JP2011088094A - Apparatus for producing freshwater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for producing fresh water which has a high efficiency of producing fresh water and moreover does not damage a permeation membrane of a membrane module. <P>SOLUTION: A pump capable of pressurizing sea water to a high pressure so as to make a boiling temperature of sea water higher than the boiling temperature at a normal temperature is used as the pump 2. A heating means capable of heating sea water at a temperature higher than the boiling temperature at a normal temperature and lower than the boiling temperature after being pressurized by the pump is used as the heating means 4 for heating sea water. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fresh water producing apparatus for producing fresh water from raw water such as seawater or brine using a permeable membrane.

  Conventionally, there is a fresh water production apparatus that produces fresh water from seawater as one of such production apparatuses. This fresh water producing apparatus includes a membrane module as described in Patent Document 1 below. The membrane module has a liquid chamber and a separation chamber that are in contact with each other via a permeable membrane, and a seawater introduction chamber that is in contact with the separation chamber via a partition. Seawater is supplied to the seawater introduction chamber by a pump. Seawater exiting the seawater introduction chamber is heated by the heating means and then introduced into the liquid chamber.

When the seawater heated by the heating means is introduced into the liquid chamber, the water vapor is separated from the seawater by the water vapor partial pressure difference corresponding to the temperature difference between the liquid chamber and the separation chamber, and the separation chamber passes through the permeable membrane. Get in. As a result, the seawater in the liquid chamber has a high salinity and is discharged to the outside as concentrated seawater. On the other hand, the water vapor entering the separation chamber is cooled by the seawater introduced into the seawater introduction chamber through the partition wall. And it is condensed and recovered as fresh water. The water vapor that has entered the separation chamber preheats the seawater in the seawater introduction chamber.

Japanese Patent Laid-Open No. 2-9490

  In the fresh water production apparatus having the above configuration, the production efficiency of fresh water can be increased as the temperature of the seawater introduced into the liquid chamber is increased. However, in the conventional freshwater production apparatus, seawater was heated only in the range of 100 ° C. or less. This is because when the temperature of the seawater exceeds 100 ° C., the seawater will boil in the liquid chamber and the permeable membrane may be damaged. Further, the pressure in the liquid chamber may increase due to boiling, and the liquid component in the liquid chamber may be expelled. For this reason, there existed a problem that the temperature of seawater could not be made high temperature exceeding 100 degreeC, and the production efficiency of fresh water could not be made high.

In order to solve the above problem, the present invention provides a membrane module having a liquid chamber, a separation chamber in contact with the liquid chamber through a permeable membrane, and a raw water introduction chamber in contact with the separation chamber through a partition, and the raw water A pump that supplies the raw water to the introduction chamber, a power source that operates the pump, and the raw water that is installed between the raw water introduction chamber and the liquid chamber and that is supplied from the raw water introduction chamber to the liquid chamber. In the fresh water production apparatus in which water vapor is separated from the raw water in the liquid chamber into the separation chamber through the permeable membrane, and fresh water is obtained from the water vapor, the pump has a boiling point of the raw water. A pressure pump that can pressurize the raw water until it exceeds 100 ° C is used, and as the heating means, the temperature at the time of introduction of the raw water into the liquid chamber exceeds 100 ° C. It is characterized by the fact that a heating means that can be used is used.
In this case, it is desirable to further include driving means driven by the concentrated raw water discharged from the liquid chamber, and the driving means is used as an auxiliary power source for operating the pump.
It is preferable that the apparatus further includes second driving means driven by fresh water discharged from the separation chamber, and the second driving means is used as a second auxiliary power source for operating the pump.
A second membrane module having a second liquid chamber, a second separation chamber in contact with the second liquid chamber via a second permeable membrane, and a second raw water introduction chamber in contact with the second separation chamber via a second partition; In addition, the raw water is sucked into the pump through the second raw water introduction chamber, the concentrated raw water discharged from the liquid chamber is introduced into the second liquid chamber, and water vapor from the concentrated raw water passes through the second permeation. It is desirable to separate into the second separation chamber through a membrane.
Desirably, fresh water discharged from the separation chamber is introduced into the second separation chamber.
A second membrane module having a second liquid chamber, a second separation chamber in contact with the second liquid chamber through a second permeable membrane, and a second raw water introduction chamber in contact with the second separation chamber through a second partition; Further, the raw water is introduced into the second raw water introduction chamber, the concentrated raw water that has driven the driving means is introduced into the second liquid chamber, and water vapor passes from the concentrated raw water in the second liquid chamber to the second permeate. It is desirable to separate into the second separation chamber through a membrane.
The apparatus further comprises second driving means driven by fresh water discharged from the separation chamber, and the second driving means is used as a second auxiliary power source for operating the pump to drive the second driving means. It is desirable that the fresh water is introduced into the second separation chamber.

