US2721065A - Blast furnace pressure regulator - Google Patents

Description

Oct. 18, 1955 w J INGRAM BLAST FURNACE PRESSURE REGULATOR Filed May 51, 1952 Inven for United States Patent BLAST FURNACE PRESSURE REGULATOR Walter J. Ingram, Chicago, Ill.

Application May 31, 1952, Serial No. 291,003

1 Claim. (Cl. 261-124) This invention is directed to an improved system and apparatus for pressurized operation of blast furnaces.

In the operation of blast furnaces it has been found that pressurized operation, that is to say, operation of the furnace by maintaining the gases escaping from the furnace at a pressure higher than normal, leads to greater elficiency in furnace operation. In conventional practice the pressure of these gases escaping from the blast furnace is slowly built up over a period of several days.

The gases escaping from the blast furnace in this type of operation are generally put to some useful purpose. They may, for example, be utilized in the same area of operations where the blast furnace is employed to serve as a fuel in gas burners. On the other hand, the escaping gases may be sold to consumers for other uses. The escaping gases should be relatively free from impurities for these reasons.

Accordingly, it is an object of my invention to provide a system of operation of blast furnaces wherein a pressure regulating device employed to build up the pressure of the gases flowing from the blast furnace also subjects the gases to a washing action to free the gases from impurities.

Another object of this invention is to facilitate the pressure operation of blast furnaces and the like.

A further object of my invention is to construct an improved pressure regulator which is automatically responsive to the pressure of the gases flowing from the blast furnace to maintain the pressure of the gases at a predetermined datum or level.

A further object of this invention is the provision of pressure regulating means for gases flowing in a conduit which is self-cleaning and maintains its efliciency for sustained periods of time.

A still further object of this invention is the provision of an improved system of operation or pressure regulators which includes novel means for selectively varying the datum or set pressure of the flowing gases.

Other objects will appear from time to time in the course of the ensuing specification and claim.

Referring now to the drawing, the figure is an elevational view of my apparatus and system as employed with a blast furnace with some parts in sectional form for purposes of clarity.

Referring specifically now to the drawing wherein like parts are designated by like characters throughout, A designates a blast furnace of conventional construction, details of which do not form a part of my invention. Disposed at the upper end is a gas outlet passage in the form of a conduit 3 which conducts gases from the furnace. C represents a second conduit or passage adapted to direct and carry gases from the outlet conduit B to any suitable structure, adapted to dispose of the gases. It will be understood that gases may flow from the blast furnace A through the outlet passage B and to the end of the passage C from whence they may be delivered to any suitable main or similar structure designed to carry the gases for consumer or other use. Intermediate "ice the furnace A and the passage C of the gas outlet passage is a suitable dust catcher D connected to outlet passage B and a primary gas washer E connected to dust catcher D. The primary gas washer B may take the form of a series of guides or the like having a liquid spray directed along the guides so that the gases passing from the blast furnace A to the outlet C must pass through the spray of liquid, thus providing a washing action of the gases that pass through the washer E. It will be understood that this form of washer is old and well known and the details of the washer do not form part of my invention. Essentially, the water spray will collect particles of dust or other impurities carried by the gases and carry them to the lower portion of the washing structure where they may be suitably drained oif.

Since all impurities are usually not removed from the gases by the primary gas washer, I provide a secondary gas washer in the line of flow of gases. In this secondary washer the gases are forced to pass through a body of liquid. The body of liquid serves to collect impurities carried by the gases and serves also to regulate the pressure of the flowing gases.

