JP3243677B2 - Leak detector for membrane breakage in membrane filtration device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leak detector at the time of membrane breakage in a membrane filtration device used in water purification equipment and the like.

[0002]

2. Description of the Related Art In water treatment equipment, raw water is passed through a filtration membrane to allow permeation, and solid-liquid separation is performed. However, the membrane is damaged due to long-term use or sharp substances contained in the raw water. There are cases. In this case, the raw water leaks from the damaged part to the permeated water side, and it does not make sense to purify the water.
It is necessary to stop the operation of the membrane filtration device and replace the membrane. Conventionally, a method of detecting a leak at the time of membrane breakage has been a method in which permeated water is periodically sampled and its turbidity is measured by an optical turbidity meter or the like.

[0003]

However, in this conventional detection method, leak is not detected by continuously sampling permeated water, and therefore, when a turbidity meter detects membrane breakage, it has already been detected. A large amount of raw water leaked from the damaged part to the permeated water side, and there was a defect that membrane damage could not be detected early. In addition, when attempting to continuously sample the permeated water, the optical turbidity meter is not always accurate when air enters the permeated water or when dew condensation occurs. However, there is a problem that it is not suitable as an instrument for measuring leaks.

[0004] The present invention solves the above-mentioned problems of the prior art, and continuously samples permeated water to detect a leak due to membrane breakage at an early stage, thereby stopping the operation of the membrane filtration device. It is an object of the present invention to provide a leak detector at the time.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a filtration membrane module through which raw water is permeated.
Membrane filter to obtain permeated water
A plurality of membrane modules for filtration are arranged in parallel,
Part of the excess water is diverted by a sampling pump and
Water diversion paths to be pulled and installed on each diversion path
The permeation area compared to the membrane of the filtration membrane module
And the diameter of the perforation hole is the same or larger
Leak detection filter and this leak detection filter
And a leak detection measuring device attached to the monitor
A leak detector is installed before and after each filtration membrane module.
Automatically activated by a signal from the leak detector.
A valve, and a valve among the plurality of membrane modules for filtration.
One or more of these are selectively used for membrane filtration.
Damage to the selectively used filtration membrane module
When this occurs, the membrane module for filtration that has been damaged
Close the automatic valve corresponding to
Membrane filtration .

[0006]

When a part of the treated water passing through the water separation path for sampling passes through the leak detection filter, the presence or absence of an increase in the membrane inlet pressure or a decrease in the amount of the permeated water is measured. Leaks due to breakage can be detected.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a flowchart showing a first embodiment of a membrane filtration device provided with a leak detector at the time of membrane breakage according to the present invention. In FIG. 1, raw water 1 in a raw water tank 2 is continuously supplied to a filtration membrane module 4 by a supply pump 3, and permeated water passing through the filtration membrane module 4 is supplied to a pipe 5.
Is sent to the permeated water tank 6 and stored there. And the permeated water 7 is provided as treated water for water purification.

A part of the permeated water supplied to the permeated water tank 6 through the pipe 5 is divided by a separately provided sampling pump 11, passes through a water separation path 12, and is continuously supplied to the leak detector 10 side. Carried. The amount of water diverted to the water diversion path 12 is very small, about one-hundredth to one-hundredth of the amount of permeated water sent to the permeated water tank 6. A leak detection filter 13 having a smaller transmission area than the membrane of the filtration membrane module 4 is provided on the water separation path 12.
Is installed, and the water diverted to the water diversion path 12 is filtered again by the leak detection filter 13. The diameter of the permeation hole of the leak detection filter 13 is set to be the same or larger than the diameter of the membrane of the filtration membrane module 4. Uses a UF membrane.
Therefore, in a normal state where the membrane is not damaged, a part of the permeated water diverted to the water diversion path 12 hardly clogs even if the permeated water passes through the leak detection filter 13. The leak detection filter 13 includes:
A UF membrane, filter paper, filter cloth, cartridge filter or the like may be used.

The leak detecting filter 13 has a pressure gauge 1 as a leak detecting measuring device 15 attached thereto.
6, a flow meter 17 and a thermometer 18 are mounted, the water flow path 12, the leak detecting filter 13
Together, they constitute the leak detector 10. When the filtration membrane module 4 is not damaged and is normal, clogging does not occur due to the water continuously diverted to the water separation path 12, so that the pressure gauge 16 and the flow meter 17 always maintain predetermined measurement values. ing. The permeated water 19 that has passed through the leak detection filter 13 may be led to the permeated water tank 6 that has passed through the filtration membrane module 4, or may be returned to the raw water tank 2.

If the filtration membrane module 4 is damaged, the raw water 1 containing turbidity and the like flows into the permeated water tank 6 and flows into the water separation path 12. Causes clogging, and when the amount of water discharged from the sampling pump 11 is constant, the inlet pressure of the leak detection filter 13 increases. When the water pressure discharged from the sampling pump 11 is constant, the amount of water permeated through the leak detection filter decreases. Therefore, the pressure gauge 16 or the flow meter 17 appears as a fluctuated value as compared with the normal measurement value in which the clogging does not occur, and the monitor can detect the leak due to the breakage of the membrane. Upon receiving a signal from the leak detector 10, the supply pump 3 is stopped. Further, the filtration membrane module 4
Automatic valves may be provided before and after the above, and the automatic valves may be operated. Since the inlet pressure and the amount of permeated water of the leak detection filter 13 vary depending on the temperature, it is necessary to measure the temperature with the thermometer 18 and use the correction value.

