JPS60103108A - Gas blowing tuyere for melting and refining furnace or reaction vessel - Google Patents

Abstract

PURPOSE:To decrease fluctuation in the blowing rate of gas and to perform stable operation with a tuyere loaded with plural pieces of small-diameter metallic pipes to be passed with gas in refractories by interposing a heat insulating layer between the small-diameter metallic pipes and the refractories. CONSTITUTION:A steam chamber 2 playing the role of a surge tank for the supplied gas is connected to the top end of a gas supply pipe 1. Plural pieces of small-diameter metallic pipes 4 are loaded into refractories consisting of MgO-C as a base metal provided above the chamber 2 and the bottom ends of the pipes 4 are integrally coupled to the chamber 2 so as to open into the cham- ber 2. On the other hand, the top ends of the pipes 4 are opened in the furnace or the vessel at the top end of the tuyere and a heat insulating layer 5 is interposed between the outside surface of the pipes 4 and the refractories 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas injection panel for a melting and refining furnace or reaction vessel.

Conventionally, in metallurgical operations, for purposes such as refining processing, degassing processing, or stirring, a molten metal container is provided with a gas-sucking wall made of refractory material mainly at the bottom to prevent melting during the molten metal. It is well known that various gases are injected into the furnace, and in refining furnaces such as converters, it is difficult to inject gas from the bottom of the furnace. Conventional tuyeres are known for the structure of the tuyeres, which are mainly made of refractory material, and are installed at the bottom of these molten metal containers for blowing gas.

A: A refractory lining that is attached to the bottom of a reaction vessel containing molten metal, and is filled with a plurality of small diameter metal pipes that allow the blown gas to pass through.

B. A panel made of refractory material attached to the bottom of a melting and refining furnace such as a converter, and MgO-c, which is a highly durable material, is used as a large base material forming the panel. Feather 1-
1゜The reason stated in Section A of Section 2 is that the multiple small-diameter metal pipes packed into the refractory are made up of dozens of pipes with an inner diameter of about 0.1 to 5 mm, and they pass through a large flow of gas. In addition, the opening of the vibrator that opens into the furnace will not be blocked by molten metal even if the blown gas level is close to zero. In addition, in the case described in item B above, Mgo-c large resistant material, which is a highly durable material, is used as the base material of the refractory, so it is characterized by excellent fire resistance.

Therefore, the present inventors believe that if a refractory whose base material is the refractory described in section B above is used for the structure described in section A above, it will be possible to achieve a structure that combines both the features shown in sections A and B above. Based on the belief that it was possible to obtain an excellent tuyere, we manufactured a tuyere based on the above idea, installed it in a converter, and subjected it to a practical test. However, we were unable to obtain the designed bottom-blown gas flow rate. It could not fully fulfill its function as a bottom blowing nozzle.

The object of the present invention is to provide a tuyere which has removed and improved the jC defect found in the tuyere made in the past and in the practical tests conducted by the present inventors,
The above object can be achieved by providing a gas blowing panel as described in the claims.

Next, the present invention will be explained in detail.

After encountering the above unexpected trouble, the inventors of the present invention conducted a detailed study on the situation of gas injection from the siding during furnace operation. It has been found that the actual amount of gas that can be supplied to the The inventors investigated this phenomenon and found that although Mg0-C refractories are superior in terms of fire resistance, they have a higher heat transfer coefficient than conventional wall refractories, so Mg0-C refractories are When using refractories, the temperature of the refractory increases rapidly over time after the start of use, and the temperature of the small diameter metal pipe loaded in the refractory also increases with the temperature of the refractory. As a result, the inventors have come to the conclusion that a so-called thermal choke phenomenon occurs in which the gas flowing inside the small-diameter metal pipe is heated and expands, and the actual amount of gas fil flowing inside the pipe is reduced. Therefore, when we conducted a table test on a small diameter fully open pipe, we were able to confirm that the actual amount of gas that can flow through the pipe changes depending on the amount of heat received from the pipe wall. Therefore, in order to prevent the thermal choke phenomenon, it is necessary to remove the small diameter metal via from the
It is necessary to suppress heat transfer to the pipe as much as possible, and the present inventors interposed a heat insulating layer between the outer surface of the small-diameter metal pipe and the refractory, which significantly prevented the thermal choke phenomenon. I was able to do this.

