Limestone is crushed, grinded and slurried and then transported to the absorption tower. The slurry in the absorber is sent to the spraying device by circulating pump for spraying.
After the flue gas is extracted from the flue, it is pressurized by a booster fan and cooled by a GGH flue gas heater and then entered into an absorption tower. The flue gas contacts with the sprayed limestone slurry in the absorption tower, removes SO2 from the flue gas, and the clean flue gas is discharged from the absorption tower and heated by the flue gas heater and discharged into the flue.
CaSO3 formed after SO2 absorption in the absorption tower is oxidized to form CaSO4. CaSO4 discharged from the absorption tower is separated by cyclone (concentrated) and recycled after vacuum dehydration.
Powder Requirements
Raw material: limestone, quick lime (CaO), Gypsum
Powder fineness: 250 mesh, d90; 350 mesh, d90
In order to ensure the comprehensive utilization of desulfurization gypsum and reduce wastewater discharge, the content of CaCO3 in limestone used for desulfurization should be higher than 90%. The fineness of limestone powder should guarantee 90% screening rate of 250mesh for boilers burning medium and low sulphur fuel coal, and 90% screening rate of 325mesh for boilers burning medium and high sulphur content coal. Quicklime can also be used as absorbent. The purity of quicklime should be higher than 85%.
