JP2000189964A - Fresh water generator and fresh water method - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To prevent the processing liquid from overflowing from the processing liquid storage tank, to always obtain a sufficient amount of the processing liquid, to perform a reliable operation at low cost, and to reduce noise. It is an object of the present invention to provide a desalination apparatus and a desalination method that do not cause any problems. SOLUTION: An activated carbon cartridge 2 is provided at a stage preceding a fresh water cartridge 4, and a water supply valve 11 is provided at a raw water inlet of the activated carbon cartridge 2. The bypass pipe 13 is connected so as to bypass the water supply valve 11 and the activated carbon cartridge 2 and the bypass valve 12 is inserted. The flushing valve 9 is provided in the concentrated water extraction pipe 7 of the fresh water producing cartridge 4, and the permeated water extraction pipe 5 is connected to the permeated water storage tank 200 provided with the level detector 150. The control device 201 controls the opening and closing operation of the water supply valve 11 based on the state of the output of the level detector 150.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a desalination apparatus and a desalination method for supplying a liquid to be treated containing residual chlorine to a desalination cartridge provided with a reverse osmosis membrane.

[0002]

2. Description of the Related Art When desalinating a liquid to be treated containing residual chlorine such as tap water or industrial water (hereinafter referred to as raw water), a desalination cartridge having a reverse osmosis membrane (RO membrane) is provided. Raw water is separated into permeated water and concentrated water by a fresh water generator. As a method for obtaining a necessary and sufficient amount of permeated water in a desalination apparatus of a limited scale, a permeated water storage tank is provided in the desalination apparatus, and when the permeated water is not used, the permeated water is stored in the permeated water storage tank. Or a method of increasing the amount of permeated water per unit membrane area by providing a pressure pump in a fresh water generator.

FIG. 8 is a configuration diagram showing an example of a conventional fresh water generator equipped with a pressurizing pump. In the fresh water generator shown in FIG. 8, the pressure pump 100 and the fresh water cartridge 4 are used for desalination. The fresh water cartridge 4 includes a reverse osmosis membrane. When the reverse osmosis membrane is exposed to chlorine for a long time, the durability becomes poor. Therefore, the activated carbon cartridge 2 is used for pretreatment in order to remove residual chlorine contained in raw water.

[0004] Raw water is supplied to an activated carbon cartridge 2 through a raw water supply pipe 1. The permeated water of the activated carbon cartridge 2 is supplied as pretreatment water to the fresh water cartridge 4 through the pretreatment water supply pipe 3 by the pressure pump 100. The pretreated water is separated into permeated water and concentrated water by the fresh water producing cartridge 4 having the reverse osmosis membrane. The separated permeated water is taken out as treated water through the permeated water take-out pipe 5. The permeated water taken out is temporarily stored in a permeated water storage tank, for example. When using the permeated water, the permeated water is appropriately taken out of the permeated water storage tank.
On the other hand, the concentrated water is discharged to the outside through the concentrated water extraction pipe 7. Note that a pressure adjusting valve 6 is provided in the concentrated water discharge pipe 7, and is set so as to suppress the amount of concentrated water. Thereby, the permeation of the membrane in the fresh water cartridge 4 is promoted.

[0005]

In the above-mentioned fresh water generator, a driving device (not shown) such as a motor or a motor is required to drive the pressurizing pump 100, and these driving devices are used. Control device for controlling (not shown)
is necessary. Therefore, the cost of fresh water is increased and the price of the fresh water is increased. Further, the pressurizing pump 100
Also, the noise generated by the driving device becomes a problem.

When the balance between the amount of permeated water obtained by operation of the fresh water generator and the amount of permeated water taken out of the permeated water storage tank is lost, the permeated water overflows from the permeated water storage tank. In some cases, the water leaks to the outside or a necessary amount of permeated water cannot be obtained during use.

Further, when the fresh water producing operation by the fresh water producing apparatus is stopped for a long time, the bacteria grow inside the fresh water producing cartridge, and when the fresh water producing operation is resumed, the bacteria that have propagated are mixed into the permeated water.
There is a problem that the quality of permeated water deteriorates.

An object of the present invention is to prevent a processing liquid from overflowing from a processing liquid storage tank, to obtain a sufficient amount of a processing liquid at all times, to perform a reliable operation at a low cost, and to reduce noise. It is an object of the present invention to provide a desalination apparatus and a desalination method that do not cause any problems.

Another object of the present invention is to provide a processing liquid storage tank that does not overflow with a processing liquid and that a sufficient amount of the processing liquid can be always obtained. It is an object of the present invention to provide a desalination apparatus and a desalination method which can perform a highly reliable operation at the same time and do not cause a noise problem.

[0010]

Means for Solving the Problems and Effects of the Invention The present inventor conducted various experiments and studies to desalinate the liquid to be treated without using a pressurized pump and suppressing the growth of bacteria. As a result, the rejection of a 0.05% NaCl aqueous solution was 95% or more and the amount of permeated water was 0.1 m ³ / m ^2.
When a reverse osmosis membrane having a performance of not less than ² kgf / cm ² is used, the liquid to be treated having a pressure of ² kgf / cm ² or less is supplied to a fresh water cartridge equipped with a reverse osmosis membrane without using a pressure pump. Has been found to be able to carry out desalination.

The inventor of the present invention supplies a liquid to be processed to a fresh water cartridge via a pre-treatment device for removing residual chlorine, and bypasses the pre-treatment device to appropriately supply the liquid to be processed to the fresh water cartridge. It was found that by supplying to the freshwater cartridge, the growth of bacteria in the fresh water cartridge could be suppressed.
The inventor has devised the following invention based on these findings.

In the fresh water generator according to the first aspect of the present invention, a supply system for supplying a liquid to be treated having a predetermined pressure to a fresh water producing cartridge provided with a reverse osmosis membrane without passing through a pressure increasing means for increasing the pressure of the liquid to be treated. A processing liquid take-out path of the fresh water cartridge is connected to the processing liquid storage tank, and a level detector for detecting the level of the processing liquid in the processing liquid storage tank and a supply system in response to the output of the level detector are provided. Control means for controlling is provided.

In the fresh water generator according to the present invention, the level detector detects the water level (level) of the processing liquid in the processing liquid storage tank, and based on this, the supply system is controlled by the control means. This makes it possible to always store a constant amount of the processing liquid in the processing liquid storage tank. In addition, it is possible to prevent the processing liquid from leaking due to excessive fresh water.

In the above-mentioned fresh water generator, the liquid to be treated having a predetermined pressure is supplied to the fresh water cartridge without power, without using a pressurizing pump as a pressure increasing means. And a control device for controlling the driving device are not required. Therefore, the fresh water production cost is reduced and the rise in the price of the fresh water generator is suppressed. Further, there is no problem of noise generated by the pressurizing pump and the driving device. Further, since a pressurizing pump, a driving device, and a control device are not required, the fresh water generating device is compact, and an electricity bill is not required.

The level detector detects whether or not the level of the processing liquid in the processing liquid storage tank has reached a predetermined height, and the control means determines that the level of the processing liquid in the processing liquid storage tank has reached the predetermined height. May be stopped when the level detector detects that the liquid has been reached. This makes it possible to prevent the processing liquid from leaking due to excessive fresh water.