Designated generally at F is a secondary gas Washer which also serves as a pressure regulator. The secondary washer F is preferably positioned intermediate the primary gas washer E and the second conduit C. The device includes a means which is responsive to the pressure of the gases flowing in the passage B to automatically raise or lower this pressure in order to maintain the pressure at a predetermined datum. The device includes an inner conduit 1 disposed generally vertically, having a curved upper end In in communication with gas washer E, and having a lower end 2 formed with a series of apertures 3 which are arranged in parallel rows around the periphery of conduit 1 and spaced at equal intervals in the vertical plane. Any number of rows necessary to bring about the desired result may be employed. Gases flowing from the outlet passage B and through the inner conduit 1 may escape through these apertures or openings 3. Since the pressure of a moving fluid is approximately inversely proportional to the cross sectional area of a passage through which the fluid may pass, it is apparent that an increase or decrease in the number of open apertures in the inner conduit 1 will result in a fall or rise in pressure of the flowing gases. By varying the number of apertures through which the gases may pass, the pressure of the gases flowing in the inner conduit 1 will be accordingly varied. That is to say, when a large number of openings permit the passage of gas therethrough, the pressure of the flowing gases will be at a relatively low amount. When a smaller number of openings or perforations permit the passage of gases therethrough, the flow of gases in the conduit 1 will be accordingly restricted and the pressure of the flowing gases will rise.

A gas outlet port 11) is provided in the upper end of the inner conduit 1. Port 112 provides for the escape of gas from the inner conduit when all of the apertures 3 are closed. When maximum pressure is desired, all of the apertures 3 are closed and the port 1b affords the only escape of gas from the inner conduit 1.

While any number of apertures or openings 3 may be provided in the inner conduit 1, it will be apparent that the combined outlet area of all of the apertures should be at least equal to the cross-sectional area of the inner conduit 1, in order to provide for substantially no restriction on the flow of gases when all of the apertures are open.

In order to selectively vary the number of openings or perforations through which the gases may pass, I provide means for opening and closing the apertures. This means takes the form of an outer conduit or vessel 4 which may be cylindrical or rectangular in form or any other suitable form of a closed vessel. The outer conduit 4 suresets. the hue! squish! 24 has as we; end all in sealing engagement with the inner conduit 1. It will be apparent that the walls of the outer conduit 4 are eated sin s the huesqs u t The outer etf' git th lower end po ti n e w ll Q whish is e rally e' niea and i sweet! a. ub anti d stance h l wer ar of th inner ondui Oh e esnsl t s terme and. ada t d o co ain a s itable l u d sueh as Water shown th ra as ha in a ev 7 Wh n t e level o he qu d d s at d generally a 7 i heated above he u permo t series o ape ures 3. and h samenressu e s m i ned i t a ou le pas e B..- sus the o er eqnd t 4 abo e the liq id evel 7, i wi l be a paren that h l quid n ute c du w ll nsid t e inne onduit 1 ug t op n lower end 2.4 2 a l vel appro imati g vel 7 of liquid in e ou er nnduit- Th s follow h well-known rule h t the height of a column of liquid is dependent upon the pres sure 9f thearea above the column. As the pressure of gases in the inner conduit is greater or less than the pres sure of gases in the outer conduit, the level of liquid in the inner eorrduit will be lower or higher than the level of'liquid in the Outer conduit, as the case may be. In my system, this lowering and raising of the liquid in the inner conduit is "utilized to vary the number of apertures, or outlet area, for the gases flowing from the inner conduit to the Outer conduit or vessel and thus control the pressure of the flowing gases.

It will be apparent that upon occurrence of a rise of pressure in the inner conduit, the liquid level in the inner conduit will be forced downwardly a sufficient amount to uncover some of the apertures 3 in the lower end 2 of the inner conduit. Upon the uncovering or opening of these aperturesiby the fall of liquid level in the inner conduit, an outlet for the flowing gases will be provided and tlre'pressure of the gases will fall an amount proport tl l t0 t umber of perforations opened. As the gases pass through the apertures, they will flow upwardly h u h the liquid, which serves to trap impurities car: ried by the gases. By raising or lowering the head of liquid the outer conduit 4, the pressure .of gases in the nner pnduit .1 may he maintained at any desired level or datum, b f re passin outw rdly throug an p n 8 n h upper end or the outer conduit 4 to which the as ou l tpassageuiseonneeted.

When it is ,desired to operate the furnace A at a certain 'pressure, the liquid in the outer conduit 4 is raised to a 1 sufliei nt to close enough apertures in theinner conduit to properly restrict the flow of gases and bring about the desired pressure.

