JPS59219406A - Annealing method of converter body - Google Patents

Abstract

PURPOSE:To anneal uniformly a converter body with a short time of treatment by penetrating a fuel supply piping into a trunnion shaft for tilting the converter, connecting the pipe to heating burners inserted into the furnace body and heating the body with the burners while rotating said body. CONSTITUTION:A piping 9 is penetrated through the center of a trunnion shaft 10 via a rotary joint 8 and is connected to plural nozzles 7 of heating burners provided in the furnace bottom so that gas or heavy oil can be supplied. A heat insulating cover 12 having a ventilation port 11 is attached in a furnace port 2 and the surface of a furnace body 1 is covered with a heat insulating material. While the body 1 is rotated in this state around the shaft 10, said body is heated and annealed by the burners. The residual stress accumulated in the body 1 is thus relieved.

Description

[Detailed description of the invention] The present invention relates to a method for sweetening a converter furnace body.

After the converter body is repaired by welding, etc., the residual stress accumulated in the converter body is removed by the repair, and the toughness of the furnace body is restored, thereby preventing brittle fracture of the converter body. As a means, annealing of the converter furnace body has been conventionally performed. According to the conventional method, as shown in the vertical cross-sectional view of FIG. 1, the converter is placed upside down at a location other than the operating installation location, with the furnace lobe facing downward, and flame is blown from the furnace lobe by gas or heavy oil burner 3. According to this method, the deep part of the furnace body, that is, the upper part when it is inverted, is easily scorched and heated to a high temperature, but the area near the mouth of the furnace body, that is, the lower part, when it is inverted, is heated. Hard to get caught.

Therefore, there is a possibility that a temperature difference will occur between the upper and lower parts, and new residual stress will be generated, or cracks or furnace body deformation will occur during the annealing process. Although a method using an electric heater is also known, there are difficulties in using this method in terms of heating equipment, power supply capacity, construction period, etc.

Further, depending on the conventional method described above, it is practically impossible to perform annealing heat treatment on the furnace body at the operating location where the converter is installed.

An object of the present invention is to provide a method for annealing a converter furnace body that eliminates the drawbacks of conventional methods, and by providing the method described in the claims, the object is as follows. can be achieved. That is, the present invention relates to a method for annealing a converter furnace body, which is performed in order to remove residual stress accumulated in the furnace body after construction or repair of the converter body. The outer surface of the converter body was covered with a heat insulating material, the opening of the converter was covered with a cover having a ventilation hole, and the tilting trunnion shaft of the converter was passed through through a rotary joint. A method for annealing a converter furnace body, characterized in that a fuel supply pipe is connected to a heating burner inserted into the furnace body, and the furnace body is heated by the heating burner while being rotated by a converter tilting device 6. It is related to.

Next, the present invention will be explained in detail.

After trying various methods to eliminate the drawbacks caused by the conventional methods described in Section 2, the inventors of the present invention discovered that the furnace body was heated during heating in order to eliminate the temperature difference during the annealing process of the furnace body. The present invention was completed by coming up with the idea of rotating the robot.

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a front view of the converter suspended on a tilting trunnion, and FIG. 3 is a side view of the converter shown in FIG. 2.

1 and 3, the converter furnace body l is tiltable or rotatable about a trunnion shaft 10 by a tilting means comprising a pull gag, a speed reducer 5, and a motor 6.

According to the present invention, a plurality of heating burner fire lowers are connected to a part of the furnace body, for example, the bottom of the furnace, through a rotary joint g to a pipe disposed through the center of the trunnion shaft 10. While burning gas or Fi heavy oil, the furnace body l is rotated around the trunnion shaft 10 in Fig. 7 (A,), ('B
), (C), and (D).

According to the present invention, the outer surface of the furnace body l is made of asbestos in order to improve the heating efficiency and reduce the temperature difference between the inner and outer surfaces of the furnace body l.
Heat is maintained using heat insulating material such as heat-resistant wool, and a heat insulating lid with a ventilation hole is attached to the furnace opening. In order to advantageously perform excellent temperature control, one thermocouple is installed in the furnace body as shown in Figure 3.
3 and transmitter/4' are installed, and this transmitter P! Receiver 15 receives the temperature signal output from 4/lI, records it in recorder il/6, and sends a temperature signal to temperature controller/7.If there is a difference between the temperature and the preset temperature, Advantageously, a signal is applied to the feed gas flow control valve /g to control the gas flow to the set temperature ml f8j.

As described above, according to the present invention, it is possible to uniformly heat the converter furnace body with simple equipment and short processing time, so that
trt remaining in the furnace body after dyeing or repair of the furnace body
, it is possible to remove the force and restore the temporary state, and
When heated and grilled using the traditional method, sweet medium or grilled beans 7
By the method of the present invention, the brittle fracture of the furnace body that occurred later can be completely prevented.

[Brief explanation of drawings]

Figure 1 is a longitudinal sectional view of the converter and heating burner in an inverted state, Figure 2 is a front view of the converter suspended on a tilting tosignion, and Figure 3 is a side view of the converter shown in Figure 2. figure,
FIGS. 4(A), 4(B), 4(C), and 4(D) are explanatory longitudinal cross-sectional views showing the rotational state of the converter body over time when the method of the present invention is used. l... Converter furnace body, K... Furnace mouth, 3... Burner, <
Pull gear for z, y...reducer, 6...motor, 7
...Bar 6 craters, t...rotary joint, w...disc'fl, 10...trunnion shaft, //...
Ventilation vent, 12...Heat insulation lid, /3...Thermocouple, /4'
... transmitter, 15 ... receiver, 16 ... recorder,
/ri...Temperature controller, 1g...Flow rate control valve. Patent Applicant Kawasaki Steel Co., Ltd. Representative Patent Attorney Mura 1) Political Procedure Amendment (Method) 1 Appeasement SG July 6, 2015 Commissioner of the Patent Office Kazuo Wakasugi 141 Displays 1982 Special J1' Application No. 91509 No. 2,
Title of the invention Converter furnace body annealing method 3 Person making the amendment Relationship between fI + 7 Particularly; 'Applicant (Y) Address: 7-chome Kitahonmachi-dori, Chuo-ku, Kobe, Hyogo Prefecture Name: ( Masterpiece) (125) Kawasaki Steel Co., Ltd. 4th Representative 104 Specification Page 6 No. 4 Change the description of Tj to iJ as in the sentence in F.
Correct.

Claims (1)

[Scope of Claims] 1. Two converter operations are carried out in a method of softening a converter furnace body, which is carried out to remove residual stress accumulated in the converter body after the converter body is constructed or repaired. Cover the outer surface of the converter body installed in a position with a heat insulating material; cover the furnace opening of the converter with a heat insulating lid having a ventilation hole; connect the tilting trunnion shaft of the converter through a rotary joint A converter furnace characterized in that a fuel supply pipe at the top of the page is connected to a heating burner inserted into the furnace body; the furnace body is heated by the heating burner while the furnace body is rotated by a converter tilting device. Body annealing method.