The control means supplies the liquid to be processed to the fresh water producing cartridge by the supply system when the level detector does not detect that the level of the processing liquid in the processing liquid storage tank has reached a predetermined height. Is also good. This makes it possible to always store a constant processing liquid in the processing liquid storage tank, and to always take out a necessary and sufficient amount of the processing liquid.

A pretreatment device for removing residual chlorine contained in the liquid to be treated having a predetermined pressure is provided at a stage preceding the fresh water producing cartridge, and a bypass path is provided so as to bypass the pretreatment device. Opening and closing means for opening and closing the route may be provided.

In this case, the liquid to be treated having a predetermined pressure is supplied to the pretreatment device, and the residual chlorine contained in the liquid to be treated is removed. The liquid to be treated obtained from the pretreatment device is supplied to a fresh water cartridge provided with a reverse osmosis membrane to perform a desalination treatment.

When the liquid to be treated from which residual chlorine having a bactericidal action has been removed accumulates inside the fresh water producing cartridge, bacteria can easily propagate. Thus, by opening the bypass path by the opening and closing means, the liquid to be treated containing residual chlorine can be supplied to the fresh water producing cartridge. Thereby, propagation of bacteria in the fresh water cartridge can be suppressed. As a result, deterioration of the permeate quality due to propagation of bacteria is prevented.

The liquid to be treated is 0.3 kgf / cm ² or more and 3 k
It may have a pressure of gf / cm ² or less. In this case, the desalting treatment can be performed without using a pressure increasing means such as a pressure pump.

A flushing means for flushing the reverse osmosis membrane of the fresh water producing cartridge may be provided. Here, flushing refers to washing the surface of the separation membrane with a water flow.

In this case, the reverse osmosis membrane of the fresh water producing cartridge is flushed by the flushing means.
Impurities accumulated on the reverse osmosis membrane surface of the fresh water producing cartridge can be released to the outside of the fresh water producing cartridge. As a result, the deterioration of the permeate quality in a short period of time and the decrease of the permeate amount over time caused by the shortage of the linear velocity of the reverse osmosis membrane are prevented.

A plurality of fresh water producing cartridges may be provided in parallel or / and in series. In this case, it is possible to obtain a large amount of permeate while preventing deterioration of the permeate due to propagation of bacteria.

According to a second aspect of the present invention, in the fresh water producing method, a liquid to be treated having a predetermined pressure is supplied to a fresh water producing cartridge provided with a reverse osmosis membrane without passing through a pressure increasing means, and the treatment liquid of the fresh water producing cartridge is supplied. The processing liquid is stored in the processing liquid storage tank, and the supply of the liquid to be processed to the fresh water cartridge is controlled in accordance with the level of the processing liquid in the processing liquid storage tank.

In the fresh water producing method according to the present invention, the supply of the liquid to be treated to the fresh water producing cartridge is controlled in accordance with the level (level) of the treatment liquid in the treatment liquid storage tank. It is possible to always store a constant processing liquid. In addition, it is possible to prevent the processing liquid from leaking due to excessive fresh water.

In the above-mentioned fresh water producing method, the liquid to be treated having a predetermined pressure is supplied to the fresh water producing cartridge without power without using a pressurizing pump as a pressure increasing means. This eliminates the need for a driving device and a control device for controlling the driving device. Therefore, the fresh water production cost is reduced and the rise in the price of the fresh water generator is suppressed. Further, there is no problem of noise generated by the pressurizing pump and the driving device.

The liquid to be treated may be supplied to the fresh water producing cartridge via a pretreatment device for removing residual chlorine, and may be supplied to the fresh water producing cartridge at a predetermined timing by bypassing the pretreatment device.

In this case, a liquid to be treated having a predetermined pressure is supplied to a pretreatment device to remove residual chlorine contained in the liquid to be treated. Furthermore, the liquid to be treated obtained from the pretreatment device is supplied to a fresh water cartridge provided with a reverse osmosis membrane to perform a desalination treatment.

If the liquid to be treated from which residual chlorine having a bactericidal action has been removed accumulates inside the fresh water producing cartridge, bacteria will easily propagate. Therefore, the liquid to be treated containing residual chlorine can be supplied to the fresh water cartridge by supplying the liquid to be processed to the fresh water cartridge at a predetermined timing, bypassing the pretreatment device. Thereby, propagation of bacteria in the fresh water cartridge can be suppressed. As a result, deterioration of the permeate quality due to propagation of bacteria is prevented.

The reverse osmosis membrane of the fresh water producing cartridge may be flushed at a predetermined timing. This makes it possible to discharge the impurities accumulated on the reverse osmosis membrane surface of the fresh water producing cartridge to the outside of the fresh water producing cartridge. As a result, the deterioration of the permeate quality in a short period of time and the decrease in the permeate amount over time caused by the shortage of the membrane surface linear velocity in the reverse osmosis membrane are prevented.

[0031]

FIG. 1 is a configuration diagram showing a first example of a fresh water generator according to the present invention.

In the fresh water generator shown in FIG. 1, an activated carbon cartridge 2 is used for pretreatment. The fresh water cartridge 4 is used for desalination.

The raw water supply pipe 1 is connected to the raw water inlet of the activated carbon cartridge 2 via a water supply valve 11. The permeated water outlet of the activated carbon cartridge 2 is connected to the raw water inlet of the fresh water producing cartridge 4 via the pretreatment water supply pipe 3. A bypass pipe 13 is connected so as to bypass the water supply valve 11 and the activated carbon cartridge 2, and a bypass valve 12 is inserted in the bypass pipe 13. Water valve 1
1 and the bypass valve 12 are composed of automatic valves.

A permeate outlet pipe 5 is connected to the permeate outlet of the fresh water producing cartridge 4, and a concentrate outlet pipe 7 is connected to the concentrate outlet.

A pressure adjusting valve 6 is interposed in the concentrated water extracting pipe 7, and a flushing valve 9 is connected in parallel with the pressure adjusting valve 6 via a washing water pipe 8. The flushing valve 9 comprises an automatic valve.

The opening and closing operations of the flushing valve 9 and the bypass valve 12 are controlled independently or simultaneously by a timer 10. The flushing valve 9 and the timer 10
Used for cleaning the fresh water cartridge 4.

The permeate extraction pipe 5 is connected to a permeate storage tank 200. The permeated water storage tank 20
0 may be provided inside the fresh water generator or may be provided outside. The permeated water storage tank 200 is provided with a permeated water outlet 155. When using the permeated water (treated water) obtained from the fresh water generator, the permeated water is appropriately taken out from the permeated water outlet 155 of the permeated water storage tank 200. Further, the permeated water storage tank 200 is provided with a level detector 150.

FIG. 2A is a schematic sectional view showing an example of a permeated water storage tank provided in the fresh water generator according to the present invention. In the permeated water storage tank 200 shown in FIG. 2A, the electrode type level detector 15 is used as the level detector 150.
0a is provided.

FIG. 2B is a schematic sectional view showing another example of the permeated water storage tank provided in the fresh water generator according to the present invention. In the permeated water storage tank 200 shown in FIG. 2B, a float type level detector 150b is provided as the level detector 150.

When the level of the permeated water in the permeated water storage tank 200 reaches a predetermined height, the level detectors 150a, 150
The output of 0b is turned on or off. Here, it is assumed that when the level of the permeated water in the permeated water storage tank 200 reaches a predetermined height, the outputs of the level detectors 150a and 150b are turned on.

