JP2012239956A - Desalination apparatus and method for producing fresh water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a desalination apparatus high in energy efficiency, low in cost and miniaturizable, and a method for producing fresh water.SOLUTION: The desalination apparatus for producing fresh water by condensing after evaporating raw water includes a raw water tank for storing raw water; a vaporizer installed in the raw water tank, for vaporizing raw water to produce water vapor; a condensing part for condensing the water vapor to obtain fresh water; a water vapor delivery part in which a water vapor pump for sucking water vapor from the raw water tank and delivering water vapor compressed and heightened in temperature, to the condensing part is provided at a connection part for connecting the raw water tank to the condensing part; and a heat exchanger for imparting the heat energy of water vapor delivered from the water vapor pump and/or the heat energy of the fresh water to the raw water. The heat exchanger functions to accelerate vaporization of raw water.

Description

  The present invention relates to a desalination apparatus and a method for producing fresh water.

As a method for desalinating seawater, a multistage flash method and a reverse osmotic pressure method are known.
The multistage flash method is a method of obtaining fresh water (distilled water) by liquefying water vapor generated by applying heat to seawater using a condenser. In the multistage flash method, the decompression chamber is usually multistaged to increase energy efficiency. Therefore, the apparatus becomes large-scale.
The reverse osmotic pressure method is a method in which fresh water is obtained by applying pressure to seawater and passing it through a reverse osmosis membrane (RO membrane, Reverse Osmosis Membrane) to separate the salinity of the seawater. A reverse osmosis membrane is a membrane that allows water molecules to pass through but does not allow impurities such as various ions and salts contained in seawater to pass through. The pores of the membrane are about 2 nanometers or less. The reverse osmotic pressure method is more energy efficient than the multi-stage flash method, but it needs to be pretreated so that the RO membrane is not clogged with microorganisms, precipitates, impurities, etc. in seawater. Moreover, the lifetime of the RO membrane itself is relatively short.
Further, as a method for desalinating seawater or the like or a desalination apparatus, specifically, for example, desalination apparatuses described in Patent Documents 1 to 4 have been proposed.

International Publication No. 1997/048646 Pamphlet JP 2001-070929 A JP 2009-532655 A JP 2009-072734 A

However, the above-described multi-stage flash method has very low energy efficiency, and a large amount of energy has to be input. In addition, since the decompression chamber is multi-staged, an increase in the size of the apparatus itself is inevitable.
Further, the reverse osmotic pressure method has a problem in that a pretreatment for avoiding clogging is necessary and the life of the RO membrane itself is relatively short, resulting in an increase in cost.
Moreover, about the desalination apparatus which uses sunlight for the energy saving of patent document 1, 2, there existed room for improvement in operation time, energy efficiency, cost, etc. Patent Document 3 is an example of a heat pump. Furthermore, Patent Document 4 discloses a seawater desalination apparatus using air circulation. However, the desalination apparatus described in Patent Document 4 requires a heating source for heating an airflow containing seawater or water vapor. In addition, since seawater concentrated to a high concentration is sprayed from a nozzle or the like, there is a problem that salt is deposited and clogged in the nozzle or the like, and maintenance is troublesome.

This invention makes it a subject to solve said subject.
That is, an object of the present invention is to provide a desalination apparatus and a method for producing fresh water, which are high in energy efficiency, low in cost, and capable of downsizing the apparatus.

The present inventor diligently studied to solve the above problems and completed the present invention.
The present invention is a desalination apparatus that evaporates raw water and then condenses to produce fresh water, and is installed in the raw water tank for storing the raw water, and vaporizes the raw water to vaporize the raw water. A vaporizer to generate, a condensing unit for condensing the water vapor to obtain fresh water, a water vapor pump for sucking and compressing the water vapor from the raw water tank, and sending the water vapor whose temperature has been raised to the condensing unit, A water vapor delivery unit provided at a connection part connecting the raw water tank and the condensing unit, a heat exchanger that imparts to the raw water the heat energy provided by the water vapor delivered from the water vapor pump and / or the fresh water, A desalination apparatus in which the heat exchanger plays a role in promoting vaporization of the raw water.
Hereinafter, such a desalination apparatus is also referred to as “the apparatus of the present invention”.

