| abstract |
The use of mixtures of 1,1,1,2-tetrafluoroethane and an ester having a molecular weight of greater than 250 as retrofill working fluid/lubricant combinations for mechanical vapor recompression heat transfer devices. Despite the presence of residual lubricant, e.g. hydrocarbon lubricants, from working fluid/lubricant combinations in which working fluids such as R12, R22, R502 or R511 are used, anticipated problems resulting from immiscibility such as excessive wear have not been observed. |