Device for recovering waste heat in heat treatment tempering process of steel strip

Abstract

The invention provides a device for recovering waste heat in the heat treatment tempering process of a steel strip. The device comprises an unwinding wheel, a winding wheel and the steel strip for connecting the unwinding wheel and the winding wheel, wherein a heating furnace, a quenching device and a tempering furnace which are used for performing heat treatment on the steel strip are arranged between the unwinding wheel and the winding wheel in turn; a waste heat absorption heat exchanger for vaporizing inlet water to form vapor is arranged on the steel strip between the tempering furnace and the winding wheel; a waste heat release heat exchanger for liquefying the vapor to form outlet water is arranged on the steel strip between the unwinding wheel and the heating furnace; and the waste heat absorption heat exchanger conveys the vapor to the waste heat release heat exchanger through a vapor conveying pipe. The device is high in waste heat recovery rate and has a simple structure.

Description

technical field [0001] The invention relates to the field of heat treatment, in particular to a heat treatment and tempering waste heat recovery device for a steel strip. Background technique [0002] Steel strip heat treatment generally requires first heating the steel strip to 840 to 900 degrees to make the steel strip structure completely austenitized, and then rapidly cooling to below the martensitic transformation temperature Mf, quenching the steel strip to transform the structure into martensitic body, and then heat the steel strip to 400 to 500 degrees for tempering to transform the structure into troostite, and finally let it cool naturally for winding. Energy saving and emission reduction is the long-term strategic policy of national economic development, and heat treatment of steel strip consumes a lot of energy, so energy saving has more important practical significance. After the steel strip is tempered, its temperature is still above 400 degrees, with a large ...

AI Technical Summary

Problems solved by technology

But the waste heat recovery rate of the system is low, and the structure is more complicated

Reasons for the low waste heat recovery rate of the system: First, the length of the pressing plate is too short, which makes the heat exchange time too short, resulting in a small amount of heat exchange; Low temperature, only about 70 degrees, unable to vaporize water into steam, so the heat transfer efficiency is low; third, the pressure plate has no heat preservation device, and the heat dissipation is large, resulting in large heat loss

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