  In the apparatus of the present invention, the heat exchanger is installed inside the condensing unit, and further, raw water sending means for sending the raw water in the raw water tank to the heat exchanger, and the heat exchanger The raw water to which the thermal energy is applied via the raw water return means for sending to the vaporizer, the raw water in the raw water tank is sent to the heat exchanger by the raw water delivery means, and further, the raw water return means It is preferable to have a raw water circulation means to be sent to the vaporizer.

  In the apparatus of the present invention, the heat exchanger is installed inside the raw water tank, and the water vapor sent from the water vapor pump can be moved from the condensing unit into the heat exchanger. Or a raw water sending means and a raw water circulation means for sending the raw water in the raw water tank to the vaporizer. It is preferable that it has.

  Furthermore, it is preferable that the apparatus of the present invention further includes an exhaust pump for depressurizing the inside of the raw water tank at a later stage than the water vapor pump in the water vapor delivery unit or in the condensing unit.

Further, the present invention is a method for producing fresh water by evaporating the raw water and then condensing the raw water, vaporizing the raw water to obtain water vapor, sucking and compressing the water vapor, temperature A step of obtaining steam having an increased temperature, a step of imparting steam having an increased temperature and / or thermal energy included in the fresh water to the raw water, and a step of condensing the steam having an increased temperature to obtain fresh water. And a method for producing fresh water that promotes vaporization of the raw water by applying the thermal energy to the raw water.
Hereinafter, such a method for producing fresh water is also referred to as “the production method of the present invention”.

  The production method of the present invention is preferably performed using the apparatus of the present invention.

  According to the present invention, it is possible to provide a desalination apparatus and a fresh water production method that are high in energy efficiency, low in cost, and capable of downsizing the apparatus. The desalination apparatus of the present invention can be downsized, but conversely can be increased in size, and the amount of fresh water obtained by installing a plurality of small desalination apparatuses of the present invention in parallel can be increased. it can. In addition, boiling water can be obtained by operating at normal pressure.

It is the schematic for demonstrating the suitable aspect (aspect 1) of the apparatus of this invention. It is the schematic for demonstrating another suitable aspect (aspect 2) of the apparatus of this invention. It is the schematic for demonstrating another suitable aspect (aspect 3) of the apparatus of this invention. It is the schematic for demonstrating another suitable aspect (aspect 4) of the apparatus of this invention.

  About the apparatus of this invention, the aspect 1, aspect 2, aspect 3, and aspect 4 which are suitable aspects are mentioned, and each is demonstrated using figures. However, the apparatus of the present invention is not limited to the first aspect, the second aspect, the third aspect, and the fourth aspect.

<Aspect 1>
In the embodiment 1 shown in FIG. 1, the apparatus 10 of the present invention includes a raw water tank 12, a water vapor delivery unit 14, a condensing unit 16, a heat exchanger 18, a raw water circulation pump 26, raw water circulation pipes 28 and 30, a raw water return pipe 32, A raw water spray 34 and an exhaust pump 36 are provided. The water vapor delivery unit 14 includes a water vapor pump 20, a water vapor input pipe 22, and a water vapor output pipe 24.

[Raw water tank]
The raw water tank 12 has a function of storing the raw water 3 at the bottom of the inner side, and a function of storing water vapor 5 formed by evaporation of the raw water 3 at the upper part of the inner side. Moreover, the raw | natural water tank 12 has the raw | natural water spray 34 as a vaporizer in the inner upper part. The raw water spray 34 plays a role of making the raw water 3 ′ into the water vapor 5 easily by making the raw water 3 ′ into fine water droplets (for example, mist form) by shower or ultrasonic waves.
In the present invention, “raw water” means seawater or water such as lakes and marshes that are not suitable for drinking.

The raw water tank 12 has a raw water inlet 92 through which the raw water 3 is injected, from which the raw water 3 can be injected. The raw water tank 12 has a raw water outlet 94, from which the concentrated raw water 3 can be discharged. In order to prevent this, for example, when raw water having a certain salt concentration such as seawater continues to evaporate, the salt concentration gradually increases, the desalination efficiency decreases, and salt and impurities are deposited. This is because fresh raw water is poured into the raw water tank and raw water having a high salinity concentration is taken out.
The devices of the present invention in modes 2 to 4 to be described later include the same devices for the same reason.

