Continuous Heating, Cooling & Predrying

When Coperion Waeschle GmbH in Germany (U.S. offices in Houston) introduced its Bulk-X-Change continuous tubular heat exchanger for solids at the K 2004 show in Dusseldorf, the firm wasn’t sure where it might fit in polymer processing. (All 20 commercial applications have been in minerals and fillers.) The firm thought it might be used primarily for cooling—e.g., of PET chips after solid-stating.

When Coperion Waeschle GmbH in Germany (U.S. offices in Houston) introduced its Bulk-X-Change continuous tubular heat exchanger for solids at the K 2004 show in Dusseldorf, the firm wasn’t sure where it might fit in polymer processing. (All 20 commercial applications have been in minerals and fillers.) The firm thought it might be used primarily for cooling—e.g., of PET chips after solid-stating. But the first plastics application—being installed now in Brazil—is for preheating PET chips before fiber spinning, and Waeschle sees more interest in heating/drying than cooling. With some modification, for example, the unit could predry PET. Each heat-exchange tube is custom designed for plant height, throughput, material, and pellet or chip size. Material enters the vertical tube through a special feeder plate (right). The tube has a flow valve at the bottom. Air is forced upward through the chips to remove heat and some moisture.