JP2009072734A - Seawater desalting apparatus using air stream circulation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seawater desalting apparatus that sharply conserves necessary energy by simple handling and a simple mechanism to perform the desalting of seawater while enhancing the concentration of a substance dissolved in seawater at the same time and utilizes salt in seawater as byproduct resources of the desalting of seawater to relax even environmental pollution. <P>SOLUTION: An evaporation region 1 and a condensing region 2, both of which are adjacent to each other through a heat exchanger, communicate with each other up and down in the seawater desalting apparatus. This seawater desalting apparatus is equipped with a heat supply part 13 for heating the upper part in the seawater desalting apparatus to store the heat of the upper part in the apparatus, an air stream circulation means for circulating an air stream between the evaporation region 1 and the condensing region 2, a seawater preheating pipe for sending raw material seawater 4 to the evaporation region 1 while preheating the same, and an evaporation means for evaporating the seawater toward the evaporation region 1. The raw material seawater 4 preheated by the seawater preheating pipe to raise temperature is evaporated by the evaporation means and the air stream in the apparatus is circulated within the apparatus by the air stream circulation means to condense steam formed by evaporation while evaporating and condensing the raw material seawater 4 to desalt the seawater 4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a seawater desalination apparatus using air circulation.

As a conventional seawater desalination apparatus, an apparatus employing a seawater evaporation method such as a multistage flash method or a seawater desalination method using a reverse osmosis membrane excellent in energy saving is disclosed (for example, see Patent Document 1).
JP 2004-025108 A

  However, the multistage flash method has a complicated mechanism and consumes a large amount of energy. Moreover, seawater desalination using reverse osmosis membranes still involves a considerable amount of energy consumption in the seawater desalination process inside the equipment. In addition, it takes time for chemical treatment and maintenance, and may involve disposal of concentrated seawater 6 and pollution such as noise. Saving energy, preventing pollution, and simultaneously enabling the use of salt and other rare resources in seawater meet the demands of the times.

  Therefore, in the present invention, by simple handling and a simple mechanism, the required energy is greatly saved and seawater desalination is performed. At the same time, the concentration of substances dissolved in seawater is increased, and salt in seawater is desalinated. It is an object of the present invention to provide a seawater desalination apparatus that can alleviate the pollution by making it available as a by-product resource.

  In order to solve the above problems, the present invention takes the following means (1) to (3).

(1) That is, the seawater desalination apparatus using the air circulation according to the present invention is:
A vaporizing region 1 for vaporizing seawater in the region to obtain water vapor and a condensing region 2 for condensing water vapor in the region to obtain fresh water are adjacent to each other through a heat exchanger constituting a boundary wall between these regions. ,
Each region communicates with the upper communication portion 7 and the lower communication portion 8 located above and below the apparatus, respectively.
A heat supply unit 13 provided in the vicinity of the upper communication part 7 above the apparatus and heating and storing the upper part of the apparatus;
An airflow circulation means provided near the lower communication portion 8 below the apparatus and circulates an airflow between the vaporization region 1 and the condensation region 2 in the device;
A seawater preheating pipe 3 that passes from the raw material seawater tank 40 outside the apparatus to the lower part of the apparatus, passes through the inside of the apparatus, and feeds the raw material seawater 4 to the vaporization region 1 in the vicinity of the upper communication part 7;
Vaporization means for discharging seawater to a high place in the vaporization region 1 and evaporating in the vicinity of the heat supply unit 13;
Then, the raw seawater 4 preheated by the seawater preheating pipe 3 is vaporized by the vaporizing means, and the airflow in the apparatus is circulated in the apparatus by the airflow circulating means to condense the vapor generated by the vaporization. The raw seawater 4 is desalinated by vaporization condensation.

  The heat supply unit 13 can keep the upper part at a higher temperature than the lower part in the apparatus.

  The vaporizing means vaporizes the raw seawater 4 or the concentrated seawater 6 that could not be primarily vaporized into the vaporization region 1. Efficient vaporization is possible by releasing from the upper part of the vaporization area | region 1 which is the heat supply part 13 vicinity.

(2) The seawater preheating pipe 3 passes through the condensation region 2 in the apparatus, and heat exchange inside and outside the seawater preheating pipe 3
A heat recovery step for recovering the heat of the condensed water 9 in the condensed region 2 taken out of the apparatus to the raw seawater 4;
A condensing promotion step for promoting raw material seawater 4 to condense water vapor in the lower airflow in the condensing region 2;
-And it is preferable to give the high temperature step which makes raw material seawater 4 high temperature by the condensing effect | action of the water vapor | steam which is the airflow in the condensing area | region 2.

  (3) It is preferable that a vaporization means comprises the seawater spray apparatus S which sprays seawater from the area | region upper part. If it is such, cleaning will become easy even if the salt 5 and scale in the raw material seawater 4 precipitate.

  As one of the seawater desalination apparatuses described above, a structure in which the vaporizing region 1 and the condensing region 2 are in contact with each other through a slope or a tubular body may be employed. The slope or tube body is formed of a heat exchanger, and extends, for example, spirally or stepwise from the upper part to the lower part in the apparatus.

  As an example of the condensing means in the above structure, there is one that allows vaporized water vapor to pass from the upper side to the lower side in the condensing region 2 partitioned by a slope or a tube in the condensing region 2. During the passage of the vaporized airflow in the condensation area 2, the condensed water 9 can be continuously obtained from the noble airflow by performing heat exchange with a heat exchanger that forms a partition with the vaporization area 1. At this time, the condensed water 9 is easily recovered by flowing down the slope or the floor of the pipe body.

  As the vaporizing means, in addition to the above (3), the vaporization region 1 and the condensation region 2 are overlapped in the vertical direction, and each region is in contact with the upper and lower surfaces of the tray made of a heat exchanger, A structure in which seawater is vaporized from the surface of the raw seawater 4 formed in the tray can be employed. In this method, the raw seawater 4 flows down on the slope or tube floor in the vaporizing region 1, and the seawater is vaporized from the seawater while heat exchange is performed by the heat exchanger that forms the floor.

  In the present invention, seawater desalination can be carried out by taking the above-mentioned means while enabling a significant energy saving that cannot be achieved by a conventional seawater desalination apparatus by simple handling and a simple mechanism. In addition, it can open the way to acquisition of salt 5 dissolved in seawater and corporate resources other than salt 5, and can suppress the occurrence of pollution that occurs during seawater desalination.

  Embodiments of the present invention will be described in detail with reference to the drawings. 1 to 3 show a seawater desalination apparatus according to the first embodiment of the present invention, in which seawater desalination apparatus is shown. FIG. 1 is an explanatory view schematically showing a longitudinal sectional structure, and FIGS. FIG. Example 1 is a structure example of one system in which the raw seawater 4 is sprayed and vaporized only once, and the concentrated seawater 6 can also be recovered.

  FIG. 4 is a schematic diagram illustrating a longitudinal cross-sectional structure of a seawater desalination apparatus using airflow circulation according to Embodiment 2 of the present invention. In addition to Example 1, Example 2 has a lower chamber 20 partitioned by an inner bottom B3, and has a secondary system for vaporizing the concentrated seawater 6 again (within the same vaporization region 1). The production and recovery of the salt 5, which is a by-product, can also be performed at the same time.

  FIG. 5 is a schematic diagram for explaining a longitudinal cross-sectional structure of a seawater desalination apparatus using air flow circulation according to a third embodiment of the present invention. In addition to Example 1, Example 3 has an inner cylindrical part partitioned by an inner wall B2, and also has a secondary system for re-evaporating the concentrated seawater 6 in the inner cylindrical part, and a salt that is a byproduct. 5 can also be collected at the same time.