[Water vapor delivery section]
The steam input pipe 22 constituting a part of the steam delivery section 14 connects the upper space inside the raw water tank 12 and the steam pump 20, and the steam output pipe 24 is connected to the steam pump 20 and a condensation described later. The upper space inside the part 16 is connected. That is, the steam input pipe 22 and the steam output pipe 24 constitute a connection part that connects the raw water tank 12 and the condensing part 16. Then, by the action of the water vapor pump 20, the water vapor 5 existing in the upper space inside the raw water tank 12 can be sucked and sent out to the upper space inside the condensing unit 16. Here, a filter 40 is installed inside the water vapor input pipe 22, and impurities, foreign matter, salt, and the like contained in the water vapor 5 can be removed.
The steam pump 20 can use power such as an electric motor, an engine, wind power, hydraulic power, and human power. The same applies to modes 2 to 4 described later.

[Condensation part]
The condensing unit 16 has a tank shape, and the water vapor 5 ′ sent from the water vapor sending unit 14 and having a raised temperature can be taken into the upper space inside the condensing unit 16. The water vapor 5 ′ is cooled in contact with a heat exchanger 18 to be described later, and at least a part thereof becomes the fresh water 7. Fresh water 7 is stored at the bottom inside the condenser 16.

  In addition, an exhaust pump 36 capable of depressurizing the inner upper space is connected to the condensing unit 16 via an exhaust pipe 35. The exhaust pump 36 reduces the pressure by exhausting the gas in the upper space inside the condensing unit 16, and as a result, the pressure in the upper space inside the raw water tank 12 can be reduced. Then, by the action of the exhaust pump 36, the pressure in the upper space inside the raw water tank 12, the pressure in the upper space inside the condensing unit 16, the pressure inside the steam input pipe 22, and the pressure inside the steam output pipe 24 are As the saturated water vapor pressure, the efficiency of the water vapor pump 20 can be increased. Furthermore, even when the steam 5 and 5 ′ contain an unnecessary component, it can be discharged out of the system and removed by the action of the exhaust pump 36.

In addition, the apparatus 10 of the present invention in the mode 1 shown in FIG. 1 has the exhaust pump 36 via the exhaust pipe 35 connected to the upper space of the condensing unit 16, thereby the upper space inside the raw water tank 12. However, in the present invention, the position of the exhaust pump 36 is connected to the condensing unit 16 as in the aspect 1, or connected to the subsequent stage of the water vapor pump 20 in the water vapor delivery unit 14. Is preferred. When the exhaust pump 36 for depressurizing the inside of the raw water tank 12 is provided at such a position, it is pressurized by the steam pump 20 as compared with the case where the exhaust pump 36 is connected to the raw water tank 12 or the steam input pipe 22. As a result, the concentration of the impurity gas is high, and the load on the exhaust pump 36 is reduced. Therefore, power saving can be achieved, and in some cases, the pump capacity can be reduced.
Also in modes 2 to 4 described later, for the same reason, it is preferable to have an exhaust pump for decompressing the inside of the raw water tank at a later stage than the water vapor pump in the water vapor delivery unit or at the condensing unit.

[Heat exchanger]
The heat exchanger 18 is installed inside the condensing unit 16, and heat energy of the water vapor 5 ′ and / or the fresh water 7 existing inside the condensing unit 16 is given to the raw water 3. Since the temperature of the raw water 3 is increased by obtaining thermal energy from the steam 5 ′ and / or the fresh water 7, the evaporation of the raw water 3 is promoted.
The heat exchanger 18 is connected to the raw water circulation pipes 28 and 30, and the raw water 3 in the raw water tank 12 is sent to the heat exchanger 18 through the raw water circulation pipes 28 and 30 by the action of the raw water circulation pump 26. Further, the heat exchanger 18 is connected to the raw water return pipe 32, and the raw water 3 ′ after the heat energy is given is sent to the raw water spray 34 through the raw water return pipe 32.
With such a configuration, the raw water 3 in the raw water tank 12 reaches the heat exchanger 18 through the raw water circulation pipes 28 and 30 and is heated to obtain heat energy (raw water 3 ′), and then the raw water return pipe. 32 is discharged from the raw water spray 34.

