US3259143A - Cooled valve for high temperature gases - Google Patents

Description

July 5, 1966 R. A. POWELL ETAL Filed Nov. 6.

GOOLED VALVE FOR HIGH TEMPERATURE GASES 5 Sheets-Sheet 1 INVENTORS RUSSELL A. POWELL Y RUFUS EASTUN y 1966 R. A. POWELL ETAL 3,259,143

COOLED VALVE FOR HIGH TEMPERATURE GASES Filed Nov. 6. 1963 5 Sheets-Sheet 3 INVENTORS RU56ELL A. POWELL 4 RUFUS EASTON BY 15M Meir 2:5 02

y 5, 1966 R. A. POWELL ETAL 3,259,143

COOLED VALVE FOR HIGH TEMPERATURE GASES Filed Nov. 6. 1963 5 Sheets-Sheet 5 INVENTORS 21/555 ,4. POWELL RUFUS EASTU/V United States Patent 3,259,143 COOLED VALVE TEMPERATURE Russell A. Powell and Rufus Easton, Pittsburgh, Pa., as-

signors to Koppers Company, Inc., a corporation of Delaware Filed Nov. 6, 1963, Ser. No. 321,841 3 Claims. (Cl. 137-340) This invention relates to valves for controlling the fiow of high temperature gases and, particularly, to water cooled valves adapted to control the hot air blast to a metallurgical blast furnace.

Heretofore, valves of this type have been subject to failure due to warping, erosion and radial cracking at the seating surfaces because of the extreme heat to which they are subjected in metallurgical furnaces by the passage through the valve of high temperature gases up to 2500? F. This has caused problems in maintenance and continued operation of the furnace.

An object of this invention is to provide a valve which can operate for extended periods of time even in the case of hot blast valves which are subjected to extreme temperatures up to 3 000" F. In accordance with the invention, the valve is provided with cooling water passages in the closure disc and valve seat that are designed to give the maximum cooling water velocity in the areas subjected to the greatest heat. The high cooling water velocity provides rapid heat transfer away from these areas.

This invention contemplates a valve for a hot blast stove which is subjected to extreme heats from air passing through the valve wherein the housing of the valve has a hollow annular seat with means for introducing cooling media into and removing it from said seat, a Y

hollow closure disc for said seat having a double mushroom configuration to cooperate with the seat as the valve is opened and closed to control the flow of hot gases therethrough, the position of the disc being controlled by a stem which includes means for introducing cooling media into and removing it from said disc, and a cooling media control for the seat and the disc including solid inserts so shaped as to define passageways for cooling media so that the cooling liquid moves past the heated surface with the highest velocity at those locations where said seat and said disc are adapted to be in contact.

The above and further objects and novel features of the invent-ion will appear more fully from the following detailed description when the same is read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are not intended as a definition of the invention but are for the purpose of illustration only.

In the drawings wherein like parts are marked alike:

FIG. 1 illustrates a vertical section of an embodiment of the novel valve of the invention with portions broken away.

FIG. 2 illustrates an enlarged vertical cross section of the valve assembly on line IIII of FIG. 1; and

FIG. 3 is a plan view of the valve seat.

Refen'ing in more detail to FIG. 1 a portion of the upper valve housing 1 is substantially cylindrical in shape and is adapted to control the flow of hot gases as, for example, the hot air blast to a metallurgical blast furnace. The upper housing has an outlet duct 3 for the discharge of hot blast air, a top cover 5 and a valve seat 7 which is held in place between upper housing 1 and lower valve housing 9 by suitable means such flanges as 11 and bolts 14. Lower valve housing 9 contains an inlet passageway 15 for the hot blast air coming from the blast furnace stove.

A hollow closure disc 17 having a double mushroom configuration cooperates with valve seat 7 to close the "ice valve and stop the flow of air therethrough. The disc is positioned by a stem 19 that is connected to a suitable prime mover, such for example by a fluid ram as is conventional. Tubular stem 19 also contains a pipe 21 for introducing cooling water to disc 17. The tubular stem assembly 19, as illustrated, is connected to a standard air cylinder piston. A portion of the air cylinder sup port is shown at 25. Water inlet 27 and water outlet 29 are provided so that cooling water flows down through pipe 21 to disc 17 and then out through the annular space between stem 19 and pipe 21 to water outlet 29.

