By the research of the flue main structure of gas desulfurization tower and combining experience in engineering design, the definite steps to determine the size of desulfurization towers main structure were given. The mass transfer units number and height of the spray tower were calculated to determine the absorption height particularly, and the major factors which impacted the desulfurization efficiency were discussed. The result show that the velocity of the tower flue gas distributed evenly and the effective transfer mass area of gas-liquid contacting which impacted the mass transfer efficiency is increased, by adjusting flue gas inlet and outlet angle, using computer software to simulate the absorber tower, increasing the air distribution plate to improve the spray effectiveness and so on. 

Flue gas desulfurization,   ,  Spray tower,   ,  Number of transfer unit