Research of Improving the Technique of Electrostatic Collection to High Resistivity Dust by Humidifying and Cooling through Ultrasonic Atomization

Abstract

In order to study the effect of dust removal in the electrostatic precipitator under the influence of change of temperature and air moisture of flue gas, the ultrasonic atomization and electrical heating has been adopted for simulated gas to change its air moisture and temperature. The specific resistance of fly ash of fluidized bed boiler, the V-j characteristics of the precipitator model and the efficiency of dust removal has been tested in gas working conditions. The measured results of dust specific resistance shows that: when the temperature of gas at range of 100°C to 150°C, the specific resistance of dust was lower when the air moisture is at 23.73% than at 5.21%, especially when the gas temperature is below 120°C, the specific resistance of dust reduce more,and it can reach the orders of magnitude at1010Ω·cm when the moisture of 23.73%; then keep the temperature at 150°C and make the moisture increased, the specific resistance of dust is decreased, however it is still more than 1011Ω·cm when the moisture is increased to 23.73%. The measured results of V-j characteristics of the precipitator model shows that: when the moisture keeps at 23.73% and the temperature is below 120°C, the electric field does not occur the phenomenon of anti-corona. The test result of the efficiency of dust removal indicated that: when we make the moisture increased to 23.73% and the gas temperature below 120°C, the efficiency of dust removal shows a significant increase. The results confirmed that we can improve the purification efficiency of high resistivity dust through flue gas humidification and proper temperature maintain.