The Controlled Rotary Vane Gas- Handling Machine

The CONTROLLED ROTARY VANE GAS-HANDLING MACHINE Thomas Edwards. Ph.D. The ROVAC Corporation Product Design Office Rockledge, Florida 32955 The de~ign, development, test and application of a n advanced rotary gas-handling device, termed a controlled Rotary Vane (CRV) mac hine is reported. This machine is related to conventional sliding vane compressors @Xcept that the motion of the vanes of the CRV is controlled. This control is such th at the vane tips closely approach but do not contact the interior of the stator con tour; the visco-inertial effect of the circulating lubricant aids in sealing. Stator contour-independent vane motion control in the CRV machine not only results in a significant reduction in direct mech anical friction but, as important, allows low-loss internal fluid dynamic design for further increases in overall gashandling efficiency. This design flexibility is m anifested as generous porting, optimized volumetric change/rotation derivatives a nd effective internal peripheral sealing across the inlet and output ports. Such compressor design yields an efficient and compact machine suitable for operati ng with low density gases. This machine operates on such refrigerants as low press ure aerosol spray can propellents. These propellants are approved both by the U.S. E nvironmental Protection Agency and the U.S. Consumer Product Safety Commission as rep lacements for CFC propellants that were banned in the u.s. and several other countri'e s in 1978. Laboratory and field testing of this type of mach ine has empirically demonstrated significant performance enhancements resulting from de-coupling vane motion from the stator contour. Independent tests conducted on a 30 cid (490 cc) CRV compressor operating as a refrigerant compressor u sing CFC-114 demonstrated a COP of 4,67 while operatin~ across a standard tes t condition of 45F/120F (7C/49C). This performance reflects an overall isentropic e fficiency closely approaching 80% and a volumetric efficiency of nearly 90% while p roducing about 40,000 BTUH (10,000 kcal/hr) of cooling.