Dry-process fine continuous desulfurization device and method for CFB (Circulating Fluidized Bed) boiler

Abstract

The invention relates to a dry-process fine continuous desulfurization device and method for a CFB boiler and belongs to the desulfurization field of boilers. The device consists of a furnace hearth, a cyclone separator, a tail flue path, a lime stone roaster, an air pre-heater, a preliminary dust collector, an SO2 absorber, a circulating liquid tank, a digesting tank, a dust storeroom a, a dust storeroom b, a bag dust collector and a chimney. The method is characterized in that the lime stone roaster and the cyclone separator are arranged in parallel, lime stone powder is sprayed in the roaster from the left upper part, a part of flue gas at the outlet of the furnace hearth is blown in the roaster from the left lower part; CaO decomposed after roasting is collected at the bottom of the roaster and fed to the digesting tank for semi-dry process desulfurization; and decomposed CO2 is exhausted from the top part of the roaster together with the flue gas, and then is mixed with the flue gas in front of the air pre-heater, then passes through the air pre-heater, the preliminary dust collector, the desulfurization absorber, the bag dust collector in sequence and is finally exhausted from the chimney. According to the method, the used desulfurization agent is simple in preparation process, investment and operation cost are low; and the prepared desulfurization agent CaO can satisfy use demand of the semi-dry process desulfurization in the continuous process; meanwhile, the yield of the desulfurization agent can be adjusted by controlling the adding amount of the lime stone powder according to the needs; moreover, the continuous desulfurization process combining the in-furnace dry-process desulfurization and the tail semi-dry process desulfurization can be used for improving the utilization rate and desulfurization efficiency of the desulfurization agent, so that the enterprises can operate economically and the environment-friendly emission requirements can be satisfied.

Description

technical field [0001] The invention belongs to the field of boiler desulfurization, and in particular relates to a dry fine continuous desulfurization device and method for CFB boilers. Background technique [0002] With the further increase of environmental protection standards, the requirements for emission limits of air pollutants are becoming more and more stringent. In view of the desulfurization situation of the current circulating fluidized bed unit, it is difficult to control factors such as bed temperature and desulfurizer quality to the optimum range, and it is impossible to achieve SO 2 Therefore, it is necessary to use a combination of furnace desulfurization and tail flue gas desulfurization to reduce SO in flue gas 2 content in order to meet the emission requirements of pollutants stipulated by environmental protection. [0003] At present, the common methods of flue gas desulfurization include limestone-gypsum wet flue gas desulfurization, semi-dry flue gas...

AI Technical Summary

Problems solved by technology

In view of the desulfurization situation of the current circulating fluidized bed unit, it is difficult to control factors such as bed temperature and desulfurizer quality to the optimum range, and it is impossible to achieve SO 2 Therefore, it is necessary to use a combination of furnace desulfurization and tail flue gas desulfurization to reduce SO in flue gas 2 content to meet the pollutant discharge requirements of environmental regulations

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