US3840219A

US3840219A - Tuyeres

Info

Publication number: US3840219A
Application number: US00385058A
Authority: US
Inventors: A Sheridan; I Stewart
Original assignee: British Steel Corp
Current assignee: British Steel PLC
Priority date: 1972-08-23
Filing date: 1973-08-02
Publication date: 1974-10-08
Anticipated expiration: 1991-10-08
Also published as: FR2197454A5; ES418093A1; CA998527A; SE401521B; NL7311530A; ZA735284B; IT996612B; JPS4986202A; GB1407078A; LU68272A1; DE2339997A1

Abstract

This invention relates to a water-cooled tuyere having an annular body of hollowed section and an inlet tube extending into the hollow terminating adjacent the nose in a lateral aperture. The tube passes through a ''half-baffle'' and the design of this member and the tube termination are such as to promote the maintenance of much higher velocities of the water coolant in the nose portion than hitherto. Good circulation is also maintained in the main body, the water following a spiral pattern. The tuyere is preferably monolithic and may readily be made from a single copper casting.

Description

United States Patent 1191 Sheridan et a1.

[451 Oct. 8, 1974 i 1 TUYERES [75] Inventors: Anthony Terence Sheridan, Tickhill;

Ian Stewart, Rotherham, both of England [73] Assignee: British Steel Corporation, London,

England [22] Filed: Aug. 2, 1973 [21] App]. No.: 385,058

[30] Foreign Application Priority Data Aug. 23, 1972 Great Britain 39247/72 [52] US. Cl 266/41, 110/1825, l22/6.6

[51] Int. Cl C21b 7/16 [58] Field of Search 266/35, 36 P, 41; 75/60;

[56] References Cited UNITED STATES PATENTS 6/1959 Eberhardt 266/41 12/1971 Uerlichs 266/41 Nothstein 110/1825 FOREIGN PATENTS OR APPLICATIONS v 152,566 10/1920 Great Britain 266/41 204.262 9/1923 Great Britain t. 122/66 446.866 5/1936 Great Britain 122/66 451.232 10/1927 Germany 266/41 Primary Examiner-Gerald A. Dost Attorney, Agent, or Firm-Bacon & Thomas [5 7 ABSTRACT This invention relates to a water-cooled tuyere having an annular body of hollowed section and an inlet tube extending into the hollow terminating adjacent the nose in a lateral aperture. The tube passes through a half-baffle and the design of this member and'the tube termination are such as to promote the maintenance of much higher velocities of the water coolant in the nose portion than hitherto. Good circulation is also maintained in the main body, the water following a spiral pattern The tuyere is preferably monolithic and may readily be made from a single copper casting.

10 Claims, 7 Drawing Figures TUYERES failure, and a uniform flow pattern is desirable to prevent local hot spots.

Various designs have been adopted hitherto with these characteristics in mind but difficulty has been experienced in making a satisfactory design compatible with simplicity in manufacture and reliability in service. Further, composite tuyeres incorporating separate nose and body sections have been fabricated and secured to gether by fusion techniques but frequently these lead to failure in sevice in the fusion zone.

It is an object of this invention to mitigate some or all of the above drawbacks.

From one aspect the present invention provides a tuyere comprising an annular body of hollowed section for accommodating a liquid coolant, and an inlet tube extending from the rear end of the body into the hollow and terminating adjacent the nose in a lateral aperture, the body having an outlet in the rear and a baffle fin adjacent the nose extending around the interior of the hollow body and through which the tube extends, the disposition and design of the tube termination and the baffle together promoting a uniform unidirectional flow pattern around the nose.

Preferably the baffle extends from the outer wall of the body by an amount greater than half the width of the hollow, and a gap may be provided in an otherwise continuous symmetrical design of this baffle for accommodating the tube. Further baffle fins of this type may be provided along the length of the body.

The whole body of the tuyere may be monolithic and may be cast in a conventional manner in, e.g. copper alternatively, the tuyere may be forged, the baffle fin being welded in position.

With a tuyere in accordance with this invention much higher velocities of the coolant (water) may be maintained in the critical nose portion than with other comparable designs hitherto, the half baffle being quite sufficient to maintain the required velocity around the whole circumference by reason of the high inertia of the coolant issuing from the tube. In addition good circulation is promoted in the main body of the tuyere, the water following a spiral pattern. The provision of the baffle also improves performance by effecting heat transfer, being cooled on both sides, and this characteristic is more marked if more baffle fins are employed. The pressure drop may be higher than that experienced on current tuyeres of other designs depending on the diameter of the inlet tube but in the majority of cases this will be masked by the much greater pressure drops occasioned by the entry and exit pipework. Thus this or hot blast cupolas etc.

