Application and performance evaluation of desulfurization wastewater spray drying technology

In order to realize zero discharge of desulfurization wastewater, spray drying technology of desulfurization wastewater was used in 2x330MW unit of a power plant. Its principle was to use a rotary atomizer for atomization,and a part of hot flue gas was drawn from the SCR denitrification reactor and air preheater into the drying tower, the heat was used to evaporate the desulfurization wastewater in a spray drying tower. The salt in the waste water was mixed with the dust, which was collected and removed by the electric dust remover. Then the water vapor was mixed with the flue gas and finally enters the desulfurization tower.The field test was carried out under the condition that the unit load was 100% and the amount of desulfurization wastewater treated was 5.1m3/h.The results showed that the hot smoke gas volume of drying tower was about 64896m3/h, The smoke temperature at the inlet and outlet of the drying tower were 335℃ and 205℃ respectively,the moisture content of drying products was only 0.05%. The content of HCl in the flue gas at the inlet and outlet of the drying tower were 55mg/L and 195mg/L respectively, the mass fractions of Cl removal and Cl volatilization in desulfurization wastewater were 87.7% and 12.3% respectively. The increase of Cl content in the dried products had little effect on the utilization of fly ash.