  6 to 8 show a seawater desalination apparatus according to Embodiment 4 of the present invention by air circulation. Specifically, FIG. 6 is a schematic diagram for explaining the longitudinal sectional structure of the fourth embodiment. FIG. 7 is an explanatory diagram of the seawater system obtained by extracting the seawater spray system from FIG. 6, and the primary system of the raw seawater 4 is shown on the left side, and the secondary system of the concentrated seawater 6 performed subsequently is shown on the right side. FIG. 8 is a system explanatory diagram of the air stream obtained by extracting the system of the air stream and condensed water 9 from FIG. 6. The primary condensation system of the air stream and the recovery system of the condensed water 9 thereby are shown in the left diagram, and the secondary condensation performed simultaneously. The system and the collection system for condensed water 9 are shown in the right figure.

<Basic configuration of seawater desalination system by air circulation (Fig. 1)>
In the seawater desalination apparatus according to the present invention, the vaporization region 1 for vaporizing seawater in the region to obtain water vapor and the condensing region 2 for condensing water vapor in the region to obtain fresh water are between these regions. The regions communicate with each other through a lower communication portion 8 located in the lower part in the apparatus and an upper communication part 7 located in the upper part in the apparatus. Moreover, the heat supply part 13 is provided in the upper part in an apparatus, and heat storage is carried out so that the upper part in an apparatus may be filled with saturated water vapor | steam higher than the lower part in an apparatus.

  In addition, the apparatus has a blower F as an airflow circulation means for circulating an airflow between the vaporization region 1 and the condensation region 2.

  Even if an appropriate air circulation is generated by the air circulation means, saturated water vapor having a large buoyancy is naturally directed upward in the apparatus and stored as described below. That is, air with a large specific gravity remains in the lower part of the apparatus, and heat flows out by collecting condensed water 9. For this reason, the temperature in the lower part in the apparatus is lower than that in the upper part, and the temperature in the lower part in the apparatus is close to the raw material seawater 4 (with a difference of only a few degrees C). For example, when the temperature of the raw material seawater 4 is 25 ° C. and the temperature of the condensed water 9 recovered outside the apparatus is about 28 ° C., the temperature inside the apparatus is 95 ° C. and the temperature inside the apparatus is about 30 ° C.

  Although heat loss due to taking out the desalinated condensed water 9 from the lower part of the apparatus is unavoidable, the heat supply unit 13 at the upper part of the apparatus supplies the same amount of heat as the amount of lost heat. However, the heat balance is balanced in the apparatus, and heat is continuously supplied to the upper part of the apparatus under the balance of the heat balance. And the buoyancy of water vapor increases as the temperature increases, and the generated water vapor moves upward in the apparatus. For this reason, in the apparatus, the temperature increases from the lower side to the upper side, so that the water vapor is saturated and the ratio of the saturated water vapor is increased, and the ratio of the air component in the airflow is decreased. The lower part of the apparatus is kept at a relatively low temperature and the heat storage region in the upper part of the apparatus is kept at a relatively high temperature by utilizing the property of the mass of heat energy that is water vapor going upward.

  Further, it is communicated from the raw material seawater tank 40 outside the apparatus, passes through the lower part of the apparatus, passes through the condensation area 2 inside the apparatus, and vaporizes in the vaporization area 1 in the vicinity of the upper communication part 7 while preheating the raw material seawater 4. A seawater preheating pipe 3 is provided. The seawater preheating pipe 3 communicates from the lower side to the upper side in the condensation region 2 to preheat the raw material seawater 4 and promote the condensation of water vapor from the airflow in the lower part of the condensation region 2 to the vaporization means in the upper part of the vaporization region 1. It is a pipe body that feeds seawater 4.

  The raw material seawater 4 carried to the upper part of the apparatus while being preheated by the seawater preheating pipe 3 is discharged into the vaporization region 1 by vaporization means, and water vapor is vaporized. In each embodiment, a seawater spray device S having a number of spray nozzles as shown in FIG. 2 is used as the vaporizing means. By spraying preheated seawater (raw seawater 4 or concentrated seawater 6) as fine particles from the height of the vaporization region 1 near the heat supply unit 13, ideal vaporization can be promoted.

  In this way, the high-temperature water vapor that has been evaporated from the raw seawater 4 or the concentrated seawater 6 and is almost saturated and the air component becomes slight is forcibly introduced into the condensation region 2 from the upper communication portion 7 by the air circulation means. . When entering the condensing region 2, a temperature difference from the vaporizing region 1 is generated, the water vapor condenses, and the condensed water 9 of hot water is produced.

  Moreover, at this time, in the vaporization area | region 1, it heats from the high temperature condensation area | region 2, the water vapor pressure of seawater rises, and the airflow temperature in the vaporization area | region 1 also rises simultaneously, and vaporization of the raw material seawater 4 is accelerated | stimulated. Thus, seawater desalination can be performed by continuing the heat exchange which combined the airflow circulation between the condensation area | region 2-vaporization area | region 1, and the vaporization and condensation effect | action of water vapor | steam.

  Here, in the conventional seawater desalination method, when water vapor separated from seawater is returned to water, seawater is used as a coolant, and condensation heat is recovered in seawater by cooling with seawater. However, it was difficult to completely recover the heat of condensation, and a large amount of heat loss during the gas-liquid phase change could not be avoided.

  In addition, a large amount of concentrated seawater 6 is also discarded by the reverse osmosis membrane method, which has conventionally been dominant in terms of energy costs.

  On the other hand, in the seawater desalination method according to the present invention as described above, most of the heat of condensation of water vapor is directly used for the vaporization of seawater. Seawater for use is not required. Therefore, seawater desalination is completed in the apparatus of the present invention, there is almost no consumption of thermal energy in the apparatus, and there is almost no need to discard the concentrated seawater 6. For this reason, the present invention is clearly superior in terms of energy cost, and the operation cost of desalination can be suppressed to an extremely low level.

(Airflow circulation means)
As shown in FIGS. 1 and 3, the blower F as an air flow circulation means is provided in the condensation region pipe 15 near the lower communication portion 8, and forcibly introduces water vapor generated in the vaporization region 1 into the condensation region 2. Airflow is circulated between each region while adjusting the flow rate.

  The airflow circulating in the apparatus repeatedly increases and decreases the amount of water vapor contained in the airflow as shown by the values on the graph of FIG. 9 due to the temperature change in each passing region. Here, in the vicinity of the lower communication portion 8 at the lower part of the apparatus, the temperature is the lowest in each region in the apparatus, and the water vapor component in the airflow is almost eliminated and the air flow is minimized. Since the specific gravity is the largest and the buoyancy is the smallest at the position where the amount of water vapor is minimized, the air flow can be efficiently controlled without countering the buoyancy by providing the blower F at the position in this state. . Even if the flow rate of the airflow passing through the airflow circulation means is small, a large amount of high-temperature saturated water vapor at the top of the apparatus is introduced into the condensation region 2, and the airflow rises later in the vaporization region 1. Circulation is performed smoothly.

  When water vapor is generated from seawater at a high location in the vaporization region 1 of the updraft, most of the air components with large specific gravity are prevented from rising, and much water vapor naturally gathers in the upper part of the device, and eventually the upper part of the device is hot. It becomes a water vapor saturation state. In the upper part of the apparatus, an air flow in which a small amount of air component is contained in a large amount of water vapor is introduced into the condensation region 2 from the upper communication portion 7, and then the air flow circulation provided in the vaporization region 1 near the lower communication portion 8. By means of the blower F as a means, forced air is exhausted from the condensation region 2 to the vaporization region 1. In this way, the air current circulates in the apparatus.

  In this way, the present invention allows the vaporization in the vaporization region 1 and the condensation in the condensation region 2 to proceed simultaneously on the front and back by forcibly introducing water vapor having a large buoyancy into the condensation region 2.

