Abstract: In various embodiments, a vapor condensation thermoplastic part finishing technique is provided that smooths and ensures color saturation of thermoplastic parts. The technique uses nonhazardous vapor condensation to rapidly heat a thermoplastic part to a temperature higher than its melting temperature. The part then may be cooled to a temperature lower than its melting temperature (and preferable lower than its glass-transition temperature. In some cases, evaporation may be employed to rapidly cool the part. Condensation and, where applicable evaporation, may be promoted by pressure changes to the nonhazardous vapor (e.g., increasing pressure to above atmospheric pressure and then decreasing pressure back to atmospheric pressure), exposure of the part to a separately-heated cloud of nonhazardous vapor (e.g., moving the part into and then out of the separately-heated cloud or injecting and then stopping injection of separately-heated vapor), or by other techniques.

Abstract: A method is disclosed for generating a thermal difference in a working medium between an inlet and an outlet of an enclosure and transferring the thermal difference to a region being cooled. The working medium is drawn into the enclosure (45) through the inlet (76). A force is applied to compress the working medium in the enclosure with decreasing entropy in the working medium and with an input of work to the working medium. The working medium is allowed to expand through the outlet (56) with a change in entropy between zero and no greater than the magnitude of the decrease in entropy during the step of compression and with an output of work from the working medium equal to or greater than the work input to the working medium in the step of compression. Thereby, a thermal difference is caused in the working medium between the inlet and the outlet. The thermal difference is transferred to the region being cooled.

Abstract: A heating and cooling device (10) generates a thermal difference using air and includes an impeller assembly (40) having a plurality of radial compartments (45), a channel (76) for air inlet, and an air outlet (56). Air drawn in through inlet channel (76) is compressed within compartment (45) by centrifugal force producing a pressure, temperature and density variation in the compartment (45) and a decrease in the entropy of the air. As the air is ejected through air outlet (56), work produced by the expansion is transferred to drive shaft (80) as torque, and entropy does not change more than the magnitude of the decrease in entropy during compression.