公开(公告)号：EP0858576A4

公开(公告)日：1999-11-17

申请号：EP96923621

申请日：1996-07-02

申请人： APD CRYOGENICS INC

发明人： BOIARSKI MICHAEL ,  LONGSWORTH RALPH C ,  YUDIN BORIS ,  HILL DENNIS H ,  KLUSMIER LAWRENCE A ,  KHATRI AJAY N ,  OWOC ANTHONY L

IPC分类号： F17C3/08 ,  F25B9/02 ,  F25B41/06 ,  G05D23/02 ,  F25B41/04

CPC分类号： F17C3/085 ,  F17C2205/0326 ,  F17C2205/0329 ,  F17C2223/0161 ,  F17C2227/0353 ,  F17C2227/0355 ,  F17C2250/0631 ,  F17C2250/0636 ,  F25B9/02 ,  F25B41/062 ,  F25B2309/022 ,  F25B2400/12 ,  G05D23/022

摘要： An integral combination of expansion valve and evaporator in a cryostat using a single support member. The valve includes two flow orifices, one orifice (62) being used primarily for steady-state operation and the other orifice (44) being used only during cool-down. An actuator (28) having a high coefficient of thermal expansion moves a needle (46) positioned in the cool-down orifice (44) such that a large orifice flow area at the start of cool-down is automatically and continously reduced as the actuator (28) temperature decreases as refrigerant is throttled through the orifice. Within a range of approximately 30K from the desired steady-state evaporator temperature, the needle (46) completely blocks the cool-down orifice (44). Then, refrigerant flows through the steady-state orifice (62) which has a remotely adjustable needle (68). In the final stage of cool-down, the refrigerant system is entirely controlled by the steady-state orifice (62) and its associated needle (68).