Method and system for preparing soft water and utilizing afterheat by using spent steam obtained through ironmaking blast furnace slag washing

Abstract

The invention provides a method and a system for preparing soft water and utilizing afterheat by using spent steam obtained through ironmaking blast furnace slag washing. In the method, slag at high temperature of 1,500DEG C is subjected to water quenching, slag-washing water instantaneously absorbs a great deal of latent heat of vaporization, and is evaporated to form slag-washing spent steam which contains low salt content and is rich in the latent heat of vaporization; the spent steam is subjected to condensation heat transfer to prepare the soft water or demineralized water, and low-grade latent heat of vaporization is brought to terminal users such as boilers and the like through the soft water or the demineralized water; meanwhile, the spent steam is purified to reduce dust pollution. The system for implementing the method comprises a water quenching circular slag-washing device, a spent steam purifier and a water making device. The invention has the advantages that: the spent steam is prepared into the soft water or the demineralized water at low cost and light pollution, the afterheat of the spent steam is recovered, the emission of slag-washing dust and the visual pollution of the spent steam are greatly reduced, and the comprehensive benefit is obvious.

Description

technical field [0001] The invention belongs to the technical field of waste heat utilization, and in particular relates to a method and system for utilizing waste heat of ironmaking blast furnace slag flushing waste steam. Background technique [0002] In the production of the iron and steel industry, a large amount of high-temperature slag at about 1500 ° C is discharged from the iron-making blast furnace, which contains a large amount of high-temperature sensible heat, and is granulated into water slag under the impact of 6 to 8 times the water. The water is heated, and a large amount of low-temperature and low-pressure waste steam is produced, which entrains a certain amount of dust and discharges into the air, polluting the atmospheric environment, and its water mist also forms visual pollution. The exhaust steam continuously condenses into water droplets and scatter on the nearby equipment and pipelines during the rising process. The entrained dust and dissolved acid g...

AI Technical Summary

Problems solved by technology

When the slag flushing water is circulated for heating, not only the heat exchanger and pipes scale quickly, but also the water temperature drops quickly, resulting in poor heating effect

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