US2585800A

US2585800A - Bleeder and equalizer for blast furnaces

Info

Publication number: US2585800A
Application number: US771870A
Authority: US
Inventors: Viseur Kurt G Le; Larson Leonard
Original assignee: Republic Steel Corp
Current assignee: Republic Steel Corp
Priority date: 1947-09-03
Filing date: 1947-09-03
Publication date: 1952-02-12
Anticipated expiration: 1969-02-12

Description

1952 KI. G. LE VISEUR ETAL BLEEDER AND EQUALIZER FOR BLAST FURNACES Filed Sept. 5, 1947 IN V EN TORS.

KURT. G. LE VISEURF/ YLEONARD LARSON.

ATT RNEYS.

Patented Feb. 12, 1952 BLEEDEB AND EQUALIZED FOR BLAST FURNACES Kurt 'G. Le Viseur, Youngstown, and Leonard Larson, Shaker Heights, Ohio, assignors to Bepublic Steel Corporation, Cleveland, Ohio, a corporation of New Jersey Application September 8, 1947, Serial No. 771,870

Claims.

1 This invention relates generally to the art of blast furnace constr uction' and operation and is particularly concerned with apparatus by which clean gases may be used to equalize the pressure on opposite sides of the charging bell and may also be vented to the atmosphere instead of dirty gas whenever slips or rolls of the furnace occur which are of minor or moderate intensity.

Modern blast furnaces are provided with bleeders above the top of the furnace through which gases may escape in case of slips or rolls of the furnace. Such bleeders are located in upward extensionsof the downcomers and permit the escape of dirty gases from the top of the furnace. Heretofore these bleeder valves have been set to openunder low pressures to take care of minor slips or rolls. In conventional furnaces, intended to operate on pressures higher than conventional pressures which are on the order of two to three pounds per square inch, it has been proposed to remove dirty gases from the gas above the stock line and admit them into the space in the charging hopper between the two charging bells to increase the pressure on the outer or upper side of the lower or big bell to an amount approximately equivalent to the pressure within the furnace to facilitate lowering of the big bell during charging. In this connection it has. been suggested that the gas in the charging hopper between the bells should be vented to the.

atmosphere through a short pipe at the top of the furnace controlled by a valve.

There are many disadvantages to use of the foregoing proposals. Where delivery gas is vented to the atmosphere either from the hopper chamber or from the furnace by reason of slips "to the or rolls, much dirt is discharged and constitutes a nuisance to adjacent buildings and residences. Also, the solids in these gases are valuable and constitute a loss to the extent that they are carried out of the furnace.

Th present invention is capable of use with furnaces operating at conventional pressures but is particularly important for use with furnaces operating at higher than conventional pressures. This invention only vents clean gas, that is, gas from the washer, to the atmosphere, from the hopper chamber or as a result of slips and rolls ranging up to a predetermined magnitude above that experienced in ordinary practice.

Among the numerous advantages of thus venting only clean gas is the fact bleeder valve erosion, which is especially serious in furnaces operating at high top pressures, is substantially reduced. v

Our present invention further enables, the automatic equalization of pressures between the double bell chamber and the atmosphere and between said chamber and the furnace. Thus chambe is being charged. the chamber is open when tge small bell is dumping and the bell tmosphere, and when the-large bell is being dumped to charge the furnace, the bell chamber communicates with a source of gas under pressure and is closed to the atmosphere so that the large bell may be opened easily although the furnace is being operated at relatively high internal gas pressures.

Briefly described, the present invention includes the usual blast furnace, dust catcher and washer connected together for the passage of' gase; from the furnace through the dust catcher and into the washer, means to conduct clean gas from the washer to the top of the furnace where it may be discharged into the hopper chamber, and a bleeder valve in the clean gas line which is set to open at a pressure considerably lower than the pressure at which the regular bleeder valves are set.

A better understanding ofthis invention and the reasons for its advantages will be gained by those skilled in the art upon consideration of the following detailed description and the drawings accompanying and forming a part of this specification, in which,

Figure 1- is a diagrammatic sketch of a blast furnace assembly embodying the present invention, and

Figure 2 is an enlarged diagrammatic view of the upper part of the furnace of Fig. 1 including a double bell charging assembly.

In Fig. 1, the system includes a blast furnace i0 which is provided with a double bell charging assembly ll, top gas uptake conduits l2, a bleeder valve l3 in one of the uptake conduits, a downcomer i4 communicating with said conduits, a dust catcher l6 and a gas washer I. Double bell assembly H includes a small upper hell I l and a large lower bell it which are fitted to a charging hopper I! which with the two bells Bell chamber is provided with a bleeder pipe 26 equipped with a valve 26.