FIG. 2 is a flow chart showing a second embodiment of the membrane filtration device provided with a leak detector when the membrane breaks according to the present invention. In Figure 2, raw water 1 raw water tank 2 via a supply pump 3, a plurality in parallel, a filtration membrane module 4 ₁ is disposed 5 groups in this example, 4 _2, 4 _3, 4 _4, 4 Supplied to ₅ . Each of the filtration membrane modules 4 ₁ , 4 ₂ , 4
_3, 4 _4, 4 ₅ permeate 7 transmitted through are sent summarized in the transmitting water tray 6, it is stored. And it is provided as treated water for water purification. Each filtration membrane module 4 ₁ , 4 ₂ ,
4 _{3, 4} 4, 4 before and after the ₅ lines, automatic valves 8 ₁ such as an electromagnetic valve, 8 _2, 8 _3, 8 _4, 8 ₅ and 9 _1, 9 _2, 9
_3, 9 _4, 9 ₅ is provided. The pipe 5 _1, 5 _2, 5 _3, 5 _4, 5 ₅ from the membrane module for filtration, water diversion path 12 ₁ to divert part of the permeate, 12 _2, 12 _3, 12 _4, 12 ₅
And the leak detectors 10 ₁ , 10 ₂ , 10
₃ , 10 ₄ and 10 ₅ are provided. Each pipe 5 ₁ from transmitting the water tank 6, 5 _2, 5 _3, 5 _4, 5 ₅ backwash water 21 via the for periodic filtration membrane module 4 _1, 4 _2, 4 _3,
The water is sent out to 4 ₄ and 4 ₅ and returned to the raw water tank 2 as backwash drainage 22.

During normal operation, the automatic valves 8 ₁ , 8 ₂ , 8 ₃ and 9 ₁ , 9 ₂ , 9 before and after a part of the filtration membrane modules arranged in parallel, for example, 4 ₁ , 4 ₂ , 4 _{3. 3} was opened, kept closed its remaining filtration membrane module 4 _4, 4 automatic valve 8 before and after the _{5 4,} 8 ₅ and 9 _4, 9 _5. Therefore, the membrane filtration is performed by three filtration membrane modules 4 ₁ and 4.
₂ and 4 ₃ are performed.

Now, three filtration membrane modules 4₁, 4
_Two, 4_ThreeIf any of them are damaged, leak detection
Container 10₁,Ten_Two,Ten_ThreeActivate one of the automatic valve
8₁, 8 _Two, 8_ThreeAnd 9₁, 9_Two, 9_ThreeClose
With the other two filtration membrane modules 4_Four, 4_Fiveof
Automatic valve 8 before and after_Four, 8_FiveAnd 9_Four, 9_FiveIs released
As a result, two spare filtration membrane modules 4_Four, 4
_FiveIs used to perform membrane filtration. In this second embodiment,
Is a leak detector 10₁,Ten_Two,Ten_ThreeSignal from any of
By controlling the automatic valve, automation becomes possible,
Unmanned driving can be performed.

FIG. 3 is a graph showing a leak detection at the time of film breakage according to the present invention.
Flow chart showing a third embodiment of a membrane filtration device provided with an ejector
It is. In FIG. 3, as in the case of FIG.
Raw water 1 in 2 is supplied in parallel through feed pump 3
The installed filtration membrane module 4₁, 4_Two, 4_Three, 4_Four,
4_FiveSupplied to Each of the filtration membrane modules 4₁, 4
_Two, 4_Three, 4_Four, 4_FiveThe permeated water that has passed through is
Is sent to the permeated water tank 6 and stored. Each filtration membrane module
Automatic valve 8 before and after the line₁, 8_Two, 8 _Three,
8_Four, 8_FiveAnd 9₁, 9_Two, 9_Three, 9_Four, 9_FiveProvided
It is. Piping 5 of each filtration membrane module₁, 5_Two,
5_Three, 5_Four, 5_FiveDivides part of the permeated water
Route 12₁, 12_Two, 12_Three, 12_Four, 12_FiveAnd set each
Collectively, they are connected to the switching valve device 20. Switching valve device 20
The leak detector 1 is provided on the water diversion path 12 integrated by
0, and the permeated water 1 from the leak detector 10
9 is returned to the raw water tank 2.

The switching valve device 20 is operated for a predetermined time (depending on the amount of water).
(Every 2 to 10 seconds)
Two₁, 12_Two, 12_Three, 12_Four, 12_FiveOpen and close
return. Each water diversion path 12₁, 12_Two, 12_Three, 12_Four, 12_FiveIs off
Integrated in the valve changing device 20 and connected to the leak detector 10
So that each of the filtration membrane modules is connected to the leak detector 10.
4 ₁, 4_Two, 4_Three, 4_Four, 4_FiveOf permeated water
Becomes Therefore, one leak detector (detection unit)
G) At 10, a plurality of filtration membranes connected in parallel to the raw water tank 2
Module 4₁, 4_Two, 4_Three, 4_Four, 4_FiveAll damage inspection
Can go out.