  In the upper communication part 7, the high-temperature and high water vapor pressure air flow has a large buoyancy, and the air flow tries to stay in that place without the forced force of the air flow circulating means. Therefore, a fan F serving as an air flow circulating means is arranged in the lower communication portion 8 and exhausted into the vaporization region 1, whereby a gas having a large buoyancy can be sucked into the condensation region 2 and lowered in the condensation region 2. it can.

(Seawater preheating pipe 3)
The seawater preheating pipe 3 passes through the inside of the condensation area pipe 15 made of a heat exchanger, and supplies the raw seawater 4 into the vaporization area 1 in the apparatus while preheating the heat exchange inside and outside the pipe. The raw seawater 4 is subjected to a heat recovery step for recovering heat from the condensed water 9 taken out of the apparatus to the raw seawater 4 until the vaporization means in the vaporizing area 1 in the apparatus, and water vapor condensation of the lower airflow in the condensed area 2 is performed. A heat recovery step to be promoted and a high temperature step by the condensing action of water vapor which is an air flow in the condensing region 2 are performed. By these three steps, the raw material seawater 4 reaches a high temperature state before reaching the vaporizing means.

(Vaporization means)
The vaporization means is means for promoting the vaporization of seawater in the vaporization region 1. Specifically, the vaporization unit is multistage in the vaporization region 1 by the seawater spray device S (Examples 1 to 4) that sprays seawater from the upper part of the region. The raw seawater 4 flows down by seawater evaporation (not shown) from the provided seawater evaporation surface, or on a slope that spirals down in the apparatus, and seawater evaporation from the lower surface of the spiral seawater flow (not shown) ). Among these, the form of Examples 1-4 which uses the seawater spraying apparatus S provided in the vaporization area | region 1 height while using the seawater preheating pipe | tube 3 and the heat supply part 13 for preheating and heating seawater produces the most efficient water vapor | steam. Is the method.

  The raw seawater 4 heated to high temperature by the seawater preheating pipe 3 is sprayed from the height of the vaporization region 1 by the seawater spray device S, so that the floating raw seawater not only from the evaporation surface of the heat exchanger wet with seawater. Evaporates efficiently from 4 fog.

  In addition, since heat has already accumulated inside the apparatus due to continuous operation of the apparatus, the upper part of the vaporization region 1 is also in a high-temperature and high water vapor pressure state, and steam condensation heat always flows from the condensation region 2. The temperature decrease due to seawater evaporation of 1 is prevented. Since the water vapor is actively generated and the volume is increased, an air component having a large specific gravity is less likely to rise, and a high temperature and saturated airflow state can be maintained in the vicinity of the upper communication portion 7. Thus, even if the air flow rate passing through the blower F, which is the lower airflow circulation means, is small, seawater desalination by the airflow circulation is performed efficiently.

(Spiral sea current bottom)
As other vaporization means other than the seawater spraying device S, the vaporization region 1 and the condensation region 2 are adjacent to each other through a boundary plate of a heat exchanger, and this boundary plate is continuously curved in a vertical direction while drawing a spiral. An inclined slope can be formed. The raw seawater 4 flows down on the slope, and vaporization can be promoted from the lower surface of the spiral seawater flow in which a large distance is secured by the spiral shape. According to this structure, while the boundary surface of the vaporization area | region 1 comprises the seawater evaporation surface where the raw material seawater 4 flows as a 1st boundary floor surface, the boundary surface of the condensation area | region 2 serves as a 2nd boundary floor surface. Condensation region 2 constitutes the falling water surface of condensed water 9 in which water droplets generated on the ceiling have fallen. This spiral seawater flow lower plate is connected to each other by securing a long distance by drawing a spiral while continuously forming a wide heat exchange surface, and has an upper end in the upper communication part 7 near the upper heat supply part 13. The lower communication portion 8 near the lower blower F has a lower end.

  According to the configuration in which the spiral seawater flow lower surface is formed, the first boundary floor surface of the vaporization region 1 is formed of a spiral plate-like slope of a heat exchanger, and the raw material seawater 4 supplied from the seawater preheating pipe 3 is Seawater evaporates while flowing down the slope. The upper surface side of the slope constitutes the floor surface of the vaporization region 1 and the lower surface side constitutes the ceiling surface of the condensation region 2. Water vapor condenses on the ceiling surface of the condensing region 2, and the heat generated at that time is transmitted to the raw material seawater 4 on the vaporization region 1 floor side through the slope as a heat exchanger, and the vaporization of the seawater in the vaporization region 1 is promoted. It is.

In the configuration in which the spiral seawater flow lower surface is formed, the seawater preheating pipe 3 may be composed of a heat exchange hose in which the floor surface of the condensation region 2 is stretched from below to above. By this heat exchange hose, the raw seawater 4 can directly recover heat from the hot water flowing on the floor surface of the condensation region 2 outside the hose. At the same time, the raw seawater 4 is also preheated by the condensation heat generated when the condensed water 9 is generated from the air flow in the condensation region 2. A structure in which the vaporized region 1 and the condensed region 2 are alternately formed by extending spirally in the vertical direction can be said to be a relatively simple structure.
If the seawater is hot, the saturated water vapor pressure will be very high, and the evaporation power from the seawater will be considerably high. Utilizing this, a spiral seawater falling plate in which the raw seawater 4 flows for a long time on a single spiral surface can be adopted as one aspect of the present apparatus.

(Heat supply unit 13)
The heat supply unit 13 supplies heat to the vicinity of the upper communication unit 7 in the upper part of the apparatus, and heats the seawater in the apparatus or the airflow in the vaporization region 1. For more effective seawater heating, it is preferable to directly heat the airflow immediately after the raw seawater 4 is supplied into the vaporization region 1. Further, immediately after the high-temperature raw material seawater 4 is supplied into the vaporization region 1 and evaporated, the liquid component, that is, water vapor-free water vapor is supplied, heat is supplied thereto, and the seawater is near the upper communication portion 7. It is desirable to heat above the boiling temperature.

  By directly heating an air stream of water vapor that does not contain a liquid component, the air stream temperature in the vicinity of the upper communication part 7 can be made higher than the boiling point of seawater. The temperature of the raw seawater 4 sprayed from the seawater spray device S, which is a vaporization means, is increased to the boiling point by using the airflow in the upper communication portion 7 having a temperature exceeding the boiling point as a heat source, and the water vapor pressure of the airflow in the vicinity of the upper communication portion 7 is maximized. Can be made. A highly efficient seawater desalination becomes possible with the high-temperature airflow in the vicinity of the upper communication portion 7 containing only a small amount of air components.

  The heat supplied by the heat supply unit 13 is then transferred as follows. First, the heat supplied by the heat supply unit 13 provided in the vicinity of the upper communication part 7 in the upper part of the apparatus is stored in a heat storage region in the upper part of the apparatus using water vapor as a medium. For this reason, during seawater desalination operation, the upper part in the apparatus is kept at a higher temperature than the lower part in the apparatus, and a heat storage region is formed. Thereafter, this high-temperature steam is forcibly introduced into the condensation region 2 by the air flow circulation means, and the condensation region 2 releases condensation heat at the time of condensation, and heat is transferred to the raw seawater 4 in the seawater preheating pipe 3 and the vaporization region 1. Is done.

  The heat supply unit 13 is not necessarily provided near the air flow outlet of the upper communication unit 7. Moreover, as a heat source supplied by the heat supply unit 13, a heat source having a high heat quantity is not necessarily required, and thus a wide variety such as waste heat and solar heat accompanying power generation and ship engine operation can be used.

