Device for metering refrigerant flow to an evaporator and systems incorporating same

Abstract

Metering devices suitable for incorporation into vapor-compression refrigeration systems are disclosed, having adjustable features that allow them to regulate the pressure drop across them. These devices include a screw with flights positioned to define a path for the liquid refrigerant to flow through, causing frictional pressure losses. Refrigerant systems incorporating these metering devices are also disclosed.

1 . A device suitable for metering the flow of fluid therealong, comprising: 
 (c) a casing defining an inlet port, a side port and an end port; and    (d) a screw positioned within said inlet port and sufficient to block the flow of fluid therethrough, said screw comprising a member and flights positioned along all or a portion of the length of said member,    such that fluid entering said side port or said end port flows along a pathway defined by said member and said flights of said screw sufficient to achieve a desired frictional pressure loss and thereafter exits said end port or said side port, respectively.    
   
   
       2 . The metering device of  claim 1  wherein said flights of said screw extend along said member and contact said inlet port.  
   
   
       3 . The metering device of  claim 1  wherein said flights of said screw extend along said member but do not contact said inlet port.  
   
   
       4 . A vapor-compression refrigeration cycle system incorporating the metering device of  claim 1 , wherein said metering device receives fluid from a condenser and directs fluid to an evaporator.