Abstract: A rotating heat exchanger (10) has a first air turbine (16) connected to a first end of an axle (20). The second end of the axle (20) is connected to a second air turbine (18). A heat pipe (30, 40, 42, 44) extends from the first air turbine (16) to the second air turbine (18).

Abstract: A spraying system having a plurality of separate pressurized fluid supply sources, a spray gun having a discharge nozzle and a plurality of fluid inlet ports corresponding to the number of supply sources and each communicating with the discharge nozzle, lines coupling each supply source to a respective one of the inlet ports, and a selectively operable discharge control associated with the spray gun for permitting passage of fluid through the discharge nozzle from any one of the plurality of supply sources, for enabling the simultaneous passage of fluids through the nozzle from a plurality of the supply sources, and for preventing the passage of fluids through the nozzle from all of the supply sources. The discharge control includes an individual spring biased valve assembly in each inlet port and a single control lever that is movable between an operative position for actuating selective of the valve assemblies and an inoperative position in which none of the valve assemblies are actuated.