Abstract: A distiller's counterflow-heat-exchanger module includes thermally conductive distillate and concentrate dividers across which heat flows to an influent liquid from distillate and concentrate liquids, respectively. The distillate divider's shape is convoluted in such a manner as to form alternating distillate and influent channels having end openings. A peripheral gasket is so over-molded onto the distillate divider that it forms plugs that seal the end openings from each other and further forms a ridge providing surfaces against which opposed generally planar parallel surfaces of cover members can be urged to form a peripheral seal.

Abstract: A distillation unit (10) employs a fluid circuit (FIG. 8) in which a counterflow heat exchanger (102, 104, 106, 108, 110) transfers heat from condensate and concentrate to feed liquid to be distilled. The pumping system (100, 238) that drives fluid through the circuit is arranged to keep the pressure in the counterflow heat exchanger's condensate higher than that in its feed-liquid passage. This tends to discourage the contamination that could otherwise occur in the concentrate if the fluid isolation ordinarily maintained between those passages is compromised.

Abstract: A blade heat exchanger includes blades that extend axially with respect to an axis of rotation and are elongated in the radial direction. The blades are arranged about the axis such that, when they are disposed in a housing, they form composite condensation and evaporation chambers that are isolated from each other. The interiors of at least some of the blades form the composite condensation chamber. The exteriors of the blades and the inner surface of the housing cooperate to form the composite evaporation chamber.

Abstract: A distillation unit (10) employs a rotary heat exchanger (32) forming a multiplicity of evaporation chambers (56) into which a liquid to be purified is sprayed for evaporation. Spray arms (58) spray at a steady rate into all of the evaporation chambers (56) simultaneously but not at a rate that is adequate to maintain the wetting required for efficient transfer of heat to the liquid. A scanning sprayer (140) supplements this steady spray with spray from nozzles (142 and 144) into only a few of the evaporation chambers at a time, visiting all of them cyclically. The overall rate of spray from the two sources thus combined to spray the chamber cyclically maintains proper wetting even though on average it is lower than the rate that would be required of a constant-rate spray into all of the evaporation chambers.