CN101376084A - Membrane filtration device and membrane damage detection method of membrane filtration device - Google Patents

Abstract

An object of the present invention is to provide a low-cost membrane filtration device and a membrane damage detection method for a membrane filtration device capable of improving leakage sensitivity and reliably detecting damage. In the membrane damage detection mode, after the filtration mode, the control device (34) stops the supply of raw water from the raw water supply device (2), and the air supply device (5) supplies air to the raw water chamber and connects to the raw water chamber. The discharge pipe (9) is discharged, and the process of peeling off the turbid matter attached to the film for a set time to obtain high turbidity water is carried out, and the process of permeation and detection is carried out, that is, the on-off valve (15) is closed to stop the discharge of air, Permeated water is generated, and whether the membrane module (1) is damaged is judged based on the detection value of the turbidity state of the permeated water by the turbidity detection device (19).

Description

Membrane filtration device and membrane damage detection method of membrane filtration device

technical field

The invention relates to a membrane filtration device used in a membrane filtration process of a water purification plant and a method for detecting membrane damage of the membrane filtration device, which are provided for separating and removing turbidity and pathogenic protozoa contained in raw water.

Background technique

Membrane filtration processes are installed in water purification facilities that purify raw water such as groundwater and river surface water. In this membrane filtration process, a membrane module is provided. The membrane module has a built-in filtration membrane for separating and removing turbidity and pathogenic protozoa contained in raw water (hereinafter collectively referred to as turbidity) to generate clear and safe filtered water. In the membrane filtration process, there are unit methods in which multiple membrane modules are connected in parallel, series methods in which multiple units are arranged in parallel, etc., and are composed of the number of membrane modules corresponding to the scale of water purification.

In this membrane filtration process, operations such as filtration, backwashing, and chemical cleaning are repeatedly performed. Due to the pressure change accompanying these operations and the deterioration of the membrane material caused by long-term use, the filter membrane in the membrane module is damaged, damage, breakage (hereinafter collectively referred to as damage), etc. If the filter membrane is damaged, the raw water will flow out from the damaged part, so the turbidity will be mixed into the filtered water.

In this way, when the membrane is damaged, the turbidity of the raw water directly leaks from the filtered water side which becomes the purified water, thereby deteriorating safety. Therefore, in the membrane filtration process, if damage to the filtration membrane is detected, it is important to quickly specify the damaged membrane module and take early measures, and maintain the water purification ability of the normal membrane module without damage.

As a method of detecting membrane damage, there are direct method of supplying pressurized gas and grasping from its pressure reduction state, and indirect method of grasping from the degree of turbidity, fine particles and biological state of filtered water.

In the direct method, for example, as described in [Patent Document 1] and [Patent Document 2], there are various methods such as displacing the pressurized gas on the raw water side or the filtered water side, and detecting the leaked air flow rate and the change in the applied pressure. plan.

In the indirect method, as described in [Patent Document 3], there is a method of injecting membrane cleaning wastewater or membrane concentrated water into raw water to increase the turbidity concentration of raw water, and measuring the number of particles or turbidity in filtered water. In addition, as described in [Patent Document 4], there is a method of injecting harmless turbidity (kaolin, diatomaceous earth) into the raw water to increase the turbidity of the filtered water when the membrane is damaged and then detect it, and as [Patent Document 5] As mentioned above, the turbidity source injection method, such as the method of filling the membrane module with a clear gas, supplies a gas containing fine particles, and measures passing fine particles.

On the other hand, as the main components of membrane filtration facilities for water purification, as described in [Non-Patent Document 1], there are devices for monitoring the water pressure difference on both sides of the membrane, the flow rate of filtered water, and the turbidity of filtered water. In addition, as described in [Non-Patent Document 2], a membrane damage detection method is recommended, which uses both direct and indirect methods, and utilizes the respective strengths of the system.

[Patent Document 1] Japanese Patent Laid-Open No. 2006-68634

[Patent Document 2] Japanese Patent Laid-Open No. 2004-212230

[Patent Document 3] Japanese Patent Laid-Open No. 2005-87948

[Patent Document 4] Japanese Patent Laid-Open Publication No. 6-320157

[Patent Document 5] Japanese Patent Laid-Open No. 2004-216311

[Non-Patent Document 1] Ministry of Health, Labor and Welfare Order No. 15: Ministry Order Establishing Technical Standards for Waterworks Facilities (February 23, 2012)

[Non-Patent Document 2] Water Technology Research Center: Membrane Filtration Water Purification Facilities Maintenance and Management Manual (March 2017)