Further, a plurality of level detection points of the level detectors 150a and 150b may be provided to prevent chattering of the ON or OFF output.

The control device 201 includes a level detector 150
a, the opening and closing operation of the water supply valve 11 is controlled in response to the state of the output of 150b.

In this example, the raw water supply pipe 1 and the water supply valve 1
1 corresponds to a supply system, and the activated carbon cartridge 2 corresponds to a pretreatment device. Further, the control device 201 corresponds to a control unit. Further, the bypass pipe 13 corresponds to a bypass path, the bypass valve 12 corresponds to an opening / closing means, and the cleaning water pipe 8
The flushing valve 9 corresponds to flushing means.

As the fresh water producing cartridge 4, for example, a reverse osmosis membrane module is used. The reverse osmosis membrane module is obtained by loading a reverse osmosis membrane spiral type element in a pressure vessel. Here, the rejection of a 0.05% NaCl aqueous solution is 95% or more and the amount of permeated water is 0.1 m ³ / m ² ···
A reverse osmosis membrane module having a performance of not less than a day · kgf / cm ² is used.

Assuming that the concentration of the target solute in the supply water is Cf and the concentration of the target solute in the permeated water is Cp, the rejection R (%) is defined by the following equation (1).

R (%) = (1−Cp / Cf) × 100 (1) The amount of permeated water in such a reverse osmosis membrane module is the amount of permeated water in a reverse osmosis membrane module used for a normal membrane separation operation. Very large compared to. In the reverse osmosis membrane module using the fresh water generating cartridge 4, for example, water temperature 25 ° C., under the conditions of operation pressure 7.5 kgf / cm ^2, density 0.0
The rejection of a 5% NaCl aqueous solution is 95% or more, and the amount of permeated water is 0.8 m ³ / m ² · day or more. on the other hand,
In a reverse osmosis membrane module used for a normal membrane separation operation, the rejection of a 0.05% NaCl aqueous solution is 95%.
As described above, the amount of permeated water is 0.6 m ³ / m ² · day or less.

First, the pretreatment and desalination of the fresh water generator shown in FIG. 1 will be described. During the pretreatment and the desalination treatment, the water supply valve 11 is opened, and the bypass valve 12 and the flushing valve 9 are closed.

As the raw water, water supplied at a predetermined pressure, such as tap water or industrial water, or well water in which the pressure of the pump remains.

In the pretreatment, the raw water supplied by the raw water supply pipe 1 is supplied to the inside of the activated carbon cartridge 2.
In the activated carbon cartridge 2, residual chlorine contained in the supplied raw water is removed. The permeated water of the activated carbon cartridge 2 is supplied to the inside of the fresh water cartridge 4 through the pretreatment water supply pipe 3 as pretreatment water.

The pretreated water is desalted by the fresh water producing cartridge 4 and separated into permeated water from which impurities are removed and concentrated water in which impurities are concentrated. The permeated water passes through a permeated water extraction pipe 5 connected to the permeated water outlet of the fresh water producing cartridge 4 and is stored in the permeated water storage tank 200 as treated water. The concentrated water is discharged to the outside through the concentrated water outlet pipe 7 connected to the concentrated water outlet of the fresh water cartridge 4.

The pressure regulating valve 6 provided in the concentrated water discharge pipe 7 is set so that the concentrated water is equal to or less than a predetermined amount. This suppresses the amount of concentrated water and increases the amount of permeated water.

Here, the ratio b / a of the amount a of the raw water supplied to the fresh water cartridge 4 and the amount b of the permeated water obtained from the fresh water cartridge 4 is set so that b / a> 0.5. Set the pressure regulating valve 6. In this case, the permeated water can be obtained with a recovery rate higher than 50% with respect to the supplied raw water.
Efficient and economical.

As described above, in the above fresh water generator,
Supplying raw water with 0.3 kgf / cm ² or more 3 kgf / cm ² or less pressure to the fresh water generating cartridge 4 in a non-powered without using a pressure pump, it is possible to efficiently desalting treatment.

When a sufficient amount of permeated water is stored in the permeated water storage tank 200 and the permeated water level (water level) reaches a predetermined height, the output of the level detector 150 is turned on. The control device 201 closes the water supply valve 11 in response to the output of the level detector 150 being turned on, and stops the operation of the fresh water generator.

On the other hand, when the permeated water level in the permeated water storage tank 200 falls below a predetermined height due to the use of permeated water, the output of the level detector 150 is turned off. The control device 201 opens the water supply valve 11 in response to the output of the level detector 150 being turned off, and restarts the operation of the fresh water generator.

As described above, in the above fresh water generator,
The operation is controlled according to the level of the permeated water in the permeated water storage tank 200. Therefore, the permeated water storage tank 200
Inside, it is possible to maintain a constant amount of permeated water.

The bypass valve 12 is controlled by the timer 10 so that the bypass valve 12 is automatically opened for a predetermined time during the suspension of fresh water production (while the operation of the fresh water generator is stopped), or During operation (during operation of the fresh water generator), the bypass valve 12 is set to be automatically opened for a predetermined time at predetermined time intervals. When the bypass valve 12 is open, the water supply valve 11 may be closed or open. The control that the water supply valve 11 is closed only when the fresh water production operation is interrupted is simple and therefore preferable.

As a result, raw water containing residual chlorine having a sterilizing effect is supplied into the fresh water producing cartridge 4 through the bypass pipe 13. As a result, fresh water cartridge 4
The proliferation of bacteria inside can be suppressed.

When the bypass valve 12 is opened periodically while the fresh water generator is stopped, the inside of the fresh water cartridge 4 is sterilized and sterilized, and the propagation of bacteria in the fresh water cartridge 4 while the fresh water generator is stopped. Can be suppressed.

On the other hand, when the bypass valve 12 is periodically opened during the operation of the fresh water generator, the inside of the fresh water cartridge 4 is sterilized and sterilized, and the bacteria in the fresh water cartridge 4 during the operation of the fresh water generator are changed. Breeding can be suppressed.

The bypass valve 12 may be opened irregularly during the operation of the fresh water generator. In this case, for example, the bypass valve 12 is opened when the quality of the permeated water deteriorates due to propagation of bacteria. Thereby, it is possible to sterilize and sterilize the inside of the fresh water cartridge 4 and to suppress deterioration of the quality of the permeated water.

In addition to the above, at the same time when the suspended desalination operation is resumed (when the desalination unit is restarted), the bypass valve 1 is turned off.
2 may be opened. Alternatively, the bypass valve 12 may be opened at the same time as the suspension of the fresh water production operation (at the same time as the operation of the fresh water generator is stopped). The restart of the fresh water generator in this case may be the time when the main power of the fresh water generator is turned on to operate the control circuit, or the time when the operation switch is turned on after the main power is turned on. It may be. Here, the control circuit includes the timer 10 and the control device 201 of FIG. 1, and includes a bypass valve 12, a flushing valve 9, and a water supply valve 11.
And a circuit for controlling other automatic valves. The operation switch is used to instruct the control circuit to start operation. The stop of the operation is instructed to the control circuit by the stop switch.

