Carbide slag semi-dry desulfurization and low-temperature SCR denitration flue gas treatment device and process

Abstract

The invention belongs to the technical field of thermal power plant flue gas treatment environmental protection, and specifically relates to a carbide slag semi-dry desulfurization and low-temperatureSCR denitration flue gas treatment device. The carbide slag semi-dry desulfurization and low-temperature SCR denitration flue gas treatment device comprises a primary pre-dust remover, a carbide slagpowder bin, a water tank, a high-pressure water pump, a backflow type atomizing nozzle, an ash discharge conveyor, a desulfurizing tower, a bag-type dust remover, a GGH, a steam heater, a chimney, anammonia water evaporation system, an SCR reactor, an ammonia spraying grid, a catalyst, and a rectifying grid; flue gas is sequentially delivered through the desulfurizing tower, the bag-type dust collector, the GGH, the steam heater and the SCR reactor to remove SO2 and NOx in the flue gas; a low-temperature SCR denitration process is added on the basis of original SNCR denitration; indexes of SO2 and NOx concentration at a flue gas outlet after transformation reach national ultra-clean emission standards, the semi-dry flue gas desulfurization process is a novel process, SO3, HCL, HF and heavy metals such as Hg can be removed besides SO2, and due to low construction and operation cost and high cost performance, the carbide slag semi-dry desulfurization and low-temperature SCR denitrationflue gas treatment device is gradually popularized and applied in small and medium-sized thermal power generating units.

Description

Technical field [0001] The invention belongs to the technical field of flue gas treatment and environmental protection in thermal power plants, and specifically relates to a flue gas treatment device and process for carbide slag semi-dry desulfurization and low-temperature SCR denitration. Background technique [0002] Flue gas desulfurization / denitration refers to the application of chemical or physical methods to fix or remove SO2 / NOx in flue gas. According to the method of desulfurization, flue gas desulfurization after fuel combustion can be divided into dry desulfurization, wet desulfurization and semi-desulfurization. There are three types of dry desulfurization; according to the desulfurization method, it can be divided into calcium desulfurization, magnesium desulfurization, etc.; according to the denitration method, flue gas denitration can be mainly divided into selective catalytic reduction and non-selective catalytic reduction. [0003] Wet desulfurization has the advan...

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Problems solved by technology

The semi-dry desulfurization process has attracted wide attention due to its advantages of less investment, small land occupation, low operating cost, and no waste water discharge. This type of process has a strong adaptability to different forms of calcium-based desulfurizers. However, calcium carbide slag is There are not many studies on the application of semi-dry desulfurization. The main reason is that calcium carbide slag is completely dehydrated, ground and then digested or pulped with water. This process increases investment and operating costs. However, calcium carbide slag is cheap and easy to obtain Advantages have a certain advantage in the calcium carbide slag desulfurization process

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