Ammonia flue gas desulfurization device

The utility model discloses an ammonia flue gas desulfurization device which comprises a desulfurization tower and a circulating crystallization tank outside the tower; a demist segment, an absorbing segment, a concentration crystallization segment and an oxidization segment are arranged in the desulfurization tower from top to bottom; an annular hanging wall plate is arranged in the position which is 0.5-3m lower than a spraying layer of the concentration segment; the thickness of the annular hanging wall plate is 5-50 mm; a stirrer and a liquid-solid mixer are arranged on the circulating crystallization tank; the liquid-solid mixer takes a shape of an inverted hollow circular truncated cone; three to five layers of flow guide plates are arranged from top to bottom between the inner wall of the circulating crystallization tank and the outer wall of the liquid-solid mixer; and the included angle between the normal direction of the flow guide plates and the flowing direction of slurry in stirring is 0-45 degre