JP2699856B2 - How to prevent air from being sucked into the blast furnace during cold days - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing air from being sucked into a blast furnace through a blast furnace tuyere blow pipe when the blast furnace is shut off.

[0002]

2. Description of the Related Art When a blast furnace is shut off, air from the tuyere blow pipe is introduced into the blast furnace to prevent coke combustion and the formation of iron slag in the blast furnace during the stall. It is necessary to prevent intrusion. FIG. 2 is a diagram illustrating a method for preventing air from entering, which has been conventionally performed.

In FIG. 2, reference numeral 1 denotes a peep cover which is closed during operation and has a peep hole at the center. 2 is a blowpipe, the inner surface of which is lined with refractory. During operation, hot air at 1000 ° C. to 1200 ° C. is introduced into the blow pipe 2. 3
Is a small tuyere, 11 is a large tuyere, and 12 is a tuyere receiving part. Both are made of a water jacket and protect the tuyere from the inside of a high-temperature furnace. Since these parts are made of a water jacket, the air is stopped and the passage of hot air stops, and when the combustion in the furnace stops, the furnace rapidly cools down to room temperature.

[0004] A cooling stee 13 is formed of a water jacket and cools the furnace wall of the blast furnace. Reference numeral 4 denotes a side blow pipe, which is used for blowing fuel or the like. Reference numeral 14 denotes a hot-air tube, and
The inside is lined with a refractory because hot air at a high temperature of 200 ° C. is passed therethrough.

[0005] After cooling, the peep cover 1 is removed, and the irregular refractory 5 kneaded into a soft clay is made into a ball shape and pushed into the small tuyere 3 through the blow pipe 2 in a plug shape. Then, the irregular-shaped refractory 5 solidifies and closes the tuyere, thereby preventing air from being sucked into the blast furnace through the blast furnace tuyere blow pipe while the blast furnace is closed.

[0006]

However, in the above-mentioned technique, since the closing operation for pushing the amorphous refractory kneaded in a clay state into a ball and pushing it in is a manual operation using a long bar as a tool, many man-hours are required. Need. In addition, there is a drawback that the closing operation with the irregular-shaped refractory takes a long time, so that the time of the wind stop is extended.

[0007] In addition, when the wind is closed for a long time of 12 hours or more,
It is necessary to check the red hot state of the coke inside the tuyere in order to check the presence or absence of water leakage in the furnace. 2-3 times / wind break, removal of inserted refractories, re-insertion work Needed. Furthermore, since the side blow pipe 4 hinders, it is difficult to uniformly insert the irregular refractory 5 into the inside of the small tuyere.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for preventing air from being sucked into a blast furnace which can be performed in a short time and with a small number of man-hours when the blast furnace is shut off. And

[0009]

The above object is achieved by disposing a hollow body made of heat-resistant elastic rubber in a blow pipe of a blast furnace tuyere, supplying a compressed gas at a constant pressure to the hollow body, and expanding the hollow body. The problem is solved by a method for preventing air from being sucked into the blast furnace at the time of wind-down, characterized by closing the blow pipe.

[0010]

A hollow body made of heat-resistant elastic rubber is placed in a blowpipe of a blast furnace tuyere after a stall, and a constant pressure compressed gas is supplied to the hollow body so that the hollow body expands and the blowpipe is blown out. It is strongly pressed against the inside from the inside. As a result, the blow pipe is completely closed, and the suction of air from the tuyere into the furnace during the calm period is prevented. Also, when performing work to check the red hot state of the coke inside the tuyere, since the hollow body is deflated by extracting the compressed gas in the hollow body, the red hot state of the coke can be easily passed through the peephole of the blow pipe. Can be confirmed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a view showing a situation where a blow pipe is closed according to an embodiment of the present invention. In FIG. 1, the same portions as those in FIG. After the air is stopped to stop the hot air, the cover 1 is opened and the balloon 6 is inserted into the blow pipe 2 except for the balloon 6 which is a hollow body. An air pipe 9 is connected to the balloon 6, and the air pipe 9 passes through an opening of a peep hole at the center of the peep cover 1 and is connected to an outlet of an air pressure control valve 7. Reference numeral 8 is an air pressure gauge. The air pressure control valve 7 reduces the pressure of compressed air or nitrogen supplied from a compressed air source or the like to an appropriate constant pressure. The temperature in the blow pipe 2 is 10 during operation.
Although hot air of 00 ° C. to 1200 ° C. is introduced and the temperature is high, the temperature of the blowpipe drops to about 180 ° C. in about 30 minutes after cooling down.

Therefore, a balloon 6 made of heat-resistant hard rubber resistant to 200 ° C. is inserted from the peep cover 1, and then compressed air or the like having a constant pressure is supplied from the air pipe 9. The balloon 6 is inflated by the pressure of compressed air or the like, and is strongly pressed from the inside to the inner surface of the blow pipe 2, and the blow pipe 2 is completely closed. By completely closing the blow pipe 2, suction of air from the tuyere into the furnace during the shutoff period is prevented.

In the above embodiment, a balloon having a smooth peripheral surface is used as the hollow body. However, the present invention is not limited to this. Any hollow body can be used as long as it can be inflated by the pressure of compressed air or the like and can be pressed against the inner wall of the blow pipe 2. And a plurality of grooves formed in the circumferential direction can be used.

[0014]

According to the apparatus of the present invention, the blowpipe can be more completely closed with a short working time during the calm period,
The suction of air from the tuyere into the blast furnace can be completely prevented, and the work of closing work can be saved.

[Brief description of the drawings]

FIG. 1 is a view showing a situation in which a blow pipe is closed according to an embodiment of the present invention.

FIG. 2 is a diagram showing a method of preventing air from entering, which has been conventionally performed.

[Explanation of symbols]

 2 blow pipe 6 balloon

Claims (1)

(57) [Claims] 1. A hollow body made of heat-resistant elastic rubber is disposed in a blow pipe of a blast furnace tuyere, and the blow pipe is closed by supplying a compressed gas at a constant pressure to the hollow body. A method for preventing air from being sucked into the blast furnace at the time of a cold wind.