The foregoing description has described a conventional valve whose great disadvantage is that over a period of time it fails due to the extreme temperatures to which the valve seat and valve stem are subjected particularly in the areas where the two are in contact. It has been found, for example, that to provide an effective seal, the sealing surfaces must be finely machined and after the valve has been in service for a time erosion, cracking and warping of these surfaces causes leakage of extremely high temperature air through the valve which accelerates the process of deterioration. To correct the defect, the valve must be disassembled and the valve seat either rebored or replaced which is expensive and time consuming since the equipment must be shut down to effect repairs.

In accordance with this invention, a novel valve seat and closure disc is provided which greatly reduces these difiiculties and even permits the operation of the valve even when subjected to air at extreme heats up to 3000 F.

Referring now to FIG. 2, a solid lenticular shaped insert 31 of a suitable material such as mild steel, is placed within the closure disc 17 in spaced relationship to the inner surfaces of said disc and supponted by spacers 33. The spherical radius of the surface insert 31 is greater than the spherical radius of the inside surface of closure disc 17 so that they define a gradually narrowing annulus or passageway which reaches its narrowest width at the outer edge of closure disc 17 Where the disc comes in cont-act with valve seat 7. This variable passageway thus provides a thin, rapidly moving film of water in this area of greatest heating thereby providing a high rate of heat trans-fer which maximizes the cooling of disc 17 at the seating surface and surrounding areas. The cooling water flows in through pipe 21 through a hole in the center of insert 31 to the bottom of disc 17 and then up around the edge of insert 31 and out through the annular space between stem 19 and pipe 21.

There is provided for valve seat 7 a ring shaped insert 35 supported by spacers 37. A plurality of water inlets 39 introduce cooling water into distributor 41 defined by the shape of valve seat 7 and insert 35. A plurality of water outlets 43 are provided for the removal of cooling water from header 45 defined by valve seat 7 and insert ring 35. Insert ring 35 and valve seat 7 are of such dimensions and shapes to provide a narrow water passageway 47 in the area of the seating surface so as to provide a high velocity thin film of cooling water which optimizes the heat transfer from valve seat 17 to the cooling Water and provides maximum cooling of the valve seat 17 in the area subjected to the most extreme temperature.

The cooling water flows in inlets 39 to distributor 41 up through passageway 47 to header 45 and out through water outlets 43.

The foregoing has described the operation of a novel.

valve suitable for controlling the flow of high temperature gases. In operation, cooling water flows into water inlet 27 down through pipe 21 out through exits 22 at the bottom of closure disc 17, thence around and up through the space between elements 31 and 17 into the annular space between pipe 21 and stem 19 and up and out through water outlet 29. At the same time, cooling water flows into valve seat 7 through water inlets 39 to distributor 41 from which it flows into the narrow passageway 47 between elements 35 and 7 and up and around to header 45 from where it flows out of water outlets 43. The rapid flow of water through the narrow passageways provides maximum heat transfer away from the metal areas requiring the greatest cooling. An additional advantage in heat transfer is provided by the presence of the solid metal inserts themselves, which are cool, comparatively large metal bodies located close to the hottest parts of the disc and valve seat. The inserts can adsorb large amounts of radiant heat due to the large temperature gradient present and the very short distances between the inserts and the heated surfaces in the areas where the water passageways are narrowest. This novel valve in which the finely milled seating surfaces are effectively cooled is not subject to the erosion, cracking and warping which allows it to operate for extended periods of time without requiring maintenance.

