JPH03229814A - Lance nozzle - Google Patents

Abstract

PURPOSE:To reduce erosion at tip part of a nozzle and to extend the service life of lance nozzle by forming a cooling water passage surrounding a gas passage in the lance nozzle so that velocity of the cooling water of a heat receiving surface becomes the specific value or more. CONSTITUTION:The lance nozzle is made to triple pipe structure, and oxygen is caused to flow from an oxygen pipe 2 at the center part, and the cooling water is circulated into a middle cylinder 13 and an outer cylinder 4 to cool the lance nozzle. In this lance nozzle 1, by making the interval (l) between inner face at the tip part 6 of oxygen blowing hole 5 and the tip part of middle cylinder 13 narrow and adjusting the cooling water flow rate, linear velocity of the cooling water is made to >=18m/sec. By this method, as the erosion at the tip part of nozzle is reduced and the service life of lance nozzle can be extended, cost and time required for exchanging nozzles are reduced and the working efficiency can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] This invention relates to a lance nozzle used in converter blowing and the like.

[Prior Art] For example, a lance nozzle for converter blowing is generally used at a distance of about 1.5 to 4.0 m from the molten steel surface, and in order to jet high-pressure oxygen from the nozzle toward the steel bath, It is subjected to severe heat loads such as radiant heat from the bath and adhesion of base metal and slag.

Therefore, as shown in Fig. 3, a triple-pipe structure is adopted in which oxygen flows from the oxygen pipe 2 in the center, cooling water is circulated through the middle cylinder 3 and the outer cylinder 4, and the nozzle part 1 is heated. Uses pure copper, which has good conductivity.

[Problem to be Solved] However, the area around the tip 6 of the oxygen outlet 5 of the nozzle may be damaged by melting, and the desired metallurgical effect may no longer be provided. This tendency becomes more noticeable when the distance to the scene is close.

Therefore, in such cases, the nozzle is replaced.

However, there are problems such as the cost of replacing the nozzle and the reduction in work efficiency due to replacement.

An object of the present invention is to solve the above-mentioned problems.

[Means for Solving the Problems] The lance nozzle of the present invention has a gas passage and a cooling water passage surrounding the gas passage, and has a linear velocity of cooling water on the heat receiving surface of 18 m/sec or more. It is characterized by having a cooling water passage formed therein.

[Operation] By setting the linear velocity of the cooling water to 18 m/sec or more, it is possible to reduce melting damage at the tip of the nozzle and extend the life of the entire lance nozzle.

[Example] Hereinafter, one embodiment of the present invention will be described with reference to FIG.

By narrowing the distance g between the inner surface of the tip 6 of the oxygen outlet 5 and the tip of the inner cylinder 13 and adjusting the amount of cooling water, the linear flow velocity of the cooling water is set to 18 m/sec.

Thereby, it is possible to reduce melting damage at the tip of the oxygen blowpipe or the nozzle outlet.

As a result, as shown in Figure 2, the conventional linear flow rate was 14 m
If the life index is 1 in the case of /second, then the linear flow velocity is 16m/second.
If the linear velocity is set to 18 m/s, the life index will only improve to about 1.5, but by setting the linear flow velocity to 18 m/s, this can be improved to 3.5 m/s.
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[Effects of the Invention] The lance nozzle of this invention is as described above, and by increasing the linear velocity of the cooling water to 18 m/sec or more, melting damage at the tip of the nozzle is reduced and the life of the lance nozzle is extended. I can do it. Thereby, it is possible to reduce the cost required for nozzle replacement, reduce the time required for replacement, and improve work efficiency.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing one implementation of the lance nozzle of the present invention,
FIG. 2 is an explanatory diagram showing a comparison of the life index of a lance nozzle with a conventional lance nozzle, and FIG. 3 is an explanatory diagram of a conventional lance nozzle.

Claims (1)

[Claims] A lance nozzle comprising a gas passage and a cooling water passage surrounding the gas passage, the cooling water passage being formed such that the linear velocity of the cooling water on the heat receiving surface is 18 m/sec or more.