Soft-water cooling pipeline control method for blast furnace

Abstract

A soft-water cooling pipeline control method for a blast furnace belongs to the field of metallurgy. Flow division is conducted at a water outlet pipe on a cooling wall in the tuyere area of a blast furnace; the flow is gathered in a middle water return ring pipe through a small branch pipe and returned to a water return main pipe at the top of the blast furnace through a main pipe; when the temperature of the copper cooling walls at the furnace waist and the furnace bosh is reduced to be lower than 45 DEG C, a middle water return flow control valve is opened, and a cooling wall water outlet main valve is closed, so that the water flow rate of more than five cooling walls of the furnace body is 1.0-2.6 m / s, and the water flow rate of the fifth cooling wall or below of the furnace body is 2.3-2.6 m / s; when the temperature of carbon bricks on the side wall of the hearth is higher than 400 DEG C, the middle water return flow control valve is opened, meanwhile, the cooling wall water outlet main valve is opened, the total water amount of the system is increased, the water speed of 1-5 cooling walls of the furnace cylinder reaches 2.8 m / s, the water speed of the cooling wall of the furnace body reaches 2.5 m / s, and the pressure of the water inlet main pipe of the system is supplemented by adjusting the nitrogen pressure of an expansion tank to be 0.8 MPa. According to the invention, under the condition of not influencing the cooling strength of the furnace cylinder, the cooling strength above the furnace waist is reduced and bonding of a furnace lining is avoided.

Description

technical field [0001] The invention belongs to the field of metallurgy, and in particular relates to a control method for a blast furnace soft water cooling pipeline. Background technique [0002] The main body of modern blast furnaces widely adopts the structure of full cooling wall and thin fireplace lining. In the high heat load area of ​​the bosh, furnace waist and lower part of the furnace, copper staves are used, and soft water closed-circuit cooling technology is used to realize cooling without overheating and achieve a blast furnace life of 15 years. There is no goal of intermediate training for one year. [0003] However, the copper stave has higher thermal conductivity than the traditional cast iron stave, the wall temperature is lower, and the cooling intensity is higher. When the cooling system is not suitable for the smelting intensity, when the furnace condition fluctuates during the operation process of reducing and shutting down the wind, or the quality of t...

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Problems solved by technology

[0008] 1. There is only a butterfly valve for water volume adjustment, and it is difficult to adjust the water volume accurately

[0009] 2. In order to ensure uniform water distribution, the design of the pipeline is complex, and the basic process is: small diversion water branch pipe - diversion water header - diversion water ring pipe - return water main pipe

[0010] 3. It can only solve the problem of increasing the water volume in the hearth stave area to improve its cooling strength, but it cannot solve the problem of reducing the water volume in this area without affecting the water volume in the hearth area when the cooling intensity in the copper stave area of ​​the furnace body is too large. The problem of cooling intensity

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