Bleeder valves I3 and 22 are of the type which open against gas pressure within the bleeder pipes, as by downward movement of the long lever arms 21 against the counter-weights 26 on the short lever arms. Means are provided for opening these bleeder valves at different selected gas pressures within the bleeder pipes. This means includes the system of piping, valves and cylinders, shown in Fig. 1. A pipe line 29 leads from one uptake l2 and is divided into two branches. 3| which operates a valve 32 to control the flow of fluid from a supply 33 to a cylinder 34 provided with a piston 35 attached by cable 36 to the lever'arm 21 of bleeder valve 22. The other branch, 37, leads to a similar diaphragm 31a, which operates a valve 38 to control the flow of fluid under pressure from source 39 to cylinder 40 in which piston 4| is slidably mounted. Piston 4| is connected by cable 42 to the long lever arm 21 of bleeder valve I3. The controls for valve 22 are so adjusted that when the gas pressure in pipe line 29 exceeds a certain amount, for example, 13 pounds per square inch gauge, diaphragm 3| will actuate valve 32 and admit fluid under pressure from source 33 to cylinder 34 above piston 35, thereby forcing the piston downwardly and opening valve 22. Sudden moderate increases in gas pressure in the furnace caused by slips or rolls may be relieved in this way and the gas which is allowed to escape through valve 22 is clean, coming as it does from the washer and hence is not a public nuisance. When more extensive slips or rolls occur and the resulting pressure considerably exceeds that required to actuate diaphragm 3|, for example, amounts to 18 pounds per square inch gauge which is sufficient to actuate diaphragm 3|a, valve I3 is opened by the admission of fluid under pressure into cylinder 40 and dirty gas is vented through valve l3 provided for such emergency circumstances. In this manner only clean gas is vented during the moderate slips and rolls of the furnace and is supplemented by dirty gas only when slips or rolls of more than ordinary intensity occur.

Fig. 2 shows apparatus for automatically actuating the gas control valve in

gas lines

23 and 25 in predetermined sequence with the operation of the bells of the charging apparatus. In this view the stock rod cable 43 leads from the weight 44 attached thereto inside the furnace vertically up and over a pulley 45 and then downward to a move ent of cable 46in either direction.

By reason of the connection of the valve actuating cable 46 with the stock rod cable 43, the opening and closing of

valves

24 and 26 is synchronized with movements of the stock rod. The

movements of the stock rod cable are synchronized with movements of the large and small charging bells'by means of interconnecting controls which are conventional and form no part of the present invention.

The operation of this interconnected charging One branch 30 leads to a diaphragm apparatus is substantially as follows, starting with a furnace in operation with gas pressure above the stock line in the furnace of, for example, 5 pounds p. s. 1. gauge, the valve 24 closed and valve 26 open and bells l1 and I8 closed, and the stock rod weight 44 being down at the stock line in the furnace. A quantity of furnace charge is brought into the rotating hopper whose bottom is closed by small bell ll. The small hell I! is lowered and the charge is discharged into chamber 20 onto large bell I8. Another quantity of charge is brought into the rotating hopper, the hopper is rotated and the charge is dumped into the chamber adjacent to the first charge.

This procedure is continued until the desired amount of charging material has been accumulated on large bell l8. Thereupon the small bell I1 is closed, the stock rod cable 43 is actuated to pull weight 44 into the dome of the furnace and simultaneously cable 46 closes valve 26 and opens valve 24. Clean gas from pipe 2| enters chamber 20 and brings the gas pressure in that chamber up approximately to the pressure existing within the furnace. Thereupon, large bell I3 is lowered and the charge thereon is delivered into the stack of the furnace. Then large bell i8 is returned to closed position. Stock rod cable 43 is slacked off with resultant lowering of the stock rod weight 44 into the furnace and opening of valve 26 and closing of valve 24. The gas under pressure in chamber. 20 bleeds out through pipe 25 to the atmosphere. Then the above described operation may be repeated.

It will be noted that a valve 60 is shown in conduit 5| which conducts gases away from the top of the washer l6. This valve 50 serves to control the-gas pressure existing in the top part of the furnace, in the gas conduits and in the dust catcher and washer. By suitably adjusting the position of the valve, gas pressures in these parts may be regulated so that pressures higher than conventional pressures may be used, for example, pressures of 5 pounds or more p. s. i. gauge may thus be maintained in the furnace dust catcher and washer.