This invention thus provides a tuyere of markedly improved efficiency and is relatively inexpensive to manufacture since traditional casting techniques may be employed, there being no problem of core removal, cleaning out, etc.

In order that this invention may be fully understood two embodiments thereof will now be described, by way of example, with reference to the accompanying drawings in which:

FIG. 1 illustrates an axial section through a tuyere in accordance with this invention;

FIG. 2 illustrates a section on A A in FIG. 1;

FIG. 3 illustrates a detail of the inlet tube termination;

FIG. 4 illustrates an axial section through another tuyere in accordance with this invention incorporating a dipped nose; I

FIG. 5 illustrates a detail of the inlet tube termination in the FIG. 4 embodiment.

FIG. 6 illustrates a detail of an alternative inlet tube termination; and

FIG. 7 illustrates an axial section through a forged tuyere in accordance with this invention.

Referring now to FIGS. 1 and 2 in the drawings the tuyere comprises a cast copper body 1 of hollowed annular section having a central bore 2 through which a gas, e.g. air, is blasted.

The cavity (3) within the body is sealed apart from an outlet aperture 4 and an inlet aperture through which a tube 5 extends. A baffle fin 6 extends inwardly around the outer wall of the body by an amount slightly in excess of half the width of the hollow and is continuous apart from a break through which the tube 5 passes.

This tube terminates in the nose of the tuyere and has an aperture 7 in its side.

More particularly, the tube termination/aperture is produced by mitring a similar gauge tube 8 to the open end (FIG. 3), e.g. by brazing, and then machining a vee slot into the mitred section so as to define the aperture. This aperture is oriented tangentially in the annular gap and lies substantially midway between the baffle and the end wall at the nose.

In operation the water coolant is forced through the inlet tube 5 and, encouraged by the baffle, swirlsin a unidirectional fashion around the nose, following a spiral path around the body proper before issuing through the outlet 4. There are practically nostagnant regions in the flow path by reason of the pattern thus developed, the continuous circulation promoting very good heat-exchange characteristics. In this ,regard the effect of the tube in the flow path is minimised by appropriate dimensioning, a compromise being made between the conflicting requirements. of large tube diameter (for minimal pressure drop) and small tube diameter (for higher velocity flow and minimal interference to the flow pattern).

For example, in a practical arrangement, with a 12 inch diameter tuyere having an annular hollow of, say, 12 inches in length and a mean width of 2 to 2% inches, the tube diameter may conveniently be 1 inch. At a flow rate of 2500 gallons per hour a pressure drop of about 10 psi. is realised and this is quite acceptable for normal plant usage. In FIG. 4 there is shown a dip nose tuyere by which the blast is directed at an angle to the major axis of the tuyere. Like reference numerals identify the same parts as those shown in the previous figure but in this instance the tuyere orifice (9) is inclined downwardly. In addition the tube is constructed differently. In particular it is cranked at 10 so that it lies closer to the inner wall of the tuyere body than the outer wall, promoting better cooling over this latter region where it is more necessary.

The tube termination/aperture is also different from the previous one shown. In this instance (FIG. 5) a slot is machined in the lower side wall 11 so as to define a square-section recess 12 and an inclined disc 13 is brazed on to the tube end. The aperture thus formed is again oriented so as to promote tangential flow in the nose portion.

The modified tube termination and/or the cranked tube may of course also be used in the tuyere previously shown.

Although this invention has been described with reference to the particular embodiments illustrated, it is to be understood that ,various modifications may readily be made without departing from the scope of this invention. For example, the shape of the tuyere, the baffle and the tube are not to be regarded as restrictive and the relative dimensions of these parts are not necessarily those giving optimum performance. The tube termination may indeed simply be constituted by a right-angled bend the cross-section then being circular throughout as shown in FIG. 6. Further, the tuyere may not necessarily be monolithic and may be fabricated, e.g. by forging outer and inner cylindrical sections 14 and 15 (FIG. 7) and joining them by a weld as shown. The rear section 16 would be welded to the body thus formed and the baffle would likewise also be welded in position. As shown, a plurality of such baffles may be incorporated in the tuyere and this latter feature may equally well be adopted in cast tuyeres.

