Method and apparatus for preparing fresh water from sea water

Abstract

Pretreated sea water is endothermically evaporated in a evaporating chamber, water vapor is heated and pressurized to a set point different from that of sea water in the evaporating chamber by 25 deg.C, and water vapor is condensed into fresh water through heat exchange with sea water in the evaporating chamber while sea water is evaporated. The said process is repeated and bittern is finally formed and salt is separated out in the bottom of the evaporating chamber. The equipment consists of sea water evaporating chamber, heating exchanger, air compressor, etc. The present invention has high heat efficiency and low power consumption and cost and can product salt.

Description

technical field

[0001] The invention relates to a method for extracting fresh water from seawater, in particular to a method for extracting fresh water by heating and pressurizing secondary steam.

[0002] The invention also relates to a device for such a method. Background technique

[0003] At present, there are many methods for extracting fresh water from seawater, among which distillation method occupies a relatively large proportion in seawater desalination. Since the 1950s, methods such as multi-stage flash distillation and multi-effect distillation have come out one after another. The flash distillation method is to heat the seawater to 150°C in the pipeline, and then introduce the seawater into a flash chamber with a lower pressure. At this time, the seawater will be vaporized rapidly. The saturated steam temperature corresponding to the steam chamber pressure, the heat released when the seawater temperature is lowered, becomes the heat energy of seawater vaporizat...

Examples

Embodiment Construction

[0014] The present invention will be described in further detail below in conjunction with accompanying drawing:

[0015] In Fig. 1, the device diagram of the indirect heating distillation system using the normal temperature and reduced pressure distillation method is composed of an evaporation chamber 5, a condensation pipe 4, a high pressure pump 6, a water pump 7, a gas compressor 3, a heat exchanger 1, and a heating pipe 2. The evaporation chamber 5 is a hollow cylinder, and the inside is filled with spiral condenser pipes 4 made of a copper-nickel alloy. The water outlet at the lower part of the condensation pipe 4 communicates with the water pump 7. There is a steam outlet on the top of the evaporation chamber 5, which is connected to the steam inlet end of the heating pipe 2 in the heat exchanger 1 through a pipe. The heating pipe 2 is made of ordinary stainless steel. The steam outlet communicates with the steam inlet of the gas compressor 3 . The lower discharge port...

technical field

[0001] The invention relates to a method for extracting fresh water from seawater, in particular to a method for extracting fresh water by heating and pressurizing secondary steam.

[0002] The invention also relates to a device for such a method. Background technique

[0003] At present, there are many methods for extracting fresh water from seawater, among which distillation method occupies a relatively large proportion in seawater desalination. Since the 1950s, methods such as multi-stage flash distillation and multi-effect distillation have come out one after another. The flash distillation method is to heat the seawater to 150°C in the pipeline, and then introduce the seawater into a flash chamber with a lower pressure. At this time, the seawater will be vaporized rapidly. The saturated steam temperature corresponding to the steam chamber pressure, the heat released when the seawater temperature is lowered, becomes the heat energy of seawater vaporizat...

Examples

Embodiment Construction

[0014] The present invention will be described in further detail below in conjunction with accompanying drawing:

[0015] In Fig. 1, the device diagram of the indirect heating distillation system using the normal temperature and reduced pressure distillation method is composed of an evaporation chamber 5, a condensation pipe 4, a high pressure pump 6, a water pump 7, a gas compressor 3, a heat exchanger 1, and a heating pipe 2. The evaporation chamber 5 is a hollow cylinder, and the inside is filled with spiral condenser pipes 4 made of a copper-nickel alloy. The water outlet at the lower part of the condensation pipe 4 communicates with the water pump 7. There is a steam outlet on the top of the evaporation chamber 5, which is connected to the steam inlet end of the heating pipe 2 in the heat exchanger 1 through a pipe. The heating pipe 2 is made of ordinary stainless steel. The steam outlet communicates with the steam inlet of the gas compressor 3 . The lower discharge port...

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