System and method for recycling stray flue gas in smelting production process

Abstract

The invention provides a system and a method for recycling stray smoke in a smelting production technology. The stray smoke exchanges heat with high-temperature technology smoke during production, heat exchange between cold air and the high-temperature smoke in the traditional technology is replaced, the heat-exchange initial temperature is increased, and the secondary hot air temperature required by smelting production is obviously increased; the stray smoke is high in oxygen content, favorable conditions are provided for sufficient combustion of pulverized coal fuel of a metallurgical furnace, the in-furnace temperature is increased, and the consumption of the fuel is reduced. The secondary air addition amount and temperature are controlled through an arranged air volume and temperature interlocking device, and thus the temperature and the air volume are adjusted intelligently. The stray smoke is purified with a bag-type dust collector, valuable metal in the stray smoke are effectively recovered, the on-site operating environment is obviously improved, the investment and the running cost for a separate newly-built low-concentration stray smoke desulfurizer are reduced, and the environmental benefit and the economic benefit are remarkable.

Description

technical field [0001] The invention belongs to the technical field of environmental protection treatment of smelting flue gas, relates to stray flue gas in the smelting production process, and specifically relates to a system and method for recycling the stray flue gas in the smelting production process. Background technique [0002] During the smelting production process, the concentration of sulfur dioxide in the process flue gas is 7000mg / Nm 3 ~28000mg / Nm 3 , the process flue gas enters the desulfurization system after cooling and dedusting, and a large amount of low-concentration sulfur dioxide will escape from the matte outlet and slag outlet during the production process, with a concentration of 400mg / Nm 3 ~3000mg / Nm 3 Fluctuations among them seriously affect the surrounding environment and the physical and mental health of the staff. In order to maintain a good working environment in the plant, the flue gas is recovered through the fixed gas collection hood in the ...

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Problems solved by technology

[0002] During the smelting production process, the concentration of sulfur dioxide in the process flue gas is 7000mg / Nm 3 ~28000mg / Nm 3 , the process flue gas enters the desulfurization system after cooling and dedusting, and a large amount of low-concentration sulfur dioxide will escape from the matte outlet and slag outlet during the production process, with a concentration of 400mg / Nm 3 ~3000mg / Nm 3 Fluctuations among them seriously affect the surrounding environment and the physical and mental health of the staff. In order to maintain a good working environment in the plant, the flue gas is recovered through the fixed gas collection hood in the plant, but the stray flue gas has a large gas volume, high oxygen content, and sulfur dioxide. Due to the main characteristics of low concentration and low temperature, the current traditional method uses a separate set of stray flue gas desulfurization equipment to recover and process this part of the flue gas. Disadvantages of high cost

[0003] In the traditional smelting production process, low-pressure steam boilers and air preheaters are used to recover the heat in high-temperature flue gas. The steam generated by the boilers is incorporated into the heat main pipe network, and the air preheater adopts the method of indirect heat exchange between cold air and hot flue gas. Heating the cold air, which usually comes from the outside air. Because the outside air is affected by seasonal changes and temperature differences between day and night, the temperature is not constant, resulting in large fluctuations in the temperature of the secondary hot air generated after heat exchange, which increases the kiln operation control. difficulty

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