Semi-dry flue gas desulfurization and dust removal device and semi-dry flue gas desulfurization and dust removal process

The invention discloses a semi-dry flue gas desulfurization and dust collection device and a semi-dry flue gas desulfurization and dust collection process, belonging to the field of exhaust treatment of thermal power plants, and solving the problem that a desulfurization process which has the advantages of low cost and small occupying space is in shortage. The semi-dry flue gas desulfurization and dust collection device comprises a desulfurization tower, a draught fan, a chimney, a bag type dust collector, an inclined air tank and a humidifying digester. The desulfurization process has the steps of removing pollutants in the flue gas entering the desulfurization tower; collecting desulfurization dust in the flue gas entering the bag type dust collector; exhausting the flue gas through the chimney after dust collection; digesting CaO in the desulfurization dust to form Ca(OH)2 after the desulfurization dust collected by the bag type dust collector enters the humidifying digester through a dust hopper fluidized tank and the inclined air tank; humidifying the Ca(OH)2 and other parts in the desulfurization dust and finally returning the desulfurization dust to the desulfurization tower for desulfurization again. The desulfurization dust is used as a circulating dust and adopts humidification at the outside of the tower; the problem of dust accumulation and scaling on the inside wall of the tower is avoided; the utilization rate of a desulfurization agent is increased and the desulfurization efficiency is improved.