Abstract: Apparatus for heating or cooling a fluid includes a housing having a chamber, the housing having an inlet and an outlet with a flow path for the fluid defined therebetween, the inlet communicating between the chamber and a source of the fluid. A rotor is positioned within the chamber and includes a tubular member passing through the rotor and in the flow path between the inlet and the outlet. Portions of the rotor surrounding the tubular member define a hollow space, the rotor being mounted on a hollow shaft in order that means, such as another fluid, may be utilized at the periphery of the tubular member to effect a change in the temperature of the fluid passing through the tubular member.

Abstract: Apparatus for collecting heat of radiation includes a hollow member having a panel with a substantially flat exterior surface, the panel absorbing radiation incident to the surface and transferring the heat therefrom to a fluid passing through the member. A reflector body extends from the surface, and is adapted to reflect radiation incident thereto toward the radiation-absorbing surface.