CN101643248A

CN101643248A - Low-cost technique for desalting salt water

Info

Publication number: CN101643248A
Application number: CN200810145486A
Authority: CN
Inventors: 李世才
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-08-04
Filing date: 2008-08-04
Publication date: 2010-02-10

Abstract

The invention relates to a low-cost technique for desalting salt water, which aims to solve the problem of the demand of a large amount of fresh water for developing agriculture and animal husbandry in an arid desert region. Although the desert region has rich underground water, a majority is salt water and cannot be drunk or irrigate farmlands. Techniques for desalting the salt water are in a large number, but cannot supply water for irrigating a large number of farmlands because of quite high production cost. The low-cost technique for desalting the salt water adopts the technical scheme that: by using rich wind energy and solar energy in the desert region, the salt water in the depth under the ground is pumped out and is sent to a sealed and light-transmitted shelter for muggy drying; the moisture is evaporated; salt impurities are settled; and then the evaporated water vapor is introduced to cold water to be condensed into the fresh water. Where the cold water comes from is a question. Because of low temperature, the cold water adopts the salt water such as the underground water or sea water in a certain depth under the surface of the ground. Because the energy used by the scheme for producing the fresh water does not cost money, the cost for producing the fresh water is quite low. The application of the low-cost technique for desalting the salt water can supply a large amount of fresh water to the arid desert region to develop the agriculture and the animal husbandry.

Description

Low-cost technique for desalting salt water

One, technical field:

Technique for desalting salt water.

Two, background technology:

The desalination method of various countries' employing now mainly contains two kinds: first kind is distillation method, promptly earlier the boiled extremely boiling of water, makes it a large amount of gasifications, then water vapour is fed condenser, condenses into liquid water.Because salt in the water and alkali and other mineral substance can not be evaporated, so agglomerative water just becomes fresh water.Distillation method needs a large amount of man-made recoveries' the energy (as coal, oil ...) come the water heating is made the water boiling.So production cost is very high.Second kind is reverse osmosis method.Promptly the water that contains a large amount of salt, alkali, various mineral substance and bacterium is imposed severe pressure, make water molecules pass through the permeable membrane of eyelet minimum (reaching molecule and atom level), the molecule of bacterium, salt, alkali and other mineral substance is stopped and can not pass by permeable membrane, thereby make salt water obtain desalination, purify, reach drinking water standard, produce pure water.Reverse osmosis method is owing to using special-purpose cascade filtration equipment and water being imposed severe pressure, and this need consume a large amount of funds and the energy.So it is also very high to produce the cost of this fresh water, can only produce the fresh water of drinking for the people.More than the fresh water produced of two kinds of methods if be used for a large amount of field irrigations, be infeasible economically.

Three, summary of the invention:

How could be used for field irrigation to a large amount of desalinations of salt water with extremely low cost? the problem to be solved in the present invention that Here it is.Its core be do not use man-made recovery's the energy (as coal, Sweet natural gas, oil) and utilize the abundant renewable energy source of nature, the cost of producing fresh water is reduced greatly.

On the Gobi desert, desert of arid, though there is not the snow-broth of rainwater or thawing, abundant underground water is often arranged, and these underground water are salt water mostly.The snow because these areas do not rain, fine, cause the sandstorm that except blowing hard sunlight is very sufficient.So we can utilize abundant sun power, wind energy to make the saline groundwater desalination.Technical scheme is: with sun power or wind energy subterranean salt water is extracted into ground, allow the vexed on the ground solarization of these water then, make water below boiling point (75～100 ℃) in be evaporated to water vapour under (75～45 ℃) low (45～0 ℃) temperature, again water at low temperature steam in these is fed in the colder condensation pond, make it to be condensed into fresh water.In the desert area of arid, surface temperature generally all surpassed 40 ℃ and can evaporate the water owing to the irradiation of daylight daytime.What cold water in the condensation pond come again from? still (technical scheme of≤15 water, I have designed sun power fresh water factory to have utilized phreatic cold property.As accompanying drawing.

Four. description of drawings:

A. the structure of sun power fresh water factory:

1. factory's interior wall.2。Factory's exterior wall.3。Wind-power water-pumping machine.4。Cold salt water pond.5。Weep pipe.6。The generating surface that tilts.7。Evaporator room.8。Printing opacity sealing ceiling.9。Vacuum fan.10。The interior wall aspirating hole.11。The vapour condensation pipe.12。Fresh-water pool.13。Fresh water output watchroom.14。The blowdown ditch.