  According to the present invention having the above configuration, since the raw water is pressurized to a high pressure by the pump so that the boiling temperature of the raw water is higher than the boiling temperature at normal temperature, the raw water is heated to a high temperature of 100 ° C. or higher. can do. Therefore, the production efficiency of fresh water can be improved. And since raw | natural water does not boil in a liquid chamber, generation | occurrence | production of the malfunction accompanying boiling of a permeable membrane etc. can be prevented reliably.

FIG. 1 is a diagram showing a schematic configuration of the first embodiment of the present invention. FIG. 2 is a diagram showing a schematic configuration of the second embodiment of the present invention.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 shows a first embodiment of the present invention. The fresh water producing apparatus A of this embodiment is for producing fresh water from seawater (raw water), and has a membrane module 1, a pump 2, a rotational power source (power source) 3, and a heating means 4. . In addition, the fresh water manufacturing apparatus A which concerns on this invention can also manufacture fresh water from raw water other than seawater, for example, brine.

  The membrane module 1 has a casing 1a. A permeable membrane 1b and a partition 1c are provided inside the casing 1a. Thus, the inside of the casing 1a is divided into a liquid chamber 1d and a separation chamber 1e that are in contact with each other via the permeable membrane 1a, and a seawater introduction chamber (raw water introduction chamber) 1f that is in contact with the separation chamber 1e via a partition 1c. .

  The permeable membrane 1b selectively permeates only the gas component from the high temperature side to the low temperature side with a water vapor partial pressure difference corresponding to the temperature difference between the two sides. Things can be adopted. Examples include Advantech's T0101A and Donaldson's TX1301.

  Of the liquid chamber 1d and the separation chamber 1e that are in contact with each other via the permeable membrane 1b, high temperature (for example, 105 ° to 180 ° C.) seawater (not shown) is introduced from the top as described later. The Therefore, water vapor (not shown) flows into the separation chamber 1e through the permeable membrane 1b. Although this water vapor is at a lower temperature than the seawater in the liquid chamber 1d, it is at a higher temperature (for example, about 100 ° to 175 ° C.) than the normal temperature.

  The partition 1c is composed of a heat-resistant resin thin film such as a heat-resistant film or a metal thin plate such as titanium. Therefore, the separation chamber 1e and the seawater introduction chamber 1f that are in contact with each other via the partition 1c constitute a kind of heat exchanger. In this case, gas components such as water vapor are permeated into the separation chamber 1e as described above, whereas normal temperature seawater is introduced into the seawater introduction chamber 1f from the bottom. Therefore, the seawater in the seawater introduction chamber 1f is heated by the water vapor in the separation chamber 1e. On the contrary, the water vapor in the separation chamber 1e is cooled and condensed by the seawater in the seawater introduction chamber 1f to become fresh water. The temperature of the lower part of this fresh water is slightly higher than room temperature (introduction seawater temperature), for example, about room temperature + (1 ° to 5 ° C.). In this embodiment, seawater flows in the seawater introduction chamber 1f from one end side (lower end side) of the membrane module 1 to the other end side (upper end side), and fresh water is located on one end side of the membrane module 1. As is apparent from the fact that it is taken out from one end of 1e, the separation chamber 1e and the seawater introduction chamber 1f are a kind of counterflow heat exchanger. Of course, other types of heat exchangers may be configured.

