JPH10174817A - Water purifying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively use a concentrated water at the second filter means and to save an energy such as electric power by sending the primary treated water treated at the first filter means to the second filter means with a high pressure water sending means and communicating the concentrated water from the second filter means to an upstream side of the first filter means through an opening and closing means. SOLUTION: A desalting device 1 is provided with for example, one filter 2 and one reverse osmotic membrane module 3 disposed at its downstream are provided, and a boosting pump 4 sending a seawater sent with an intake pump P to the filter 2 in need. A piping 6 in which a high pressure pump 5 sending the primary treated water filtered with the filter 2 to the reverse osmotic membrane module 3 is arranged is connected at the downstream of the filter 2. A discharge pipe 9 of the secondary concentrated water is connected to the primary side of the reverse osmotic membrane module 3, and the piping 10 for back washing is connected to the filter 2 by branching from the discharge pipe 9 through the opening and closing means 11. The high pressure primary treated water is sent to the reverse osmotic membrane module 3 with the high pressure pump 5 and the pump sending water for back washing is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a water purification device. More specifically, the present invention relates to a purification device for producing useful purified water such as drinking water, using not only desalination of seawater but also river water, pond water, swimming pool water, muddy water and the like as raw water.

[0002]

2. Description of the Related Art FIG. 4 shows an example of a seawater desalination apparatus, which is a kind of water purification apparatus and usually has a first filtration means and a second filtration means. The desalination apparatus 51 includes one filter 5 as a first filtration means.
2 and one reverse osmosis membrane module 53 as a second filtration means provided downstream thereof. Further, a booster pump 54 for feeding the seawater sent by the water intake pump P to the filter 52 is provided. L is a seawater supply pipe. The boost pump 54 is unnecessary when the desalination device 51 is installed at a place close to the seawater source.

[0003] The filter 52 is a publicly known one, and functions as a so-called pre-treatment unit, and incorporates sand or so-called anthracite as a filter material. This filter 52 removes suspended matter, large-sized bacteria, and the like from the raw water.

A reverse osmosis membrane module 53 is also known, and removes finer bacteria, heavy metals, salts and the like from filtered water (primary treated water) treated by a filter 52.

[0005] An open-type (in some form of communication with the atmosphere) filtrate water tank 55 is provided downstream of the filter 52 for temporarily storing primary treated water. Filtration water pump 56 and high-pressure pump 5 for sending primary treatment water to membrane module 53
7 is connected.

[0006] The filtered water tank 55 is provided for the purpose of using primary treated water to backwash the filter 52 as necessary. Therefore, the backwash pump 59 for sending the primary treated water from the filtrate tank 55 to the secondary side of the filter.
Are connected.

[0007] The filtered water pushing pump 56 is provided to prevent the high pressure pump 57 from entraining the air in the filtered water tank 55.

Downstream of the reverse osmosis membrane module 53, a production water tank 61 for storing the production water treated by the reverse osmosis membrane module 53 is provided. A production water supply pump 62 is provided.

Reference numeral 63 denotes a discharge pipe for discharging the backwash water after backwashing the filter 52. Reference numeral 64 denotes a drain pipe for secondary concentrated water.

[0010] The treated water is water filtered by passing through a filter or a reverse osmosis membrane in a filter or a reverse osmosis membrane module. In addition, the concentrated water is water remaining in the reverse osmosis membrane module without passing through the reverse osmosis membrane.

The above desalination apparatus 51 (FIG. 4) is referred to as a first prior art.

A desalination apparatus 65 according to another conventional example shown in FIG. 5 has two filters 521, 52 as first filtration means.
2 is provided. The filters 521 and 522 use a known hollow fiber bundle 523, and further include a compressor 66 and a blower 67 for backwashing. At the time of back washing, first, the hollow fiber bundle 5 is compressed by the compressor 66.
The water in 23 is pushed out to the primary side to make it lighter, and then air is blown into the primary side water by a blower 67 to bubbling (called bubbling) to shake the hollow fiber bundle 523, to drain impurities after washing out the impurities on the outer surface thereof. It is.

When one filter 521 (522) is backwashed, the supply of raw water to the filter 521 (522) is stopped, but the raw water treatment of the other filter 522 (521) is continued, and the desalination operation is performed. Is not interrupted.