B. the principle of work of sun power fresh water factory:

The cold salt water of depths is drawn up by wind-power water-pumping machine (3) and injects cold salt water pond (4) and store for future use under the face of land.Opening valve after the sunrise allows cold salt water on the generating surface (6) below weep pipe (5) drips to after the valve controlling flow speed, because being the steel plate or the plastics sheet of black, makes generating surface, area very big (several thousand square metres approximately) is heated up very fast by heat absorption after the solar radiation.So, drip to the very fast evaporation of in the way that flows downward, absorbing heat of cold salt water on the generating surface, below the printing opacity ceiling (8) that become, cryogenic water vapour rises to evaporator room (7) top, and contained salt, alkali and other impurity slowly flows in the blowdown ditch along the generating surface that tilts in the cold salt water.Because the obstruct of printing opacity ceiling (8), water vapour can not escape in the outdoor atmosphere, and the aspirating hole of vacuum fan (9) from interior wall that is installed in the interior wall top blows to the vapour condensation pipe (11).Because prolong is to be immersed in the cold salt water pond, water temperature is lower than 15 ℃.So it is standby that steam coagulation becomes water to flow into the middle storage of following fresh-water pool (12).The workman of watchroom (13) can regularly remove sedimentary solid salt, alkali and impurity in the blowdown ditch except that the output of control fresh water.

Because evaporation area is very big, the sunshine duration is very long again, so can mass production fresh water.As, a 1000m ²The fresh water factory of generating surface produces about about 4000 tons of fresh water per year, is enough to irrigate the needs that tens mu of farmlands and people and animals drink.This just can realize the purpose of low-cost mass production fresh water.According to the know-why of this production fresh water, not only sun power fresh water factory can also can be built with this method mass production fresh water in Gan Han desert, Gobi desert on the island, supplies fresh water cheaply in a large number.The waste water that each factory is discharged with present technique is purified, and a large amount of sewage in city is purified.

Use wind-power water-pumping machine in the present technique,, can draw water with the electric power that solar generator sends, bleed in insufficient area of wind-force or calm time.When therefore building a sun power fresh water factory, also should the supporting standby solar power plant (small-sized) of building

Claims

I have following 4 technical characterictics claimed at " low-cost technique for desalting salt water " of invention:

1. utilized simultaneously two kinds natural, non-pollution of renewable energy---sun power, wind energy are produced the method for fresh water, and without man-made recovery's the energy (as coal, oil, thermoelectricity ...) and other natural energy sources (as underground heat) method of producing fresh water make and produce instinct and really reduce significantly.The method of using sun power and wind energy to reduce production costs simultaneously is claimed.The method of utilizing other man-made recovery's energy or natural energy source to produce fresh water does not belong to my claimed scope.

2. the salt water (as underground water, deep sea water) that utilizes the following certain depth in the face of land is both as the raw material of producing fresh water, again as the necessary low-temperature receiver of steam coagulation.The method of thisly utilize the amount of deep layer salt water big simultaneously, cryogenic characteristics being produced fresh water is claimed.And utilize other low-temperature receivers (as high mountain snow-broth, natural ice cube, altitude cold air ...) method of coming the condensed water steam, do not belong to my claimed scope.

3. utilized water in the evaporation of (70-45 ℃), low temperature (45-0 ℃) produce fresh water with congealing property; rather than under high temperature (70-100 ℃), make the water ebullition, gasification and the principle of condensing produce fresh water, this in, the method for producing fresh water under the cold condition is claimed.The high-temperature gasification coagulation does not belong to the scope of my application protection.

4. it is claimed prolong to utilize to enlarge the method that evaporation area and sunshine duration enlarge production fresh water quantity.Because it has utilized the big advantage of growing with the sunshine duration of area of desert, arid area just.Cost with a large amount of fresh water of method for distinguishing production is too high.Thisly utilize enlarged-area to enlarge the method for fresh water production quantity claimed with prolonging the sunshine duration.Enlarge fresh water yield with additive method, then do not belong to the scope of my application protection.