초록 ▼

A process and system for obtaining fresh water from salt water such as sea water, by direct contact heat transfer using staged evaporator-condenser units operating with a low boiling water-immiscible liquid hydrocarbon. Each stage comprises a closed vessel divided into two compartments, an evaporato

A process and system for obtaining fresh water from salt water such as sea water, by direct contact heat transfer using staged evaporator-condenser units operating with a low boiling water-immiscible liquid hydrocarbon. Each stage comprises a closed vessel divided into two compartments, an evaporator and a condenser, by a bubble cap tray similar in construction to those used in distillation. Relatively hot fresh water is introduced into the liquid hydrocarbon contained in the lower compartment of each stage, causing boiling of the hydrocarbon at a temperature differnce of 2°-4°F. Hydrocarbon vapors pass from the evaporator compartment through the bubble caps to the upper condenser compartment where they are condensed in contact with a colder saline stream, and the condensed hydrocarbon is returned to the lower compartment. The heated saline stream is flash evaporated and the vapors are condensed in direct contact with recycled fresh water from the evaporator compartments, and a portion of this combined stream is taken off as product, the remainder of the combined stream being further heated and reintroduced into the evaporator compartments of the staged units. Sea water feed is introduced into the condenser compartment of the last stage and passes into the respective condenser compartments of each of the preceding stages, and is further heated therein in each stage, and the hot fresh water introduced into the evaporator compartment of the first stage is passed through the evaporator compartments of each succssive stage and is further cooled in each successive stage.

대표청구항 ▼

A system for separating water from an aqueous solution containing a non-volatile solute by direct contact heat transfer which comprises: (a) a plurality of unitary evaporator-condenser stages, each stage comprising a lower evaporator chamber, an upper condenser chamber means for enabling vapor to pa

A system for separating water from an aqueous solution containing a non-volatile solute by direct contact heat transfer which comprises: (a) a plurality of unitary evaporator-condenser stages, each stage comprising a lower evaporator chamber, an upper condenser chamber means for enabling vapor to pass from said lower evaporator chamber into said upper condenser chamber and means for enabling condensate to pass from said upper condenser chamber into said lower evaporator chamber; (b) means for introducing hot water into the lower evaporator chamber of a first stage of said evaporator-condenser stages and into contact with an immiscible liquid therein to cause boiling of said immiscible liquid to form a vapor therefrom; (c) first conduit means, interconnecting the lower evaporator chamber of each of said evaporator-condenser stages, for passing said hot water from the evaporator chamber of said first evaporator-condenser stage to the evaporator chambers of succeeding stages to the evaporator chamber of a last stage of said evaporator-condenser stages, said hot water contacting an immiscible liquid in each of said lower evaporator chambers and causing boiling therof to form a vapor therefrom; (d) means for introducing an aqueous solution containing a non-volatile solute into the upper condenser chamber of the last stage of said evaporator-condenser stages and into contact with the vapor of the boiled immiscible liquid from the first stage lower evaporator chamber to cause heating of the aqueous solution and condensing of the boiled immiscible liquid vapor; (e) second conduit means interconnecting the upper condenser chambers of each of said evaporator-condenser stages for passing said aqueous solution from the upper condenser chamber of the last evaporator-condenser stage successively into the upper condenser chamber of preceding evaporator-condenser stages to the first evaporator-condenser stage; (f) a flash chamber; (g) means for withdrawing heated aqueous solution from the upper condenser chamber of said first evaporator-condenser stage and introducing said withdrawn heated aqueous solutes into the flash chamber for flashing vapor therefrom; (h) means for condensing the flashed water vapor, and, (i) means for withdrawing said condensed water as product.