Multi-bed type ventilation air methane regenerative thermal oxidation device

Abstract

The invention discloses a multi-bed type ventilation air methane regenerative thermal oxidation device which is used in a ventilation air methane counter-flow thermal oxidation treatment process during production of coal mines. The device comprise three or more oxidation beds, a combustion chamber, a preheater, a ventilation air inlet pipe, a flue gas outlet pipe, a purging pipeline, a flue gas extraction pipeline, a switching valve and a control unit. Oxidation beds are in a vertical structure, heat-insulating fire-resisting materials are arranged on peripheries of oxidation beds, and in addition to a heat accumulation and heat release circulation, a purging purification process is added, so that unoxidized ventilation air is prevented from being directly exhausted into the air, and the oxidation rate exceeds 99%. Besides, flue gas extraction openings are arranged between high-temperature zones and low-temperature zones of oxidation beds, so that part of high-temperature flue gases can be extracted for waste-heat utilization. The device has the advantages of being high in oxidation rate of methane, convenient for waste-heat utilization, stable to operate and the like.

Description

technical field [0001] The invention relates to a multi-bed type exhaust gas heat storage oxidation device used in the countercurrent thermal oxidation treatment process of exhaust gas. Background technique [0002] Coal mine ventilation gas, also known as exhaust gas, is directly discharged into the atmosphere due to its low methane content and lack of effective utilization methods. About 80% to 90% of the annual gas emissions from coal mines in my country are discharged through mine ventilation. According to relevant statistics, in 2008, the amount of methane discharged into the atmosphere through exhaust air has reached 16.1 billion m3. Another study shows that the greenhouse effect of methane is about 21 times that of carbon dioxide, which is extremely destructive to the ecological environment. Therefore, recycling exhaust gas has dual meanings of energy saving and environmental protection. [0003] The volume fraction of methane in the exhaust gas is very low, so it ...

AI Technical Summary

Problems solved by technology

This structure has some disadvantages: First, when the gas flow direction is switched, the regenerator that originally enters the exhaust air immediately becomes the regenerator that discharges the purified gas, so that the gas between the switching valve and the reaction space is not oxidized. It is directly discharged together with the purified gas; secondly, the inlet valve and the outlet valve are activated at the same time in a very short period of time, which may cause the incoming exhaust gas to be directly short-circuited and discharged together with the purified gas

Based on the above reasons, there may be an instantaneous unqualified peak of the discharged purified gas, which reduces the average oxidation rate of the device

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