When the bypass valve 12 is opened at the time of restarting the operation of the fresh water generator, it is possible to sterilize and sterilize the bacteria propagated in the fresh water cartridge 4 while the operation of the fresh water generator is stopped. In this way, when the operation of the fresh water generator is restarted, the operation is performed with the bypass valve 12 opened, and then the bypass valve 12 is closed to perform the normal operation. This makes it possible to suppress the growth of bacteria in the fresh water cartridge 4 during operation of the fresh water generator.

When the bypass valve 12 is opened at the same time when the operation of the fresh water generator is stopped, it is possible to sterilize and sterilize the bacteria propagated in the fresh water producing cartridge 4 during the operation of the fresh water generator. In this way, after supplying the raw water with the bypass valve 12 open at the same time as the operation of the fresh water generator is stopped, the bypass valve 12 is closed, and the fresh water generator is stopped. Thereby, it is possible to suppress the growth of bacteria in the fresh water cartridge 4 during the stoppage of the operation of the fresh water generator.

During or at the same time as the operation of the fresh water generator, the bypass valve 12 is opened and the fresh water cartridge 4 is opened.
When the raw water containing residual chlorine is supplied, the supplied raw water passes through the fresh water producing cartridge 4 and is discharged to the outside through the concentrated water extracting pipe 7. In this case, for example, by closing the permeated water side path, this raw water is
Is derived to

The time interval for opening the bypass valve 12 is preferably 10 minutes or more and 12 hours or less. If this time interval is longer than 12 hours, the effect of residual chlorine contained in the raw water supplied to the fresh water cartridge 4 through the bypass pipe 13 will be lost, and the propagation of bacteria will be promoted. On the other hand, if the time interval is shorter than 10 minutes, the quality of the permeated water deteriorates.

The opening time of the bypass valve 12 is preferably 5 seconds or more and 5 minutes or less, and 15 seconds or more and 2 minutes or less.
More preferably, it is not more than minutes. If the opening time of the bypass valve 12 is shorter than 5 seconds, the growth of bacteria in the fresh water cartridge 4 cannot be sufficiently suppressed. On the other hand, if the opening time of the bypass valve 12 is longer than 5 minutes, the reverse osmosis membrane in the fresh water producing cartridge 4 may be damaged.

Next, the washing process of the fresh water cartridge 4 will be described. To wash the fresh water cartridge 4, the flushing described below is performed.

At the time of washing, first, the flushing valve 9 provided in the washing water pipe 8 is opened. As a result, a large amount of concentrated water, whose water volume has been suppressed by the pressure regulating valve 6 during the above-described desalination treatment, is discharged to the outside through the washing water pipe 8 in large quantities. Thereby, the membrane surface linear velocity in the reverse osmosis membrane of the fresh water generating cartridge 4 is increased, and the impurities accumulated on the membrane surface can be discharged to the outside of the fresh water generating cartridge 4. In FIG. 1, the flushing valve 9 is controlled by a timer 10, and is set so that the flushing valve 9 is automatically opened for a predetermined time at predetermined time intervals.

For example, the flushing valve 9 may be set to be automatically opened for a predetermined time when the suspended fresh water producing operation is resumed (when the operation of the fresh water producing apparatus is resumed). In this case, after flushing when restarting the operation of the fresh water generator,
Normal operation is performed with the flushing valve 9 closed. Or
The flushing valve 9 may be set to automatically open for a predetermined time at predetermined time intervals during the suspension of the fresh water operation (while the operation of the fresh water operation is stopped).

When the operation of the fresh water generator is restarted, the flushing valve 9
When opening the flushing valve 9 and periodically opening the flushing valve 9 during the stoppage of the operation, the bacteria generated and accumulated in the freshwater generating cartridge 4 during the stoppage of the operation of the freshwater generator,
It becomes possible to discharge contaminant components such as impurities accumulated on the film surface to the outside by flushing.

In addition to the above, the flushing valve 9 may be opened periodically during the operation of the fresh water generator. Or,
After the flushing valve 9 is opened and flushing is performed at the same time when the operation of the fresh water generator is stopped, the flushing valve 9 may be closed to bring the operation to a stopped state. In these cases, it is possible to discharge contaminants such as bacteria generated and accumulated in the fresh water producing cartridge 4 and impurities accumulated on the membrane surface during flushing operation by flushing. During operation of the fresh water generator, the flushing valve 9 may be opened when the quality of the permeated water deteriorates. Thus, even when the flushing valve 9 is opened irregularly during operation of the fresh water generator, the same effect as described above can be obtained.

When the ratio c / d of the time interval c for opening the bypass valve 12 and the time interval d for opening the flushing valve 9 is smaller than 1, raw water containing residual chlorine is frequently supplied to the fresh water producing cartridge 4, and Deterioration of water quality occurs. Therefore, the ratio c / d of the time interval c for opening the bypass valve 12 and the time interval for opening the flushing valve 9 is preferably 1 or more.

In the above fresh water generator, the bypass valve 1
By opening 2, the raw water containing residual chlorine is supplied to the fresh water producing cartridge 4, so that the growth of bacteria in the fresh water producing cartridge 4 can be suppressed. As a result, deterioration of the quality of the permeated water due to propagation of bacteria is prevented.

Further, since the membrane performance of the reverse osmosis membrane of the fresh water producing cartridge 4 can be maintained by the flushing, the quality of the permeated water does not deteriorate even if the linear velocity of the membrane during the desalination treatment is low. Also, the amount of permeated water does not decrease with time. Therefore, as described above, the ratio b / a of the amount a of the raw water supplied to the fresh water cartridge 4 and the amount b of the permeated water obtained from the fresh water cartridge 4 is set to b / a> 0.5. be able to.

On the other hand, in the conventional fresh water generator shown in FIG.
In order to maintain the membrane performance by increasing the membrane surface linear velocity at the time of the desalination treatment by the fresh water cartridge 4, the amount b of the permeated water is reduced as much as possible, and the amount (a−b) of the concentrated water is changed to the amount of the raw water. It is necessary to approach a. For example, if the ratio b / a of the amount b of the permeated water and the amount a of the raw water is made as small as possible, such as 0.1 or 0.2, the membrane surface linear velocity in the reverse osmosis membrane is in a state close to the inlet of the raw water. Will be maintained. However, since the concentrated water is usually discharged as wastewater, if the ratio b / a between the amount b of the permeated water and the amount a of the raw water is small, the amount b of the target permeated water becomes small, which is uneconomical. .

On the other hand, in the fresh water generator shown in FIG. 1, the ratio b / a of the amount b of the permeated water and the amount a of the raw water can be made larger than 0.5 as described above, so that The amount of permeated water is obtained.

Further, the control device 201 controls the operation of the fresh water generator based on the output state of the level detector 150 provided in the permeated water storage tank 200. An amount of permeate can be stored. This makes it possible to appropriately take out and use a necessary amount of permeated water, and to prevent leakage of permeated water due to excessive fresh water production.

As described above, in the above desalination apparatus, since a pressurizing pump is not required, the desalination cost and the price of the desalination apparatus can be suppressed, and efficient desalination treatment can be performed for a long time. Over a long period of time. Therefore, fresh water can be produced at low cost without generating noise.

FIG. 3 is a block diagram showing a second example of the fresh water generator according to the present invention. In the fresh water generator shown in FIG. 3, an activated carbon cartridge 2 is used for pretreatment. Also, 10
The fresh water cartridge 4 is used for desalination.