[0016]

According to the present invention as described above, the permeated water of the filtration membrane module is continuously sampled by providing a water separation path, and a leak is detected by a pressure gauge or a flow meter. In addition, at the time when the membrane damage is detected by the turbidity meter, there is no possibility that a large amount of raw water leaks from the damaged portion to the permeated water side, and the membrane damage can be detected early.

Also, a plurality of filtration membrane modules are arranged in parallel with the raw water tank, a part of each permeated water is divided by a sampling pump, and a water separation path for continuous sampling, and a water separation path on each water separation path. In the apparatus provided with the installed leak detector, the automatic valve is controlled by a signal from any of the leak detectors, so that automation becomes possible and unmanned operation can be performed.

Further, a plurality of filtration membrane modules are arranged in parallel to the raw water tank, and a part of each permeated water is separated by a sampling pump to continuously sample and a water separation path is combined. In a device equipped with a connected switching valve device and a leak detector installed on a water diversion path integrated by the switching valve device, one leak detector (detection unit) is connected in parallel to the raw water tank. Damage detection of all the plurality of filtration membrane modules can be performed.

Therefore, according to the present invention, it is possible to detect a leak due to membrane breakage with a simple device, and it is possible to improve the safety of a water purification facility or the like using a membrane. Further, since a leak due to membrane breakage can be continuously detected, automatic operation becomes possible, which is particularly suitable for a device that is operated unmanned, such as a small-scale water purification plant.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a first embodiment of a membrane filtration device provided with a leak detector at the time of membrane breakage according to the present invention.

FIG. 2 is a flow chart showing a second embodiment of the membrane filtration device provided with a leak detector at the time of membrane breakage according to the present invention.

FIG. 3 is a flow chart showing a third embodiment of a membrane filtration device provided with a leak detector at the time of membrane breakage according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Raw water 2 ... Raw water tank 3 ... Supply pump 4 ... Filtration membrane module 5 ... Piping 6 ... Permeated water tank 7 ... Permeated water 8 ... Automatic valve 9 ... Automatic valve 10 ... Leak detector 11 ... Sampling pump 12 ... Water distribution path DESCRIPTION OF SYMBOLS 13 ... Filter for leak detection 15 ... Measuring instrument for leak detection 16 ... Pressure gauge 17 ... Flow meter 19 ... Permeated water 20 ... Switching valve device

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G01N 15/08 B01D 67/10 B01D 13/00-13/04 B65D 53/22 C02F 1/44

Claims (4)

(57) [Claims] In a membrane filtration device for obtaining permeated water by permeating raw water through a filtration membrane module, a plurality of filtration membrane modules are arranged in parallel with a raw water tank, and a part of each permeated water is sampled. A water separation path that is divided and continuously sampled by a pump, and is installed on each of the water separation paths, has a smaller permeation area as compared with the membrane of the filtration membrane module, and has the same or larger diameter of the permeation hole. A leak detection filter, a leak detector including a leak detection measuring device provided in addition to the leak detection filter, and provided before and after each of the filtration membrane modules.
Automatically operated by a signal from the leak detector.
A valve, and any one of the plurality of filtration membrane modules
Perform membrane filtration using a plurality of
If the filtration membrane module used is damaged,
Automatic valve corresponding to the membrane module for filtration where the damage occurred
Is closed and membrane filtration is performed using another filtration membrane module.
Leak detector during film breakage in the membrane filtering device being characterized in that a formed. 2. In a membrane filtration device that obtains permeated water by permeating raw water through a filtration membrane module, a plurality of filtration membrane modules are arranged in parallel to a raw water tank, and a part of each permeated water is sampled. A water separation path for diverting and continuously sampling by a pump, a switching valve device connecting the respective water separation paths together, and a membrane installed in the water separation path integrated by the switching valve apparatus, and a membrane of the membrane module for filtration. compared to permeation area is small and the, the greater the leak detection filter size is equal or than that of the transmission hole, and a leak detector comprising the the leak detection filter is attached is provided with leak detection instrumentation , Each of the filtration membrane modules
The signal from the leak detector.
And an automatic valve that operates more than once.
By repeating opening and closing sequentially, it becomes a single leak detector
Detection of membrane damage of the plurality of filtration membrane modules
Leak detector during film breakage in the membrane filtration apparatus characterized by being configured to. Wherein said leak detection instrument, if the amount of water discharged from the sampling pump is constant, according to claim 1 or claim 2 which is a pressure gauge for detecting the rise of the inlet pressure of the leak detection filter Leak detector at the time of membrane breakage in the membrane filtration device. Wherein said leak detection instrument, if the water pressure discharged from the sampling pump is constant, according to claim 1 or claim 2 which is a flow rate meter for detecting the decrease in the permeate flow rate of leak detection filter Leak detector at the time of membrane breakage in the membrane filtration device.