The other structure is the same as that of the desalination apparatus 51 (FIG. 4). That is, an open-type filtered water tank 55 for temporarily storing the primary treated water is installed downstream of the filters 521 and 522, and filtration for sending the primary treated water from the filtered water tank 55 to the reverse osmosis membrane module 53 is provided. Piping 58 provided with a water push pump 56 and a high pressure pump 57
Is connected.

However, the filtration water tank 55 is
A water filling pump 68 is provided in a pipe 60 connected to each of the pipes 1 and 522. The water filling pump 68 is used to supply primary treated water from the filtered water tank 55 to the primary side of the filters 521 and 522 after backwashing to fill the primary side. This is because, after the backwash, the primary side of the filter has no water and is filled with air, so that it is necessary to fill the water to restart the operation.

The above desalination apparatus 65 (FIG. 5) is referred to as a second prior art.

[0017]

However, in both the first prior art and the second prior art, downstream of the filters 52, 521, 522 due to backwashing (first prior art) and filling with water (second prior art). In such a case, an open-type filtered water tank 55 must be provided, which causes problems such as an increase in equipment cost and the intrusion of external foreign matter into water. In addition, installation costs, such as piping from the filtrate tank 55 to the filter and the installation of the pump 59, further increase the equipment cost.

In the first prior art, since water circulates in the filtered water tank 55 and the filter 52 through the pipe 60 during backwashing, the water intake pump P and the pressure increase pump 5
It is necessary to lower the flow rate of 4 and stabilize the amount of water supplied to the filter 52, which makes it difficult to adjust the discharge force (flow rate adjustment) of the pump.

In the second prior art, the primary treated water treated by the filters 521 and 522, which are the first treatment means, is used for backwashing and water filling. At the time of water filling, intake pump P and booster pump 5
It is necessary to increase the output of No. 4 to keep the feed rate of raw water constant, which makes it difficult to adjust the flow rate.

On the other hand, it is conceivable to use finally produced water for backwashing and filling the filters 52, 521 and 522, but using valuable production water leads to further cost increase. In addition, it is not practical because water supply equipment (pumps and piping) from the production water tank 61 to the filters 52, 521, and 522 is required.

On the other hand, considering that the raw water is used for backwashing and filling, a tank for storing the collected raw water and a water supply facility for sending water to the filters 52, 521, and 522 are required. Furthermore, it is difficult to control the amount of water supplied to the pump as described above.

[0022]

SUMMARY OF THE INVENTION A water purifying apparatus according to the present invention comprises a first filtering means, a second filtering means, a water intake means for feeding raw water to the first filtering means, and a first filtering means. High pressure water supply means for sending the primary treated water treated by the second filtration means, and a pipe for communicating the concentrated water from the second filtration means to the upstream side of the first filtration means via the opening and closing means. I have.

With this configuration, the concentrated water in the second filtration means, which has been conventionally discharged, can be effectively used, and energy such as electric power can be saved. Further, since a conventional filtered water tank and a water-filled pump are not required, equipment costs are reduced, and operation costs are further reduced. Further, since the open-type filtered water tank becomes unnecessary, invasion of foreign matter from the outside is prevented.

According to another water purifying apparatus of the present invention, in the water purifying apparatus, the concentrated water in the second filtering means is supplied to the upstream side of the filtering section of the first filtering means after backwashing and draining for water filling. It is characterized in that piping for arranging is provided.

With this configuration, similarly to the water purification apparatus of the present invention, the equipment cost is reduced, the operation cost is further reduced, and intrusion of foreign matter from the outside is prevented.

In the above water purifying apparatus, a plurality of the first filtering means are provided in parallel, and the pipes from the second filtering means are connected to the respective first filtering means via a first switching mechanism. In a water purifying apparatus in which a pipe for supplying raw water to the first filtration means is connected to each first filtration means via the second switching mechanism, the above-described operation and effect can be obtained. Of course, when backwashing some of the first filtration means, stop sending raw water to the first filtration means,
The purification treatment by the other first filtration means is continued, and the production water production operation is not interrupted. Furthermore, it is preferable in that it is not necessary to adjust the flow rate which is difficult for various water supply means such as a pump.