The size and material of the heat exchanger 18 are not particularly limited, and it is preferable that the heat exchange between the steam 5 ′ and / or the fresh water 7 and the raw water 3 can be performed as efficiently as possible. For example, it preferably has a surface area of about several m ² . A heat exchanger made of a material having high heat transfer efficiency and corrosion resistance such as stainless steel, titanium, copper, copper alloy (brass, white copper, etc.), nickel, monel, aluminum, and aluminum alloy is preferable. The same applies to heat exchangers in modes 2 to 4 described later.

Next, the operation of the aspect 1 will be described with reference to FIG.
First, the raw water 3 in the raw water tank 12 is sent to the heat exchanger 18 through the raw water circulation pipes 28 and 30. And after heat energy is given in the heat exchanger 18 and the temperature is raised, it is discharged from the raw water spray 34 through the raw water return pipe 32 and vaporized to generate water vapor 5. Here, since the pressure in the upper space inside the raw water tank 12 is reduced by the action of the exhaust pump 36, the raw water 3 'is easily vaporized. For example, the upper space inside the raw water tank 12 can be set to 20 to 30 hPa.
Next, the water vapor 5 is sucked and compressed by the action of the water vapor pump 20 to become the water vapor 5 'whose temperature has been increased. For example, when the water vapor 5 present in the upper part inside the raw water tank 12 is 20 ° C. and 23 hPa, the water vapor 5 ′ at 30 ° C. and 42 hPa can be obtained by passing the water vapor pump 20 and compressing it.
The steam 5 passes through the steam input pipe 22 and the steam output pipe 24 and reaches the upper space inside the condensing unit 16. And at least a part thereof becomes fresh water 7.
The steam 5 ′ and / or the fresh water 7 whose temperature has been increased gives the stored heat energy to the raw water 3 via the heat exchanger 18. The steam 5 ′ imparted with heat energy to the raw water 3 becomes fresh water 7.
And the fresh water 7 is stored in the bottom inside the tank-shaped condensing part 16.

The apparatus 10 of the present invention can be activated by the steps shown in the following (i) to (ix).
It can start similarly also in the aspects 2-4 mentioned later.
(I) Open the drain valves 96 and 94 to discharge fresh water and raw water.
(Ii) Close the drain valves 96, 94.
(Iii) Open the water supply valve 92 and fill the raw water tank with raw water.
(Iv) The water supply valve 92 is closed.
(V) The exhaust pump 36 is moved to reduce the pressure inside the apparatus 10 of the present invention.
(Vi) The water vapor pump 20 and the raw water circulation pump 26 are operated.
(Vii) When a predetermined amount of fresh water is stored in the fresh water tank, the discharge valve 96 is opened to discharge the fresh water. When the fresh water is discharged, the discharge valve 96 is closed.
(Viii) When the raw water in the raw water tank decreases, the water supply valve 92 is opened to supply the raw water. After supplying raw water, the water supply valve 92 is closed.
(Ix) When the concentration (salt content) in the raw water tank becomes high, the drain valve 94 is opened to discharge the raw water. After the raw water is discharged, the drain valve 94 is closed.
Thereafter, (vii) to (ix) are repeated as appropriate.
In addition, below the discharge valves 94 and 96, it is attracted | sucked by the discharge pump which is not specified in the figure.
Further, the operations (i) to (ix) are preferably controlled by a control device (not shown), and each step is preferably automatically executed after the operator instructs activation.

<Aspect 2>
2, the apparatus 60 of the present invention includes a raw water tank 62, a water vapor delivery unit 64, a condensing unit 66, a heat exchanger 68, a raw water circulation pump 76, a raw water circulation pipe 78, a raw water spray 84, and an exhaust pump 86. have. The water vapor delivery unit 64 includes a water vapor pump 70, a water vapor input pipe 72, and a water vapor output pipe 74.

[Raw water tank]
The raw water tank 62 has a function of storing the raw water 53 at the bottom of the inner side, and a function of storing water vapor 55 formed by evaporation of the raw water 53 at the upper part of the inner side. Moreover, the raw | natural water tank 62 has the raw | natural water spray 84 as a vaporizer in the inner upper part. The raw water spray 84 is connected to the bottom of the raw water tank 62 via the raw water circulation pipe 78, and the raw water 53 stored in the bottom of the raw water tank 62 is pumped up by the action of the raw water circulation pump 76. The raw water 53 can be discharged from the spray 84 in the form of a shower or mist.

