CA1123598A

CA1123598A - Oxygen lance nozzle

Info

Publication number: CA1123598A
Application number: CA351,609A
Authority: CA
Inventors: Kenneth C. Sharp
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-06-19
Filing date: 1980-05-09
Publication date: 1982-05-18

Abstract

OXYGEN LANCE NOZZLE
ABSTRACT OF DISCLOSURE

This invention relates to apparatus for manufacturing steel from molten iron and in par-ticular, it relates to a lance of the type used in steel making utilizing a method involving a blown stream of oxygen.

Description

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OXYGEN LANCE NOZZLE
sACKGROUND OF THE INVENTION

A typical oxygenating processis the L~
process in which a long tube, called a lance, ls used to conduct high pressure oxygen onto the surface of molten iron in a converter. A typical lance may be approximate]y seventy five feet in length, or thereabout and has a nozzle close to the molten iron that is usually made of copper.
The oxygen lance nozzle is subject to very high temperatures, in excess of 2000C
when operating in a converter vessel, and its survival is due solely to the cooling arrangement utilized to reduce the temperature of the nozzle.
The cooling arrangement conventionally applied to the lance nozzle typically included water jackets around the oxygen supply bore; these jacXets defined annular water conduits for the inlet and outlet of cooling water~
In order for the cooling water to have an appreciable effect it was necessary that the copper walls between the surface of the lance tip and the cooling water be relatively thin. How~
ever, the copper walls are eroded during operation, with the possibility that dangerous water ingress into the converter became highly probable. This ~ ' danger is compounded by the fact that the cooling water is supplied at relatively high pressure to obtain the necessary transfer of heat.

SUMM~RY OF THE INVENTION
~ roadly speaking the present invention provides an oxygen lance nozzle including a block of copper, a central bore for conduc ing a flow of oxygen to the block, a plurality of cooling pipes disposed in equally spaced relation around the central bore, the block of copper comprising a relatively thick tip for the nozzle with the ends of the cooling pipes being mounted in the thick tip to conduct heat from the tip, certain of the cooling pipes be.ing diagonally opposed and curved inwardly toward the center of the nozzle to cool the central area of the nozzle, a plurality of venturi tubes extending through the tip and conducting oxygen through the tip, an oxygen supply pipe in communication with the central bore, a water sleeve surround-ing the plurality of cooling pipes, and an outer water jacket surrounding the cooling pipes disposed between the sleeve and the jacket, both the sleeve and the jacket being secured to the thick copper tip of the nozzle, and the water sleeve being provided with one or more openings affording communi-cation through the sleeve between chambers formed by the outer jacketl the water sleeve and the supply pipe, the coollng pipes extending verticallv into the chambers at opposite sides of the sleeve and cooling the tip by water from the chambers.
OBJECTS OF THE INVENTION
-The primary purpose the of the present invention is to provide an improved form of nozzle for an oxygen lance~
The principal object of the present invention is to provide a nozzle for an oxygen lance having at least one cooling pipe operative to cool the walls of the nozzle.

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An important object of the invention is to form a number of cooling pipes around a central bore through which oxygen is supplied, the cooling pipes being connected with a source of cooling fluid at their condensing ends.
A more specific object of the invention is the provision of a lance nozzle wherein the nozzle wall at its tip comprises a relatively thick portion of copper, into which the evapo-rating ends of the cooling pipes are inserted.
A still more specifie objeet of the invention is realized in an oxygen lanee and nozzle wherein the oxygen -tube is arranged to feed a number of venturi tubes passing through the thiek portion of the eopper nozzle and whieh venturi tubes are lined with eeramie inserts.
A further objeet of the invention is the provision of at least one eooling pipe for the oxygen lance that is cooled at its condensing end by oxygen vapour.

DESCRIPTION OF THE DRAWINGS

An embodiment of the invention will now be deseribed with referenee to the aeeompanying drawings, wherein Figure 1 is an axia] section -through the nozzle of an oxygen lanee; and Figure 2 is a transverse section through the nozzle, taken on the line 2-2 of Fiyure 1.

