US3385587A

US3385587A - High-capacity multijet oxygen lances

Info

Publication number: US3385587A
Application number: US457387A
Authority: US
Inventors: George H Smith
Original assignee: Union Carbide Corp
Current assignee: Union Carbide Corp
Priority date: 1965-05-20
Filing date: 1965-05-20
Publication date: 1968-05-28
Anticipated expiration: 1985-05-28
Also published as: GB1082887A; DE1508271A1

Description

May 28, 1968- G. H. SMITH 3,385,587

HIGHCAPACITY MULTIJET OXYGEN LANCES Filed May 20, 1965 2 Sheets-Sheet 1 INVENTOR GEORGE H. SMITH United States Patent 3 385 587 ntoH-cAPAcrrY Murrimr OXYGEN LANCES George H. Smith, New Providence, N.J., assignor to Union Carbide Corporation, a corporation of New York Filed May 26, 1965, Ser. No. 457,387 5 Claims. ((31. 266-34) ABSTRACT OF THE DKSCLGSURE A forged oxygen jet tip having a plurality of oxygen passages, and a plurality of clusters of cooperating cooling water passages located in the body of the tip, between the oxygen passages for coolin the tip especially in the critical zones adjacent the front face of the tip. The inlet passages for the relatively cold water are located closer to the working face of the tip than the outlet passages for the relatively hot water so that incipient steam bubbles are swept upwardly out of such outlet passages by the combination of the water flow and thermal convection currents.

This invention relates to metallurgical lances, and more particularly to multijet oxygen lances for use in making steel with oxygen.

The invention provides a lance comprising tip composed of thermally conductive metal having a plurality of downwardly extending oxygen discharge ports that diverge outwardly with respect to the vertical axis of the lance, and a plurality of clusters of uniquely cooperating cooling water passages for keeping the tip cool in use, especially in critical zones thereof adjacent the front face of tip between such ports. The relatively cold water inlets of such passages are located closer to the working face of the tip than the relatively hot water outlets thereof, whereby incipient steam bubbles are swept upwardly out of such outlet passages by the combination of the water flow and thermal convection currents, inhibiting undesirable trapping of such bubbles in such passages especially in the zones closest to such face.

The main object of this invention is to increase the useful life of lance tips by the provision of a novel cooling water passage system for adequately cooling the tip in use for several hundred hours, thereby making it possible to reduce the cost of making steel.

In the drawings:

FIGURE 1 is an isometric perspective view of a tip illustrating the invention; and

FIGURE -2 is a vertical section of a lance provided with such tip.

Referring to the drawings, the illustrated tip 10 is composed of good thermally conductive material, such as oxygen-free copper, preferably made by forging as distinguished from casting. The tip is provided with a plurality of oxygen gas outlet ports 12, three of which are used in the illustrated assembly, but more may be used. As a matter of fact, six or as many as ten are possible. The ports 12 are preferably arranged symmetrically about the vertical axis of the lance, or subst-antially equally spaced from one another, and extend downwardly from the top surface .14 to the bottom face 16 of the tip. The ports 12 also diverge outwardly from such axis, preferably from a common point 18 intersecting such axis above the upper surface 14. The ports are made as large as possible to get the maximum capacity out of a given tip.

The tip is also provided with an upwardly facing,

3,385,587 Patented May 28, 1968 annular channel 20 for cooling water located adjacent the lower outer end 22 and side wall 24 of the tip. Such channel 20 encircles the ports 12, the inner side wall 26 of the channel merging with a conical wall surface 28. Located in and below the bottom of the channel 20 are a plurality of equally spaced upwardly facing cooling water sockets 30. The bottom-s 32 of such sockets are preferably hemispherical.

A plurality of relatively short cooling water passages 34 extend inwardly and downwardly into the tip from the inner side 26 of the channel 20. A plurality of vertical cooling water passages 36 extend downwardly from the upper surface 14 of the tip so that the lower end of each mates with the bottom end of a corresponding one of the short passages 34. The upper ends of each :of the vertical passages 36 is closed by a plug 38, welded or soldered in place.

The tip 10 is also provided with a plurality of relatively long, downwardly inclined cooling water passages 40 which also extend inwardly from the inner side of the conical wall surface 28 just above the area where the inner side 26 of the channel merges with such surface. The lower ends of all of such relatively long passages 40 terminate in a common zone 42 located in the center of the tip adjacent the front face 16 thereof. A plurality of upwardly and outwardly inclined intermediate cooling water passages 44 extend from such zones 42. Each of the elongated passages 40 in such zone communicates with a corresponding intermediate passage 44.