We claim:

1. A valve for a hot blast stove comprising:

(a) a hollow seat;

(b) an insert in said hollow seat defining narrow annular fluid passages therein;

(c) means for introducing and removing cooling fluid from said annular fluid passages in said seat;

(d) a hollow valve disc having a lenticular configuration for cooperation with said valve seat to form a fiuid seal therewith;

(e) a tubular conduit joined to said disc for moving the same and having a fluid conducting passage there- (f) a lenticular shaped member fixed substantially coaxially within said hollow valve disc and annularly spaced therefrom, said annular spaces narrowing as the distance from the common axis increases and being narrowest adjacent the point of maximum width of said disc; and

(g) means to introduce cooling fluid into said disc annular spaces whereby the same traverses said annular spaces seriately and emerges from said disc via said tubular conduit.

2. The invention set forth in claim 1 further characterized in that:

(a) the annular spaces within said valve disc are so proportioned that the cooling fluid traverses said annular spaces at maximum velocity in a zone immediately adjacent the zone of contact between said disc and said valve seat.

3. A valve for a hot blast stove comprising:

(a) a hollow valve seat;

(b) a hollow valve disc having a double mushroom configuration adapted to cooperate with said valve seat and form a fluid seal therewith;

(c) a hollow valve stem joined to said disc for moving the same;

(d) an insert member coaxially fixed within said disc and annulariy spaced from the inner surface thereof, said insert member having an arcuate surface of less curvature than the adjacent inner surface of said disc whereby the annular space is narrower in the zone of contact between said disc and said seat than the annular space in the zone adjacent the common axis;

(e) a conduit coaxially disposed in said valve stem and communicating with the annular space in the zone of greatest width;

(f) means to conduct cooling fluid into said coaxial conduit and into said disc annular space whereby said fluid traverses said annular space at maximum velocity in the zone immediately adjacent the zone of contact between said disc and said seat and emerges from said disc via said hollow valve stem;

(g) an insert disposed in said hollow valve seat in spaced relation to the interior surfaces thereof forming annular fluid passages having minimum cross sectional dimensions in the zone immediately adjacent the zone of contact between said disc and said seat;

(h) conduit means to introduce cooling fluid into the annular spaces of said valve seat, said fluid traversing the annular spaces in said valve seat at maximum velocity in the zone immediately adjacent the zone of contact between said disc and said said seat; and

(i) a fluid conduit communicating with the seat annular spaces for conducting said fluid therefrom.

References Cited by the Examiner UNITED STATES PATENTS 997,461 7/1911 McCarthy 137340 2,204,724 6/1940 Cope 137-640 2,575,875 11/1951 Johnson 137-340 OTHER REFERENCES German Application 1,106,572, Godel, May 1961.

M. CARY NELSON, Primary Examiner.

H. T. KLINKSIEK, Assistant Examiner.

Claims (1)

1. A VALVE FOR A HOT BLAST STOVE COMPRISING: (A) A HOLLOW SEAT; (B) AN INSERT IN SAID HOLLOW SEAT DEFINING NARROW ANNULAR FLUID PASSAGES THEREIN; (C) MEANS FOR INTRODUCING AND REMOVING COOLING FLUID FROM SAID ANNULAR FLUID PASSAGES IN SAID SEAT; (D) A HOLLOW VALVE DISC HAVING A LENTICULAR CONFIGURATION FOR COOPERATION WITH SAID VALVE SEAT TO FORM A FLUID SEAL THEREWITH; (E) A TUBULAR CONDUIT JOINED TO SAID DISC FOR MOVING THE SAME AND HAVING A FLUID CONDUCTING PASSAGE THEREING; (F) A LENTICULAR SHAPED MEMBER FIXED SUBSTANTIALLY COAXIALLY WITHIN SAID HOLLOW VALVE DISC AND ANNULARLY SPACED THEREFROM, SAID ANNULAR SPACES NARROWING AS THE DISTANCE FROM THE COMMON AXIS INCREASES AND BEING NARROWEST ADJACNET THE POINT OF MAXIMUM WIDTH OF SAID DISC; AND (G) MEANS TO INTRODUCE COOLING FLUID INTO SAID DISC ANNULAR SPACES WHEREBY THE SAME TRANSVERSE SAID ANNULAR SPACES SERIATELY AND EMERGES FROM SAID DISC VIA SAID TUBULAR CONDUIT.

Images