from said charging chamber, a valve in said conduit, an operating mechanism for said discharge bell and an operating mechanism for said valve connected to said bell operating mechanism to be operable thereby for moving the valve to open position when the discharge bell is closed and for closing said vent when the discharge bell is moved to open position.

3. In a blast furnace, a charging chamber having a small bell in the top for charging said chamber and a large bell in the bottom for discharging said chamber, a vent for said chamber communicating with the atmosphere to at all times maintain atmospheric pressure between the bells when both are in their closed position, a vent stack extending from said charging chamher having an opening to the atmosphere at the top thereof, a valve controlling said opening, up-

crating mechanism for said discharge bell and operating mechanism for said valve including a motor for actuating said bell, and means responsive to the movement of said bell operating mechanism for energizing the motor circuit of the valve operating mechanism to coordinate the opening and closing of said valve with the opening and closing of the discharge bell.

4. In a blast furnace, a charging chamber having a small bell in the top for charging said chamber and a large bell in the bottom for discharging said chamber, a vent for said chamber communicating with the atmosphere to at all times maintain atmospheric pressure between the bells when both are in their closed position, a vent stack extending from said charging chamber having an opening in the top thereof, a valve controlling said opening, a lever for actuating the discharge bell and a lever for actuating the vent valve, an operating cylinder connected to said first-named lever and a motor for actuating the second-named lever, said first-named lever having switch terminals connected to the operating motor of the second-named lever, whereby the motor circuit is energized and deenergized in response to movement of said bell operating lever to vent the charging chamber to the atmosphere when the discharge bell is closed and to close said vent when the discharge bell is open.

GUY WEI-IR.

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