Patent ID: 10126054

Abstract:
An auxiliary single-pass tube bundle heat exchanger for improving the melting efficiency of melter kettles used to melt thermoplastic pavement marking materials. The auxiliary single-pass tube bundle heat exchanger includes a heat transfer tube bundle having a plurality of heat transfer tubes in which the flow of molten thermoplastic material reverses directions at least once. Hot heat transfer oils flows around the plurality of heat transfer tubes. Vertical material transfer tubes connect between the bottom of the melter kettle and the top of the auxiliary single-pass tube bundle heat exchanger and between the bottom of the auxiliary single-pass tube bundle heat exchanger and the top of the melter kettle. Augers within the vertical material transfer tubes driven by reversible drive motors cause molten thermoplastic material to flow from the bottom of the melter kettle, through the auxiliary single-pass tube bundle heat exchanger, and into the top of the melter kettle.