The invention discloses a circulating
fluidized bed flue gas desulfurization process which takes a
calcium-based desulfurizing agent as a
bed material and a device thereof. The process and the device are characterized in that a
lime preparation and supply
system comprises a main
powder silo and a digester; a
flue gas inlet structure, a circulating
fluidized bed desulfurization reaction
tower, a primary
dust collector, a secondary
dust collector are connected from beginning to end; the
lime preparation and supply
system is connected with a venturi
fluidization throat pipe arranged at the lower part of the circulating
fluidized bed desulfurization reaction
tower; the upstream of a feed back distributing tank is connected with an ash hopper of the primary
dust collector, and the downstream thereof is connected with a
discharge pipe and a circulating ash humidification activator, and the humidified and activated circulating ash enters a venturi
pipe outlet arranged at the lower part of the circulating fluidized
bed desulfurization reaction
tower. The
flue gas enters from the bottom of the desulfurization reaction tower, contacts and reacts with a desulfurizing agent and the circulating ash in the tower, desulfurization by-products enter the dust collector together with the
flue gas, most of the circulating ash separated by the dust collector is delivered to the tower by the humidification activator. The circulating fluidized
bed flue gas desulfurization process and the device thereof have the advantages that when the amount of the water in the tower is the same, desulfurization efficiency can be greatly improved; when the desulfurization reaction tower is not injected with water or injected with little water, the problems of sticking wall and scale formation can be effectively avoided.