Regenerative combustion type coal-based shaft furnace and direct reduction production method

Abstract

The invention relates to a regenerative combustion type coal-based shaft furnace and a direct reduction production method. The shaft furnace comprises a combustion chamber and at least one reaction chamber; at least one group of combustion devices are arranged on the combustion chamber; each group of combustion devices comprises a reversing valve, an air pipe, a smoke pipe, a first gas circulating pipe and a second gas circulating pipe, the reversing valve has a first valve position and a second valve position, the first gas circulating pipe communicates with the air pipe and the second gas circulating pipe communicates with the smoke pipe when the reversing valve is located in the first valve position, and the first gas circulating pipe communicates with the smoke pipe and the second gas circulating pipe communicates with the air pipe when the reversing valve is located in the second valve position; each of the first gas circulating pipes and the second gas circulating pipes is connected with at least one burner; and the burners are connected with regenerative chambers. Periodic alternating combustion is realized through the burners, so that the smoke flow field in the combustion chamber can be changed periodically, dead zones in the combustion chamber are favorably reduced, the temperature uniformity in the combustion chamber can be improved substantially, and the uniformity of reduction reactions in the reaction chambers can be guaranteed.

Description

technical field [0001] The invention belongs to the technical field of coal-based direct reduction, and in particular relates to a thermal storage combustion type coal-based shaft furnace and a direct reduction production method. Background technique [0002] Direct reduction technology is mainly divided into gas-based and coal-based processes. Due to the rich coal resources and the lack of natural gas resources in my country, and the coal-to-gas technology is not mature enough, coal-based direct reduction technology has received more and more attention. Although the direct reduction gas-based process accounts for more than 90% in the world, the development of coal-based direct reduction technology is more in line with my country's national conditions. [0003] Coal-based direct reduction refers to the method of directly using solid coal as a reducing agent to reduce metal oxides. Coal-based direct reduction can use cheap non-coking coal as a reducing agent. my country's c...

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Problems solved by technology

Although the flue gas waste heat recovery device is used to preheat the air or gas, due to the low efficiency of the heat exchanger, the preheating temperature can only reach 400-500°C, and the waste heat recovery rate of the flue gas is low

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