The design of a pre-collector for cyclone collectors

Abstract

Tests were conducted on small laboratory scale ID-3D and 2D-2D cyclones to demonstrate the reduction in emission concentrations resulting when a pre-cyclone collector is used to collect large trash particles prior to cyclone fine dust collection. Cyclones were tested as fine dust collectors, simultaneous fine dust/trash collectors, and in series with a baffle-type pre-collector placed upstream of the cyclone. Cotton gin trash was utilized as the trash component while corn dust, sieved to less than 100 []m Aerodynamic Equivalent Diameter (AED), was utilized as the fine dust component. Results indicated that cyclones, if designed and operated properly as fine dust collectors, can be utilized as particulate abatement devices in situations where filtration technology is perceived as the only suitable solution. Emission concentrations below 23 mg/m3 (0.01 gr/dscf) were achieved using the ID-3D cyclones. It was shown that the ID-3D cyclone will have lower emission concentrations as compared to the 2D-2D cyclone at similar loading conditions. Tests showed that using ID-3D and 2D-2D cyclones to simultaneously collect trash and fine dust will result in significantly higher emission concentrations as compared to emissions from cyclones collecting only fine dust. Significant reductions in emissions can be achieved if a baffle-type pre-collector is utilized to remove trash particles prior to cyclone fine dust removal. Utilizing the baffle-type pre-collector resulted in lower cyclone en-fission concentrations than when the cyclones were used to collect only fine dust. A pre-collector design guide was developed to aid in the design of precollector/cyclone systems. An equation was also developed to quickly and easily estimate the pressure drop across a pre-collector/cyclone system.