By connecting ten fresh water producing cartridges 2 in series two by two and making each of the two fresh water producing cartridges 4 connected in series as one unit, five units 1
01 to 105 are configured. 5 units 101 to 1
05 are arranged in parallel.

The raw water supply pipe 1 is connected to the raw water inlet of the fresh water producing cartridge 4 at the preceding stage of each of the units 101 to 105 via a water supply valve 11, an activated carbon cartridge 2 and a pretreatment water supply pipe 3. A bypass pipe 13 is connected to bypass the water supply valve 11 and the activated carbon cartridge 2, and a bypass valve 12 is inserted in the bypass pipe 13. The water supply valve 11 and the bypass valve 12 are composed of automatic valves. The concentrated water outlet of the fresh water cartridge 4 in the preceding stage of each of the units 101 to 105 is connected to the raw water inlet of the fresh water cartridge 4 in the subsequent stage of each of the units 101 to 105 via the concentrated water extracting pipe 7a. Each unit 101-
105, the concentrated water outlet of the fresh water cartridge 4 is connected to the concentrated water outlet pipe 7b via the concentrated water outlet pipe 7b.
It is connected to the. A pressure regulating valve 6 is interposed in each concentrated water outlet pipe 7b. In addition, each pressure regulating valve 6
Each flushing valve 9 is connected in parallel with the washing water pipe 8. The opening and closing operations of the five flushing valves 9 and the bypass valve 12 are controlled independently or simultaneously by a common timer 10. Each unit 101-1
The permeated water outlets of the fresh water cartridges 4 at the front and rear stages of 05 are connected to the permeated water extraction pipe 5 via the permeated water extraction pipes 5a and 5b.

The permeated water extraction pipe 5 is connected to a permeated water storage tank 200. The permeated water storage tank 200 is provided with a level detector 150. In this case, the permeated water tank storage 200 includes the electrode type level detector 1
The permeated water storage tank 200 shown in FIG. 2A provided with 50a or the permeated water storage tank 200 shown in FIG. 2B provided with a float type level detector 150b is used.

The permeated water storage tank 200 may be provided inside the fresh water generator, or may be provided outside. When using the permeated water (treated water) obtained from the fresh water generator, the permeated water outlet 1 of the permeated water storage tank 200 is used.
Take out the permeated water from 55 as appropriate.

When the level of the permeated water in the permeated water storage tank 200 reaches a predetermined height, the output of the level detector 150 turns on or off. Here, it is assumed that when the level of the permeated water in the permeated water storage tank 200 reaches a predetermined height, the output of the level detector 150 is turned on.

The control device 201 controls the opening / closing operation of the water supply valve 11 in response to the output state of the level detector 150.

As the fresh water producing cartridge 4, the reverse osmosis membrane module described in the fresh water producing apparatus of FIG. 1 is used.

The pretreatment and desalination of the fresh water generator shown in FIG. 3 will be described below. During the pretreatment and the desalination treatment, the water supply valve 11 is opened, and the bypass valve 12 and each flushing valve 9 are closed. Also, as the raw water, the raw water described in the fresh water generator of FIG. 1 is used.

In the pretreatment, the raw water supplied from the raw water supply pipe 1 is supplied to the inside of the activated carbon cartridge 2.
In each activated carbon cartridge 2, residual chlorine contained in the supplied raw water is removed. The permeated water of the activated carbon cartridge 2 is supplied as pre-treatment water through the pre-treatment water supply pipe 3 to the inside of the fresh water cartridge 4 in the preceding stage of each of the units 101 to 105. The pretreatment water is supplied to each unit 1
The water is desalinated in the fresh water producing cartridge 4 at the stage 01 to 105 and separated into permeated water from which impurities are removed and concentrated water in which impurities are concentrated. The concentrated water is supplied to each unit 10
Each unit 101-105 is supplied to the inside of the fresh water cartridge 4 of the latter stage through each concentrated water extraction pipe 7a connected to the concentrated water outlet of the fresh water cartridge 4 of the preceding stage. On the other hand, the permeated water is
The water passes through the permeated water outlet pipe 5a connected to the permeated water outlet of the fresh water producing cartridge 4 at the front stage 105, passes through the permeated water outlet pipe 5, and is stored in the permeated water storage tank 200 as treated water.

In the fresh water cartridge 4 at the subsequent stage of each of the units 101 to 105, the concentrated water of the fresh water cartridge 4 at the previous stage is further desalted and separated into permeated water from which impurities are removed and concentrated water in which impurities are concentrated. Is done. The permeated water passes through each permeated water outlet pipe 5b connected to the permeated water outlet of the fresh water producing cartridge 4 at the subsequent stage of each of the units 101 to 105, further passes through the permeated water outlet pipe 5,
The treated water is stored in a permeated water storage tank 200. On the other hand, the concentrated water passes through each concentrated water outlet pipe 7b connected to the concentrated water outlet of the fresh water cartridge 4 at the subsequent stage of each of the units 101 to 105, and further passes through the concentrated water outlet pipe 7b.
Is discharged to the outside through Each pressure regulating valve 6 provided in each concentrated water extraction pipe 7b is connected to each unit 101.
It is set so that the concentrated water in the fresh water producing cartridges 4 in the preceding and subsequent stages of -105 is less than a predetermined amount. This suppresses the amount of concentrated water and increases the amount of permeated water.

Here, the amount a of the raw water supplied to the fresh water cartridge 4 at the front stage of each of the units 101 to 105, the fresh water cartridge 4 at the front stage, and the fresh water cartridge 4 at the rear stage
B / a with the amount b of the permeated water obtained from
Each pressure regulating valve 6 is set to 0.5. In this case, the permeated water can be obtained at a recovery rate higher than 50% with respect to the supplied raw water, so that it is efficient and economical.

As described above, in the above fresh water generator,
Raw water having a pressure of 3 kgf / cm ² or less is supplied to each of the units 101 to 105 without power using a pressure pump.
It is possible to supply the water to the fresh water cartridges 4 of the first and second stages of the above to efficiently desalinate.

In the above fresh water generator, the permeated water storage tank 2
At 00, when a sufficient amount of permeated water is stored and the level (water level) of the permeated water reaches a predetermined height, the level detector 150
Is turned on. The control device 201 closes the water supply valve 11 in response to the output of the level detector 150 being turned on, and stops the operation of the fresh water generator.

On the other hand, when the level of the permeated water in the permeated water storage tank 200 falls below a predetermined height due to the use of the permeated water, the output of the level detector 150 is turned off. The control device 201 opens the water supply valve 11 in response to the output of the level detector 150 being turned off, and restarts the operation of the fresh water generator.

As described above, in the above fresh water generator,
The operation is controlled according to the level of the permeated water in the permeated water storage tank 200. Therefore, the permeated water storage tank 200
Inside, it is possible to maintain a constant amount of permeated water.

The bypass valve 12 is controlled by the timer 10 so that the bypass valve 12 is automatically opened for a predetermined time during the suspension of the fresh water producing operation, or at predetermined time intervals during the fresh water producing operation. The bypass valve 12 is set to automatically open at predetermined time intervals. When the bypass valve 12 is open, the water supply valve 11 is closed.

As a result, raw water containing residual chlorine having a sterilizing effect is supplied into the fresh water cartridge 4 through the bypass pipe 13. As a result, fresh water cartridge 4
The proliferation of bacteria inside can be suppressed.