In this water purifying apparatus, an internal pressure detecting means for detecting the internal pressure of the first filtering means is provided, and the internal pressure detecting means makes the internal pressure of one first filtering means reach a predetermined pressure. If the first switching mechanism is configured to stop supplying concentrated water from the second filtration means to the first filtration means based on the detection of the When the first filtration means is filled with water, the water pressure required for restarting the production water production operation can be compensated, so that the operation can be switched without causing pressure fluctuation of the device.

In the water purifying apparatus, the first switching mechanism may switch the second filtering means based on the fact that the internal pressure detecting means detects that the internal pressure of the first filtering means has reached a predetermined pressure. Stopping supplying the concentrated water to the one first filtration means, and thereafter, the second switching mechanism is configured to switch to feed the raw water to the one first filtration means. That is, a smooth and stable continuous operation can be performed.

As the internal pressure detecting means, for example, a water level gauge or a pressure gauge installed in the first filtering means, or a pressure gauge installed in the pipe connecting the second filtering means and the first filtering means is used. it can.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a water purifying apparatus according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a flowchart showing one embodiment of the water purification apparatus of the present invention, FIG. 2 is a flowchart showing another embodiment of the water purification apparatus of the present invention, and FIG. 3 is a water purification apparatus of the present invention. 15 is a flowchart showing a main part of still another embodiment of FIG.

The desalination apparatus 1 shown in FIG. 1 has one filter 2 and one reverse osmosis membrane module 3 installed downstream thereof.
And a booster pump 4 for feeding the seawater sent by the water intake pump P to the filter 2 as necessary. The primary effluent filtered by the filter 2 is provided downstream of the filter 2 in reverse osmosis. A pipe 6 provided with a high-pressure pump 5 for sending to the membrane module 3 is connected to the reverse osmosis membrane module 3.
Water tank 7 for storing secondary treated water (product water)
In addition, it is common to the conventional desalination apparatus 51 (see FIG. 4) in a range where the production water supply pump 8 for taking out the production water from the production water tank 7 is provided. In addition, L is a raw water supply pipe.

However, the desalination apparatus 1 differs from the conventional desalination apparatus 51 in that the backwash water is collected from the reverse osmosis membrane module 3.

That is, a drain pipe 9 of the secondary concentrated water is connected to the primary side of the reverse osmosis membrane module 3, and a pipe 10 for back washing is connected to the filter 2 branching from the drain pipe 9. ing. Since high-pressure primary treated water is sent to the reverse osmosis membrane module 3 by the high-pressure pump 5, a pump is required to send the high-pressure water (generally, about 56 kg / cm ² G) to the filter 2 for backwashing. And not. Simply plumbing 1
It is only necessary to provide the stop valve 11 at 0. Of course, it is the same as the prior art in that the intake pump P and the booster pump 4 need to be adjusted, but the secondary concentrated water can be used effectively, and the conventional filtrate tank 55 and the reverse water tank 55 shown in FIG. Since the washing pump 59 is not required, equipment costs and operation costs are reduced. Furthermore, the open type filtered water tank 5
Since the step 5 becomes unnecessary, invasion of foreign matter from the outside is prevented.

The desalination apparatus 21 shown in FIG. 2 is provided with a booster pump 4 if necessary, and has two filters 221 and 22.
2, a backwash compressor 23 and a blower 24, a reverse osmosis membrane module 3, and a high-pressure pump 5 for sending primary treatment water from the filters 221 and 222 to the reverse osmosis membrane module 3. The pipe 6 is connected,
A production water tank 7 for storing the production water is provided, a production water supply pump 8 for appropriately taking out the production water is provided, and the filters 221 and 222 and the reverse osmosis membrane module 3 are provided.
And a drain pipe 2 for discharging the concentrated water therefrom.
5 and 26 are connected to the conventional desalination apparatus 6.
5 (see FIG. 5). In addition, L is a raw water supply pipe.

Therefore, in the present desalination apparatus 21, when one filter 221 (222) is backwashed, the supply of the raw water to the filter 221 (222) is stopped, but the other filter 222 (221) is stopped. Is continued so that the desalination operation is not interrupted.

However, the desalination apparatus 21 differs from the conventional desalination apparatus 65 in that the water for backfilling after the backwash is collected from the reverse osmosis membrane module 3.

