The invention discloses a high efficiency wet-type desulfurization method through
ammonia recovery method for oxidation and concentration outside a
tower, and a device thereof. The method comprises the following steps: (1) feeding
flue gas into the top part of a concentrating
tower after dust removal,
cooling down and humidifying the
flue gas, then feeding the
flue gas into a first level venturi section of a desulfurization absorption
system to contact atomized
ammonia water so as to have the first level absorption reaction, performing the second level and the third level desulfurizations, and discharging the
flue gas after the purification; (2) oxidizing the
ammonium sulfite solution generated in a desulfurizing
tower and then overflowing the
ammonium sulfite solution into a
mother liquor tank from the top part of an oxidation tank; and (3) pumping the
ammonium sulfate solution in the
mother liquor tank to the top part of the concentrating tower through a
mother liquor pump to perform heat exchange with the high temperature
flue gas after atomization so as to form a supersaturated solution containing 3 to 5 percent of
crystal, wherein the supersaturated solution flows out of the bottom of the concentrating tower and is pumped into a hydraulic
cyclone through a
slurry pump to perform the first level
solid-liquid separation, and then the clear solution automatically flows into the mother liquor tank; the
crystal-liquid
mixed solution flowing out of the bottom of the concentrating tower automatically flows into a centrifugal
machine to perform the second level
solid-liquid separation, and then the clear solution automatically flows into the mother liquor tank; and
solid ammonia sulfate is fed into an automatic
packaging machine to be packaged and put into storage. The method has simple processes, greatly reduces investment, and can reclaim agricultural level ammonia
sulfate and industrial level ammonia sulfate.