ELECTRICAL AGGLOMERATION OF AEROSOL-PARTICLES IN AN ALTERNATING ELECTRIC-FIELD

A laboratory scale test system has been designed and constructed to st udy the electrical agglomeration of charged aerosol particles as a met hod to increase the fine particle collection efficiency of electrostat ic precipitators. The system consists of test aerosol generator, aeros ol charger, agglomerator chambers, and aerosol measurement equipment. Air atomizing nozzles and the TSI six-jet atomizer have been used as t he test particle generators. The test particles have been charged by a corona discharge. Two types of agglomerator chambers have been invest igated. In one agglomerator the gas flows between two parallel plates, across which the alternating high voltage is applied. The other agglo merator is a quadrupole structure with cylindrical electrodes position ed between the grounded plates. Particle concentration and size distri bution measurements have been carried out downstream of the agglomerat or with agglomerator voltage on and off. Particle concentrations and s ize distributions have been measured with differential mobility analyz er (DMA) and a Berner low pressure impactor. These measurements show t hat agglomeration causes about a 4%-8% decrease in the fine particle c oncentration when the total mass concentration is between 1 and 2 g/m3 . There was no difference between the results measured with the parall el plate and the quadrupole agglomerator.