When the bypass valve 12 is opened periodically during the suspension of the fresh water producing operation (while the operation of the fresh water producing device is stopped), the inside of the fresh water producing cartridge 4 is sterilized and sterilized, and the fresh water produced during the operation of the fresh water producing device is stopped. Proliferation of bacteria in the water cartridge 4 can be suppressed.

On the other hand, when the bypass valve 12 is opened periodically during the fresh water producing operation (during the operation of the fresh water producing device), the inside of the fresh water producing cartridge 4 is sterilized and sterilized, and the fresh water produced during the operation of the fresh water producing device is produced. Proliferation of bacteria in the cartridge 4 can be suppressed.

The bypass valve 12 may be opened irregularly during the operation of the fresh water generator. In this case, for example, the bypass valve 12 is opened when the quality of the permeated water deteriorates due to propagation of bacteria. Thereby, it is possible to sterilize and sterilize the inside of the fresh water cartridge 4 and to suppress deterioration of the quality of the permeated water.

In addition to the above, the bypass valve 12 may be opened when the suspended fresh water production is resumed (when the operation of the fresh water generator is resumed), or simultaneously with the suspension of the fresh water production (fresh water production). The bypass valve 12 may be opened at the same time as the operation stoppage. In this case, the restart of the fresh water production operation is as described above in the fresh water generator shown in FIG.

When the bypass valve 12 is opened when the operation of the fresh water generator is resumed, it is possible to sterilize and sterilize the bacteria that have propagated in the fresh water cartridge 4 while the operation of the fresh water generator is stopped. After the operation of the fresh water generator with the bypass valve 12 opened at the start of the operation, the bypass valve 1
2 is closed and normal operation is performed. This makes it possible to suppress the growth of bacteria in the fresh water cartridge 4 during operation of the fresh water generator.

When the bypass valve 12 is opened at the same time when the operation of the fresh water generator is stopped, it is possible to sterilize and sterilize the bacteria propagated in the fresh water producing cartridge 4 during the operation of the fresh water generator. After supplying raw water with the bypass valve 12 opened at the same time as the operation of the fresh water generator is stopped in this way,
The bypass valve 12 is closed, and the fresh water generator is stopped. Thereby, it is possible to suppress the growth of bacteria in the fresh water cartridge 4 during the stoppage of the operation of the fresh water generator.

During or at the same time as the operation of the fresh water generator, the bypass valve 12 is opened and the fresh water cartridge 4 is opened.
When the raw water containing residual chlorine is supplied, the supplied raw water passes through the fresh water producing cartridge 4 and is discharged to the outside through the concentrated water extracting pipe 7. In this case, for example, by closing the permeated water side path, this raw water is led out to the concentrated water extraction pipe 7.

Next, a description will be given of a process of cleaning the fresh water cartridges 4 at the front and rear stages of each of the units 101 to 105. Flushing is performed for washing the fresh water cartridge 4.

At the time of washing, first, the flushing valve 9 provided in each washing water pipe 8 is opened simultaneously. As a result, a large amount of concentrated water, whose water volume has been suppressed by the pressure regulating valve 6 during the above-described desalination treatment, is discharged to the outside in large quantities through the respective washing water pipes 8 and the concentrated water removal pipes 7.
As a result, the membrane surface linear velocity in the reverse osmosis membrane of the fresh water cartridge 4 at the front and rear stages of each of the units 101 to 105 is increased, and the impurities accumulated on the membrane surface are discharged to the outside of the fresh water cartridge 4 at the front and rear stages. It is possible to do. In FIG. 2, each flushing valve 9 is controlled by a common timer 10, and is set so that each flushing valve 9 is simultaneously opened for a predetermined time at predetermined time intervals.

For example, each flushing valve 9 may be set to be automatically opened for a predetermined time when the suspended fresh water producing operation is resumed (when the operation of the fresh water producing apparatus is resumed). In this way, after flushing is performed when the operation of the fresh water generator is restarted, each flushing valve 9 is closed and normal operation is performed. Alternatively, the flushing valve 9 may be set to be automatically opened for a predetermined time at predetermined time intervals during the suspension of the fresh water production operation (while the operation of the fresh water generator is stopped).

When each flushing valve 9 is opened when the operation is restarted, and when each flushing valve 9 is opened periodically during the operation stop, bacteria generated and accumulated in the fresh water producing cartridge 4 while the operation of the fresh water generator is stopped, Contamination components such as impurities accumulated on the film surface can be discharged to the outside by flushing.

In addition to the above, each flushing valve 9 may be opened periodically during operation of the fresh water generator. Alternatively, after the flushing valves 9 are opened and flushing is performed at the same time when the operation of the fresh water generator is stopped, the flushing valves 9 may be closed to bring the operation to a stopped state. In these cases, it is possible to discharge contaminants such as bacteria generated and accumulated in the fresh water producing cartridge 4 and impurities accumulated on the membrane surface during flushing operation by flushing. During operation of the fresh water generator, the flushing valve 9 may be opened when the quality of the permeated water deteriorates.
Thus, even when the flushing valve 9 is opened irregularly during operation of the fresh water generator, the same effect as described above can be obtained.

The time interval for opening the bypass valve 12, the time for opening the bypass valve, and the ratio c / to the time interval c for opening the bypass valve 12 and the time interval d for opening the flushing valve 9
d is as described above in the fresh water generator shown in FIG.

In the above fresh water generator, the bypass valve 1
By opening 2, the raw water containing residual chlorine is supplied to the ten fresh water cartridges 4, so that the growth of bacteria in the fresh water cartridge 4 can be suppressed. As a result, deterioration of the quality of the permeated water due to propagation of bacteria is prevented.

Further, each unit 10 is flushed.
Since it is possible to maintain the membrane performance of the reverse osmosis membranes of the fresh water cartridges 4 in the first and second stages 1 to 105, the water quality of the permeated water is deteriorated even if the linear velocity of the membrane surface in the desalination process is small. And the amount of permeated water does not decrease with time. Therefore, as described above, the ratio b / of the amount a of the raw water supplied to the fresh water producing cartridge 4 at the front stage of each of the units 101 to 105 and the amount b of the permeated water obtained from the fresh water producing cartridges 4 at the front and rear stages is used. a can be set to b / a> 0.5.

Further, the control device 201 controls the operation of the fresh water generator based on the output state of the level detector 150 provided in the permeated water storage tank 200. An amount of permeate can be stored. This makes it possible to appropriately take out and use a necessary amount of permeated water, and to prevent leakage of permeated water due to excessive fresh water production.

As described above, in the above-mentioned fresh water generator, a pressurizing pump is not required, so that the fresh water cost and the price of the fresh water generator can be suppressed, and efficient desalination treatment can be performed for a long time. Over a long period of time. Therefore, fresh water can be produced at low cost without generating noise.

The fresh water generator shown in FIG. 3 is an example of a configuration in which a plurality of fresh water cartridges 4 are provided.
Other configurations are also possible. When a plurality of fresh water producing cartridges 4 are provided in parallel or in series, each fresh water producing cartridge 4 may have a built-in flushing valve. A valve may be provided. Further, a unit in which a flushing valve is provided at the end of a connecting portion of a concentrated water outlet pipe of a predetermined number of fresh water cartridges 4 arranged in parallel or in series is regarded as one unit, and a plurality of units are arranged in parallel or in series. May be.

