Abstract: The ice content of a mixture of ice and liquid water is determined by (a) measuring the electrical conductivity C.sub.i of the original water at a temperature above its freezing point and before any of it has been converted to ice; (b) cooling the water to produce a mixture of ice and a liquid water phase; (c) measuring the electrical conductivity C.sub.n of the liquid water phase; and (d) computing the fraction of ice in the mixture by use of the equationF=1-C.sub.i /C.sub.nwherein F is the fraction of ice in the mixture, C.sub.i is the electrical conductivity of the original water before ice formation therein, and C.sub.n is the electrical conductivity of the liquid water phase in the mixture having the ice fraction F.

Abstract: An ice slurry is produced at the triple point of water in a freezer vessel having vertical freezer tubes on which feed water falls as an outside film and coolant tubes on which cold coolant falls as an outside film, with the liquid coolant and liquid feed distributed to the tubes by a pan over the tubes. The resulting warmer coolant flows to a collecting pan at the vessel bottom and then through an outlet for withdrawing the coolant from the vessel, while the ice slurry is withdrawn through an outlet at the vessel bottom.

Abstract: Apparatus and methods are disclosed for concentrating aqueous liquids which increase in viscosity with concentration using three stages employing screw concentrators in series which separate ice crystals from the liquid.

Abstract: A falling film heat exchanger in which a continuous weld circumferentially joins each tube to the outer surface of the upper, and desirably also the lower, tubesheet. The welds seal the crevices between the tubes and tubesheet holes and prevent corrosion. Since the circumferential welds cannot be deposited if the tube ends extend more than about 2 inches past the tubesheet, extensions can be added by welding.

Abstract: A heat exchanger comprising a shell connected to vertically spaced apart horizontally arranged circular upper and lower tube sheets; a plurality of vertically positioned parallel tubes, with each tube extending through and connected to a hole in each tube sheet; a bottom sleeve-supporting plate positioned above, and spaced apart from, the lower tube sheet; a top sleeve-supporting plate positioned below, and spaced apart from, the upper tube sheet; a plurality of sleeves joined to holes in the top and bottom sleeve-supporting plates; each of said tubes being axially positioned in a sleeve so as to provide an annular space between the tube outer surface and the sleeve inner surface so that liquid can flow into the sleeve bottom end and out the sleeve upper end; an inlet to feed a heat exchange liquid into a space between the bottom sleeve-supporting plate and the lower tube sheet; an outlet to withdraw heat exchange fluid from the shell side of the heat exchanger above the bottom sleeve-supporting plate; and a

Abstract: A falling film heat exchanger of the shell and tube type has the tubes positioned in concentric rings. A liquid distribution box is positioned above the tube upper ends. Short pipes extend downwardly from the box to feed liquid between the rings of tubes to distribute the liquid uniformly to the tubes. The box desirably rotates slowly. Also, the pipes desirably extend between upwardly extending tube ends so as to provide a uniform pool of liquid which overflows uniformly into the tubes.

Abstract: A falling film freeze exchanger having a shell connected to vertically spaced apart horizontally arranged circular upper and lower tube sheets; a plurality of vertically positioned parallel tubes, with each tube extending through and connected to a hole in each tube sheet; an inlet to feed a liquefied refrigerant gas to the lower part of the shell side of the heat exchanger and an outlet to withdraw refrigerant vapor from the upper part of the shell side of the heat exchanger; a liquid distribution box positioned above the upper tube sheet and a conduit to deliver an aqueous feed liquid to the liquid distribution box; a solid walled sleeve, surrounding and spaced outwardly from each tube, joined to the upper tube sheet and extending downwardly a short distance below the refrigerant liquid/gas interface on the shell side thereby providing a refrigerant vapor space between each sleeve and tube; and a hole in and through the upper part of the sleeve wall near the upper tube sheet.