Collection Efficiency Evaluation of Baffle-Type Pre-Separator Configurations: Effects of Baffle Location and Inlet Velocities

Abstract

Some cotton gins across the Cotton Belt use an abatement system consisting of a baffle-type pre-separator followed by cyclones to control the emissions from the cotton gin's various exhausts. Very limited information exists in the literature which discusses the effects of baffle location and critical velocity on the pre-separator's collection efficiency. In this study, a range of critical air velocities and loading rates were evaluated to determine the effect of baffle location of the pre-separator's collection efficiency when using cotton gin waste. None of the treatments significantly affected the over-sized cyclone or over-all collection efficiency. The pre-separator collection efficiency was higher (81%) when the baffle placed at one-third the overall width of the pre-separator from the inlet than when placed at one-half (78%) or two-thirds (75%). The pre-separator collection efficiency was 79.4% at 18.3-m s-1 (3600-fpm) inlet velocity which was significantly higher than 78.2% at 20.3 m s-1 (4000 fpm) and 78.5% at 22.4 m s-1 (4400 fpm). Loading rate did significantly affect the pre-separator efficiency, but not to the extent of inlet velocity. The sieve analysis indicated that the pre-separator removed the majority of material larger than 180 µm; however, the pre-separator did allow a substantial amount of lint to pass through to the cyclone. The baffle-type pre-separator performed well in reducing the course material loading rate entering the cyclone.