For example, as a third example of the fresh water generator according to the present invention, as shown in FIG.
The raw water inlets of the fresh water producing cartridges 4 of the first stage 05 are respectively connected to the common activated carbon cartridge 2 via the on-off valves 15, and the common pressure adjustment is made to the concentrated water outlets of the fresh water producing cartridges 4 of the subsequent stage of the five units 101 to 105. A valve 6 and a flushing valve 9 may be provided. As a fourth example of the fresh water producing apparatus according to the present invention, as shown in FIG. 5, two fresh water producing cartridges 4 of units 101 to 105 are connected in parallel, and two fresh water producing cartridges 4 connected in parallel are provided. The raw water inlet of the water cartridge 4 may be connected to the common raw water supply pipe 1 via the activated carbon cartridge 2 and the common water supply valve 11, respectively. Further, the fifth aspect of the fresh water generator according to the present invention.
As an example of each, as shown in FIG.
05 are connected in parallel, the raw water inlet of each of the two fresh water cartridges 4 connected in parallel is connected to the common activated carbon cartridge 2 via the on-off valve 15, and the five units 101 to A common pressure regulating valve 6 and a flushing valve 9 may be provided at the concentrated water outlet of the fresh water cartridge 4 of 105. As a sixth example of the fresh water generator according to the present invention, as shown in FIG. 7, in each of the units 101 to 105, the permeated water extraction pipe 5 a of the fresh water cartridge 4 of the preceding stage The two fresh water producing cartridges 4 of each unit 101 to 105 are connected in series, and the raw water inlet of the fresh water producing cartridge 4 in the preceding stage of the five units 101 to 105 is connected to the common activated carbon cartridge 2, A pressure regulating valve 6 and a flushing valve 9 which are common to the concentrated water outlet of the fresh water producing cartridge 4 in the preceding stage of the two units 101 to 105.
May be provided, and a common pressure adjusting valve 6 and a flushing valve 9 may be provided at the concentrated water outlet of the fresh water producing cartridge 4 at the subsequent stage of the five units 101 to 105. Third above
Also in the sixth to sixth examples, the permeated water extraction pipe 5 is connected to the permeated water storage tank 200, and the operation of the fresh water generator is controlled by the control device 201 according to the permeated water level in the permeated water storage tank 200. You.

FIG. 8 is a configuration diagram showing a seventh example of the fresh water generator according to the present invention. The fresh water generator shown in FIG. 8 has the same configuration as the fresh water generator shown in FIG. 1 except for the following points.

In the fresh water generator shown in FIG. 8, a permeated water discharge pipe 51 in which a permeated water discharge valve 52 is inserted is connected to a permeated water extraction pipe 5. Further, a permeated water extraction valve 50 is interposed in the permeated water extraction pipe 5.
In this case, the permeate extraction valve 50 and the permeate discharge valve 5
Reference numeral 2 may be an automatic valve, and the opening / closing operation may be controlled independently or simultaneously by a timer or the like.

In the fresh water generator shown in FIG. 8, pretreatment and desalination are performed in the same manner as in the fresh water generator shown in FIG. In addition, at the time of pretreatment and desalination treatment, while opening the permeate extraction valve 50 of the permeate extraction pipe 5,
The permeated water discharge valve 52 of the permeated water discharge pipe 51 is closed.

In the above fresh water generator, 0.3 kgf
Raw water having a pressure of not less than / cm ^{2 and not} more than 3 kgf / cm ² can be supplied to the fresh water producing cartridge 4 without using a pressurizing pump without power and can be desalted efficiently.

The pressure b is set so that the ratio b / a of the amount a of the raw water supplied to the fresh water cartridge 4 and the amount b of the permeated water obtained from the fresh water cartridge 4 becomes b / a> 0.5. Since the regulating valve 6 is set, the supply water 5
Permeate is obtained with a recovery greater than 0%. Therefore,
Efficient and economical.

In the above fresh water generator, the control unit 201 is controlled in accordance with the level of the permeated water in the permeated water storage tank 200.
The operation is controlled by. Therefore, it is possible to maintain a constant amount of permeated water in the permeated water storage tank 200.

Further, similarly to the fresh water generator shown in FIG. 1, raw water containing residual chlorine is supplied into the fresh water cartridge 4 through the bypass pipe 13, and sterilization and sterilization of the fresh water cartridge 4 are performed. As a result, fresh water cartridge 4
The proliferation of bacteria inside can be suppressed.

Here, when the bypass valve 12 is opened at the same time when the operation of the fresh water generator is stopped, and when the bypass valve 12 is periodically opened while the operation of the fresh water generator is stopped, the bypass piping 13
After passing through the fresh water producing cartridge 4, the raw water supplied through the permeate water discharge pipe 5 and the permeated water discharge pipe 51 may be discharged to the outside. In this case, while closing the permeate extraction valve 50 of the permeate extraction pipe 5,
The permeated water discharge valve 52 of the permeated water discharge pipe 51 is opened. Thereby, the permeated water extraction pipe 5 is sterilized and sterilized by the raw water containing residual chlorine. As a result, it is possible to suppress the growth of bacteria in the permeated water extraction pipe 5 while the operation of the fresh water generator is stopped, and to prevent contamination components from being mixed into the permeated water extracted from the permeated water extraction pipe 5. It becomes possible.

The time interval for opening the bypass valve 12 and the time for opening the bypass valve 12 are the same as described above in the fresh water generator shown in FIG.

In the above fresh water generator, flushing is performed through the washing water pipe 8 in the same manner as in the fresh water generator shown in FIG. Thereby, fresh water cartridge 4
It is possible to discharge impurities retained on the membrane surface of the fresh water producing cartridge 4 to the outside.

The ratio c / d of the time interval c for opening the bypass valve 12 and the time interval d for opening the flushing valve 9 is as described above in the fresh water generator shown in FIG.

Further, in the above fresh water generator, when the suspended fresh water producing operation is resumed (when the operation of the fresh water generator is restarted), the permeated water discharge valve 52 is opened and the permeated water outlet valve 50 is closed. Operate in the state. In this case, the permeated water of the fresh water producing cartridge 4 is discharged outside through the permeated water discharge pipe 51. After the permeated water discharge valve 52 is opened to discharge the permeated water when the operation of the fresh water generator is restarted in this manner,
Close the permeate discharge valve 52 and the permeate discharge valve 5
Open 0 and perform normal operation.

By discharging the permeated water as described above, contaminant components such as bacteria generated and accumulated in the fresh water cartridge 4 and the permeated water discharge pipe 5 during the operation of the fresh water generator are removed together with the permeated water to the outside. Can be discharged to As a result, it is possible to remove the contaminant components in the fresh water producing cartridge 4 and the permeated water extraction pipe 5, and to prevent the contamination components from being mixed into the permeated water extracted through the permeated water extraction pipe 5. It becomes possible.

In the above-mentioned fresh water generator, the raw water containing residual chlorine is supplied to the fresh water cartridge 4 by opening the bypass valve 12 periodically.
The proliferation of bacteria inside can be suppressed. As a result, deterioration of the quality of the permeated water due to propagation of bacteria is prevented.

