Patent ID: 6886361
Filing Date: 2005-05-03
Classification: C09K,F25B,F25D,F28D

Abstract:
1. A liquid chiller for cooling very low temperature coolant, said coolant being cooled to outlet temperature T 2 from inlet temperature T 1 at a predetermined mass flow and with limited pressure drop, comprising: a cylindrical outer casing having an initial internal volume, and including a coolant inlet and a coolant outlet, said coolant inlet and outlet communicating with said initial internal volume, said outer casing further including a refrigerant inlet and refrigerant outlet; an inner cylinder within said outer casing and having a common longitudinal axis with said outer casing, said inner cylinder occupying a substantial portion of said initial internal volume; a finned tubing of extended length connected between said refrigerant inlet and said refrigerant outlet for refrigerant flow therethrough, said finned tubing being wrapped around and contacting said inner cylinder and further occupying said initial internal volume, fins of said tubing extending toward an inner surface of said outer casing; in operation, coolant entering said volume at said coolant inlet flowing over said finned tubing to said coolant outlet, a cold refrigerant flowing through said finned tubing from said refrigerant inlet to said refrigerant outlet absorbing heat from said coolant, said outer casing and inner cylinder being constructed in materials and dimensions, and said fins and tubing being selected, to provide low mass and a coolant flow passage between the outer casing and inner cylinder around the finned tubing, said chiller providing rapid cool down of said coolant at start up and, in steady state operation, reducing the inlet temperature T said coolant has a kinematic viscosity of at least 10 centistokes at −80 degrees C.