Effects of thermophoresis, vapor, and water film on particle removal of electrostatic precipitator

The effects of thermophoresis, vapor, and water film on the collection efficiency of wet electrostatic precipitators (wet ESPs) were experimentally investigated. The results showed that the fractional collection efficiency curve on the influence of thermophoresis, vapor, and water film was similar to that of traditional ESPs, which exhibited the minimum value at particle diameters of about 0.5 μm. Thermophoresis was beneficial to the collection efficiency of ESPs but the promotion of collection efficiency was not obvious due to the suppression of the ion current caused by lower gas temperature. Vapor significantly improved the collection efficiency of small particles (with diameters smaller than 0.2 μm). However, it had little effect on the removal of large particles (those with diameters over 2 μm). When water was injected into the wet ESP, water film formed on the surface of the collection electrode greatly improved the collection efficiency of submicron particles and it also promoted the removal of large particles significantly. The effect of the water film on the collection efficiency of wet ESPs was a combined result of thermophoresis, vapor, and water flushing.