Blast furnace pulverized coal injection gun

Abstract

The invention relates to a coal dust spraying and blowing gun for a blast furnace. The coal dust spraying and blowing gun comprises a spraying gun main body and a straight blowing pipe which are fixedly connected, wherein the spraying gun main body is provided with a coal spraying pipe and a gas spraying pipe which are assembled and welded into an integral whole in an axial direction, and a cooling gas spraying and blowing cavity with a crescent-shaped section is formed between the coal spraying pipe and the gas spraying pipe; the inlet end of the coal spraying pipe is connected with a coal dust spraying and blowing connecting pipe and a blowing and sweeping connecting pipe, a plurality of annular ceramic layers are arranged on the inner wall of the outlet end part of the coal spraying pipe, and a gap is formed between two adjacent annular ceramic layers; the inlet end of the gas spraying pipe is connected with a cooling gas spraying and blowing pipe, a ceramic lining layer is arranged at the outlet end of the gas spraying pipe, and the upper surface of the ceramic lining layer is parallel to the center line of the straight blowing pipe. A crescent-shaped cooling gas transporting cavity which is formed is beneficial to coal dust to disperse and sufficiently combust at the spraying-out opening of the coal dust. The ceramic lining layer arranged at the outlet end of the gas spraying pipe increases the wear resistance of the gas spraying pipe to the coal dust, so that the service life of the coal dust spraying and blowing gun is prolonged.

Description

technical field [0001] The invention relates to a blast furnace pulverized coal injection gun, which is suitable for a blast furnace pulverized coal injection system. Background technique [0002] Blast furnace pulverized coal injection is to inject finely ground coal powder directly into the furnace from the tuyere of the blast furnace to replace coke to provide heat and reducer, thereby reducing the coke ratio, reducing the cost of pig iron, and reducing environmental pollution. It is a modern A major technological revolution in blast furnace smelting. [0003] As one of the key equipment in blast furnace coal injection process, coal powder spray gun has a direct impact on the stability and reliability of the blast furnace coal injection ratio and the normal production and operation of the blast furnace. The pulverized coal is sprayed into the tuyere of the blast furnace through the spray gun through the straight blow pipe. During the normal production process of the bla...

AI Technical Summary

Problems solved by technology

The biggest advantage of the straight tube type is that the structure is simple, and it is convenient to insert and pull out the gun in actual production, but its biggest disadvantage is that the pulverized coal stream deviates from the center of the tuyere, and is aligned with the small wall of the tuyere, which is easy to cause erosion and wear on the tuyere; To avoid the above disadvantages, a curved pipe spray gun is produced. Its biggest advantage is that the curved pipe design at the end can effectively avoid the erosion and wear of the coal flow on the tuyere. In the process, it is easy to collide with the straight blowing pipe and damage the related equipment. In addition, the pulverized coal is suddenly blocked at the bend during the conveying process in the nozzle, so this type of spray gun is easy to wear and even break down at the bend.

Compared with the single cylinder type, the sleeve type increases the cooling of the spray gun by compressed air, thereby prolonging the service life. However, since the inner tube for pulverized coal delivery is placed in the center of the sleeve, when the compressed air and pulverized coal are sprayed out together, the pulverized coal will Being "surrounded" by compressed air, it is not easy to disperse, forming a "stream" of pulverized coal, which is not conducive to full contact between pulverized coal and air, and pulverized coal cannot be completely burned after entering the tuyere swirl area, which affects the increase of coal injection ratio. , due to the coal powder "stream" formed by the sleeve straight tube spray gun, the wear of the coal powder on the small sleeve of the tuyere is accelerated, which affects the life of the equipment

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