That is, the drain pipe 26 of the secondary concentrated water is connected to the primary side of the reverse osmosis membrane module 3. The drain pipe 26 is branched from the drain pipe 26, and each of the filters 221 and 222 is provided with a drain pipe 27. Is connected.

As in the desalination apparatus 1 according to the above-described embodiment, since high-pressure primary treated water is sent to the reverse osmosis membrane module 3 by the high-pressure pump 5, the high-pressure water (generally, about 56 kg / cm ² G) is supplied. No pump is required to send water to the filter 2 for filling. It is only necessary to provide the stop valves 32 and 28 on the drain pipe 26 and the water filling pipe 27 simply.

According to the desalination apparatus 21, the secondary concentrated water can be effectively used, and the conventional filtered water tank 55 and the water filling pump 59 shown in FIG.
Equipment and operating costs are reduced. Further, since the open-type filtered water tank 55 becomes unnecessary, invasion of foreign matter from the outside is prevented. The compressor 2
A well-known HEPA (high-performance filter) 3 is mounted on 3 to prevent foreign substances from entering from outside.

In the present desalination apparatus 21, it is possible to maintain a steady operation by backwashing one by one as described above, and to use secondary concentrated water to be discharged for filling with water after backwashing. There is no fluctuation of water flow in
There is no need for difficult flow regulation of each pump P, 4,5.

Stop valves indicated at 29 and 40 in FIG.
The stop valves indicated by 0 and 41 are used for the compressor 23 during back washing.
This is for switching between the case where compressed air is sent into the hollow fibers 223 in the filters 221 and 222 and the case where primary treated water is sent downstream from inside the hollow fibers 223 during normal operation.

The stop valves indicated by 38 and 39 allow the secondary concentrated water from the reverse osmosis membrane module 3 to be supplied to one of the filters 2 when filled with water.
21 (222) for switching to the primary side.

Stop valves indicated by reference numerals 36 and 37 are for stopping supply of raw water to the filter 221 (222) and for supplying secondary concentrated water for filling with water at the time of filling with water.

The flow chart of FIG. 3 shows that the filter 221 (222) of the desalination apparatus 21 shown in FIG. The operation is switched to the filter 222 (221), that is, the supply of the raw water is performed without causing the pressure fluctuation of the system.
Filter 222 that has been backwashed and filled with water from 1 (222)
It shows a mechanism for switching to (221).

In the figure, reference numeral 32 denotes a secondary concentrated water drain pipe 2
6 is a stop valve provided downstream of the branch point with the water filling pipe 27, and indicated by 33 is the water filling pipe 27.
And a pressure sensor 34 for detecting the internal pressure of the primary side of the filter 222 (221) communicating with the water filling pipe 27 and the pipe. is there. 35 is a filter 222, 22
1 is an air vent valve provided for each, and is constituted by a kind of check valve.

Filters 221 and 22 in the raw water supply pipe L
Stop valves 36 and 37 are disposed in front of 2, and stop valves 38 and 39 are disposed in front of the filters 222 and 221 in the water filling pipe 27, respectively.

Also, stop valves 40 and 41 are provided on the pipe 6 for supplying the primary treated water from the filters 222 and 221 to the reverse osmosis membrane module 3 respectively.

In the apparatus having such a configuration, when one filter 221 is backwashed and the other filter 222 is in production water production operation, the filter 221 after backwashing is filled with water to produce product water. A procedure for switching the operation from the other filter 222 to the one filter 221 will be described.

After the backwash, the stop valve 38 of the water filling pipe 27 for the filter 221 is opened, and the stop valve 32 of the secondary concentrated water drain pipe 26 is closed. Then, the secondary retentate is supplied to check valve 3
3. The filter 22 through the pressure sensor 34 and the stop valve 38
1 is injected into the primary side. At this time, air is purged from the air vent valve 35 of the filter 221 and the internal pressure between the primary side of the filter 221 and the water filling pipe 27 increases as the secondary concentrated water is filled. The pressure sensor 34 detects the pressure, and when the pressure reaches a predetermined pressure, the stop valve 32 of the secondary concentrated water drain pipe 26 is opened by the signal from the pressure sensor 34, the stop valve 38 is closed, and the filter 221 is filled with water. Is completed.

After the above operation, the pressure of the system does not fluctuate whenever the production water production operation is switched from the other filter 222 to the one filter 221.

