Abstract: An ice harvesting/water chiller machine with an improved evaporator assembly having a plurality of plate-type heat exchangers oriented vertically in face-to-face parallel relation. A water reservoir is located above the heat exchangers. Water is distributed from the reservoir downwardly to flow over the outside surfaces of the heat exchangers to effect a substantially even distribution of water over the outside surfaces as it flows downwardly thereover. Cold refrigerant is distributed to the tops of the heat exchangers to cascade downwardly over the inside surfaces of the heat exchangers to effect a substantially even distribution of refrigerant over the inside surfaces as it cascades downwardly thereover. A cold refrigerant feed tube extends across the top of each heat exchanger substantially the entire width thereof. The tube has spaced openings along the tube over substantially the entire width of the heat exchanger which openings communicate with the interior of the heat exchanger.

Abstract: A dual-walled coiled plate heat exchanger with vented interface includes four plates of stainless steeel welded together and inflated to form a refrigerant passage between two of the plates, a water passage between another two of the plates, and a vented interface between the two passages such that leakage from either of the passages into the interface is vented to the atmosphere and not to the other passage.