The invention discloses a double-groove wet-process
flue gas desulfuration device and a double-groove wet-process
flue gas desulfuration method operating on the basis of two pH values, which relate to a
flue gas desulfuration device and a
flue gas desulfuration method. The aim of the invention is to remove SO2 from the
flue gas under a high pH value condition by using desulfurating spray
slurry and to dissolve limestone and oxidize
calcium sulfite under a low pH value condition so as to improve desulfuration efficiency and quality of
gypsum and reduce limestone consumption, investment and operation cost. In the invention, a circulating oxidization tank at the bottom of an absorption
tower is divided into two parts, an
oxidation pond receives desulfurizating
slurry flowing out from a desulfurization
tower, the
oxidation pond operates in a
pH range from 4.0 to 5.5, and in the
oxidation pond,
sulfite ions are oxidized, and byproduct of desulfuration is led out from the oxidation pond; and fresh limestone
slurry is added into a circulating pond, the circulating pond operates in a
pH range from 6 to 6.5, and slurry is led from the circulating pound into the absorption
tower to be sprayed for deselfuration. The device and the method contribute to improving quality of
gypsum, desulfuration efficiency, reducing limestone consumption and lowering investment and operation cost, and are suitable for
flue gas desulfuration when
sulfur coal is burnt or different kinds of fire
coal are burnt.