Although we have shown and described only one embodiment of our present invention, we contemplate others of substantially the same effect and equivalent construction, as will be understood by those skilled in the art. We have in mind,-for instance, operating

valves

24 and 26 independently of the stock rod in installations where such independence is desirable. In such.

case instead of

cables

43 and 46 being connected as shown in Fig. 2, each would be free and clear of the other.

Having thus described the invention so that A others skilled in the art may be able to understand and practice the same, we state that what we desire to secure by Letters Patent is defined in what is claimed.

What is claimed is:

l. The method of operating a blast furnace having a bell chamber which comprises the steps of removing from the furnace top gases carrying entrained solids and having the pressures existing in the furnace about the stock line, removing solids from substantially all of said gases, separating the thus cleaned gas into a constantly flowing stream and a stream flowing intermittently to said bell chamber, maintaining the pressures of the gases while being cleaned and in the streams of cleaned gases at approximately the pressures existing above the furnace stock line, and releasing gases from the asaaeoo intermittently flowing stream to the atmosphere when the'pressure above-the furnace stock line and in last mentioned stream reaches a predetermined pressure above the normal furnace stocl: linepressure.

2. The method of operating a blast furnace having a bell chamber which comprises the steps of removing from the furnace top gases carrying entrained solids and having the pressures existing inthe'furnace above the stock line, removing solids from substantially all of said gases, separating the thus cleaned gas into two streams, maintaining the pressures of the gases while being cleaned and in the streams of cleaned gases at approximately the pressures existing above the furnace stock line, and periodically releasing gases from one of said streams into the bell chamber of the furnace and from the other stream into theatmosphere.

3. Themethod of operating a blast furnace having a bell chamber which comprises the steps of removing from the furnace top gases carrying entrained solids and having the pressures existing in the furnace above the stock line, removing solids from substantially all .of said gases, separating the -thus cleaned gas into two streams, maintaining the pressures of the gases while being cleaned and in the streams of cleaned gases at approximately the pressures existing above the furnace stock line, periodically releasing gases from one of said streams into the bell chamber of the furnace during charging of solids into the furnace and to the atmosphere from same stream when the pressure above the furnace stock line and in said stream reaches a predetermined pressure above the normal furnace stock line pressure.

4. In apparatus of the class described, a blast furnace having a bell chamber, a gas cleaner and -a conduit from said cleaner to a gas main, a conduit connecting the top of the furnace with the cleaner to conduct top furnace gases to said cleaner, a bleeder to permit escape of top gases from the second conduit when such gases attain a predetermined high pressure above their normal pressures, a pipe communicating at one end with said cleaner and having a main outlet to the atmosphere and a branch outlet having a control valve to the bell chamber, a valve for said main outlet, and means for opening said main outlet mined pressure of top furnace gases which is below said high pressure and above the normal top gas pressure. 1

5. In apparatus of the class described, a blast furnace having a bell chamber, a gas cleaner, a conduit from said cleaner to a gas main, a conduit connecting the top, of the furnace with the cleaner to conduct top furnace gases to said cleaner, a bleeder to permit escape of top gases from the furnace when such gases attain a predetermined high pressure above their normal pressures, a pipe communicating at one end with said cleaner and having a main outlet to the atmosphere and a branch outlet having a control valve to the bell chamber, a valve for said main outlet, a valve for said bleeder, and means responsive to said predetermined high pressure of top furnace gases to open said bleeder valve and 1 means responsive to a predetermined gas pressure below said high pressure and above normal top gas pressure to open said main outlet valve.

KURT G. LE VISEUR. LEONARD LARSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 721,418 Berg Feb. 24, 1903 759,991 Hamfeldt May 17, 1904 1,727,100 Edwards Sept. 3. 1929 1,856,897 Whitcomb May 3, 1932 1,881,272 Grilli Oct; 4, 1932 2,200,488 Clemmitt et a1. May 14, 1940 2,215,872 Fox et a1. Sept. 24, 1940 2,408,945 Mohr, Jr., et a1. Oct. 8, 1946 2,411,487 Whitcomb Nov. 19, 1946 2,516,190 Daugherty July 25, 1950 OTHER REFERENCES American Institute of Mining and Metallurgical Engineers, Transactions, Iron and Steel Division,

' vol. 67 (1922), pages-609 and 615.

J. H. Slater: Operation of the Iron Blast Furnace at High Pressure, Yearbook of the American Iron and Steel Institute for 1947, May 21, 1947, pages to 127.