PERFORMANCE OPTIMIZATION OF THE SCREEN-BOWLCENTRIFUGATION PROCESS

摘要

Screen-bowl centrifugation process is widely used for fine coal dewatering due to its relativelylow capital and operating cost,high capacity of providing low moisture content product as wellas relative ease of operation and maintenance.However in the presence of large proportion ofminus 45 micron coal,the screen-bowl centrifuge tends to lose a significant amount of clean coalto the main effluent and screen-drain streams.Thus,this investigation concentrated on enhancingespecially the clean coal recovery performance of the screen bowl centrifuge with due regard toproduct moisture content.Determining an optimum particle size distribution for the dewateringfeed to minimize the clean coal loss from screen-bowl dewatering has been a major objective ofthis study.Factorial experiments have been conducted using a continuously operated centrifugehaving a bowl diameter of 0.5 meter to study the effects of operating and design parameters onthe performance of screen-bowl centrifuge.The results of this study indicate that a clean coalrecovery greater than 94% is achievable from the screen-bowl dewatering of feed slurry havingnearly 20% of minus 45 micron size solid particles while producing a moisture content of nearly12%.