Influence of gas velocity on collection efficiency and re-entrainment phenomena in an electrostatic precipitater

摘要

One of the Electrostatic Precipitator (ESP) applications is cleaning the air and increasing visibility index in highway tunnels. Almost of particles in highway tunnels are carbon exhausted from diesel engine. During the ESP operation collectingcarbon particles, we observed often decreasing large particle collection efficiency. This means that the number of particles down stream is greater than that upstream of ESP. Generally, this phenomenon is explained by re entrainments of particles.Because, carbon particles are low resistance. One of the factors of happening reentrainment may be the gas velocity. Therefore, influence of the gas velocity for re entrainment in ESP was discussed. Experiments were done to measure the collectionefficiency as a function of gas velocity for various particle size ranges. Results show that re entrainment depend on the gas velocity. It may be due to the particle agglomeration on the collection electrodes.