(Seawater desalination method by air circulation)
The seawater desalination method according to the present invention is operated under natural atmospheric pressure, and almost all of the thermal energy required for seawater evaporation in the vaporization zone 1 is covered by the steam condensation heat in the steam condensation zone 2. is there. Due to the air circulation, the heat exchanger at the boundary of each region exchanges heat to desalinate the seawater. Specifically, the water vapor evaporated from the seawater in the vaporization region 1 is condensed in the condensation region 2 by the air flow circulation between the vaporization region 1 and the condensation region 2, and the water vapor that has not been fully condensed enters the vaporization region 1 again. .

  This vaporization and condensation action proceeds simultaneously on the front and back sides due to a change in the state of the air flow and a temperature difference between the vaporization region 1 and the condensation region 2. The specific gravity of water vapor is very small compared to the atmosphere, and the effect of temperature expansion is added to the point where the saturated water vapor pressure increases rapidly in the high temperature region, so that the gas in the high place inside the apparatus has a large buoyancy. For this reason, high temperature steam can be reliably confined in the upper part of the apparatus by a simple mechanism.

  The high-temperature steam confined in the upper part of the apparatus is sent to the lower part of the apparatus by the blower F, and then repeatedly forcibly circulates in the vertical direction in the apparatus. Seawater is continuously desalinated by repeating air flow circulation with heat exchange, which passes through the vaporization region 1 when the air flow flows upward and passes through the condensation region 2 when it flows downward.

  Moreover, the raw material seawater 4 is pumped by the pumping pipe which passes in the inside of the apparatus, and is sprayed and sprayed in the vaporization area | region 1 of the upper part in an apparatus. Heat exchange is carried out both inside and outside of this pumping pipe, which is intended to serve the purpose of reducing thermal energy in seawater desalination.

  By performing seawater desalination in this way, heat loss due to heat release during gas-liquid phase change can be suppressed to the limit, and the seawater desalination rate can be increased to the limit. Although this seawater desalination apparatus is a simple mechanism, a large amount of freshwater freshwater can be produced with very little energy, and there is little pollution. In addition, it does not require manufacturing costs and maintenance. These are achievements that could not be achieved by conventional seawater desalination methods.

  The air circulation type seawater desalination method as described above performs seawater desalination at a temperature equal to or lower than the boiling temperature of seawater under atmospheric pressure.

  Dirt such as precipitation of the salt 5 in the vaporization region 1 can be washed away by the cleansing apparatus 14 for the clean raw seawater 4. Moreover, the process of the scale stuck around the seawater spray apparatus S can be cleaned by storing the gas generated during seawater desalination. If necessary, a chemical solution in which a chemical is dissolved in the jet cleaning device 14 can be used and washed away with this chemical solution.

  This device can reduce the supply amount of raw seawater 4 little by little and adjust the seawater desalination rate (referring to the weight ratio of fresh water generated relative to the raw seawater 4). It becomes. If the supply amount of raw seawater 4 is drastically reduced, the concentrated seawater 6 cannot reach the lower part of the vaporization area 1 and the dried salt 5 minutes deposits and adheres to the vaporization area 1. 5 can also be performed. Increasing the water production rate reduces the cost of water production and eliminates pollution caused by the disposal of the concentrated seawater 6. In this way, by making the seawater desalination rate variable according to the purpose, it is possible to secure the value of resources such as useful trace elements in seawater. Hereinafter, it explains in full detail based on an Example.

  Example 1 (FIGS. 1 to 3) includes one vaporization system that heats and evaporates the raw seawater 4 only once in the vaporization region 1, and one condensation system that feeds and condenses the heat-evaporated gas into the condensation region 2. The gas is circulated between the two regions, and vaporization and condensation are continuously performed in one system that combines them.

  Specifically, as shown in FIG. 1, a duct made of a heat exchange element that spirally runs along the vertical direction in the apparatus main body B is provided as the condensation region pipe 15. The condensation region pipe 15 is opened into the apparatus main body B at the lower communication portion 8 at the upper end and the lower communication portion 8 at the lower end, respectively.

  The condensing region pipe 15 of the first embodiment is configured such that one circular duct is piled up and down while drawing a spiral, but as another form, a vortex is drawn in the same plane, and the outermost circumference and the center are drawn. A plurality of vortex ducts having both ends thereof may be connected to each other at intervals in the vertical direction (not shown). In this case, the condensation region 2 is formed in a stepped shape in the vertical direction in the apparatus main body B.

  Further, a blower F which is an airflow circulation means is provided in a tube near the lower end of the condensation region tube 15. By this air flow circulation means, an air flow is caused to flow from the upper end of the condensation region pipe 15 to the lower end through the inside of the tube and from the lower end into the apparatus main body B outside the tube, so that the lower end of the condensation region pipe 15 enters the device main body B. It is assumed that the jetted airflow circulates in and out of the condensation region pipe 15 through the apparatus main body B to the upper end of the condensation region tube 15 again.

  Further, a seawater spray device S is provided as a vaporizing means for vaporizing the raw seawater 4 near the upper end of the condensation region pipe 15. As a result, the inside of the condensation region pipe 15 becomes the condensation region 2, and the entire space inside the apparatus main body B outside the tube becomes the vaporization region 1. The open portion at the upper end of the condensation region pipe 15 becomes an upper communication portion 7 that connects the vaporization region 1 and the condensation region 2 in the upper part of the apparatus main body B, and the open portion at the lower end of the condensation region tube 15 is the vaporization region 1 and the condensation region. 2 is a lower communication part 8 that communicates with the lower part in the apparatus main body B.

  A heat exchange hose that is a seawater preheating pipe 3 runs from the vicinity of the lower communication portion 8 to the upper communication portion 7 in the condensation region pipe 15, and then the heat exchange hose protrudes from the upper communication portion 7, and the apparatus main body B It communicates with the seawater spraying device S located inside and above. The heat exchange hose serving as the seawater preheating pipe 3 communicates with the water supply pipe at the lower end near the lower communication portion 8. The water pipe is communicated from the raw seawater tank 40 via the raw seawater 4 pump and a valve, penetrates into the pipe of the branch pipe 150, passes through the branch pipe 150, and the seawater preheating pipe at the branch portion of the branch pipe 150. It communicates with 3 heat exchange hoses.

  The raw material seawater 4 in the raw material seawater tank 40 is fed into the apparatus main body B by a pump, and further passes through the seawater preheating pipe 3 that goes into the condensation region 2 and is preheated, and the seawater spraying device S located above and below the apparatus is preliminarily heated. The raw seawater 4 is sprayed from the seawater spraying device S to the vaporization region 1 in the device main body B. The upper part in the apparatus is heated by the heat supply unit 13, and most of the sprayed seawater is vaporized by being released from the upper part to the lower part in the apparatus.

  The vaporized water vapor is directed upward in the apparatus main body B by the overwhelmingly small specific gravity and the blower F which is an air flow circulation means, and is guided into the condensation region pipe 15 from the upper communication portion 7.

  Thereafter, the vaporized air flow condenses in the condensation region pipe 15, and the condensed water 9 flows down in the condensation region pipe 15. The vicinity of the lower communication portion 8 of the condensation region pipe 15 is directed substantially in the horizontal direction, and a branch pipe 150 is communicated downward from the pipe body facing the horizontal direction. The branch pipe 150 is further connected to the check valve 17. And it is connected to the condensed water tank 90 outside the apparatus main body B through the valve. The check valve 17 prevents the airflow from flowing into the apparatus main body B through the branch pipe 150. The condensed water 9 generated in the condensation region pipe 15 and flowing down in the condensation pipe 15 is guided to the branch pipe 150 without going to the lower communication portion 8, and then collected in the condensed water tank 90.

  The raw seawater 4 that has been sprayed into the vaporization region 1 and has not been vaporized is stored as concentrated seawater 6 in the concentrated seawater basin at the bottom of the apparatus main body B, which is the lower part of the vaporization region 1. The bottom of the apparatus main body B communicates with the upper part of the raw material seawater tank 40 provided outside the apparatus main body B via a valve, whereby the stored concentrated seawater 6 can be recovered.

