The inner/outer self-cleaning phenomenon in the granular bed filter-cyclone coupled separator

Abstract

This paper presented an experimental study for a noticeable phenomenon named by the self-cleaning in a granular bed filter-cyclone coupled gas–solid separator. This phenomenon brought about positive effects on the dust cake destruction and the operating time extension in the separation process. It was analyzed under different inlet gas velocity, inlet dust concentration as well as the bed operating modes. The inner tangential velocity distribution was also measured with the five-hole probe. The dust cake porosity was deduced by combing the pressure, the deposited dust mass as well as the proposed correlations in published literatures. The experimental results showed that the inner/outer self-cleaning phenomenon resulted in significant improvement on the collection efficiency and the pressure drop. The tangential velocity played the most important role in the outer self-cleaning. The friction effect induced by the downward-moving collector particles was the other key to restrain the formation of the dust cake on the inner Johnson screen, which was conducive to the inner self-cleaning phenomenon. Only the dense particle packed dusts left on the screen surface under the full-bed operating mode and a high collection efficiency was achieved by the self-cleaning phenomenon.