JPH07242919A - Method for preventing suction of air into blast furnace at the time of stopping blasting - Google Patents

Abstract

PURPOSE:To execute a plugging work in a short time and with a small man- hour at the time of stopping blasting of a blast furnace. CONSTITUTION:At the time of completing an ignition work at the furnace top of the blast furnace after stopping the blasting, the temp. in a blow pipe 2 is lowered to about 180 deg.C. A balloon 6 composed of a heat resistant hard rubber withstanding to 200 deg.C is inserted from a peephole cover 1, and compressed air, etc., having the constant pressure is supplied from air piping 9. The balloon 6 is bulged with the pressure of the compressed air, etc., and intensively pushed to the inner surface from the inside of the blow pipe 2 to perfectly plug the blow pipe 2. By this method, the suction of the air into the furnace from the tuyere part during stopping the blasting is prevented.

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 blown off.

[0002]

2. Description of the Related Art When the blast furnace is blown off, the air from the tuyere blow pipe into the blast furnace is prevented so that the reaction such as the combustion of coke and the production of iron slag does not occur in the blast furnace. Intrusion must be prevented. FIG. 2 is a diagram showing a conventional method for preventing the entry of air.

In FIG. 2, reference numeral 1 denotes a peeping cover which is closed during operation and has a peeping hole in the center. 2 is a blow pipe, the inner surface of which is lined with a refractory material. Hot air of 1000 ° C. to 1200 ° C. is introduced into the blow pipe 2 during operation. Three
Is a small tuyere, 11 is a large tuyere, and 12 is a tuyere receiving material, all of which 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, they are cooled rapidly to normal temperature when there is no air flow to stop the passage of hot air and when combustion inside the furnace is stopped.

Reference numeral 13 denotes a cooling steve, which is composed 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 injecting fuel and the like. 14 is a hot air tube, 1000 ° C to 1
Since the hot air at a high temperature of 200 ° C. is introduced, the inner surface is lined with a refractory material.

After the air is blown off, the peep cover 1 is removed, and the irregular refractory 5 kneaded into a soft clay is formed into a ball shape and is pushed through the blow pipe 2 into the tuyere 3 in a plug shape. Then, the amorphous refractory 5 is solidified to close the tuyere, and prevents air from being sucked into the blast furnace through the blast furnace tuyere blow pipe during the blast of the blast furnace.

[0006]

However, in the above technique, the closing work of pushing the clay-like kneaded indeterminate refractory material into a ball shape and pushing it in is a manual work using a long bar as a tool, so that many man-hours are required. Need. In addition, since the clogging work with the amorphous refractory takes a long time, there is a drawback that the time for resting air is extended.

[0007] In addition, during a long break of 12 hours or more,
In order to confirm the presence or absence of water leakage in the furnace, it is necessary to confirm the red hot state of the coke inside the tuyere, 2-3 times / quiescent, removal of inserted refractory, and reinsertion work. Was needed. Furthermore, since the side blow pipe 4 is an obstacle, it is difficult to uniformly insert the irregular refractory material 5 into the inside of the tuyere.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a method for preventing air suction into the blast furnace, which can be performed in a short time and with a small number of steps when the blast furnace is in a blast. And

[0009]

[Means for Solving the Problems] The above-mentioned problem is that a hollow body made of a stretchable heat-resistant rubber is arranged in a blow pipe of a tuyere of a blast furnace, and a compressed gas having a constant pressure is supplied to the hollow body to expand the hollow body. This is solved by a method for preventing air suction into the furnace of a blast furnace at the time of resting air, which is characterized by closing a blow pipe.

[0010]

The hollow body made of stretchable heat-resistant rubber is placed in the blow pipe of the tuyere of the blast furnace after resting, and a compressed gas of a constant pressure is supplied to the hollow body so that the hollow body swells and blows out of the blow pipe. It is strongly pressed from the inside to the inside. As a result, the blow pipe is completely closed and air is prevented from being sucked into the furnace from the tuyere during the period of rest. In addition, when performing the work to check the red hot state of the coke inside the tuyere, the hollow body is deflated by removing the compressed gas from the hollow body, so the normal red hot state of the coke can be easily passed through the peep hole of the blow pipe. Can be confirmed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A description will be given below with reference to FIG. 1 showing an embodiment of the present invention. FIG. 1 is a view showing a situation in which a blow pipe is closed according to an embodiment of the present invention. In FIG. 1, the same parts as those in FIG. After the air is rested and the hot air is stopped, the balloon 6 which is a hollow body is looked into and the cover 1 is opened and inserted into the blow pipe 2. An air pipe 9 is connected to the balloon 6, and the air pipe 9 penetrates through the opening of the peep hole in the center of the peep cover 1 and is connected to the outlet of the 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 blow pipe is lowered to about 180 ° C after about 30 minutes of non-use of air.

Therefore, a balloon 6 made of heat-resistant hard rubber that can withstand 200 ° C. is inserted from the peeping cover 1, and then compressed air or the like having a constant pressure is supplied from an air pipe 9. The balloon 6 is inflated by the pressure of compressed air or the like and is strongly pressed from the inside of the blow pipe 2 to the inner surface thereof, so that the blow pipe 2 is completely closed. By completely closing the blow pipe 2, it is possible to prevent air from being sucked into the furnace from the tuyere during the rest period.

In the above-mentioned embodiment, a balloon having a smooth peripheral surface was used as the hollow body, but the hollow body is not limited to this and may be any balloon that 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. It is possible to use, for example, one having a plurality of grooves formed in the circumferential direction.

[0014]

According to the device of the present invention, the blow pipe can be more completely closed in a short working time during the rest period,
Air can be completely prevented from being sucked into the blast furnace from the tuyere, and labor for closing work can be saved.

[Brief description of 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 conventional method for preventing air from entering.

[Explanation of symbols]

 2 blowpipe 6 balloons

Claims (1)

[Claims] 1. A blow pipe at a tuyere of a blast furnace is provided with a hollow body made of elastic heat-resistant rubber, and a compressed gas having a constant pressure is supplied to the hollow body to expand the hollow body to close the blow pipe. A method for preventing air suction into the blast furnace during a blast.