JPH065413Y2 - Blown lance with vibration prevention structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a structure of a gas blowing lance for agitating or refining a molten metal by immersing it in the molten metal and supplying a blowing gas or an additive.

[Conventional technology]

As such a blowing lance, for example, a straight pipe type lance disclosed in JP-A-57-203728 is widely used.

However, in this straight pipe type, as shown in FIG. 3, the mixture b of the gas and the additive discharged from the discharge port a of the lance C immersed in the molten metal B in the container A is b.
Since the molten steel flow d formed by the ascending rises while directly contacting the lance C, the refractory R on the surface of the lance C is gradually abraded, and the vibration of the lance C itself at the time of gas discharge is also added to the refractory proof. There is a drawback that the exfoliation and wear of the product becomes severe.

Further, Japanese Utility Model Laid-Open No. 53-119403 proposes a structure in which the tip of a lance is bent and a porous member is attached to the upper surface thereof. In the lance of this structure, the wear of the surface refractory due to the discharged gas is reduced, but the vibration at the time of discharging the gas has a disadvantage that the wear of the refractory is further increased as compared with the straight pipe type.

[Problems to be solved by the device]

The problem to be solved in the present invention is to suppress the vibration at the time of gas or additive discharge, which is a drawback of the above-mentioned conventional lance, without lowering the refining effect of the molten metal by gas or additive injection at all, and the injection lance. It is to provide a blowing lance with less wear and peeling loss of the refractory material forming the outer periphery of the.

[Means for Solving the Problems]

The present invention has a pedestal that is covered with a refractory and has a discharge port opened downward from the horizontal position at the tip of a curved tube, and a pedestal part that is in contact with the bottom surface of the container and further the inner wall surface of the container to fix the lance near the discharge port. The above problems are solved by forming the same.

〔Example〕

The present invention will be described below with reference to FIG. 1 showing an embodiment of the present invention and FIG. 2 showing its usage.

In FIG. 1, reference numeral 1 indicates the lance of the present invention. The core of the lance 1 is composed of a steel pipe 4 having an inert gas supply port 2 and an additive supply port 3 at the base end. Same steel pipe 4
Is provided with a stud 5, and the stud 5 is used to coat the outer surface of the steel pipe with a refractory material 6.

The front end 7 of the lance 1 is curved, and the discharge port 8 located at the front end opens at a constant inclination angle θ from a position horizontal to the molten metal surface. The inclination angle θ is 30 ° below the horizontal position.
Within the range, the molten metal flow by gas discharge can be generated closer to the bottom of the container, and the maximum stirring effect by the discharged gas can be obtained. When the tilt angle θ is upward from the horizontal position, only the molten metal above the discharge port 8 is stirred regardless of the gas discharge amount, and when it is larger than 30 °, the gas collides with the bottom surface of the container. May increase the power of and damage the refractory on the bottom of the container.

A pedestal portion 9 is formed below the tip of the curved tip portion 7 of the lance 1, the lower surface of which is seated on the bottom surface of the container and which prevents vibrations due to gas discharge from the lance. In addition to this, a pedestal portion 91 having a bottom surface that abuts on the inner wall surface of the container can be formed also in the vertical portion of the lance.

FIG. 2 is a view showing a usage mode of the lance of the present invention having the above-mentioned structure.

Referring to FIG. 1, the lance 1 is attached to the container 1 so that the pedestal 9 formed near the discharge port 8 is brought into contact with the container bottom.
It is immersed in the molten metal 11 in 0 and gradually moved from the position indicated by the dotted line, and the lance pedestal 91 comes into contact with and is fixed to the inner wall surface of the container 10. In this state, the lance 1 does not move any further, and in particular, vibration due to gas or additive discharge is absorbed by the pedestals 9 and 91, and the vibration of the lance 1 does not increase.

Further, the molten metal flow 13 generated by the discharge of the gas, the additive, or the mixture 12 thereof discharged from the tip.
Also, since the discharge port 8 is separated from the main body of the lance 1,
There is no direct contact with the refractory material 6 to erode it. Argon and nitrogen are used as the blowing gas, and aluminum powder, lime, carbide and the like are used as additives at present.

[Effect of device]

As described above, the lance of the present invention has a stirring effect by bending the pipe body and opening the tip of the gas and additive discharge port downward in the range of 0 to 30 ° from the horizontal position and separating it from the pipe portion. Needless to say, as the molten metal flow and the gas and additives do not come into contact with the refractory material covering the pipe, the wear is reduced, and in particular, the pedestal is provided on the pipe to contact the container. By doing so, since it is possible to prevent the pipe body from vibrating due to the discharge force at the time of discharging the gas and the additive, peeling wear of the coated refractory material is also reduced,
It has the effect of enabling long-term use.

[Brief description of drawings]

FIG. 1 is a sectional view of a blow lance according to the present invention, FIG. 2 is a use example, and FIG. 3 is a use example in a conventional blow lance. 1 ... Lance, 2 ... Inert gas supply port 3 ... Additive supply port, 4 ... Steel pipe 5 ... Stud, 6 ... Refractory material 7 ... Tip curved portion, 8 ... Discharge port 9,91 …… Pedestal part, 10 …… Container 11 …… Molten metal, 12 …… Discharge mixture 13 …… Molten metal flow

Claims (1)

[Scope of utility model registration request] 1. A curved portion is formed in the vicinity of the tip, a discharge port is formed at the tip of the curved portion, and a pedestal portion whose lower surface abuts the inner surface of the container is formed at one or more locations including the curved portion. A blow-in lance with a vibration-preventing structure.