A Plastic-Core Compact Heat Exchanger for Energy Conservation

Abstract

This paper describes a compact, single-pass, cross-flow type, gas-to-gas heat exchanger with a polyolefin (polyethylene or polypropylene) core whose seams are welded through a proprietary process. It is constructed of several extruded polyolefin sheets with passageway cross-section of 4 mm (0.159 inch) by 4.4 mm (0.173 inch) which are separated by ribs of the same material that form the cross-flow passages of 137 mm (5.4 inches) by 3.8 mm (0.15 inch). The overall dimensions of a typical single-core unit are 1676 mm (5.5 ft) x 1219 mm (4 ft) x 3048 mm (10 ft) high including the core, the supply, and exhaust gas assemblies. The efficiency of this heat exchanger is on the order of 60-80% and it does not deteriorate with time because the exposed surfaces tend to resist fouling. Pressure drop was in the range of 0.2 -0.6 inches of water column. Applications include efficiency improvements in boiler and HVAC operations, drying, food processing, and the paper, chemical, and agricultural industries.