Patent ID: 7640756
Filing Date: 2010-01-05
Classification: F26B

Abstract:
1. In a lyophilization system, the system comprising a lyophilization chamber having a plurality of shelves, a product holder adapted to hold products to be treated, a silicon oil heater/cooler adapted to heat and cool said products via channels or tubes within said shelves, a vacuum pump for drawing air from the chamber and thereby reducing pressure in the chamber, and a refrigeration unit for cooling air which has been drawn out of the chamber, the refrigeration unit including a refrigeration coil and a compressor for conveying a refrigerant through the coil, the improvement comprising: a) a source of cryogenic liquid, b) a conduit adapted to convey a stream of cooled air into the refrigeration coil instead of the refrigerant, and c) an air stream cooler adapted to cool said stream of cooled air by transferring heat from said air to said cryogenic liquid, wherein the air stream cooler includes a first heat exchanger connected to the source of cryogenic liquid, and a second heat exchanger connected to said conduit adapted to convey said stream of cooled air and connected to a conduit adapted to withdraw air from the refrigeration coil, the first and second heat exchangers being thermally connected through a heat transfer liquid which circulates through both of said first and second heat exchangers.