[Heat exchanger]
The heat exchanger 68 is installed inside the raw water tank 62. Further, the heat exchanger 68 is connected to a condensing unit 66 described later, and the water vapor 55 ′ in the condensing unit 66 can be moved into the heat exchanger 68.
The heat exchanger 68 gives the raw water 53 heat energy included in the water vapor 55 ′ that has moved from within the condensing unit 66. The heat exchanger 68 supplies heat energy to the raw water 53 sprayed from the raw water spray 84 onto the upper surface of the heat exchanger 68. As a result, the temperature of the raw water 53 rises by obtaining thermal energy on the surface of the heat exchanger 68. The raw water 53 whose temperature has risen tends to become water vapor. Further, the pressure of the upper space inside the raw water tank 62 is lowered by the action of the exhaust pump 86 described later, so that the raw water 53 is easily vaporized.

[Condensation part]
The condensing part 66 is a tubular thing, The water vapor | steam 55 'sent out from the water vapor | steam delivery part 64 and having raised temperature can be taken in the inside. The taken water vapor 55 ′ reaches the heat exchanger 68, where heat energy is supplied to the raw water 53, and the water vapor 55 ′ is cooled and condensed into fresh water 57. The fresh water 57 generated in the heat exchanger 68 flows in a path connecting the heat exchanger 68 and the condensing unit 66 and is stored in a fresh water tank attached to the bottom of the condensing unit 66. As shown in FIG. 2, the fresh water tank is disposed below the heat exchanger 68, and a path connecting the heat exchanger 68 and the condensing unit 66 gradually moves from the heat exchanger 68 toward the fresh water tank. Since it is arranged with an oblique gradient so as to be low, the fresh water 57 generated in the vicinity of the heat exchanger 68 flows to the fresh water tank by the action of gravity.
There is a fresh water outlet 96 at the bottom of the fresh water tank, from which fresh water 57 can be discharged.

  Further, an exhaust pump 86 capable of depressurizing the inner upper space is connected to the condensing unit 66 via an exhaust pipe 85. The exhaust pump 86 reduces the pressure by exhausting the gas in the upper space inside the condensing unit 66, and as a result, the pressure in the upper space inside the raw water tank 62 can be reduced. That is, by the action of the exhaust pump 86, the pressure in the upper space inside the raw water tank 62, the pressure in the upper space inside the condensing unit 66, the pressure inside the steam input pipe 72, and the pressure inside the steam output pipe 74 are reduced. As the saturated water vapor pressure, the efficiency of the water vapor pump 70 can be increased. Further, even when the steam 55 and 55 ′ contain unnecessary components, it can be discharged out of the system and removed by the action of the exhaust pump 86.

[Water vapor delivery section]
The water vapor input pipe 72 constituting a part of the water vapor delivery section 64 connects the upper space inside the raw water tank 62 and the water vapor pump 70, and the water vapor output pipe 74 is connected to the water vapor pump 70 and a condensation which will be described later. The upper space inside the part 66 is connected. That is, the steam input pipe 72 and the steam output pipe 74 constitute a connection part that connects the raw water tank 62 and the condensing part 66. Then, by the action of the water vapor pump 70, the water vapor 55 existing in the upper space inside the raw water tank 62 can be sucked and sent to the upper space inside the condensing unit 66. Here, the filter 90 is installed inside the water vapor input pipe 72, whereby impurities, foreign matters, salts, and the like contained in the water vapor 55 can be removed.

Next, the operation of the aspect 2 will be described with reference to FIG.
First, the raw water 53 in the raw water tank 62 reaches the raw water spray 84 through the raw water circulation pipe 78 and is discharged from here to the upper surface of the heat exchanger 68. And it vaporizes in the upper surface of the heat exchanger 68, and the water vapor | steam 55 generate | occur | produces. Here, since the heat exchanger 68 is in contact with the raw water 53 accumulated at the bottom of the raw water tank 62, the temperature of the raw water 53 accumulated at the bottom also increases to some extent and is easily vaporized. Further, since the pressure in the upper space inside the raw water tank 62 is reduced by the action of the exhaust pump 86, the raw water 53 is easily vaporized. For example, the upper space inside the raw water tank 62 can be set to 20 to 30 hPa.

