APPARATUS AND METHOD FOR DESICCATING AND DEAGGLOMERATING WET, PARTICULATE MATERIALS

摘要

The apparatus includes three primary components: a pneumatic friction dryer; a flash duct dryer; and a ring dryer. The pneumatic friction dryer includes an elongate shredding conduit (26), with apparatus at its upstream end for driving sludge cake therethrough at high speed along with high-pressure gas, e.g. air. The elongate shredding conduit's downstream end (30) opens into the flash duct dryer, which is a larger-diameter conduit (32) connected to the ring dryer (38). The ring dryer is a toroid ring which may include one or more deagglomeration tubes (52) directing high-speed gas generally transverse to the direction of process gas-flow in the ring. Apparatus to effect back-mixing of dry product with incoming sludge cake is also provided. The method is a direct-drying process which, first, includes the step of driving sludge cake through the elongate shredding conduit (26) with heated, high-pressure, high-speed gas for a sufficient time and distance to produce a shredded, partially-dried output product. That output product emerges at high speed and pressure into a suddenly lower-pressure environment in the flash duct (32). This output is directed into the ring dryer (38), where the heaviest, wettest particules in the cone shaped pattern are caused to collide, roughly perpendicularly, with the heaviest, wettest particules remaining in the rig's toroid circuit.