Experimental Investigation on Flue Gas Desulfurization by Electrostatic Spray

Abstract

The enhancement of SO2 absorption efficiencies in a wet flue gas desulfuriztion system are investigated and analyzed by adopting electrostatic spray. The SO2 absorption efficiencies with different liquid to gas ratios, Ca/S ratios and electrostatic voltages, are compared. The experiment data indicate an increment of 5-10% in SO2 removal efficiency could be obtained; the efficiency increases with the liquid to gas ratio, Ca/S ratio and electrostatic voltages adding, and the trend of increasing gradually becomes slow and stop. The theoretical analyses on WFGD by charged spray are carried out based on the electrostatic spray, double film, and reaction face theory. The analysis show that the charging droplets could advance the surface absorption characteristics, add the Ca2+ concentration on the droplets surface, minishing of droplets surface tension could reduce the mass transfer resistance between the droplets and flue gas. At the same time, droplets electrification and non-excess charge polarization enhance the mass transfer impulse force of droplets absorption SO2. Moreover, the charging droplets producing the second atomization could minish the droplets diameter and add the reacting surface, the droplets could distribute uniformity in the tower for the droplets provided with the same polarity charge. The SO2 absorption efficiency increasing is the complicated course under the above important factors.