Jingcai Chang

Performance Test of a New Wet ESP with Flexible Collection Electrodes

Wet electrostatic precipitator (WESP) has been modernized over the last few decades. They were suitable for controlling slurry droplet, fine particles and acid aerosols. However, the applicability of current wet precipitators was badly limited for the imperfect mode of water film generation, back-corona, higher power consumption, corrosion of the collector surfaces. Tests were performed to investigate the performance of WESP with new flexible collection electrode in Shandong Haihua Group Co.,Ltd., The relationships between efficiency and velocity, electrode material, discharge electrode shape had been studied, it was observed that at 1-5m/s velocities with 728 electrodes and barbed wires the efficiencies of slurry droplet and fine particles were in the range of 99.10-94.22% and 99.60-93.21%, respectively. The higher gas velocity with the lower collection efficiency; The performance of the new WESP was related to the type of flexible collection electrode and the shape of discharge electrode; Compared with the conventional devices, it could be operated economically, especially in removing fine particles, slurry droplet and acid aerosols as long as the new flexible collection electrode could be kept wet.

Removal of Coal-Fired Pollutants in Wet Electrostatic Precipitators with Flexible Collection Electrodes

Rigorous new regulations in coal-fired pollutants emissions by power plant have caused new demands for electrostatic precipitator (ESP) technology. The study was inspired by the requirement to use cheaper flexible polypropylene fiber and Terylene fabrics as substitutes for typical collection electrodes to save energy and structural materials, and to solve the adverse impacts caused by wet flue gas desulfurization (WFGD) and selective catalytic reduction (SCR) systems at the same time. The characteristic of flexible collection electrodes used in this work, an experimental setup and a pilot-scale unit had been illustrated. And then, contrastive distribution of non-uniform air velocity zones was investigated by a CFD model. Finally, the removals of coal-fired pollutants including acid aerosol, ammonia aerosol, slurry droplets, PM10 were performed in new wet ESPs with different assembled modes, as well as to quantify the key properties of flexible collection electrodes. The results show that the new wet ESPs were consistent with the conventional behavior of typical ESP using a thimbleful of water penetrating flexible collection electrodes via capillary flow. Performance of flexible collection electrodes were measured to exceed that of fiberglass reinforced plastics (FRP), the discharge characteristic of barbed wires was superior to that of diamond-shaped corona wires. The new wet ESP device acts in synergy with WFGD and SCR systems for controlling coal-fired pollutants emissions.

Application of Wet Electrostatic Precipitators in Coal-Fired Power Plant for Acid Mists Control

Large amount acid mists will be produced by the technology of Wet flue gas desulphurization (WFGD) and selective catalytic reduction (SCR) produce in the coal-fired power plant, which will cause serious corrosion of pipeline and air pollution. Experiment and pilot test efficiencies of removing acid mist from WFGD were conducted using wet electrostatic precipitators (WESP) in this work. The effect of voltage, stay time and inlet concentration on the acid mist removal efficiency were studied. It was observed that the efficiency showed a quick rise tendency with the voltage, stay time and inlet concentration, slower than before after 40 kV, 1.6s and 170mg/m3, respectively. High performance of the WESP had been indicated by the experiment and pilot test results for acid mists control.