I provide a means for varying the level of liquid .or head of liquid inside the outer conduit 4. This means takes the form .Of an adjustable conduit 9 in communication with the outer conduit 4. While one conduit is shown, any number may be employed. The conduit 9 is preferably flexible and may be formed of any suitable material .such as rubber or a rubber compound. Conduit 9 hasone end portion 10 in communication with the lower endlof the outer conduit 4 by means of a suitable coupling 11. The other end 12 of the conduit 9 is open and is '4 V which is joined to and in communication with the lower enabrur outer conduit or vessel 4 as 'at 21. Any suitable check valve 22 is disposed in the outlet passage in order to regulate the flow of liquid therethrough. Reservoir 18 is positioned beneath the adjustable conduit 9. In operation, the pump delivers fluid from the reservoir to the outer conduit 4, through the adjustable conduit 9, and then back to the reservoir. As liquid is continuously lated it wil sp ll saver the inn u let d o the adjustable conduit 9 and flow downwardly into the reservoir 18. The height'of' the liquid in the outer conduit 4 is ruises b thehei ht .e th d us b e c nd For example, by raising and lowering the adjustable conduit 9 through the medium of the winches 13 and 14, the level of liquid 7 in the outer conduit 4 will be accordingly raised or lowered. Suitable means, such as a spigot 22a, connected to any suitable source, may be employed ts tl liyer s sliti hsl fl a de t t reservoir s as s sw hem the .h he s iislh 1 to the tle smash Q h ough he a er es 3 i through the liquid s he ester 9 149 4 the l .Iesleive W in by the iqu d impurities harried b th gases Will PP hy the hts athe mit sh h t 4 an e impurities n earned f b th .sit ul i li ui a be drained off rom the ate ssnsi i 4 th u h the medium of whable .vglve member 23. Suitable gas drying means such as a. rie haflle st u ure t e be interposed i the spies .eh 9 th est hd 4 s that any liquid rie b he a es ma he ll s d b t bathe Structures and t tt ue t9 t quid in the Outer sqhdvit T further the drying process, the gas outlet passage C may he t med ith a eve se i r i- 9-: it Insy be di d upward em h Q et esndv t 4121s t 24 a e e curveddownwardly as at 25 and then curve upwardly a a n a a 26 in enter t c le t t e li ab mean shah a a eye sed sun e e ca y disposed Pa a 27. a in a a liquid s al a st th e ea e of se may be empl yed to e iqu e l e t in the rv supported by suitable winches 13 and 14 and cables 15 V and 1.6. The winches rnay be rotated by suitable motors M to take in or let out the cables 15 and 16. Since these winch assemblies may take any one of several formsfit is not thought necessary to illustrate them in detail and therefore they are shown diagrammatically in the figure. Essentially, the winches serve to raise and lower the 7 upper end 12 of the conduit 9. The level of liquid in the iQ-and delivering fluid through an outlet passage 20 28 designates a liquid seal in communication with the upper end o he ou e cond t 4 a d a -sh p Portion 30 end ne i u a d y fr m he membe 9- U- hap d PQI iQI 39 eenta h a y i e q d a p e e ap of gas hrou h he iq se l 2. .Hew r, hou d the level of liquid 7 in the outer conduit 4 rise to the le el o th m m er 2.9, t e q id in the out r on i will flow through the member 29, U-shaped portion 3!! an ou hro gh an ou le 31, hus p i g a m ximum limitfor the level of liquid in the outer conduit 4.

a A qui k op ing alve memb r 32 y e po ed in a conduit 33 positioned adjacent the lower end of the outer cylindrical conduit 4 in order to provide a means for lowering the level of liquid in the outer conduit 4 in case the win hes 13 and 14 are inoperative for any reason.

Although I have shown an operative form of my invention, it will be recognized that many changes in the form, shape and arrangement of parts can be made without departing from the spirit of the invention, and my showing is, therefore, to be taken as, in a sense, diagrammaticjand not in any limiting sense, and the invention herein should be limited only as defined by the scope of thehereinafter appended claim. V

The use and operation of my invention are as follows:

Assuming that operation of the blast furnace A is initiated and that a gradual build up of pressure in the outlet passage B is desired, the pump 17 is set in operation to circulate liquid through the outer conduit 4, adjustable conduit 9, and then back to the reservoir 18. The adjustable conduit 9 is then raised an amount suflicient to close some of the apertures 3 in the lower end of the inner conduit 1 which will result in restriction on the flow of gases from the inner conduit to the outlet passage 0.