We claim:

1. A tuyere comprising an annular body of hollowed section for receiving a liquid coolant. said body defining an outlet at its rear end communicating with the hollow.

an inlet tube extending from the rear end of the body into the hollow and terminating adjacent the nose of the tuyere in a lateral aperture, and

a baffle fin located adjacent the nose and extending around the interior of the hollow body partially across the width of the hollow. said tube extending through the baffle fin, the disposition and design of the tube termination and the baffle fin together promoting a uniform unidirectional flow pattern of the coolant around the nose.

2. A tuyere according to claim 1, wherein said baffle fin defines a gap in its otherwise symmetrical design whereby to accommodate the tube, the tube lying closer to the downstream than the upstream end of the gap.

3. A tuyere according to claim 2. wherein the baffle fin extends from the outer wall of the body by an amount greater than half the width of the hollow.

4. A tuyere according to claim 3, wherein the tube aperture is formed in a side wall adjoining its end. the end orifice itself being sealed.

5. A tuyere according to claim 3. wherein the tube terminates in a right-angled bend so that its end orifice constitutes the said aperture, the cross-section of the tube being circular throughout.

6. A tuyere comprising an annular body of hollowed section for receiving water coolant, said body defining a water outlet at its rear end communicating with the hollow, I

an inlet tube for said water extending from the rear end of the body into the hollow and terminating adjacent the nose of the tuyere in a lateral aperture. and

a baffle fin located adjacent the nose and extending around the interior of the hollow body, the baffle fin extending inwardly from the outer wall of the body partially across the hollow by an amount greater than half the width thereof, and said tube extending through the baffle fin, the disposition and design of the tube termination and the baffle fin together promoting a uniform unidirectional flow pattern of the water around the nose and generating a spiral flow pattern throughout the hollow body.

7. A tuyere to claim 6, wherein said baffle fin is integrally cast with the annular body and defines a gap in its otherwise symmetrical design whereby to accommodate the tube. the tube lying closer to the downstream than the upstream end of the gap.

8. A tuyere according to claim 7, wherein the tube is so positioned or fabricated that it lies closer to the inner wall of the body along a major portion of its length than the outer wall of said body.

9. A tuyere according to claim 8, wherein a plurality of said baffle fins are disposed along the body.

10. A tuyere according to claim 6 wherein said body comprises a plurality of forged sections, said sections being secured together by welded joints, and wherein said baffle fin is welded to the forged body, the baffle fin defining a gap in its otherwise symmetrical design whereby to accommodate the tube, the tube lying closer to the downstream than the upstream end of the

Claims

1. A tuyere comprising an annular body of hollowed section for receiving a liquid coolant, said body defining an outlet at its rear end communicating with the hollow, an inlet tube extending from the rear end of the body into the hollow and terminating adjacent the nose of the tuyere in a lateral aperture, and a baffle fin located adjacent the nose and extending around the interior of the hollow body partially across the width of the hollow, said tube extending through the baffle fin, the disposition and design of the tube termination and the baffle fin together promoting a uniform unidirectional flow pattern of the coolant around the nose.

3. A tuyere according to claim 2, wherein the baffle fin extends from the outer wall of the body by an amount greater than half the width of the hollow.

4. A tuyere according to claim 3, wherein the tube aperture is formed in a side wall adjoining its end, the end orifice itself being sealed.

5. A tuyere according to claim 3, wherein the tube terminates in a right-angled bend so that its end orifice constitutes the said aperture, the cross-section of the tube being circular throughout.

6. A tuyere comprising an annular body of hollowed section for receiving water coolant, said body defining a water outlet at its rear end communicating with the hollow, an inlet tube for said water extending from the rear end of the body into the hollow and terminating adjacent the nose of the tuyere in a lateral aperture, and a baffle fin located adjacent the nose and extending around the interior of the hollow body, the baffle fin extending inwardly from the outer wall of the body partially across the hollow by an amount greater than half the width thereof, and said tube extending through the baffle fin, the disposition and design of the tube termination and the baffle fin together promoting a uniform unidirectional flow pattern of the water around the nose and generating a spiral flow pattern throughout the hollow body.

7. A tuyere to claim 6, wherein said baffle fin is integrally cast with the annular body and defines a gap in its otherwise symmetrical design whereby to accommodate the tube, the tube lying closer to the downstream than the upstream end of the gap.

10. A tuyere according to claim 6 wherein said body comprises a plurality of forged sections, said sections being secured together by welded joints, and wherein said baffle fin is welded to the forged body, the baffle fin defining a gap in its otherwise symmetrical design whereby to accommodate the tube, the tube lying closer to the downstream than the upstream end of the gap.