Next, the water vapor 55 is sucked and compressed by the action of the water vapor pump 70 to become the water vapor 55 'whose temperature has been increased. For example, when the water vapor 55 existing in the upper part inside the raw water tank 62 is 20 ° C. and 23 hPa, the water vapor 55 ′ at 30 ° C. and 42 hPa can be obtained by passing the water vapor pump 70 and compressing it.
The steam 55 passes through the steam input pipe 72 and the steam output pipe 74 and reaches the upper space inside the condensing unit 66. And at least a part thereof becomes fresh water 57.
The steam 55 ′ and / or the fresh water 57 whose temperature has been increased gives the heat energy it holds to the raw water 53 via the heat exchanger 68. The water vapor 55 ′ imparted with heat energy to the raw water 53 becomes fresh water 57.
Then, the fresh water 57 is stored at the bottom inside the condensing unit 66.

<Aspect 3>
Aspect 3 shown in FIG. 3 is an aspect similar to aspect 2 described above. In FIG. 3, the same symbols are attached to the components that mean the same configuration as in the aspect 2 shown in FIG. 2.
For aspect 3, only the differences from aspect 2 will be described.

In the second aspect, the steam 55 ′ moves in the path connecting the heat exchanger 68 and the condensing unit 66, and reaches the inside of the upper heat exchanger 68 from the lower side. Is configured to reach the inside of the heat exchanger 68 from above and pass downward.
Other configurations and operations are the same as those in the second aspect.

<Aspect 4>
4, the apparatus 160 of the present invention includes a raw water tank 162, a steam delivery unit 164, a condensing unit 166, a heat exchanger 168, a raw water circulation pump 176, a raw water circulation pipe 178, a raw water spray 184, and an exhaust pump 186. have. Further, the water vapor delivery unit 164 includes a water vapor pump 170 and a connection unit 173.

[Raw water tank]
The raw water tank 162 has a function of storing the raw water 153 at the inner bottom portion, and has a function of storing water vapor 155 formed by evaporation of the raw water 153 at the upper portion of the inner side. Moreover, the raw | natural water tank 162 has the raw | natural water spray 184 as a vaporizer in the upper part inside. The raw water spray 184 is connected to the raw water circulation pipe 178, and the raw water 153 stored at the bottom inside the raw water tank 162 is pumped up by the action of the raw water circulation pump 176, and the raw water 153 is drawn from the raw water spray 184 into a shower-like shape or It can be released as a mist.

[Heat exchanger and condenser]
The heat exchanger 168 is installed inside the raw water tank 162.
As shown in FIG. 4, the heat exchanger 168 has a sawtooth shape in which a straight line is bent many times, or a pipe is spirally wound. Such a configuration is preferable because the contact area with the water vapor 155 and / or the raw water 153 increases, and the heat exchange rate of the heat exchanger increases. Moreover, as shown in FIG. 4, it is more preferable to have a heat sink 169 because the heat exchange rate is further increased.

  The heat exchanger 168 has a tubular shape, and the steam 155 ′ sent from the steam delivery unit 164 and having a high temperature can be taken into the heat exchanger 168. The introduced water vapor 155 ′ supplies heat energy to the water vapor 155 and / or raw water 153, and the water vapor 155 ′ is condensed by being cooled to become fresh water 157. The fresh water 157 generated in the heat exchanger 168 is stored in a fresh water tank that is a part of the condensing unit 166. As shown in FIG. 4, since the fresh water tank is arrange | positioned under the condensation part 166, the fresh water 157 flows into a fresh water tank by the effect | action of gravity.

  In addition, an exhaust pump 186 that can depressurize the inner upper space is connected to the condensing unit 166 via an exhaust pipe 185. The exhaust pump 186 reduces the pressure by exhausting the gas in the upper space inside the condensing unit 166, and as a result, the pressure in the upper space inside the raw water tank 162 can be reduced. That is, by the action of the exhaust pump 186, the pressure of the upper space inside the raw water tank 162, the inside of the condensing unit 166, the inside of the heat exchanger 168, and the inside of the connection unit 173 are set to the saturated water vapor pressure, and the steam pump 170. Can increase the efficiency. Furthermore, even when the steam 155 and 155 ′ contain unnecessary components, it can be discharged out of the system and removed by the action of the exhaust pump 186.

