PELTIER BASED FREEZE-THAW VALVES AND METHOD OF USE

摘要

A freeze-thaw valve is provided using a Peltier heat pump where the thermal short-circuit path between a cooled thermal mass and a heated thermal mass is reduced or absent and the valve state transition time is minimized. The freeze-thaw valve comprises a Peltier heat pump mounted to a heat exchange surface that comprises a cross-drilled copper water jacket or manifold. The Peltier heat pump is operated to maintain a cooled thermal mass at a substantially constant low temperature. A resistance heating element is used to produce a heated thermal mass. The freeze-thaw segment of a fluid conduit is commutated to contact either the heated or the cooled thermal mass to thaw and therefore open the valve or cool and thus close the valve. The operation of the Peltier heat pump at a constant temperature avoids problems inherent in the use of a Peltier heat pump to both heat and cool a freeze thaw segment.