  The pump 2 is for pressurizing seawater from normal pressure to high pressure and supplying it to a fresh water production apparatus. The seawater is brought to a high pressure so that the seawater boils at a temperature higher than the boiling temperature (100 ° C) at room temperature. Pressurize. For example, the seawater is pressurized to an absolute pressure of about 0.15 to 1 MPa so that the boiling temperature of the seawater is 105 ° to 180 ° C. Desirably, the seawater is heated to an absolute pressure of about 0.2 to 0.5 MPa so that the boiling temperature of the seawater is 120 to 150 ° C. As such a pump 2 for pressurization, for example, a multistage centrifugal pump is preferably used, but a reciprocating pump may be used. The pump 2 includes a rotational power source (power source) 3 composed of an electric motor or the like, and first and second rotational driving means (driving means, second driving means) 5 and 6 as auxiliary rotational power sources (auxiliary power sources) described later. Is operated by. That is, it is rotationally driven.

  The heating means 4 is composed of, for example, a heat exchanger, and a counter flow heat exchanger is used in this embodiment. Of course, other types of heat exchangers or other heaters such as a heater may be used as the heating means 4. The heating means 4 has a casing 4a. A partition 4b is provided inside the casing 4a. The partition 4b is comprised with the material excellent in thermal conductivity, such as a metal. By providing the partition 4b in the casing 4a, the inside of the casing 4a is divided into a low temperature chamber 4c and a high temperature chamber 4d.

Seawater pressurized by the pump 2 and preheated in the seawater introduction chamber 1f is introduced into the low greenhouse 4c from one end side of the casing 4a. Seawater introduced into the low greenhouse 4c flows in the low temperature chamber 4c toward the other end of the casing 4a. On the other hand, water and other high-temperature heat medium (not shown) are introduced into the high temperature chamber 4d. A heat medium flows toward the one end side from the other end side of the casing 4a, and heats seawater in the meantime. In this case, since the seawater is pressurized by the pump 2, the boiling temperature is higher than the boiling temperature at normal pressure, and is heated to a high temperature that is slightly lower than the boiling temperature in the pressurized state. For example, it is heated to a high temperature of about 105 ° to 180 ° C. Desirably, it is heated to 120 ° to 150 ° C.

  The heated high-temperature and high-pressure seawater is introduced into the liquid chamber 1d of the membrane module 1 as described above. A portion of the seawater introduced into the liquid chamber 1d passes through the permeable membrane 1b as water vapor and flows into the separation chamber 1e. While the water vapor flowing into the separation chamber 1e heats the seawater in the seawater introduction chamber 1f, the water vapor itself is cooled and condensed by the seawater in the seawater introduction chamber 1f to become fresh water.

  The seawater from which the water vapor has been separated flows out of the liquid chamber 1d as concentrated seawater with a high salinity. On the other hand, the water vapor entering the separation chamber 1e flows out from the separation chamber as fresh water. Concentrated seawater may be returned to the sea as it is, and fresh water may be recovered as it is. However, they are normal temperature, higher temperature and higher pressure than normal pressure, and have high energy. In order to use this energy, a first rotation driving means (driving means) 5 is provided in the subsequent stage of the liquid chamber 1d, and a second rotation driving means (second driving means) 6 is provided in the subsequent stage of the separation chamber 1e. Is provided.

