Method and device for reclaiming residual heat emitted by aluminum electrolysis bath

Abstract

The invention relates to a method and a device thereof for recycling waste heat dissipated from an aluminum cell. The device is formed by that: a first heat exchange pipe which is arranged inside a flue on the upper part of the aluminum cell and on the lower part of a gas collecting system and a second heat exchange pipe which is arranged on the outer shell of the electrolytic cell wall are connected with a condensing system through gas pipes; an outlet of the condensing system is connected with inlets of the first heat exchange pipe and the second heat exchange pipe through return passages. The method comprises the following steps that: the first heat exchange pipe and the second heat exchange pipe are heated by the waste heat generated during the process of aluminum electrolysis of the aluminum cell, and heat exchange media in the heat exchange pipes are gasified and flow to the condensing system; after condensation and recycling of released heat, and heat exchange medium liquid after condensation returns to the first heat exchange pipe and the second heat exchange pipe and then performs reciprocating cycle operation. The method and the device thereof for recycling the waste heat dissipated from the aluminum cell is characterized in that: the structure of the device is simple; the manufacturing cost is low; the heat exchange media can perform cycle operation; the operation cost is low; the waste heat recycling rate is high and can reach 60 percent of the total heat dissipating capacity of the aluminum cell.

Description

Technical field [0001] The invention relates to a method and a device for recovering the waste heat emitted by an aluminum electrolytic cell during the aluminum electrolysis process. Background technique [0002] The metallurgical industry, whether it is non-ferrous metallurgy or ferrous metallurgy, is a big energy consumer, there are a lot of energy-saving problems. The coke oven blast furnace and steelmaking process of iron and steel enterprises have a considerable amount of waste heat that cannot be recycled (the waste heat temperature is as high as 1600°C). Similarly, the waste heat of aluminum electrolysis cells in the aluminum electrolysis industry has not yet been recycled. At present, the aluminum electrolysis industry has always adopted the traditional Hall-Heroult method. The electrolyte used is cryolite-alumina molten salt system. The carbon anode and carbon cathode are placed up and down. When the current passes through the molten electrolyte, a large amount of resist...

AI Technical Summary

Problems solved by technology

In fact, aluminum electrolysis needs to consume a lot of electric energy, but its energy utilization rate is less than 50%, that is to say, 50% of the energy is dissipated and lost. Recycling and utilizing this part of energy is an urgent problem to be solved by the aluminum electrolysis industry.

The cost of this technology is relatively high, and the utilization rate of waste heat is relatively low (the electric energy generated per ton of aluminum is 200 kWh, and only two-sevenths of the total heat dissipation is recovered)

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