Discharge of prills e.g. of urea from prilling tower - using central discharge hopper and rotating table

摘要

A process and appts. for discharging prills (e.g. fragile urea prills) from the bottom of a cylindrical prilling tower are claimed. Gentl discharge is guaranteed by direct discharge of the prills through a stationary central discharge hopper and/or indicte discharge along a relatively short travel path via a rotating table surrounding the central hopper. Specifically, the base of the prilling tower has sloping sides and a central discharge hopper. Between these is a rotating table mounted on rollers on a circular track. The rotating table has a flat base and a sloping inner wall, the top of which is attached to a rigid arm with an inclined scraper adapted to the slope of the tower wall. One side of the base of the tower has a fixed scraper arranged to as to remove rpills from the table as it rotates and thus discharge tehm via the indirect path.