Abstract: The expanded bed direct-contact system uses a multistage expanded bed chamber for heat exchange between heated particles, falling under the force of gravity, and an upwardly directed stream of cool fluid. As the heated particles fall through a plurality of vertically-arrayed stages of the multistage expanded bed chamber and exchange thermal energy with the stream of cool fluid, a stream of heated fluid, and a volume of cooled particles, are produced. Porous plates are respectively received within the stages of the multistage expanded bed chamber for increasing residence time of the particles, and the porous plates, as well as the plurality of stages, are connected to one another by a plurality of downcomers, each also formed from a porous material.

Abstract: The particle-to-working fluid heat exchanger is a particle-to-working fluid counter-flow direct contact heat exchanger formed from a heat exchange chamber having opposed upper and lower ends. A diameter of the heat exchange chamber decreases from the upper end to the lower end, with a fluid inlet positioned adjacent the lower end for receiving a stream of fluid. The stream of fluid is tangentially and upwardly directed within the heat exchange chamber. The heat exchange chamber also has a fluid outlet positioned adjacent the upper end thereof. A distribution manifold for the heat exchange chamber produces a plurality of streams of heated particles which exchange thermal energy with the stream of fluid to generate a stream of heated fluid and a volume of cooled particles. A solar power generator, in the form of a solar tower, is further provided, which incorporates the particle-to-working fluid counter-flow direct contact heat exchanger.