  Further, outside the apparatus main body B, a condensed water tank 90 is provided at the tip of the branch pipe 150 communicating from the inside of the apparatus via the check valve 17 and the valve, and further, the tip of the water supply pipe penetrating the branch pipe 150. The raw material seawater tank 40 is provided in communication with the pressure pump P.

  Example 2 (FIG. 4) has one vaporization region 1, one condensation region 2, and two systems of vaporization means passing through the one condensation region 2. That is, a first vaporization system that heats and evaporates the raw seawater 4 in the vaporization region 1 and a second vaporization system that heats and evaporates the concentrated seawater 6 stored in the inner bottom B3 of the vaporization region 1 without being completely evaporated by heating. And one condensing system in which the gas after the first and second vaporization is sent to the condensing region 2 to condense. The secondary vaporization and condensation are repeatedly performed after the primary vaporization and condensation while circulating the air flow between both regions.

(Lower chamber 20)
In Example 2, the lower part of the vaporizing region 1 is partitioned by the inner bottom B3, and the lower chamber 20 partitioned by the inner bottom B3 is provided below the apparatus main body B.

  The lower chamber 20 is formed below the apparatus main body B with an inner bottom B3 closing the lower part of the vaporization region 1 as a boundary wall. A communication duct with the vaporization region 1 of the apparatus main body B is passed through the inner bottom B3, and a blower F that blows an airflow from the lower chamber 20 to the vaporization region 1 is provided as an airflow circulation means in the communication duct. . The airflow that has passed through the condensation region pipe 15 is discharged from the lower communication portion 8 into the lower chamber 20, and flows upward from the communication duct to the vaporization region 1 of the apparatus main body B by the blower F. By being guided again into the condensation region 2 from the upper communication part 7 at the upper part of the vaporization region 1, the air current circulates in the vertical direction in the apparatus and circulates and circulates in each region through the lower chamber 20.

  The vicinity of the lower end of the condensation region pipe 15 penetrates the inner bottom B <b> 3, and the lower end is opened as the lower communication portion 8 in the lower chamber 20. The vicinity of the lower end does not have the branch pipe 150 as in the first embodiment, and the condensed airflow and the condensed water 9 flow out into the lower chamber 20 from the lower communication portion 8 at the lower end of the pipe.

(Two systems of vaporization)
The two types of vaporization means are: primary vaporization means for heating and pressure-feeding raw seawater 4 from an external raw material seawater tank 40 to perform primary vaporization in the vaporization area 1, and concentrated seawater 6 accumulated below the vaporization area 1 without being completely vaporized. And a secondary vaporization means for performing secondary vaporization in the same vaporization region 1 by heating and pressure feeding again from the reservoir.

  The primary vaporization means communicates with the water supply pipe penetrating from the raw material seawater tank 40 into the lower chamber 20 via the first pressure feed pump P1, and includes a lower preheating pipe meandering in the lower chamber 20 and a lower preheating pipe. The first seawater preheating pipe 31 communicated with the tip and arranged from the open end of the lower communication portion 8 through the condensation region pipe 15 to the open end of the upper communication portion 7 and the tip of the first seawater preheat pipe 31. And a first seawater spraying device S1 provided in the upper part of the device main body B.

  The secondary vaporization means communicates with the water supply pipe penetrating from the reservoir of the concentrated seawater 6 stored in the inner bottom B3 of the apparatus main body B into the condensation region pipe 15 via the second pressure feed pump P2, and from this penetration part. A second seawater preheating pipe 32 that runs through the condensation region pipe 15 to the open end of the upper communication portion 7 and a second seawater spray that is connected to the second seawater preheating pipe 32 and provided in the upper part of the apparatus main body B. It consists of device S2.

  That is, the first seawater preheating pipe 31 from the lower end in the lower chamber 20 to the upper end in the upper part of the apparatus main body B and the lower penetrating part in the apparatus main body B along the condensation region pipe 15 of the second embodiment. Two seawater preheating pipes 3 with the second seawater preheating pipe 32 up to the upper end at the upper part of the main body B pass. The two seawater preheating pipes 3 both crawl inside the condensation region pipe 15 and project from the upper communication part 7 which is the upper end between the condensation regions 2 and are respectively connected to the first seawater spraying device S1 and the second seawater spraying device S2. Communicate.

(Inner bottom B3)
In the inner bottom B3, a concentrated seawater pond in which the concentrated seawater 6 that has not been vaporized by spraying is stored as condensed seawater is formed. The inner bottom B3 has a mortar shape or a lower cone as shown in FIG. 4, and the salt recovery communicates from the lowest projecting portion of the inner bottom B3 through the lower chamber 20 to the salt recovery apparatus 18 outside the apparatus. A tube is provided. A plurality of disk-shaped heat exchange fins 19 are fixed outside the salt recovery pipe so as to protrude into the lower chamber 20. The heat exchange fins 19 prevent heat from being released to the external salt recovery device 18 side when the salt 5 is recovered.

  Other configurations and desalination steps not specifically mentioned are the same as those in the first embodiment.

  Example 3 (FIG. 5) includes two vaporization systems that heat and evaporate the raw seawater 4 / condensed seawater in the first / second vaporization region 12, respectively, and gas that is heated and evaporated in the respective vaporization systems. Two condensing systems that are fed into the second condensing region 22 and condense each, and two systems are connected while circulating airflow between the vaporization region 1 and the condensing region 2 of each system through the heat storage region above the inside of the apparatus. Each of them is continuously vaporized and condensed.

  In the third embodiment, the cylindrical can-shaped device main body B is partitioned by a cylindrical inner wall B2 that is lower than the height of the device main body B and a circular inner bottom B3 that closes the lower end of the inner wall B2. And has a double structure. The inner wall B2 is provided inside the apparatus main body B with a gap for the concentrated seawater 6 and the heat storage area respectively below and above the apparatus main body B (FIG. 5). As the inner bottom B3 closes the lower end of the inner wall B2, a cylindrical part of the secondary system is formed by the inner bottom B3 and the inner wall B2.

  After primary desalination at the outer cylinder, the concentrated seawater 6 in the supernatant of the concentrated seawater pond is sent to the second seawater preheating pipe 32 in the inner cylindrical part by the second pumping pump P2, and further the second seawater preheating pipe 32 is supplied. Is heated by the second seawater spraying device S2 in the inner cylindrical portion while being preheated in the inner cylindrical portion, and is vaporized by being heated and sprayed to the second vaporization region 12 in the inner cylindrical portion. Secondary desalination is performed by being fed into the second condensation region pipe 152. Secondary desalination is composed of a second vaporization region 12 and a second condensation region tube 152 that spirals through this region.

  In FIG. 5, the condensing region 2 runs with two outer and inner circular ducts piled up and down while drawing a spiral. The outer duct runs spirally in the first vaporization region 11 of the outer cylinder portion and is open at both ends at the upper and lower portions of the same region, and the inner duct spirals in the second vaporization region 12 of the outer cylinder portion. Run and open at the top and bottom of the same area. With the structure of FIG. 5, the concentration of concentrated seawater 6 flowing below the first vaporization region 11 is kept at a seawater desalination rate that does not cause salt 5 to precipitate, and a 100% seawater desalination rate is achieved in the second vaporization region 12. The salt 5 can be deposited at the lower part of the second vaporization region 12.