The upper ends of the intermediate passages 44 are connected to corresponding enlarged cooling water passage-s 46, each of which is in communication with the outer end of a corresponding one of the intermediate passages 44, and the side of which is in communication with two of the vertical passages 36, one "at each side thereof. All of the cooling water passages are preferably made by drilling the metal of the tip in the locations indicated. The cooling water passages are arranged in clusters, as shown, there being a cluster located between each pair of oxygen ports.

The lower end of a cylindrical wall 48, preferably composed of steel, is located substantially in the center of the channel 20 for separating cooling water flowing downwardly toward the tip from water flowing upwardly away from the tip, as indicated by the arrows. The wall 48 is provided with an inclined hole 50 corresponding to each enlarged passage 46, and an inclined short water tube 52 fits into such hole and the corresponding enlarged passage.

The lower end of an inner pipe 54 is connected by an annular Weld 55 to the upper-inner rim 56 of the tip 10 for conducting oxygen gas downwardly to the ports 12. An outer pipe 58 is connected at its lower end by an annular weld 59 to the lower outer im 60 of the tip. The pipe 58 is substantially concentrically related to the cylindrical wall 48 and is spaced therefrom to provide an annular outlet way 62, the annular space between the inner pipe 54 and the intermediate wall 48 providing an inlet way 64 for the cooling water.

The interior of pipe 54 is connected to a suitable oxygen supply under pressure, and is about 50 feet long. Similarly, the water inlet way 64 is connected to a cooling water supply, and the outlet way 62 to a drain. The intermediate cylindrical wall 48 and the outer pipe 5'8 are also about 50 feet long.

In operation, the lance is lowered into a stcelmaking furnace, not shown, with the tip from three to ten feet above the level of the molten steel in the furnace. Oxygen is supplied to the inner pipe 54 and flows out of the tip 10 through the ports 12, reacting violently with the molten iron. Cooling water is supplied to the tip through the annular inlet way 64, and flows downwardly through the sockets 30 adjacent the hemispherical bottoms 32 thereof, to cool the face 16 of the tip 10 adjacent the lower annular corner thereof, increasing heat flow in such zones due to the fact that the water is relatively cold and the surface areas in contact therewith are relatively large by virtue of the hemispherical shape.

Also, the water flows at a relatively high velocity through the sockets under the intermediate wall 48, the free How area of the water out of the sockets being less than that of the water entering such sockets. This creates a pressure drop therebetween which also forces water to flow through the inclined and vertical passages 34, 36, 4t), 44, 46 and 50, cooling the tip in the zones located between the oxygen ports 12 and adjacent the face 16 in the central zone 42. The zone 66 of the tip adjacent the lower ends of the passages 34 and 36 are also kept cool.

Lances incorporating the invention have proved to be quite successful in actual use in the oxygen steel making process, lasting for hundreds of heats, i.e., approximately double the life of prior multijet forged tip lances. This is due primarily to the unique cooling water passage system of the invention, because vital zones adjacent the face of the tip, between the oxygen ports, are much more adequately cooled than any tips of the prior art. The ports are so arranged so that if boiling should happen to take place, the rising of steam bubbles promotes most beneficial circulation of the water in all of the vital and critical areas involved.

The size and location of the cooling water passages comprising each cluster are such that the cooling water is constrained to flow in the desired and most efiicient direction through such passages to keep the metal adjacent the face of the tip relatively cool in use. By the use of multiple passages which intersect one another, the wetted area of the metal is increased. This also promotes better cooling of the metal of the tip in use.

As an actual working sample, a lance 10 inches in diameter, as illustrated in the drawing, was supplied with about 1 /2 million cu. ft./hr. of high purity oxygen, and about 35,000 gaL/hr. of water. This size lance is capable of making about 300 tons of steel per hour, and is good for several hundred hours or heats-a real advance in the art.