Further, since the membrane performance of the reverse osmosis membrane of the fresh water generating cartridge 4 can be maintained by the flushing, the quality of the permeated water does not deteriorate even if the linear velocity of the membrane surface during the desalination treatment is low. Also, the amount of permeated water does not decrease with time. Therefore, as described above, the ratio b / a of the amount a of the raw water supplied to the fresh water cartridge 4 and the amount b of the permeated water obtained from the fresh water cartridge 4 is set to b / a> 0.5. And an economical amount of permeated water can be obtained.

Further, the control device 201 controls the operation of the fresh water generator based on the output state of the level detector 150 provided in the permeated water storage tank 200. An amount of permeate can be stored. This makes it possible to appropriately take out and use a necessary amount of permeated water, and to prevent leakage of permeated water due to excessive fresh water production.

Further, the above-mentioned discharge of the permeated water makes it possible to discharge the contaminated components in the fresh water producing cartridge 4 and the permeated water extraction pipe 5 to the outside. As a result, the membrane performance of the reverse osmosis membrane of the fresh water producing cartridge 4 can be maintained, and the deterioration of the quality of the permeated water can be prevented.

As described above, in the above desalination apparatus, since a pressurizing pump is not required, desalination cost and price of the desalination apparatus can be suppressed, and efficient desalination treatment can be performed for a long time. Over a long period of time. Therefore, fresh water can be produced at low cost without generating noise.

In the above, the case where the permeated water discharge valve 52 is opened when the operation of the fresh water generator is restarted has been described.
The permeated water discharge valve 52 may be opened periodically while the operation of the fresh water generator is stopped. Also in this case, it is possible to discharge contaminants such as bacteria generated and accumulated in the fresh water cartridge 4 and the permeated water extraction pipe 5 to the outside while the fresh water generator is stopped operating.

Further, in the above description, the fresh water producing device composed of one fresh water producing cartridge 4 has been described.
A fresh water generator having a configuration in which a plurality of fresh water cartridges 4 are provided in parallel or in series is also possible.

When a plurality of fresh water producing cartridges 4 are provided in parallel or in series, a permeated water discharge valve 5
2 is connected to the permeated water discharge pipe 51. Further, a permeated water extraction valve 50 is inserted into the permeated water extraction pipe 5 downstream of the connection portion of the permeated water discharge pipe 51. Further, the above-described permeated water discharge pipe 51, permeated water discharge valve 52, and permeated water discharge valve 50 are provided at the end of the connection portion of the permeated water discharge pipes 5 of the predetermined number of fresh water cartridges 4 arranged in parallel or in series. These units may be regarded as one unit, and a plurality of units may be arranged in parallel or in series. Also in these cases, similarly to the fresh water generator shown in FIG. 7, a pressurizing pump is not required, and the cost of fresh water and the price of the fresh water generator can be suppressed. It can be performed stably. Therefore, fresh water can be produced at low cost without generating noise.

The treated water obtained by the above fresh water generator may be used as washing water. Here, the cleaning water is used for improving the cleaning effect and for preventing generation of surface residues at the time of drying after cleaning. Further, the obtained treated water is softened for boiler,
Soft water for food production, agricultural water for hydroponics, laboratory pure water,
It may be used for humidifier water or drinking water. further,
This treated water may be supplied to an ion exchanger or a continuous electric regeneration ion exchanger. In this case, since the purity of the treated water is further increased, ultrapure water is obtained. In addition, the continuous electric regeneration ion exchange device described here is a device that continuously performs ion exchange by applying current from the outside, such as electrodialysis without using an ion exchange membrane or electrodialysis using an ion exchange membrane. Means

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first example of a fresh water generator according to the present invention.

FIG. 2 is a schematic sectional view showing an example of a permeated water storage tank provided in the fresh water generator according to the present invention.

FIG. 3 is a configuration diagram showing a second example of the fresh water generator according to the present invention.

FIG. 4 is a configuration diagram showing a third example of a fresh water generator according to the present invention.

FIG. 5 is a configuration diagram showing a fourth example of a fresh water generator according to the present invention.

FIG. 6 is a configuration diagram showing a fifth example of a fresh water generator according to the present invention.

FIG. 7 is a configuration diagram showing a sixth example of a fresh water generator according to the present invention.

FIG. 8 is a configuration diagram showing a seventh example of a fresh water generator according to the present invention.

FIG. 9 is a configuration diagram showing an example of a conventional fresh water generator provided with a pressure pump.

[Explanation of symbols]

 Reference Signs List 2 activated carbon cartridge 4 fresh water cartridge 6 pressure regulating valve 9 flushing valve 11 water supply valve 12 bypass valve 51 permeate discharge pipe 52 permeate discharge valve 150 level detector 150a electrode type level detector 150b float type level detector 200 permeate storage Tank 201 control device

Claims (10)

[Claims] 1. A water supply cartridge having a reverse osmosis membrane, a supply system for supplying a liquid to be treated having a predetermined pressure without a pressure increasing means for increasing the pressure of the liquid to be treated is provided. A processing liquid take-out path is connected to the processing liquid storage tank, and a level detector that detects a level of the processing liquid in the processing liquid storage tank and a control unit that controls the supply system in response to an output of the level detector are provided. A desalination apparatus characterized by being provided. 2. The processing apparatus according to claim 1, wherein the level detector detects whether or not the level of the processing liquid in the processing liquid storage tank has reached a predetermined height. 2. The supply of the liquid to be treated to the fresh water producing cartridge by the supply system is stopped when the level detector detects that the level of the liquid has reached the predetermined height. Fresh water generator. 3. The control system according to claim 2, wherein the supply system supplies the fresh water cartridge with the supply system when the level detector does not detect that the level of the processing liquid in the processing liquid storage tank has reached the predetermined height. The fresh water generator according to claim 1 or 2, wherein the liquid to be treated is supplied. 4. A pretreatment device for removing residual chlorine contained in the liquid to be treated is provided at a stage preceding the fresh water cartridge, and a bypass path is provided so as to bypass the pretreatment device. The fresh water generator according to any one of claims 1 to 3, wherein an opening / closing means for opening / closing the bypass path is provided. Wherein said fresh water generator according to claim 1, the liquid to be treated and having a pressure of 0.3 kgf / cm ² or more 3 kgf / cm ² or less. 6. The fresh water generator according to claim 1, further comprising a flushing means for flushing a reverse osmosis membrane of the fresh water cartridge. 7. The fresh water producing cartridge according to claim 1, wherein a plurality of fresh water producing cartridges are provided in parallel and / or in series.
A fresh water generator according to any one of claims 1 to 6. 8. A processing liquid having a predetermined pressure is supplied to a fresh water cartridge provided with a reverse osmosis membrane without passing through a pressure increasing means, and the processing liquid of the fresh water cartridge is stored in a processing liquid storage tank. A fresh water producing method, wherein the supply of the liquid to be treated to the fresh water cartridge is controlled according to the level of the treatment liquid in the treatment liquid storage tank. 9. The liquid to be treated is supplied to the fresh water cartridge via a pretreatment device for removing residual chlorine, and the liquid to be treated is passed through the pretreatment device at a predetermined timing. The fresh water producing method according to claim 8, wherein the fresh water is supplied to a fresh water producing cartridge. 10. The fresh water producing method according to claim 8, wherein the reverse osmosis membrane of the fresh water producing cartridge is flushed at a predetermined timing.