Abstract: A feed liquid, which can be aqueous, is frozen in tubes of a freeze exchanger by indirect cooling with a cold liquefied refrigerant to form a solid tubular shaped product. A warm liquefied refrigerant is used to indirectly melt a thin layer of the frozen tubular product to release it from the tubes. The freed tubular product is cut into pieces which can be used for cooling purposes and, in the case of ice, to give potable water.

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: In a combination of apparatus for storing liquefied natural gas which includes an insulated separation tank in which solidified carbon dioxide is settled out of liquefied natural gas and a liquefied natural gas-solidified carbon dioxide slurry accumulates, an insulated liquefied natural gas storage tank, and a conduit for delivering liquefied natural gas from the separation tank to the storage tank, the improvement comprising a conduit for withdrawing natural gas boil-off from the storage tank and feeding it to a compressor, a conduit for feeding compressed natural gas boil-off from the compressor to a heat exchanger for indirect heat exchange with a liquefied natural gas-solidified carbon dioxide slurry in the separation tank to cool the compressed natural gas to reliquefied natural gas, and a conduit to feed the reliquefied natural gas from the heat exchanger to the storage tank.