Converter bottom blowing air brick, special drilling machine and quick thermal replacement method of air brick

Abstract

The invention relates to a converter bottom blowing air brick, a special drilling machine and a quick thermal replacement method of the air brick, which belong to the technical field of converter top and bottom composite blowing equipment and a method and are used for performing quick thermal replacement on the converter bottom blowing air brick. The technical scheme is as follows: the adopted air brick consists of an upper section, a middle section and a lower section. A protecting sleeve brick consists of an upper sleeve brick and a lower sleeve brick. The upper sleeve brick is a magnesia carbon brick, and the lower sleeve brick is made of a corundum-cast material. The protecting sleeve brick is sleeved outside the air brick. A converter bottom flange is welded at a converter bottom opening and is connected with the special drilling machine. The method comprises the following steps of: preparing the air brick, the protecting sleeve brick, the converter flange, a cylinder flange and the drilling machine; disassembling an old air brick; cleaning the cone frustum part of the lower sleeve brick of the protecting sleeve brick; drilling by using the drilling machine; installing the air brick; and connecting a tail pipe. According to the invention, a damaged bottom blowing air brick is replaced in short time under a hot state and the protecting sleeve brick can be replaced for several times without being damaged, so that the combined blowing of a converter in the whole service life can be realized.

Description

technical field [0001] The invention relates to a bottom blowing air brick of a steelmaking converter, a special drilling machine for the air brick and a method for rapid hot replacement of the air brick, belonging to the technical field of converter steelmaking top-bottom composite blowing equipment and methods. Background technique [0002] Converter top-bottom combined blowing technology combines many advantages of oxygen top-blown converter technology and oxygen bottom-blown converter technology, and has advantages in reducing iron oxide content in slag, increasing metal yield, and reducing ferroalloy consumption. It is widely used in foreign steelmaking enterprises. In the application of this technology, it is found that because the use conditions of the breathable brick are very bad and the damage is rapid, it cannot be synchronized with the furnace age. The molten steel brings huge stirring power, and the rapid flow of molten steel has a strong mechanical impact on t...

AI Technical Summary

Problems solved by technology

In the application of this technology, it is found that because the use conditions of the breathable brick are very bad and the damage is rapid, it cannot be synchronized with the furnace age. The molten steel brings huge stirring power, and the rapid flow of molten steel has a strong mechanical impact on the breathable brick

2. The molten steel contains a large amount of harmful impurities to refractory materials, which have serious chemical corrosion on refractory materials at high temperature

3. The temperature of the stirring gas is low before it exits the breathable brick, which has a certain cooling effect on the refractory material, and the end face of the breathable brick is molten steel at about 1700 ° C. This kind of sharp temperature change refractory material is very easy to burst and peel off

4. In addition, bottom blowing can also be stopped due to slag layer coverage or sudden gas cut-off due to various accidents

At present, only a small number of enterprises in China can replace in a hot state, but each replacement takes 4 to 7 hours, and it takes longer if it is not smooth, which greatly affects production. If it is damaged, it cannot be guaranteed to be replaced more than 4 times, and it is still impossible to realize the normal reblowing of a converter for the whole furnace

There are many reasons for the above situation. At present, the core brick structure of the breathable brick, the structure and material of the protective sheath brick, the flange structure of the furnace bottom, and the performance of the drilling machine cannot meet the requirements of quick replacement.

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