Blast furnace soft water cooling method for coping with instantaneous mass-heat shock of lower portions of furnace bosh, furnace belly and furnace stack

Abstract

The invention provides a blast furnace soft water cooling method for coping with instantaneous mass-heat shock of lower portions of a furnace bosh, a furnace belly and a furnace stack and belongs to the technical field of cooing of iron-smelting furnaces. The method is characterized in that a common soft water cooling system and a soft water supply system are involved, a novel 6-channel copper cooling wall is used on the lower portions of the furnace bosh, the furnace belly and the furnace stack, automatic control is performed by combining a high-sensitivity thermocouple with a throttle plate, impact of high cooling on normal blast furnace running is reduced as far as possible, on the other hand, sufficient surplus can cope with instantaneous mass-heat shock, the shortcoming that a traditional copper cooling wall cannot cope with the instantaneous mass-heat shock is overcome, cooling flexibility of the soft water system is greatly increased, and various smelting requirements can be adapted.

Description

Technical field [0001] The invention belongs to the technical field of ironmaking furnace body cooling, and specifically provides a blast furnace soft water cooling method that responds to the instantaneous impact of large heat at the lower part of the furnace body and shaft. Background technique [0002] Blast furnaces are currently the main equipment for the production of molten iron at home and abroad. Generally, water cooling staves are installed on the furnace shell to ensure the smooth progress of blast furnace smelting. Since 2000, nearly 300 large domestic blast furnaces have gradually adopted copper staves in high-temperature areas. During the design process of the blast furnace cooling system, due to changes in the smelting environment inside and outside the blast furnace, such as fluctuations in the quality of external raw materials, deterioration of coke quality, rain, fluctuations in the moisture content of the furnace charge, equipment failures, control failures, im...

AI Technical Summary

Problems solved by technology

"Benxi Steel 4000m 3 At the beginning of the design of the blast furnace, three sections of copper staves were used in the high temperature section. However, due to the quality of raw materials and management level, it is difficult to meet the requirements of the blast furnace water system, and the furnace conditions fluctuate greatly, resulting in a large area of ​​copper staves after 6 to 7 years of operation. damaged, forced to overhaul the blast furnace

[0005] The document "Zou Zuqiao, Chen Lingkun, Analysis on the Damage Causes of WISCO's No. 7 Blast Furnace Cast Iron Stave, Proceedings of the Ninth China Iron and Steel Annual Conference, Beijing, Metallurgical Industry Press, 2015" introduced the 3200m 3 Copper stave damage. Although Wuhan Iron and Steel No. 7 blast furnace has perfect experience in using soft water, due to design reasons, due to the small contact area and insufficient cooling coordination at the junction of copper stave and cast iron stave, slag and iron invade the back of the stave. Burnt water pipes caused damage to the copper stave

[0006] Literature "Chen Lingkun, Song Musen, Causes of Stave Breakage in No. 4 Blast Furnace of WISCO, Ironmaking, Volume 27, Issue 5, October 2008" In order to cope with the heat shock in the high heat load area, cast iron cooling with serpentine tube was specially used Due to the quality of the casting, the contact between the tube and the wall is not good. In addition, the serpentine tube has a large resistance loss, the cooling flow is small, and the cooling effect is not ideal. After a period of use in the blast furnace, the cooling wall is still damaged a lot

[0007] Literature "Lian Cheng, Huang Deyou, Comparison of Soft Water Closed Circulation Cooling System for WISCO Blast Furnace, Ironmaking, Issue 2, 2002, Vol.21, No.1" In order to deal with heat shock, a cooling stave with a hook was specially used, due to the slag skin The falling off will cause the refractory brick lining to peel off, exposing the hook head to high temperature gas, the cooling capacity of the hook head will not be enhanced by the falling off of the slag skin, and it is still difficult to cope with the impact of instantaneous large heat flow

[0008] So far, more than 100 blast furnaces in China have suffered damage to the copper cooling staves. Without exception, these damages are caused by the shedding of slag skin, the erosion of high-temperature gas flow, and the difficulty of the cooler to adapt to the impact of instantaneous large heat flow. The traditional cooling system is dealing with The flexibility of the instantaneous large heat flow impact is not high, and whether it can withstand the impact depends on whether the design parameters are reasonable, whether the exposure time is short enough, and whether the impact frequency is within a reasonable range. This design itself cannot automatically adjust the cooling parameters. Make the cooling capacity actively adapt to changes in external conditions, so in the long run, damage is inevitable

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