Abstract: A method and apparatus are disclosed for improving the available pump net positive suction head in a system for pumping liquid from a storage tank. When the liquid in the system is at or near its boiling point, a pump suction vessel is used to store and cool the liquid. The liquid in the pump suction vessel is kept at a temperature lower than its boiling point by surrounding the vessel with a jacketed space containing liquid from the storage tank. As the liquid in the jacketed space evaporates, the vapor is vented to the storage tank and more liquid is fed into the jacketed space.

Abstract: In the method of the invention, an unknown mass fraction (F) of solid cryogen in a stored cryogenic refrigeration system is determined. The method includes the steps of adding mass (T) of a trace substance which is soluble in the liquid phase of the system. The total mass amount (M) of the cryogen in the system is determined at the time of charging the system. The initial mass concentration (C.sub.I) of the trace substance is determined by dividing (T) by (M). During operation of the stored cryogenic refrigeration system, a small sample of the liquid phase cryogen is extracted from the system. The sample is analyzed to determine the new concentration (C.sub.N) of the trace substance in the sample. The new concentration (C.sub.N) of the sample is dependent on the amount of solid cryogen which has been produced in the system. Thereafter, the mass fraction (F) of solid cryogen in the system is determined by solving the equation:F=1-(C.sub.I /C.sub.

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: A method and apparatus for cooling a warm feed stream of aqueous liquid to close to but above the freezing point of the aqueous liquid and delivering it to a mixing tank; withdrawing an aqueous ice slurry from an ice slurry receiver-crystallizer and delivering it to the mixing tank to further cool the contents and produce temperature control of the mixing tank contents; withdrawing an aqueous slurry from the mixing tank and delivering it to a slurry thickener tank for precipitate separation thereof; removing the precipitate from the slurry thickener tank and disposing of it; withdrawing aqueous liquid from the thickener tank and delivering it to the ice slurry receiver-crystallizer; and withdrawing an aqueous ice slurry from the ice slurry receiver-crystallizer, feeding it through a freeze exchanger to produce additional aqueous ice slurry and withdrawing the aqueous ice slurry from the freeze exchanger and feeding it to the ice slurry receiver-crystallizer.

Abstract: An improved heat exchanger in which a liquid is cooled by contacting a surface to crystallize a component therefrom by indirect heat exchange with a fluid on the otherside of the surface, having a layer of a polymeric material, to which the crystallized component does not significantly adhere, on the surface which contacts the liquid, and with said layer being sufficiently thin for efficient heat transfer through the surface.An improved method of crystallizing a component from a liquid by indirect heat exchange by passing the liquid into contact with a surface covered with a thin layer of a polymeric material to which the crystals do not substantially adhere, and cooled by a cooling fluid which is sufficiently cold to cool the liquid to a temperature low enough to form crystals as the liquid contacts the surface.