  The 1st rotation drive means 5 is for taking out the high temperature / high pressure energy which concentrated seawater has as a rotational force, for example, a turbine is used. The first rotation driving means 5 is connected to the pump 2 and rotationally drives the pump 2 together with the rotation power source 3 as an auxiliary rotation power source. On the other hand, the second rotation driving means 6 is for taking out high-pressure energy of fresh water as a rotational force, and for example, a turbine is used. The second rotational driving means 6 is connected to the pump 2 and rotationally drives the pump 2 together with the rotational driving source 3 and the first rotational driving means 5 as a second auxiliary power source. Thus, since the pump 2 is rotationally driven by the first and second rotational driving means 5 and 6, the energy used for the rotational power source 3 can be reduced and energy saving can be achieved. . In order to adjust the rotation speeds of the first rotation driving means 5 and the second rotation driving means 6, a speed reducer may be provided in each of the means 5 and 6.

  According to the fresh water producing apparatus A having the above configuration, since the seawater is heated to a high temperature of 105 ° to 180 ° C. exceeding 100 ° C., the desalination efficiency by the membrane module 1 can be improved, and thereby the fresh water The production efficiency can be improved. Moreover, since seawater (raw water) introduced into the liquid chamber 1d is pressurized and its boiling temperature is higher than the actual heating temperature, the seawater does not boil in the liquid chamber 1d. Therefore, it is possible to reliably prevent problems that occur due to boiling such as liquid displacement due to breakage of the permeable membrane 1b and high pressure in the liquid chamber 1d.

  Next, a second embodiment of the present invention shown in FIG. 2 will be described. The fresh water producing apparatus B of this embodiment further includes a second membrane module 7. The second membrane module 7 is configured in the same manner as the membrane module 1, and corresponds to the casing 1a, the permeable membrane 1b, the partition 1c, the liquid chamber 1d, the separation chamber 1e, and the seawater introduction chamber 1f of the membrane module 1, respectively. 2 casing 7a, 2nd permeable membrane 7b, 2nd partition 7c, 2nd liquid chamber 7d, 2nd separation chamber 7e, and 2nd seawater introduction chamber (2nd raw | natural water introduction chamber) 7f.

  The concentrated seawater that has passed through the first rotation driving means 5 is introduced into the second liquid chamber 7d. The concentrated seawater introduced into the second liquid chamber 7d maintains a temperature higher than room temperature, for example, a temperature of about 80 ° C to 105 ° C. Therefore, the water in the concentrated seawater becomes steam and passes through the second permeable membrane 7b and enters the second separation chamber 7e. Concentrated seawater that has passed through the second liquid chamber 7d and has a higher salinity is discharged into the seawater.

  As described above, fresh water separated from the concentrated seawater enters the second separation chamber 7e. The temperature of this fresh water is 76 ° C to 100 ° C. Moreover, the fresh water which rotated the 2nd rotation drive means 6 enters into the 2nd separation chamber 7e. The temperature of this fresh water is 79 ° to 101 ° C. Seawater sucked by the pump 2 is introduced into the second seawater introduction chamber 7f that is in contact with the second separation chamber 7e via the second partition 7c. This seawater is preheated by water vapor and fresh water in the second separation chamber 7e. On the other hand, the water vapor in the second separation chamber 7e is cooled and condensed by seawater to become fresh water. And it flows out from the 2nd separation chamber 7e with the fresh water which passed through the 2nd rotation drive means 6, and entered into the 2nd separation chamber 7e, and is collect | recovered as fresh water.

  According to this fresh water producing apparatus B, not only the fresh water is separated by the membrane module 1, but also fresh water is further separated from the concentrated seawater by the second membrane module 7, so that the production efficiency of fresh water can be further improved. it can.

  Next, experimental examples for clarifying the above effects of the present invention will be introduced. In this experimental example, the fresh water producing apparatus A shown in FIG. 1 is used. And in the Example of this invention, seawater was pressurized to 0.5 MPa by the absolute pressure with the pump 2, and was heated to 145 degreeC by the heating means after that. In the comparative example, seawater was pressurized to 0.1 MPa in absolute pressure and heated to 95 ° C. At this time, the flow rate was adjusted so that the energy required for heating was 1 kW in both cases. In the embodiment of the present invention, fresh water was produced at 8.4 cc / sec, and in the comparative example, fresh water was produced at 4.1 ccl / sec. As is clear from this, in the examples of the present invention, the production efficiency of fresh water was approximately doubled compared to the comparative example.

