US3674248A

US3674248A - Closed end tuyere coil

Info

Publication number: US3674248A
Application number: US79379A
Authority: US
Inventors: Donald J Shellenberger
Original assignee: Jones and Laughlin Steel Corp
Current assignee: Jones and Laughlin Steel Inc; Ltv Steel Co Inc
Priority date: 1970-10-09
Filing date: 1970-10-09
Publication date: 1972-07-04
Anticipated expiration: 1989-07-04
Also published as: CA935427A; DE2144348A1; FR2112278A1; GB1329885A; FR2112278B1; SU382300A3

Abstract

Tuyeres and like articles employed to deliver fluids in extremely hot environments include an arrangement for their cooling comprising a conduit in the form of a coil having a plurality of turns for passing a cooling fluid through the article at high velocities. The conduit consists of an outer tubular member closed at one end to fluid flow and an inner tubular member located within the outer tubular member so as to form an annular passageway between the members. The tubular members are in fluid communication adjacent the closed end of the outer member. Cooling fluid introduced into the conduit first passes through the conduit along the annular passageway, enters the inner tubular member adjacent the closed end of the outer member, and passes through the inner tubular member to exit from the conduit.

Description

July 4, 1972 United States Patent Shellenberger 541 CLOSED END TUYERE COIL FOREIGN PATENTS 0R APPucATloNs Inventor: Donald J. Shellenberger, Bethel Park, Pa.

7/1856 GreatBritain..................,.......

[73] Assignee:

Jones & Laughlin Steel Corporation, Pitt- Primary Examiner Roben D. Baldwin Sburgh AttameyT. A. Zalenski and G. R. Harris T C A R T S B A .H 5 0 7 9 l n 07 0 N 1 0- MP FA .4 22

Tuyeres and like articles employed to deliver fluids in extremely hot environments include an arrangement for their [52] [1.8. Cl.............;.................266/4l,110/1825,122/6.6,

cooling comprising a conduit in the form of a coil having a plurality of turns for passing a cooling fluid through the article at high velocities. The conduit consists of an outer tubular member closed at one end to fluid flow and an inner tubular member located within the outer tubular member so as to form an annular passageway between the members. The tubu- 56] Ref n Ci lar members are in fluid communication adjacent the closed end of the outer member. Cooling fluid introduced into the UNITED STATES PATENTS conduit first passes through the conduit along the annular er e mn t.m W6 h t .dg m m m s S e m u u .m MD. F l B umn .m .03 W u t m flbm D nmm 4 .m o m m m m n i tm h sm C m 4 t I ame se m m Wd wmm C r. da m m S m Pdw 22 XX ll22 55mm 66// fifi m l m u. no mm m mmm m m e cero SKKH 67 8356 8999 llll 007 2 9730 25000 1 ,9 5305 4 30 28 7 3 23 P'ATENTEDJUL' 4 mm 3.674.248

Fig.2

INVENTOR Donald JLSheHenberger 6 BY I his ATTORNEY CLOSED END TUYERE COIL This invention relates generally to equipment for use in transferring fluids in an extremely hot environment, and, more particularly, to tuyeres, monkeys and like apparatus having improved arrangements for their cooling for use with metallurgical furnaces.

Conventionally, tuyeres, monkeys and like apparatus used in extremely hot environments are provided with some arrangement for their cooling and their service life is dependent on the effectiveness of the cooling arrangement. While many techniques for cooling such apparatus have been developed, a need still exists for a cooling arrangement which will eliminate or at least substantially reduce the frequency of failures of such apparatus. The benefits to be gained by doing so are significant. For example, failures of blast furnace tuyeres, in addition to the cost of furnishing a replacement tuyere, result in a loss in hot metal capacity and efficiency which in turn increases coke consumption. Also, it is important that in case the tuyere fails along its forepart, the back of the tuyere continues to be cooled and is kept intact and in place. The hazards resulting from melting or yielding of the tuyere and the subsequent rupturing of the hot blast system at that point are well understood by those skilled in the blast-fumace art.

