A new cooling method lets a company cool and dry plastic pellets using circular fluidized-bed cooling.

A new cooling method for a Clifton, N.J., manufacturer lets the company cool and dry plastic pellets using circular fluidized-bed cooling. Compounding Engineering Solutions (CES) purchased equipment from Millburn, N.J.-based Kason Corp. for moisture-sensitive 50% cellulose-filled plastic composite. Wood- flour plastic pellets can not be cut and cooled by standard water-quenching techniques because moisture degrades cellulose.

When the cellulose-plastic composite exits the compounder at 350°F (177°C), a hot-face die cutter pelletizes it into 1à8 to 1à4" sizes. The high heat imparted by the compounder demands rapid cooling of the pellets. A conveyor transports them to a cyclone from which they fall into the 60" dia. circular vibrating fluidized-bed processor, which cools the pellets to 100°F (38°C) and dries them to less than 1% moisture. The transfer between cutting chamber and cooler takes two sec. at 4,000 lb./hr.

CES chose the compact circular fluid-bed processor because it fits on a caster-mounted skid with blower, hopper and controls. Mobility allows the system to cool and dry pellets at other compounding lines in the plant.