The invention will now be explained in detail with reference to the drawings.

Fig. 1 is a longitudinal cross-sectional view of the gas injection lining of the present invention, Fig. 2 is a plan view taken along arrows ■-■ in Fig. 1, and Fig. 3 is an enlarged longitudinal cross-section of the portion E surrounded by the circle in Fig. 1. It is a front view.

The main feature of the present invention is that an air storage chamber 2 is connected to the upper end of the gas supply pipe 1 and serves as a surge tank for the supplied gas.
Several small-diameter metal pipes 4 are loaded into a refractory 3 made of Mg0-C as a base material, which is provided above the air storage chamber 2, and the lower ends of the multiple small-diameter metal pipes 4 are each placed inside the air storage chamber 2. On the other hand, the upper end of the small-diameter metal vibrator 4 opens into the furnace or container at the tip of the blade, and connects the outer surface of the small-diameter metal pipe 4 with the refractory Q4. F3
A heat insulating layer 5 is interposed between the two.

The heat insulating layer 5 is mainly made of gold 1.4 oxide, which has high corrosion resistance unlike the slag in the furnace and has low thermal conductivity. In order to cover the surface of the small-diameter metal pipe 40 with the Nli thermal layer material, the oxide in the oxide state in a slurry state is applied to the pipe 4, and the thickness of the coating heat insulating layer is reduced to about 1 to 5 coats. shall be. The heat insulating layer 5 in the examples described below is made of simple MgO.
Powder, water glass, ノ (ingu as slurry)', Q
This is done by immersing a group of small-diameter metal pipes integrally connected to the air storage chamber 2 into the heat insulating material L' in a slurry state. Other gold-1.14 oxides with low thermal conductivity include alumina, zirconia, and silica, and these can be used alone or in combination depending on the conditions of use. As the binder, other materials commonly used in J1N, such as resin, can be used as appropriate.

Next, an actual example of the present invention will be described.

Actual Jif + i example j1711 fM factory 1801: / Tweet on the 8th tube installed in the converter, the relationship between the furnace mouth 37 (I L--I・) and the maximum gas flow ff'c Nm3/min ii'! l!
However, the above relationship in conventional operation is shown in band J in Figure 4.
It is now indicated by jl A.

The conventional feather 1. ．． -1 and the shape U and L are exactly the same, but the only difference is that the small diameter metal pipe is covered by heat). \憫-=Two:
,...ShoheihVTjo 2 Fun^suke 1μRh hunting is now indicated by band B in the key of flute L. In the same figure, there is no difference in the maximum gas amount t'' between the two wings at the start of use, but for example, when the number of times the furnace is used is 400, the maximum gas amount m (Nm in) of the present invention and the conventional one is 13.2~ 1
0.3: 8.6 to 4.6, and 13.5 to 10.5: 7.0 to 3.4 when 1000 times, and the maximum gas flow pNm''/min of the present invention It can be seen that the number is significantly higher than that of the conventional method.

As described above, in the melting and refining furnace or reaction vessel equipped with the gas injection panel of the present invention, there is little variation in the amount of gas injection, and stable operation is possible. Furthermore, by using MgO-C, which is a highly durable abrasive material, as the base material for the lining, it is possible to obtain feathers with a long length [1].

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of the gas injection lining of the present invention, Fig. 2 is a plan view taken along arrows ■-■ in Fig. 1, and Fig. 3 is an enlarged longitudinal cross-section of the portion E surrounded by the circle in Fig. 1. The plan view and FIG. 4 are comparison diagrams of the furnace operation of the present invention and the conventional furnace operation. 1... Gas supply t''17, z2... Air storage chamber, 3...
・Refractory, 4...Small diameter metal wire 4 vibes, 5...Insulating layer. Patent applicant Kawasaki Steel Co., Ltd. Agent Patent attorney Mura 1) Masaru Oil cylinder 2 Figure 4 Furnace number (heat)

Claims (1)

[Claims] t. In a melting and refining furnace or a gas line for a reaction vessel in which a plurality of small diameter metal pipes for passing gas are packed in a refractory, a heat insulating layer is interposed between the outer surface of the small diameter metal pipe and the refractory. Gas injection for melting and refining furnaces or reaction vessels.