[Water vapor delivery section]
A connection part 173 constituting a part of the water vapor delivery part 164 connects the upper space inside the raw water tank 162 and the inside of the heat exchanger 168. Then, by the action of the steam pump 170, the steam 155 existing in the upper space inside the raw water tank 162 can be sucked and sent out to the inside of the heat exchanger 168. Here, the filter 190 is installed on the entry side of the connection portion 173 (the front stage of the water vapor pump 170), whereby impurities, foreign matter, salt, and the like contained in the water vapor 155 can be removed.
In aspect 4, the water vapor pump 170 is preferably a centrifugal fan.

Next, the operation of aspect 4 will be described with reference to FIG.
First, the raw water 153 in the raw water tank 162 reaches the raw water spray 184 through the raw water circulation pipe 178 and is discharged therefrom. And the discharged | emitted raw | natural water 153 is vaporized in the surface etc. of the heat exchanger 168, and becomes the water vapor | steam 155. FIG. Here, since the heat exchanger 168 is in contact with the raw water 153 accumulated at the bottom of the raw water tank 162, the temperature of the raw water 153 accumulated at the bottom is increased to some extent and is easily vaporized. Further, since the pressure in the upper space inside the raw water tank 162 is lowered by the action of the exhaust pump 186, the raw water 153 is easily vaporized. For example, the upper space inside the raw water tank 162 can be set to 20 to 30 hPa.

Next, the water vapor 155 is sucked and compressed by the action of the water vapor pump 170 to become the water vapor 155 ′ whose temperature has been increased. For example, when the water vapor 155 existing in the upper part inside the raw water tank 162 is 20 ° C. and 23 hPa, the water vapor 155 ′ at 30 ° C. and 42 hPa can be obtained by passing the water vapor pump 170 and compressing it.
The steam 155 ′ passes through the heat exchanger 168, and at least a part thereof becomes fresh water 157.
The steam 155 ′ and / or the fresh water 157 whose temperature has been increased imparts the stored thermal energy to the raw water 153 in the process of passing through the heat exchanger 168. The water vapor 155 ′ with the heat energy applied to the raw water 153 becomes the fresh water 157.
The fresh water 157 is stored in a fresh water tank below the condensing unit 166.

In the raw water tank 12, the raw water tank 62, and the raw water tank 162 in the first to fourth aspects, the heat for vaporizing the raw water is only the heat from the condensing unit 16, the condensing unit 66, and the condensing unit 166 (heat exchanger 168). In addition, other external heat sources such as outside air, hot water, hot water, solar heat, and combustion can be used.
Moreover, it is preferable to cover the entirety of the device 10 of the present invention, the device 60 of the present invention, and the device 160 of the present invention in Embodiments 1 to 4 with a heat insulating material or the like so as not to let the heat escape to the outside. It is preferable to cover at least the steam output pipes 24 and 74 and the connection portion 173 with a heat insulating material or the like.

  In the first to fourth aspects, the pressure in the upper space inside the raw water tanks 12, 62 and 162 is reduced by the action of the exhaust pumps 36, 86 and 186. However, in the apparatus of the present invention, the exhaust pump is You may not have it. In this case, in order to evaporate the raw water, it is necessary to heat the raw water to 100 ° C. or higher. However, since the obtained fresh water is boiled and disinfected, it is preferable for use as drinking water.

  The device of the present invention having such a mode 1 to a mode 4 as a preferred mode is a desalination apparatus that is high in energy efficiency, low in cost, and capable of downsizing the apparatus. Further, since the apparatus of the present invention has the above-described configuration, it can be reduced in size, but conversely, it can also be increased in size. Furthermore, the amount of fresh water obtained can be increased by installing a plurality of small devices of the present invention in parallel.

  Examples of the present invention will be described. The present invention is not limited to the examples described below.