  The high concentration concentrated seawater 6 generated in the first vaporization region 11 accumulates in the lower concentration seawater pond. It is from the density | concentration of about 35% or more that salt 5 precipitates in seawater. Since the salt water 5 does not precipitate unless the raw material seawater 4 becomes high in concentration, the amount of the raw material seawater 4 to be supplied is increased or decreased at regular time intervals in the first vaporization region 11, and the seawater is desalinated while periodically cleaning the inside. It can be performed. Most of the seawater mist reaches the bottom of the second vaporization region 12 by pumping the seawater of the concentrated seawater pond with a pump, sending it back into the second vaporization region 12 and spraying it on the upper portion of the second vaporization region 12. The product salt 5 is deposited below the second vaporization region 12.

  In the condensation area 2, the airflow from the airflow circulation means is discharged from the lower end to the vaporization area 1, and the condensed water 9 is recovered through a pipe connected to the outside of the apparatus by the condensed water 9 recovery means. The raw material seawater 4 is communicated with the seawater spraying device S from the open end of the upper part of the condensation region 2 through the raw material seawater 4 preheating pipe 3 composed of a hose passing through the condensation region 2. Water vapor condenses inside the condensation region 2, and the heat release accompanying this condensation is used for seawater evaporation in the vaporization region 1. In the condensation region 2, the amount of condensed water 9 increases and the flow rate of the airflow passing through the condensation region 2 decreases from the upper part to the lower part in the apparatus. The air flow that has decreased in temperature and contains only a small amount of water vapor is forcibly discharged into the vaporization region 1 by the blower F from the lower communication portion 8 opened at the lower end of the condensation region 2.

  In the structure of Example 3, the raw material seawater 4 which became high temperature by the 1st seawater preheating pipe | tube 31 and the heat supply part 13 is sprayed from a 1st spraying apparatus. Accordingly, if, for example, nearly 90% is evaporated in the first vaporization region 11, the concentration of the concentrated seawater 6 in the concentrated seawater reservoir stored in the inner bottom B3 exceeds 30%. When this concentrated high-concentration seawater 6 is pumped to the second seawater preheating pipe 32 and evaporated in the second vaporization region 12 by nearly 90%, almost no water remains in the lower part of the second vaporization region 12, and the seawater The contained salt 5 will be deposited. Therefore, as in the second embodiment, a salt recovery pipe that communicates from the inner bottom B3 to the outside of the apparatus is provided, and the tip communicates with the salt recovery apparatus 18 via the check valve 17 and the valve outside the apparatus.

  The first condensing region pipe 151 and the second condensing region pipe 152 are both in the vicinity of the lower communication portion 8, the same branch pipe 150 as in the first embodiment, and the same raw material as in the first embodiment that penetrates the middle of the branch pipe 150. It has a water pipe for seawater 4. As shown in FIG. 5, the branch pipe 150 of the second condensation region pipe 152 passes through the inner wall B <b> 2 and joins with the branch pipe 150 of the first condensation region pipe 151. The valve 17 communicates with the upper part of the condensed water tank 90 through the valve.

  Other configurations and desalination steps not specifically mentioned are the same as those in the first embodiment.

  Example 4 (FIGS. 6 to 8) includes two vaporization systems that heat and evaporate the raw seawater 4 / condensed seawater in the first / second vaporization region 12, respectively, and the gas that is vaporized by heating in each vaporization system. Two condensing systems that are fed into the first / second condensing region 22 to condense each, via a heat storage region above the inside of the device and a lower chamber 20 that communicates with the vaporizing region 1 of both systems inside the device. The vaporization and the condensation are continuously performed in the two systems while circulating the air flow between the vaporization region 1 and the condensation region 2 of each system.

(Double structure)
Similarly to the third embodiment, the fourth embodiment is also provided with a cylindrical inner wall B2 having a cylindrical shape smaller than the outer wall B1 on the inner side of the cylindrical outer wall B1 of the apparatus main body B. It has a double structure.

(Second system)
After primary desalination in the outer cylinder, the supernatant of the 6 concentrated seawater ponds passes through the concentrated seawater 6 communication pipe 33 by the second pumping pump P2 and penetrates into the second condensation region pipe 152 of the inner cylindrical part. It communicates with the second seawater preheating pipe 32 in the pipe and is sent to the second seawater spray device S2. By being sprayed from the second seawater spraying device S2 into the second vaporization region 12 in the inner cylindrical portion, the vaporized airflow flows into the second condensation region pipe 152 from the second upper communication portion 72, and in the second pipe, Next condensation takes place. Secondary condensation takes place in a second condensation zone tube 152 that spirals through the second vaporization zone 12. The second condensing region pipe 152 is in the cylindrical portion in the plan view and is opened at the upper end in the heat storage region above the apparatus main body B, and the second lower communicating portion 82 opened in the lower chamber 20. And at both ends.

(First / second condensation region 22)
The condensing region 2 of Example 4 is formed in the first condensing region tube 151 / the second condensing region tube 152 composed of two circular ducts on the outer side (the left diagram in FIG. 8) and the inner side (the right diagram in FIG. 8). Is done. The first condensation region pipe 151 and the second condensation region pipe 152 run while being stacked up and down in the first and second vaporization regions 12, respectively, while drawing a spiral. The outer duct has a first upper communication portion 71 whose upper end is opened in the upper heat storage region in the first vaporization region 11 of the outer cylinder portion, and the inner duct is the second vaporization region 12 of the outer cylinder portion. The upper upper heat storage region has a second upper communication portion 72 opened at the upper end.

(Deposition of salt 5 in each vaporization region 1)
The high-concentration concentrated seawater 6 generated in the first vaporization region 11 is accumulated in the concentrated seawater basin at the inner bottom B <b> 3, which is a lower part of the outer cylinder portion of the first vaporization region 11 and is a section of the lower chamber 20. The concentrated seawater 6 in the concentrated seawater pond is pumped up by the second pumping pump P2 and sent again into the second vaporization region 12 and fed to the upper part of the second vaporization region 12 and sprayed by the spraying device in the second vaporization region 12. By doing so, most of the seawater mist does not reach the lower part of the second vaporization region 12, and the generated salt 5 is deposited at the lower part of the second vaporization region 12.

  In addition, it is said that the salt 5 is precipitated in the seawater from a concentration of about 35% or more, and the salt water 5 does not precipitate unless the raw material seawater 4 has a high concentration. Using this property, the amount of the raw material seawater 4 to be supplied can be increased or decreased at regular time intervals in the first vaporization region 11, and seawater desalination can be performed while periodically performing internal cleaning.

    With this structure, the concentration of concentrated seawater 6 flowing below the first vaporization region 11 is kept at a seawater desalination rate that does not allow salt 5 to precipitate, and a seawater desalination rate of 100% is achieved in the second vaporization region 12. The salt 5 can be deposited at the lower part of the vaporization region 12.

(Lower chamber 20)
In the fourth embodiment, a lower chamber 20 provided adjacent to the lower part of the apparatus main body B is provided via an inner bottom B3 having the same plane shape as the apparatus main body B common to the lower part of the outer cylinder and the inner cylindrical portion having a double structure. ing. Both the lower part of the outer and inner ducts penetrate the lower chamber 20, and the lower end of each duct is opened into the lower chamber 20. The lower chamber 20 is partitioned and disposed below as a planar region including both the outer cylinder part and the inner cylinder part, and communicates with each of the outer cylinder part and the inner cylinder part.

(Airflow movement in condensation region pipe 15)
In the first / second condensation region pipe 151/152, the amount of condensed water 9 increases and the flow rate of the airflow passing through the condensation decreases from the upper part to the lower part in the apparatus. Both the first lower communicating portion 81 of the first condensing region pipe 151 and the lower communicating portion 8 of the second condensing region tube 152 are opened into the lower chamber 20 without the branch pipe 150 as in the second embodiment. ing.