In addition, this invention is not limited to said embodiment, A various modification is employable in the range which does not deviate from the summary.
For example, in the above-described embodiment, the pump 2 is installed in front of the seawater introduction chamber 1f, but the pump 2 may be installed between the seawater introduction chamber 1f and the low temperature chamber 4c. In addition, a pump may be provided in front of the second seawater introduction chamber 7f separately from the pump, and the raw water may be introduced into the second raw water introduction chamber by this pump.

A fresh water production apparatus B fresh water production apparatus 1 membrane module 1b permeable membrane 1c partition 1d liquid chamber 1e separation chamber 1f seawater introduction chamber (raw water introduction chamber)
2 Pump 3 Rotation power source (Power source)
4 Heating means 5 First rotation driving means (driving means)
6 Second rotation driving means (second driving means)
7 second membrane module 7b second permeable membrane 7c second partition 7d second liquid chamber 7e second separation chamber 7f second seawater introduction chamber (second raw water introduction chamber)

Claims (7)

A liquid chamber, a separation chamber in contact with the liquid chamber through a permeable membrane, a membrane module having a raw water introduction chamber in contact with the separation chamber through a partition, a pump for supplying the raw water to the raw water introduction chamber, and the pump And a heating means that is installed between the raw water introduction chamber and the liquid chamber and that heats the raw water supplied from the raw water introduction chamber to the liquid chamber. In the fresh water production apparatus in which the water vapor is separated into the separation chamber through the permeable membrane, and fresh water is obtained from the water vapor.
As the pump, a pressure pump that can pressurize the raw water until the boiling point of the raw water exceeds 100 ° C is used,
An apparatus for producing fresh water, characterized in that a heating means capable of heating the raw water to a temperature exceeding 100 ° C. when introduced into the liquid chamber is used as the heating means.   The fresh water according to claim 1, further comprising drive means driven by the concentrated raw water discharged from the liquid chamber, wherein the drive means is used as an auxiliary power source for operating the pump. Manufacturing equipment.   A second drive means driven by fresh water discharged from the separation chamber is further provided, wherein the second drive means is used as a second auxiliary power source for operating the pump. The fresh water production apparatus according to 1 or 2.   A second membrane module having a second liquid chamber, a second separation chamber in contact with the second liquid chamber via a second permeable membrane, and a second raw water introduction chamber in contact with the second separation chamber via a second partition; In addition, the raw water is sucked into the pump through the second raw water introduction chamber, the concentrated raw water discharged from the liquid chamber is introduced into the second liquid chamber, and water vapor from the concentrated raw water passes through the second permeation. The fresh water producing apparatus according to claim 1, wherein the fresh water producing apparatus is separated into the second separation chamber through a membrane.   The fresh water producing apparatus according to claim 4, wherein fresh water discharged from the separation chamber is introduced into the second separation chamber.   A second membrane module having a second liquid chamber, a second separation chamber in contact with the second liquid chamber through a second permeable membrane, and a second raw water introduction chamber in contact with the second separation chamber through a second partition; In addition, the raw water is introduced into the second raw water introduction chamber, the concentrated raw water that has driven the driving means is introduced into the second liquid chamber, and water vapor passes through the second permeated water from the concentrated raw water in the second liquid chamber. The fresh water producing apparatus according to claim 2, wherein the fresh water producing apparatus is separated into the second separation chamber through a membrane.   The apparatus further comprises second driving means driven by fresh water discharged from the separation chamber, and the second driving means is used as a second auxiliary power source for operating the pump to drive the second driving means. The fresh water producing apparatus according to claim 6, wherein the fresh water is introduced into the second separation chamber.

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