It is known that the heat transfer coefficient of a moving cooling fluid, such as water, increases as the velocity of the fluid increases, so long as the flow rate exceeds some minimum value. It is, of course, possible to obtain high velocities by employing high flow rates which in turn require high pressure drops; but for various reasons, it is unsatisfactory to provide a cooling arrangement for a tuyere or like apparatus which requires the use of high flow rates and high pressure drops.

Accordingly, an object of the invention is to provide tuyeres and like apparatus having a cooling arrangement by means of which improved cooling of the apparatus is obtained, thereby extending their service lives.

Another object of the invention is to provide such apparatus wherein the cooling arrangement enables extremely high cooling fluid velocities to be established at low flow rates and pressure drops.

Another object of the invention is to provide such apparatus wherein the cooling arrangement maintains the feed end of the apparatus cooled and intact even though the other end has failed.

These and other objects and advantages of the invention will appear from the following detailed description which in connection with the accompanying drawings describes embodiments of the invention presently preferred by me.

In the drawings, where like elements are designated by like reference characters throughout the several views:

FIG. I is a longitudinal view, partly in section, of a cooling arrangement embodying the principles of the invention;

FIG. 2 is a cross-sectional view of the cooling arrangement encased in a tuyere body;

FIG. 3 is a longitudinal view, partly in section, of the cooling arrangement embodied in a tuyere structure in a manner to form part of the hot blast conducting surface;

FIG. 4 is an enlarged cross-sectional view of a part of the cooling arrangement.

In FIG. 2, a tuyere generally indicated at comprises a body or shell 11 having a generally circular cross-sectional configuration. Body 11 is made of copper, copper alloy, aluminum alloy or other material of high thermal conductivity, and includes a back end portion, generally indicated at 12, and having a conical outer surface 14 and a front end portion, generally indicated at 13. In use, the tuyere is mounted in a blast furnace by means of back end portion 12, the outer surface 14 of which rests in a mating surface in a tuyere cooler mounted in the blast furnace wall. Substantially the entire front end portion 13 of the tuyere extends into the interior of the blast furnace, and hot blast is delivered into the furnace through passage 15 extending from the back end portion to the front end portion of the tuyere.

Encased in shell 11 is a cooling arrangement, generally indicated at 16 as shown in FIG. 1, for circulating a cooling fluid, such as water, through the tuyere to cool it and keep it from failing from the effect of the hot environment in which it is located. The cooling arrangement comprises a conduit in the form of a coil having a plurality of turns 17l7 for both supplying a cooling fluid to the tuyere and discharging the fluid from the tuyere. The conduit consists of an outer tubular member 18 closed at one end 19 to fluid flow and adapted to be connected to a source of water at its other end 20. Positioned within outer tubular member 18 is an inner tubular member 21 which is open to fluid flow at its end 22 adjacent the closed end 19 of member 18 and adapted to be connected to a means for receiving water discharged from the tuyere at its other end 23. The outer tubular member is constructed of copper, copper alloys or other material of high thermal conductivity. The inner tubular member can be constructed of a material of high thermal conductivity also, although satisfactory operation of the cooling arrangement does not require it.

The outside diameter of inner tubular member 21 is smaller than the inside diameter of outer tubular member 18 whereby the tubular members cooperate to form an annular conduit passageway 24, the inside surface of inner tubular member 21 forming a central conduit passageway 25. It will be understood that cooling water supplied to end 20 of outer tubular member 18 circulates through the conduit and tuyere by first passing along annular conduit passage 24, then entering central conduit passage 25 at its end 22, and passing therealong to be discharged from the tuyere at end 23. Spacing means 30, such as a copper rod of small diameter, is positioned between and along essentially the entire lengths of

tubular members

21 and 18 along the outside of turns 1717. This structure insures good cooling fluid flow along the outside of the turns, which is the area in a tuyere structure requiring the greatest amount of cooling. The spacing means provides essentially only a point contact between the inner and outer tubular members, whereas the absence of the spacing means might result in the inner and outer tubular members coming in much greater contact along the outside of turns 17-17 and essentially blocking off cooling fluid flow to that area.