    After passing through the first and second condensing region pipes 151 and 152, the air flow that has been reduced in temperature and contains only a small amount of water vapor is discharged from the first and second lower communication portions 82 into the lower chamber 20, respectively. The first vaporization region 11 and the second vaporization are respectively mixed by the first blower F1 and the second blower F2 from the communication duct which is mixed in the lower chamber 20 and communicated with the first vaporization region 11 and the second vaporization region 12. It is sent to area 12.

  The condensed water 9 released in the lower chamber 20 together with the air flow in the condensation region 2 at the lower communication portion 8 at the lower end of the duct is accumulated in the lower chamber 20 and is connected to the apparatus through a pipe communicated from the bottom of the lower chamber 20 to the outside of the apparatus. It is collected in an external condensed water tank 90.

(Movement of raw seawater 4 in the lower chamber 20)
The raw seawater 4 pumped from the raw seawater tank 40 via the pumping pump P is communicated with the hose in the duct from the lower open end of the outer duct through the lower seawater preheating pipe 30 meandering through the lower chamber 20. The

  Other configurations and desalination steps not specifically mentioned are the same as those in the first embodiment, and the configuration and operation of the lower chamber 20 are the same as those in the second embodiment.

  In addition, the present invention is not limited to the above-described embodiments or the above-described other configuration examples, and replacement and combination for each element of each embodiment, element extraction, and form change are made without departing from the spirit of the present invention. It is also possible to make various changes.

  In the present invention, there is another possibility that various rare elements dissolved in seawater are concentrated and crystallized.

It is side view explanatory drawing which shows the system | strain of the seawater desalination apparatus by the airflow circulation of Example 1 of this invention. It is plane view II cross-sectional explanatory drawing of FIG. 1 which shows the structure of the upper part in the desalination apparatus of the seawater by the airflow circulation of Example 1. FIG. FIG. 2 is a plane cross-sectional explanatory diagram of FIG. 1 showing a configuration of a lower portion in the seawater desalination apparatus using airflow circulation according to the first embodiment. It is explanatory drawing which shows the system | strain of the seawater desalination apparatus by the airflow circulation of Example 2 of this invention. It is explanatory drawing which shows the system | strain of the desalination apparatus of the seawater by the airflow circulation of Example 3 of this invention. It is explanatory drawing which shows the system | strain of the seawater desalination apparatus by the airflow circulation of Example 4 of this invention. It is explanatory drawing which shows the 1st (left) and 2nd (right) system | strain of the raw material seawater 4 and the concentrated seawater 6 in the seawater desalination apparatus by the airflow circulation of Example 4. FIG. It is explanatory drawing which shows the 1st (left) and 2nd (right) system | strain of the airflow and the condensed water 9 in the seawater desalination apparatus by the airflow circulation of Example 4. FIG. It is a graph which shows the relationship of the saturated water vapor pressure of water.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vaporization area | region 11 1st vaporization area | region 12 2nd vaporization area | region 2 1st condensation area | region 22 2nd condensation area | region 3 Seawater preheating pipe 30 Lower seawater preheating pipe 31 First seawater preheating pipe 32 Second seawater preheating pipe 4 Raw material seawater 40 Raw seawater tank 5 Salt 6 Concentrated seawater 60 Concentrated seawater tank 7 Upper communication part 71 First upper communication part 72 Second upper communication part 8 Lower communication part 81 First lower communication part 82 Second lower communication part 9 Condensed water 90 Condensed water tank 13 Heat supply unit 14 Spray cleaning device 15 Condensation area pipe 150 Branch pipe 151 First condensation area pipe 152 Second condensation area pipe 17 Check valve 18 Salt recovery device 19 Heat exchange fin 20 Lower chamber B Apparatus body B1 Outer wall B2 inner wall B3 inner bottom F blower F1 first blower F2 second blower P pressure feed pump P1 first pressure feed pump P2 second pressure feed pump S seawater spray device S1 first seawater spray device S The second seawater spraying device

In order to solve the above problems, the present invention takes the following means (1) to (3).
(1) That is, the seawater desalination apparatus using the air circulation according to the present invention is:
A pipe that runs in a spiral manner in the vertical direction in the apparatus main body and is opened in the apparatus main body B at the upper end and the lower end, respectively, and the “vaporization region 1” outside the tube and the upper and lower ends communicate with the vaporization region 1 A condensing region tube 15 that forms a boundary wall between the two regions named "condensation region 2"inside;
A heat supply unit 13 that is provided at a high position in the vaporization region and stores heat inside the apparatus main body at a high temperature;
An airflow circulation means F provided below the apparatus main body for circulating an airflow from the condensation region 2 to the vaporization region 1;
A seawater preheating pipe 3 that preheats the raw seawater 4 by exchanging heat while carrying the raw seawater 4 from the outside of the apparatus through the condensation area pipe, passing through the condensation area pipe to the upper part of the vaporization area 1;
・ Equipped with a seawater spraying device S for spraying and evaporating raw material seawater from the height of the vaporization area 1 to create high-temperature steam at the height inside the device,
-By these, a seawater desalination device that performs gas exchange and vaporization and water vapor condensation by circulating air through the vaporization region 1 and the condensation region 2 adjacent to each other through a condensation region pipe that is a heat exchanger,
・ Latent heat released when high-temperature steam with high buoyancy created in the high area of the vaporization zone is sucked from the upper end of the condensation zone pipe and returned to the low-temperature water inside the condensation zone 効果, and seawater is effective in the adjacent vaporization zone It is characterized by water vapor condensation and seawater vaporization proceeding simultaneously on the front and back by evaporating in a continuous manner .
(2) Regarding the action of the seawater preheating pipe,
A heat recovery step for recovering the heat of condensed water, which is the result of seawater desalination taken out of the apparatus, into raw seawater;
A condensation promoting step for further promoting water vapor condensation from an air flow having a reduced water vapor amount in a lower part of the condensation region;
And by having a high-temperature step to heat the raw seawater by heat exchange with high-temperature steam at high places in the condensation area, the saturated steam pressure of high-temperature seawater sprayed with seawater rises,
Even under conditions where the amount of heat energy supplied to the apparatus by the heat supply unit is small, seawater desalination is efficiently achieved by generating a large amount of high-temperature and high-purity steam at high locations inside the apparatus.
That is, the seawater preheating pipe 3 passes through the condensation region 2 in the apparatus, and heat exchange inside and outside the seawater preheating pipe 3
A heat recovery step for recovering the heat of the condensed water 9 in the condensed region 2 taken out of the apparatus to the raw seawater 4;
A condensing promotion step for promoting raw material seawater 4 to condense water vapor in the lower airflow in the condensing region 2;
-And the high temperature step which makes raw material seawater 4 high temperature by the condensing effect | action of the water vapor | steam which is the airflow in the condensing area | region 2 is given.
(3) In the seawater desalination apparatus using the air flow circulation,
The high temperature inside the device is stored with high temperature steam by the heat supply unit 13 so that the lower part in the device has a temperature difference with the upper part,
In addition, the latent heat generated when the high-temperature water vapor obtained by spraying the raw material seawater at the high area of the vaporization zone is sucked back to the water by the airflow circulation means under the low-temperature condensation zone pipe is used to vaporize the adjacent vaporization zone seawater. Used directly,
By circulating the air flow in both the condensation area and the vaporization area, the heat exchange in which the vaporization and condensation of the water vapor proceed simultaneously on the front and back sides is continued .

The vaporization means includes a seawater spray device S that sprays seawater from a high area in the vaporization region. If it is such, cleaning becomes easy even when the salt 5 and scale in the raw material seawater 4 are deposited.

As one of the seawater desalination apparatuses described above, a structure in which the vaporizing region 1 and the condensing region 2 are in contact with each other through a tubular body may be employed. This tubular body is formed of a heat exchanger, and extends in a spiral shape, for example, from the upper part to the lower part in the apparatus.