Fresh water was produced using the apparatus of the present invention of embodiment 1 shown in FIG.
Specifically, the following properties and specifications were used.
・ Raw water tank: It is tank-shaped and has a capacity of about 10 m ³ .
・ Condensation part (tank): Tank-shaped part with a capacity of 1 m ³ or more.
・ Raw water: 20 ℃ seawater, 1m ³
・ Steam pump: Exhaust capacity 1000m ³ / min
: Turbine electrical capacity 40 kW or more.
・ Raw water circulation pump: Circulation rate 1800L / min ・ Heat exchanger: Heat exchange capacity 630kWh
: Heat exchange copper plate thickness 1mm
: Heat exchange copper plate surface area of 3 m ² or more.
The apparatus according to the first aspect of the present invention has a performance capable of treating 1 m ³ of raw water in one hour.

When raw water was processed using the apparatus of the present invention having the above properties, specifications, etc., the temperature of the raw water on the outlet side of the heat exchanger (the temperature of the raw water 3 ′ in the raw water return pipe) was 25 ° C. It was. Further, the temperature of the water vapor generated by the raw water spray and stored in the upper space inside the raw water tank was 20 ° C., and the pressure was 23 hPa. Further, the water vapor present in the upper space inside the agglomeration part had a temperature of 30 ° C. and a pressure of 42 hPa.
In this way, 1 m ³ of raw water was treated for 1 hour to obtain 30 ° C. fresh water.

  As described above, the desalination apparatus and the fresh water production method of the present invention have been described in detail. However, the present invention is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the scope of the present invention. You may go.

3, 3 ′, 53, 153 Raw water 5, 5 ′, 55, 55 ′, 155, 155 ′ Water vapor 7, 57, 157 Fresh water 10, 60, 160 Apparatus of the present invention 12, 62, 162 Raw water tank 14, 64, 164 Steam delivery section 16, 66, 166 Condensing section 18, 68, 168 Heat exchanger 20, 70, 170 Steam pump 22, 72 Steam input pipe 24, 74 Steam output pipe 26, 76, 176 Raw water circulation pump 28, 30, 78,178 Raw water circulation pipe 32 Raw water return pipe 34,84,184 Raw water spray 35,85,185 Exhaust pipe 36,86,186 Exhaust pump 40,90,190 Filter 92 Raw water inlet 94 Raw water outlet 96 Fresh water outlet 173 Connection

Claims (6)

A desalinator that evaporates raw water and then condenses to produce fresh water,
A raw water tank for storing the raw water;
A vaporizer that is installed in the raw water tank and vaporizes the raw water to generate water vapor;
A condensing part for condensing the water vapor to obtain fresh water;
A water vapor pump that sucks and compresses the water vapor from the raw water tank and sends the water vapor whose temperature has been increased to the condensing unit is provided with a water vapor delivery unit provided at a connection part that connects the raw water tank and the condensing unit And
A heat exchanger that imparts, to the raw water, steam energy delivered from the steam pump and / or thermal energy of the fresh water;
A desalination apparatus in which the heat exchanger plays a role in promoting vaporization of the raw water. The heat exchanger is installed inside the condenser, and
Raw water delivery means for sending the raw water in the raw water tank to the heat exchanger;
Raw water return means for sending raw water after thermal energy has been applied through the heat exchanger to the vaporizer,
Raw water circulation means for sending the raw water in the raw water tank to the heat exchanger by the raw water delivery means, and further sending to the vaporizer by the raw water return means,
The desalination apparatus of Claim 1 which has these. The heat exchanger is installed inside the raw water tank;
A structure capable of moving the steam delivered from the steam pump from the condensing unit into the heat exchanger, or a structure capable of moving the condensate through the heat exchanger to the condensing unit; And
Furthermore, the desalination apparatus of Claim 1 which has a raw | natural water sending means for sending the said raw | natural water in the said raw | natural water tank to the said vaporizer, and a raw | natural water circulation means.   The desalination apparatus in any one of Claims 1-3 which further has the exhaust pump for decompressing the inside of the said raw | natural water tank in the back | latter stage or the said condensing part in the said water vapor | steam delivery part. A method for producing fresh water by evaporating raw water and then condensing it,
Vaporizing the raw water to obtain water vapor;
Sucking and compressing the water vapor to obtain water vapor whose temperature has been increased;
Providing the raw water with steam having an increased temperature and / or heat energy of the fresh water;
Condensing the water vapor whose temperature has been increased to obtain fresh water;
A method for producing fresh water, which promotes vaporization of the raw water by applying the thermal energy to the raw water. The manufacturing method of the fresh water of Claim 5 performed using the desalination apparatus in any one of Claims 1-4.

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