It will be understood that when raising the pressure in the outletpassage 'B of the furnace to the desired amount, it is preferable to move up to the desired pressure in small increments; that is to say, with an ultimate desired pressure twelve pounds per square inch, or twenty-eight feet of water, the adjustable conduit 9 would be raised in increments or step by step to come up to this desired working pressure. The adjustable conduit may be raised, for example, to a height necessary to operate at a pressure of three pounds per square inch and after operating the furnace at that pressure for a period of time the adjustable conduit would be raised another step or increment to bring the pressure up to approximately six pounds per square inch. In other words, the pressure in the outlet passage B is gradually built up by a series of pressure stages through the medium of the adjustable conduit 9.

When the desired working pressure, or datum pressure, is obtained by the proper positioning of the adjustable conduit 9, any increase in pressure over that datum level will result in forcing the level of liquid in the inner conduit 1 downwardly, which in turn uncovers a larger number of apertures through which the gases may escape and the pressure is thus reduced. If it is assumed that the pressure of gases in the outlet passage B falls below the predetermined datum level, at which level certain of the apertures are closed and certain of the apertures are open, the level of liquid in the interior of conduit 1 will rise, thus closing a large number of apertures in the inner conduit and restricting the flow of gases from the inner conduit to the outer conduit, resulting in building up the pressure in the inner conduit and the outlet passage B to the datum level. As the datum pressure is approached, the number of open apertures will gradually increase until the proper number of apertures for the datum pressure are open and the system is operating at the datum pressure. The system is thus responsive to fluctuations in the operating pressure to raise or lower the pressure, as the case may be, to return the pressure in the outlet passage B to the predetermined datum.

Gases flowing from the blast furnace A will pass through the liquid in the outer conduit 4. Impurities carried by the gases will be trapped by the liquid. While the circulation of the liquid will ordinarily be suflicient to carry off these impurities, the valve 23 may be opened from time to time to drain impurities settled in the bottom of the outer conduit 4. At high working pressures, a large amount of liquid will be disposed in the outer vessel 4 to subject the gases to a greater washing action than that obtained at lower working pressures.

Under some conditions, the pressure of the flowing gases may fluctuate sufficiently to force the liquid in the outer conduit below its set level, and outwardly through conduit 9. The circulating system, including the pump, will restore the liquid to its proper set level. Increasing the speed of the pump will decrease the time required to restore the set level.

By reason of the fact that the apertures 3 are disposed below the level of liquid in the outer conduit 4, the device is in efiect self-cleaning, because the liquid may flow back and forth between the inner conduit 1 and the outer conduit 4 through the perforations 3, all of which tends to eliminate the accumulation of impurities collected in the apertures.

I claim:

A gas washing and pressure regulating system for blast furnaces including a gas outlet conduit adapted to carry gases under pressure from the furnace, said outlet conduit communicating through a vertically disposed pipe with a washing tank surrounding said pipe, said pipe having a plurality of vertically spaced rows of apertures in the lower end thereof for the passage of gas therethrough, said tank being adapted to contain a body of washing liquid into which the lower end of the pipe projects, and means for setting the pressure in said pipe at a predetermined datum including an upstanding openended flexible conduit communicating with the lower portion of said tank, means for raising and lowering said conduit to vary the level of liquid within said pipe, and means for circulating the washing liquid through said tank and through said flexible conduit, raising and lowering movement of said conduit being efiective to vary the number of apertures uncovered and covered by the liquid within said pipe and to thereby vary the effective outlet area through said apertures.

References Cited in the file of this patent UNITED STATES PATENTS 154,350 St. John Aug. 25, 1874 660,346 Swinnerton Oct. 23, 1900 712,368 Ebner Oct. 28, 1902 1,562,380 Stein Nov. 17, 1925 2,387,818 Wethly Oct. 30, 1945 2,435,898 Otto Feb. 10, 1948 FOREIGN PATENTS 1,182 Great Britain Ian. 17, 1903 370,219 Germany Feb. 28, 1923

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