As an example of the condensing means in the above structure, there is one that allows vaporized water vapor to pass from the upper side to the lower side in the condensing region 2 partitioned by the tube in the condensing region 2. During the passage of the vaporized stream of the condensing region 2, by performing heat exchange by the heat exchanger to form a partition between the vaporizing region 1, it is possible to obtain a continuous condensed water 9 from the air flow. At this time, the condensed water 9 flows down the floor of the tubular body and is easily recovered.

<Basic configuration of seawater desalination system by air circulation (Fig. 1)>
In the seawater desalination apparatus according to the present invention, the vaporization region 1 for vaporizing seawater in the region to obtain water vapor and the condensing region 2 for condensing water vapor in the region to obtain fresh water are between these regions. The regions communicate with each other through a lower communication portion 8 located in the lower part in the apparatus and an upper communication part 7 located in the upper part in the apparatus. A heat supply unit 13 is provided in the upper part of the apparatus, and the upper part of the apparatus is filled with high-temperature steam to store heat.

(Airflow circulation means)
The airflow circulating in the apparatus repeatedly increases and decreases the amount of water vapor contained in the airflow according to the temperature change in each passing region (see FIG. 9) . Here, in the vicinity of the lower communication portion 8 at the lower part of the apparatus, the temperature is the lowest in each region in the apparatus, and the water vapor component in the airflow is almost eliminated and the air flow is minimized. Since the specific gravity is the largest and the buoyancy is the smallest at the position where the amount of water vapor is minimized, the air flow can be efficiently controlled without countering the buoyancy by providing the blower F at the position in this state. . Even if the flow rate of the airflow passing through the airflow circulation means is small, a large amount of high-temperature saturated water vapor at the top of the apparatus is introduced into the condensation region 2, and the airflow rises later in the vaporization region 1. Circulation is performed smoothly.

(Vaporization means)
The vaporization means is means for promoting the vaporization of seawater in the vaporization region 1, and is specifically performed by a seawater spray device S (Examples 1 to 4) that sprays seawater from the upper part of the region . The form of Examples 1-4 which uses the seawater spraying apparatus S provided in the vaporization area | region 1 high place while preheating and heating seawater with the seawater preheating pipe | tube 3 and the heat supply part 13 is the most efficient water vapor | steam generation method. .

The seawater preheating pipe 3 may be composed of a heat exchange hose in which the floor surface of the condensation region 2 is raised from below to above. By this heat exchange hose, the raw seawater 4 can directly recover heat from the hot water flowing on the floor surface of the condensation region 2 outside the hose. At the same time, the raw seawater 4 is also preheated by the condensation heat generated when the condensed water 9 is generated from the air flow in the condensation region 2. A structure in which the vaporized region 1 and the condensed region 2 are alternately formed by extending spirally in the vertical direction can be said to be a relatively simple structure. If the seawater is hot, the saturated water vapor pressure will be very high, and the evaporation power from the seawater will be considerably high .

Specifically, as shown in FIG. 1, a duct made of a heat exchange element that spirally runs along the vertical direction in the apparatus main body B is provided as the condensation region pipe 15. The condensation region pipe 15 is opened in the apparatus main body B at the upper communication portion 7 at the upper end and the lower communication portion 8 at the lower end, respectively.

The raw seawater 4 which has been sprayed into the vaporization region 1 and has not been vaporized is stored as concentrated seawater 6 in the concentrated seawater 6 pond at the bottom of the apparatus main body B which is the lower part in the vaporization region 1. The bottom of the apparatus main body B communicates with a tank provided outside the apparatus main body B via a valve, whereby the stored concentrated seawater 6 can be recovered.

In order to solve the above problems, the present invention takes the following means (1) to (3).
(1) That is, the seawater desalination apparatus using the air circulation according to the present invention is:
A pipe that runs in a spiral manner in the vertical direction in the apparatus main body and is opened in the apparatus main body B at the upper end and the lower end, respectively, and the “vaporization region 1” outside the tube and the upper and lower ends communicate with the vaporization region 1 A condensing region tube 15 that forms a boundary wall between the two regions named "condensation region 2"inside;
A heat supply unit 13 that is provided at a high position in the vaporization region and stores heat inside the apparatus main body at high temperature;
An airflow circulation means F provided below the apparatus main body for circulating an airflow from the condensation region 2 to the vaporization region 1;
A seawater preheating pipe 3 that preheats the raw seawater 4 by exchanging heat while carrying the raw seawater 4 from the outside of the apparatus through the condensation area pipe, passing through the condensation area pipe to the upper part of the vaporization area 1;
・ Equipped with a seawater spraying device S for spraying and evaporating raw material seawater from the height of the vaporization area 1 to create high-temperature steam at the height inside the device,
-By these, a seawater desalination device that performs gas exchange and vaporization and water vapor condensation by circulating air through the vaporization region 1 and the condensation region 2 adjacent to each other through a condensation region pipe that is a heat exchanger,
・ Latent heat released when high-temperature steam with high buoyancy created in the high area of the vaporization zone is sucked from the upper end of the condensation zone pipe and returned to the low-temperature water inside the condensation zone 効果, and seawater is effective in the adjacent vaporization zone It is characterized by water vapor condensation and seawater vaporization proceeding simultaneously on the front and back by evaporating in a continuous manner.
(2) The seawater preheating pipe 3
A heat recovery step for recovering the heat of condensed water resulting from seawater desalination taken out of the apparatus into raw seawater;
Performing - a set accelerating step to promote the further steam condensation from the reduced gas stream of water vapor in the condensation region lower, and a high temperature step of the raw material seawater hot by heat exchange with hot water vapor-condensing region altitude Is.
(3) In the seawater desalination apparatus using the air flow circulation,
The high temperature inside the device is stored with high temperature steam by the heat supply unit 13 so that the lower part in the device has a temperature difference with the upper part,
In addition, the latent heat generated when the high-temperature water vapor obtained by spraying the raw material seawater at the high area of the vaporization zone is sucked back to the water by the airflow circulation means under the low-temperature condensation zone pipe is used to vaporize the adjacent vaporization zone seawater. Used directly,
By circulating the air flow in both the condensation area and the vaporization area, the heat exchange in which the vaporization and condensation of the water vapor proceed simultaneously on the front and back sides is continued.

Claims (3)

A vaporization region that vaporizes seawater in the region to obtain water vapor and a condensation region that condenses the water vapor in the region to obtain fresh water are adjacent to each other via a heat exchanger that forms a boundary wall between these regions, The area communicates in the upper and lower part of the device,
A heat supply unit provided in the apparatus for heating and storing the upper part of the apparatus, an air circulation unit provided in the apparatus for circulating an air flow between a vaporization region and a condensation region in the apparatus, and a raw material passing through the apparatus A seawater preheating pipe that sends the seawater to the vaporization region near the upper communication portion while preheating the seawater, and a vaporization means for evaporating the seawater to the vaporization region near the heat supply unit,
The raw seawater that has been preheated by the seawater preheating pipe is vaporized by the vaporization means, and the airflow in the apparatus is circulated in the apparatus by the airflow circulation means to condense the vapor generated by vaporization, thereby A seawater desalination apparatus using air circulation, characterized in that it is desalinated.   The heat recovery step in which the seawater preheating pipe passes through the condensation area in the device, and heat of the condensed water in the condensation area taken out of the apparatus is recovered by the heat exchange inside and outside the seawater preheating pipe, and the lower part of the condensation area The fresh water of seawater by airflow circulation according to claim 1, wherein a condensation promoting step for promoting steam condensing of the air current to the raw seawater and a step of increasing the temperature of the raw material seawater by condensing action of the water vapor that is the airflow in the condensing region are performed. Device.   The seawater desalination apparatus according to claim 1 or 2, wherein the vaporizing means includes a seawater spraying apparatus for spraying seawater from the upper part of the vaporization region.

Images