What is claimed is:

1. An oxygen jet tip composed of metal having a plurality of oxygen discharge ports, and cooling water inlet and outlet passages located in the body of the tip between such oxygen discharge ports, the relatively cold Water inlets of such passages being located closer to the working face of the tip than the relatively hot water outlets thereof, whereby incipient steam bubbles are swept upwardly out of such outlet passages by the combination of the water flow and thermal convection currents, inhibiting undesirable trapping of such bubbles in such passages especially in the zones closest to such face, said passages being arranged in clusters of relatively closely spaced passages to effectively increase the water to metal surface contact area and heat flow thereto by the resulting metal webs between the passages constituting each cluster, a common water annular discharge located adjacent the outer side of the tip, and means connecting the outlets of all of such outlet passages thereto.

2. A tip as defined by claim 1, in which the tip is forged and the water passages are drillings from the top and an annular wall surface of the tip body and the metal at the face of the tip is solid throughout, except for the oxygen orts therein.

3. An oxygen lance tip composed of thermally conductive metal having a plurality of oxygen gas outlet ports Cit arranged symmetrically about the vertical axis thereof, an upwardly facing annular channel for cooling water located adjacent the lower outer end and side wall of the tip encircling said ports, a plurality of equally spaced upwardly facing cooling water sockets at the bottom of said channel provided with hemispherical bottoms, a plurality of relatively short downwardly inclined cooling water passages extending inwardly from the inner side of such channel, a plurality of vertical cooling water passages the lower end of each mating with the bottom end of a corresponding one of such short passages, and the upper end being closed, a plurality of relatively long downwardly inclined cooling water passages also extending inwardly from the inner side of such channel and terminating adjacent the center of the tip, 'a plurality of upwardly inclined intermediate cooling water passages each of which mates with and extends outwardly from the inner end of the corresponding long passage, a plurality of enlarged water cooling passages each of which is in communication with the outer end of a corresponding one of such upwardly inclined intermediate passages, and the sides of which are in communication with two of such vertical passages, one of each side thereof.

4. A lance comprising in combination 'a tip as defined by claim 3, and a cylindrical wall the lower end of which is located substantially in the center of such channel for separating the cooling water flowing downwardly toward the tip from the water flowing upwardly away from such p;

an upwardly and outwardly inclined water tube fitting each of the enlarged passages and extending through a corresponding hole in said wall;

an inner pipe the lower end of which is connected to the upper-inner rim of said tip for conducting oxygen gas to the such ports; and

an outer pipe the lower end of which is connected to the outer rim of lower-outer rim of said tip;

said pipe being substantially concentrically related to said cylindrical wall and providing cooling water inlet and outlet ways in communication with the inner and outer sides of the annular channel in said p;

whereby cooling water flows downwardly through the sockets adjacent the hemispherical bottoms of such sockets under the lower edge of said wall, to cool the face of the tip adjacent the lower annular corner thereof, increasing heat flow in such zones due to the fact that the water is relatively cold and the surface areas in contact therewith are relatively large by virtue of the hemispherical shapes, and the water flows at a relatively high velocity therethrough, the free flow area of the water out the sockets being less than that of the water entering such sockets, thereby creating a pressure drop therebetween, which also forces water to flow through such inclined and vertical passages, cooling the tip in the zones located between the oxygen ports and adjacent the face at the center of the tip.

5. An oxygen jet tip composed of metal having a plurality of oxygen passages, and a plurality of cooling water passages located in the body of the tip between such oxygen discharge passages; said cooling water passages comprising a plurality of relatively short downwardly inclined inlet passages extending inwardly from the external side wall of the tip, a plurality of substantially vertical outlet passages the lower end of each connecting with the bottom end of a corresponding short inlet passage, said short inlet passages being located closer to the working face of the tip than said vertical outlet passages, a plurality of relatively long downwardly inclined inlet passages also extending inwardly from the external side Wall of the tip and terminating adjacent the center of the tip, and a plurality of upwardly inclined outlet passages each of which connects with and extends outwardly from the inner end of a corresponding long outlet passages.

5 6' inlet passage, said long inlet passages being located 3,045,997 7/1962 Hudson. closer to the working face of the tip than said inclined 3,071,363 1/ 1963 Mackay.

3,112,194 11/1963 De Vries. References Cited 3,130,252 4/ 1964 Metz.

5 3,141,763 7/1964 Foresi. UNITED STATES PATENTS 3,169,161 2/1964 Kurzinski. 12/1958 Cox 2663.41

2/1964 Whipple et a1. 239-1323 2/1967 Hutton 239-1323 I. SPENCER OVERHOLSER, Przmary Exammer. 2/1967 Hutton 239132.3 10 E. MAR, Assistant Examiner.