Special Screen & Frame Help HDPE Pellet Manufacturer Prepare for Capacity Increases
When an existing manufacturer of high density polyethylene (HDPE) decided to start up a new pellet production line, it designed the line for high capacity scalping and dedusting as well as trouble-free service with minimal maintenance requirements. With good planning and foresight, the manufacturer ordered two VIBROSCREEN Circular Screen Separators with integral 360 degrees discharge screens and Auxiliary Discharge Frames to meet both current production requirements and anticipated capacity increases. Installed in 1989, the two screen separators scalp "chips" from the HDPE and dedust it. It's important to remove the chips which would create a quality problem for customers who need to ensure trouble-free processing.
The 72 in. diameter units operate around the clock, seven days a week and have served well. The VIBROSCREEN units were designed to operate at about 60,000 pounds per hour.
The peripheral discharge from the bottom deck ( see schematic A) combined with the Auxiliary Discharge Frame greatly increases capacity and dedusting capability. A 3 mesh top screen scalps the oversize pellets which discharge through an overs spout while the on-size pellets and fines pass through the screen and drop onto a feed tray or directly to the bottom screen. The feed tray directs the on-size pellets and fines to the center of the lower screen.
Screen Tips - Volume 8, Number 1 Winter 1993
Schematic A shows how pellets, overs and fines are separated.