[Sodium-enhanced limestone wet FGD in rotating-stream tray scrubber]

Adding sodium sulfate to limestone slurry can increase SO2 removal efficiency. In this paper, sodium-enhanced limestone flue gas desulfurization(FGD) tests were conducted in rotating-stream tray scrubber. Changes of SO2 removal efficiency and pH value with time were experimentally studied and, at different pH range, the dissolution rates of limestone etc. were analyzed. The effects of plate number on SO2 removal efficiency and pressure drop were investigated at temperature approximated to industrial operating value. The average plate efficiencies were calculated. According to the experimental results, increasing plate number could increase SO2 removal efficiency, but the average plate efficiency decreased. Under the experimental conditions, when the plate number was increased from 1 to 4, the removal efficiency was increased from 25.5% to 48.6% at the liquid-to-gas ratio of 4 L/m3, but the average plate efficiency was decreased from 25.5% to 15.3%. The equation of the relation between the average plate efficiency and plate number was obtained.