Provide energy efficiency and maximum throughput in a two-step, 12-hr process of heating and freeze-drying to dehydrate coffee beans.
First stage: A large cylindrical vessel with Tranter PLATECOIL® Prime Surface Heat Exchanger surfaces heats trays of coffee beans using high temperature glycol.
Second stage: Vacuum-extracted water vapor is ducted to a condensation vessel employing banked Tranter PLATECOIL Prime Surface Plates using liquid ammonia. After the bank becomes filled with ice, hot ammonia gas is injected into the plates and the ice melts.
- Complete and uniform heating of the beans in the first stage.
- Rapid condensation and freezing of extracted water; followed by rapid melting and drainage.
- Excellent heat exchange efficiency.