Therefore, when the stop valve 32 is opened and the stop valve 38 is closed, the stop valve 36 and the stop valve 37 of the raw water supply pipe L are automatically and simultaneously closed. Such a configuration can be easily achieved by a known technique.

In the above embodiment, the filters 221 and 2
Although the pressure sensor 34 is provided on the water filling pipe 27 for detecting the internal pressure of 22, the pressure sensor may be provided on the filter,
Further, a water level gauge may be provided in the filter to indirectly detect the internal pressure of the filter. In short, means for detecting that the internal pressure of the filter at the time of filling with water has reached a pressure necessary for starting the production water production operation may be provided.

In the above embodiment, a desalination apparatus for seawater is taken as an example. However, the present invention is not limited to a desalination apparatus. For example, dirt such as river water, pond water, swimming pool water, muddy water, etc. It is obvious that the present invention can be applied to an apparatus for purifying purified water such as drinking water by purifying waste water.

Further, the water purifying apparatus of the present invention is provided with a chemical injecting device such as a disinfectant, a pH adjusting agent or a desalinating reducing agent in consideration of the life and the like under operating conditions such as emergency operation and steady continuous operation. May be installed.

[0056]

According to the present invention, the concentrated water in the second filtration means, which has been conventionally discharged, can be effectively used, and energy such as electric power can be saved. Further, since the conventional filtered water tank and water pump are not required, the equipment cost is reduced, and the operating cost is further reduced. Further, since the open-type filtered water tank becomes unnecessary, invasion of foreign matter from the outside is prevented.

[Brief description of the drawings]

FIG. 1 is a flowchart showing one embodiment of a water purification device of the present invention.

FIG. 2 is a flowchart showing another embodiment of the water purification device of the present invention.

FIG. 3 is a flowchart showing a main part of still another embodiment of the water purification device of the present invention.

FIG. 4 is a flowchart illustrating an example of a conventional water purification apparatus.

FIG. 5 is a flowchart showing still another example of the conventional water purification device.

[Explanation of symbols]

 1, 21 ··· desalination device 2, 221, 222 · · · filter 223 · · · hollow fiber 3 · · · reverse osmosis membrane module 4 · · · boost pump 5 · · · high pressure Pump 6, 10, Pipe 7: Production water tank 8: Production water pump 9: Drain pipe 23: Compressor 24: Blower 25: Drain Pipe (primary) 26 ··· Drainage pipe (secondary) 27 ··· Water filling pipe 11, 28, 29, 30, 31, 32, 36, 37, 38, 39, 40, 41 ... Stop valve 33 ... Check valve 34 ... Pressure sensor 35 ... Air release valve L ... Raw water supply piping

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C02F 1/00 C02F 1/00 L 1/44 1/44 A

Claims (5)

[Claims] 1. A first filtration means, a second filtration means, a water intake means for sending raw water to the first filtration means, and a primary treatment water treated by the first filtration means to a second filtration means. A water purification device comprising: a high-pressure water supply means for supplying water; and a pipe for communicating the concentrated water from the second filtration means to an upstream side of the first filtration means via an opening / closing means. 2. A water purifying apparatus, wherein a pipe for feeding the concentrated water in the second filtration means for water filling upstream of the filtration section of the first filtration means after backwashing and draining is provided. A water purification device, characterized in that: 3. A plurality of said first filtration means are arranged in parallel, and said pipe from the second filtration means is connected to each first filtration means via a first switching mechanism. The water purifier according to claim 1 or 2, wherein a pipe for supplying raw water to the filtration means is connected to each of the first filtration means via a second switching mechanism. 4. An internal pressure detecting means for detecting an internal pressure of the first filtering means, wherein the internal pressure detecting means detects that the internal pressure of one of the first filtering means has reached a predetermined pressure. 4. The water purifying apparatus according to claim 3, wherein the first switching mechanism is configured to stop supplying the concentrated water from the second filtering means to the first filtering means based on the following. 5. The first switching mechanism sends the concentrated water from the second filtration unit to the first filtration unit based on the fact that the internal pressure detection unit has detected that the internal pressure of the first filtration unit has reached a predetermined pressure. 5. The water purification apparatus according to claim 4, wherein the supply to the one filtering means is stopped, and then the second switching mechanism is configured to switch to supply the raw water to the one first filtering means.