Study And Application Of Double Absorption Units Of WFGD

Lime/Limestone wet flue gas desulfurization(WFGD) technology with high desulfurization efficiency is being applied widely recent years in our country, which exist high capital cost and operation cost and serious corrosion. By analyzing and studying the problem of original WFGD such as complicated system, high capital cost, low efficiency of unit absorption, serious corrosion and scaling in dry/wet interface ,we draw the follow innovative conclusion by test study, theoretical analysis and project application research:a. By cancelling GGH and treating with preservatives for the following duct and stuck, the capital cost is reduced by 15% and the total pressure drop is reduced 1500Pa, it has better energy saving effect and reliability.b. By adding two layers of rods in the absorber, which makes flue gas distributes uniformly and forms primary turbulence zone, the absorber which have double absorption units can gain higher unit absorption efficiency , reduce L/G by 15% when gain equal desulfurization efficiency and reduce spraying nozzles by 20% and volume of sump by 20%.c. The wing plate with inclined angel equipped above absorber inlet and pre-spraying equipment located absorber inlet ,which can decrease the inlet temperature and clean duct, can improve the corrosion and scaling of absorber inlet duct because of the returning of flue gas and strengthen the security of the system.d. By researching important parameters in spraying zone concluding the style and arrangement of spraying and optimized design of spray layer, we can draw a conclusion that the inlet pressure of eccentric nozzle should be 0.7-0.8bar, the spraying angel of nozzles located centre of spraying zone should be 120, the nozzles located at the edge which defect a angle in order to decrease the flow along wall should be 90, the particle size of nozzle should be 2000μm～2500μm, the number of layer and distance of layer should balance enology and technology.In this article, the innovation achievement that the developing absorber which has two absorption units, the gas emitting of low temperature and the preventing corrosion and scaling of system are accomplished. This achievement is applied in 300MW power unit and realize energy saving and environmental protection. At the same time, the article provide an enlightenment of the nationalization of desulfurization system.