DESCRIPTION OF PREFERRED EMBODIMENT

Referring to the drawings, a nozzle for an oxygen lance is formed from a block of copper l, which may be a solid casting, or a forged solid block. Four venturi tubes 2 are bored through the block at angles symmetrically disposed about its centre and further, closed bores 3 and 3_ are bored into the block to form two circularly spaced arrays around the centre of the copper block l, outwardly of the venturi tubes 2 as best shown in Figure 2. The closed bores 3a and 3_ receive cooling pipes 4a and 4b respectively. Tl~e bores 3a have a depth less than that of the bores 3_ as will be discussed below. The cooling pipes 4a and 4_ are secured in the bores 3_ and 3b by welding or alternati.vely by screw threads, as at 5 and serve to conduct heat from the copper block 1 into a supply of cooling water contained in the nozzle.
An oxygen supply pipe 6 is fixedly secured to a corresponding flange 6a formed on the copper block 1 around the exterior of the venturi tubes 2. The pipe 6 is welded to the flange 62 to fix it in its correct location. A return water channel 13 is provided by a sleeve 7 located around the oxygen pipe 6 which defines -the central bore and which is also welded to the copper block 1. At its edge adjacent the copper block 1 the water sleeve 7 has a number of openings 11 through which the cooling water flows from an inlet water chamber 12, defined by an outer sleeve, or water jacket ~, which is welded to a peripheral flange 8a on the copper block 1 and which forms a chamber that is supplied with water under pressure from a suitable source.
A further bore 9 is made centrally into the copper block 1 at the centre of the venturi -tubes 2. This bore receives a cooling pipe 9a whose condensing end is located in the bore of the oxygen pipe 6. Thi.s cooliny pipe is held in po-sition by welding, or alternatively by a screw-threaded engagement (not shown).
The lance nozzle as described, can be fitted to existing lances but requires consider-ably less water pressure to provide sufficient cooling to the evaporating ends of the heat pipes than that required for conventional water cooling.
To increase the l`ife of the nozzle still further, the inner surface of each of the venturi tubes 2 may be lined with a removable refractory insert 10 which may be replaced due -to wear. I-t will be appreciated that such inserts are possible only because of the greatly increased thickness of the present nozzle over conventional types of lance nozzles. It will also be appreciated that the differing depth of the bores 3_ and 3b allows for the possibility of the walls of the nozzle being eroded back to the deepest cooling pipe 4_, which would then no longer function, while the less deeply inserted cooling pipe 4_ would continue to Eunction. Since the cooling pipes are elosed structures the fact that erosion occurs at one end does not mean that water ingress into the combustion chamber will oecur.
Various other configurations of the nozzle components may be used whieh further utilize the advan-tageous properties of the cooling pipes ineluding provision for the water flow in the two cllannels 12 and 13 to be reversed.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An oxygen lance nozzle including a block of copper, a central bore for conducting a flow of oxygen to said block, a plurality of cooling pipes disposed in equally spaced relation around said central bore, said block of copper comprising a relatively thick tip for the nozzle with the ends of said cooling pipes being mounted in said thick tip to conduct heat from the tip, certain of said cooling pipes being diagonally opposed and curved inwardly toward the center of the nozzle to cool the central area of the nozzle, a plurality of venturi tubes extending through said tip and conducting oxygen through the tip, an oxygen supply pipe in communication with said central bore, a water sleeve surrounding said plurality of cooling pipes, and an outer water jacket surrounding the cooling pipes disposed between said sleeve and said jacket, both said sleeve and said jacket being secured to the thick copper tip of the nozzle, and said water sleeve being provided with one or more openings affording communication through the sleeve between chambers formed by the outer jacket, the water sleeve and said supply pipe, said cooling pipes extending vertically into said chambers at opposite sides of said sleeve and cooling said tip by water from said chambers.

2. An oxygen lance nozzle as set forth in claim 1 wherein said venturi tubes are lined with ceramic inserts.

3. An oxygen lance nozzle as set forth in claim 2 wherein said cooling pipes ends are mounted in said thick tip at different depths.