Removal of electric-charged aerosols by radiation effect

It is well known that filtration efficiency of an aerosol is expected to be markedly improved for a charged aerosol of single polarity by an image force when the unipolar charged aerosol flows into fibrous filters. The experiments were carried out under the irradiation of gamma rays to generate the unipolar charged aerosol of DOP, to trap the charged aerosol on a wire gauge electrode of an opposite polarity shielded from the radiations, and to collect the charged aerosol by HEPA filter. The efficiency of charged aerosol above 0.4 μm was trapped on the shielded electrode for DF ≥ 103. It was also found that when the negative charged aerosol of DOP was passed through HEPA filter, the filtration efficiency was improved by the image force of the charged aerosol as about 100-1,000 times compared with that of inherent HEPA filter. This method which is capable of removing the aerosol with an extremely high efficiency finds many applications on an industrial scale, including clean-rooms used in semiconductor, electronic and biotechnological industries, the treatment of smoke in flue gases from thermal power plants and general engineering practices, the incineration of burnable radioactive medium-level wastes which have heretofore been difficult to incinerate. (author)