Flue gas purifying and discharge device and method for fire grate type biomass power station boiler

Abstract

The invention discloses a flue gas purifying and discharge device and method for a fire grate type biomass power station boiler. The device comprises a biomass boiler, an oxidizing and mixing device,a desulfurization tower, a bag dust remover and a chimney, wherein a primary air hole and a secondary air hole are formed in the biomass boiler; an outlet of the biomass boiler is connected with the desulfurization tower through the oxidizing and mixing device; an outlet of the desulfurization tower is connected with the bag dust remover; a first branch of the outlet of the bag dust remover is connected with the chimney; a second branch is connected with the primary air hole and the secondary air hole of the biomass boiler through a re-circulating fan to form a circulating loop; desulfurization, denitration and dust-removal processes are optimized, so that ultralow emission of pollutants such as biomass boiler flue gas sulfur dioxide, nitric oxide and dust is realized. The device is relatively small in influences on the boiler, flexibly operates according to the load and a practical pollutant condition, is convenient for controlling operation of the whole biomass power plant system, isflexible to operate, and saves water and operation cost.

Description

technical field [0001] The invention relates to the field of power station tail gas discharge, in particular to a grate type biomass power plant boiler flue gas purification and discharge device and method thereof. Background technique [0002] Biomass boilers are boilers that use biomass energy such as crop stalks (corn stalks, sorghum stalks, wheat straw, rice straw, bean stalks, and cotton stalks, etc.), agricultural processing industry waste (rice husks), etc. as fuel. Biomass energy is characterized by renewability, low pollution, wide distribution and abundant total amount. The content of sulfur dioxide and nitrogen oxides in the exhaust gas of biomass boilers is relatively low, but with the improvement of national environmental protection standards for boiler flue gas emissions, biomass boilers have not adapted to the new environmental protection requirements. [0003] Biomass boiler flue gas has the following characteristics: [0004] (1) The temperature in the fur...

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Problems solved by technology

[0006] (3) The amount of flue gas dust is very large, and the ash-slag ratio after biomass combustion is (10:0-8:2). Due to the small particle size of the combustion dust and the large specific resistance, the dust removal of biomass-fired boilers is only suitable For bag filter, the bulk density is generally 0.18-0.5t / m 3

[0008] (5) The soot in the flue gas is easy to burn again, and it is easy to coke when burned

[0010] Based on the above shortcomings, the flue gas of the biomass boiler has caused adverse effects on the environment and brought pollution to the environment.

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