In forming the spiral-shaped cooling conduit, a straight copper rod 30 is spot welded to a first straight length of tubing which is to constitute the member 21 and the tubing and rod are inserted within a second straight length of tubing which is to constitute member 18. The resulting; structure is coiled on a mandrel of appropriate shape and size,making sure that the rod 30 is along the outside of the turns that are formed. It will be understood that the passageway between the tubular members is not truly annular in shape, but may be considered as such for purposes of this description and the accompanying claims. After the cooling arrangement is formed, to manufacture the complete tuyere, the body or shell 11 is cast about the arrangement in accordance with conventional metal-casting techniques. If desired, the turns 17-17 can be welded together to facilitate casting and to preclude hot blast from escaping between the turns should they become exposed upon erosion of the shell by the hot materials: in the furnace.

Presently, I consider it advantageous to provide tubular members having dimensions such that a ratio of cross-sectional area of the central conduit passageway 25 to the crosssectional area of the annular conduit passageway 24 of at least about 2 to 1 is maintained. In this manner, I am able to maintain a cooling water velocity in the annular passageway in excess of about 25 feet/minute at a low flow rate and with only a low pressure drop in the central return passageway.

It will be noted that in case the front end portion 13 of the tuyere does fail and a breakout of the cooling arrangement 16 occurs, cooling water can continue to be supplied to the back end portion 12 of the tuyere to cool it and maintain it intact and in place.

In the embodiment of the invention shown in FIG. 3, the turns 17-17 of the conduit coil abut one another and are maintained in that relationship by welding the turns together as shown at 26-26. A flange 27 of copper, a copper alloy, aluminum alloy or some other material of high thermal conductivity is cast or fabricated about a number of turns 17-17 at one end of the coil. The flange has a conical surface 28 by means of which it is mounted in a mating surface of a tuyere cooler in a furnace wall. When so used, hot blast is conducted to the inside of the furnace over the inside surfaces 29-29 of the turns 17-17. Because the turns l717 are held in close abutment by welds 2626, which also serve to seal off any open spaces between successive turns, the hot blast passing through the inside of the coil along its longitudinal axis is confined within the coil and does not escape between the turns.

1 claim:

1. A tuyere, monkey or like article for use in a metallurgical furnace comprising a coil having a plurality of successive turns maintained in substantial abutment with one another, said coil including an outer tubular member closed at one end to fluid flow and an inner tubular member positioned within the outer tubular member, at least the outer tubular member being constructed of a material of high thermal conductivity, said tubular members cooperating to form an annular conduit passageway between them, said inner tubular member forming a central conduit passageway, the ratio of the cross-sectional area of the central conduit passageway to the cross-sectional area of the annular conduit passageway being at least about 2 to l and the annular conduit passageway and the central conduit passageway being in fluid communication adjacent the closed end of the outer tubular member, and flange means made of a material of high thermal conductivity secured to one end of said coil for positioning and retaining the coil in said furnace.

2. The article of claim 1 wherein the material of high thermal conductivity is one selected from the group consisting of copper, copper alloys and aluminum alloys.

3. The article of claim 1 wherein the entire coil is encased in a shell of a material of high thermal conductivity, said outer tubular member being in good heat conducting contact with the shell.

4. The article of claim 2 wherein the material of high thermal conductivity is one selected from the group consisting of copper, copper alloys and aluminum alloys.

Claims

1. A tuyere, monkey or like article for use in a metallurgical furnace comprising a coil having a plurality of successive turns maintained in substantial abutment with one another, said coil including an outer tubular member closed at one end to fluid flow and an inner tubular member positioned within the outer tubular member, at least the outer tubular member being constructed of a material of high thermal conductivity, said tubular members cooperating to form an annular conduit passageway between them, said inner tubular member forming a central conduit passageway, the ratio of the cross-sectional area of the central conduit passageway to the cross-sectional area of the annular conduit passageway being at least about 2 to 1 and the annular conduit passageway and the central conduit passageway being in fluid communication adjacent the closed end of the outer tubular member, and flange means made of a material of high thermal conductivity secured to one end of said coil for positioning and retaining the coil in said furnace.