In the direct method described in [Patent Document 1] and [Patent Document 2], in addition to replacement with pressurized gas, replacement with raw water or filtered water is required for re-filtering, and the filtration process is stopped during this period. In addition, since normal membranes do not permeate gases such as air, the injection of pressurized gas expands and contracts the membrane, applying stress and accelerating aging. Therefore, if the direct method is implemented every time on site, the production efficiency of purified water decreases, and at the same time, it becomes a cause of membrane damage and premature damage. And, the technology described in [Patent Document 1], because it is difficult to measure the gas flow with a commonly used filtered water flowmeter, so it is necessary to reset the gas flowmeter, but in this way there is the accompanying filtered water to affect and not It is easy to correct the problem of measuring the gas volume. In the technology described in [Patent Document 2], it is not common to apply pressurized gas on the filtered water side, and it is necessary to separately install a piping system and its operating equipment, and there is a problem of increased equipment cost.

The indirect method is the prior art described in [Patent Document 3]. It is necessary to pre-install storage equipment for storing cleaning drainage or concentrated water, and new equipment for transporting raw water from the storage equipment, which increases equipment and operating costs. These stored water It is obtained by counter-flowing clarified filtered water, so there is a problem that it becomes diluted low-concentration water at the end, and the effect is not good.

In the prior art described in [Patent Document 4], since a new turbidity is added, a turbidity source and its supply equipment are necessary, and there is a problem of increased equipment and operating costs.

In the prior art described in [Patent Document 5], it is necessary to newly install equipment for mixing the gas, and fine particles of rare substances having the same specific gravity as the gas are required to accompany the flow of the gas. In this way, the prior art of the indirect method has the problem of having to consider the equipment and operating costs because a new turbidity source, its storage facility, and its transportation facility are required.

Contents of the invention

The object of the present invention is to provide a membrane filtration device that can generate high turbidity raw water by using existing equipment without requiring new turbidity sources or equipment, and can increase the turbidity concentration of filtered water when the membrane is damaged by filtering the raw water And membrane damage detection method of membrane filtration device.

Another object of the present invention is to provide a low-cost membrane filtration device and a membrane damage detection method of a membrane filtration device that can reliably detect damage with improved leakage sensitivity.

Yet another object of the present invention is to provide a membrane filtration device and a membrane filtration device that can detect membrane damage in a membrane filtration process reliably at low cost by using an indirect method to determine membrane damage in advance, using a direct method to accurately grasp the correctness and damage status of the determination. Membrane damage detection method for membrane filtration devices.

In order to solve the above-mentioned problems, in addition to the normal filtration mode in which filtration, backwashing, and flushing (washing) are repeated, the present invention also provides a membrane damage detection mode. In the membrane damage detection mode, the membrane on the raw water side during the filtration process is The turbidity captured and adhered on the surface is peeled off, and the concentration of the raw water side in the module is increased by using the peeled turbidity, and the filtration process is performed in this state, and the presence or absence of damage is determined based on the change in the turbidity of the filtered water (permeated water) generation and identify damaged membrane modules.

The present invention has a membrane damage detection mode after the filtration mode, that is, by controlling the equipment, the supply of raw water from the raw water supply device is stopped, and the air supply device supplies air to the raw water chamber and discharges it to the discharge pipe connected to the raw water chamber. The detachment process of attaching turbidity to the peeling film for a certain period of time to obtain high-concentration water, and performing the permeation and detection process, that is, closing the on-off valve to stop the discharge of air to generate permeated water, according to the turbidity detection device. The detection value of the turbidity state of the permeated water is used to judge whether there is damage to the membrane module.

In addition, the present invention uses the turbidity captured on the membrane surface in the filtration process to form high-concentration water in the raw water chamber in the membrane module during the normal membrane filtration operation in which filtration treatment, backwash treatment, and rinse treatment are repeated, This high-concentration water is filtered, and whether there is membrane damage is known in advance through the concentration change of the filtered water. When the possibility of membrane damage is high, it is switched to air supply filtration, and the membrane is grasped by the turbid state of the filtered water including air bubbles. Damage state, if membrane damage cannot be determined, seal the air on the side of the raw water chamber without permeated water (residual raw water in the raw water chamber), and accurately determine whether there is membrane damage and its damaged state. In addition, the first insertion operation is carried out, and the presence or absence of membrane damage is determined in advance based on the change in turbidity in the filtered water in the high-concentration water filtration step.

In addition, if it is determined that there is no membrane damage in the first insertion operation, the insertion operation is canceled and the normal operation is returned. The filtration step is performed as the second interrupt operation, and the damage state of the membrane is diagnosed based on the change of the turbidity in the filtered water in the air supply filtration step, so that the indirect method and the direct method can be used together.

In addition, when the damage state of the membrane cannot be judged from the state of turbidity in the filtered water in the air supply filtration step during the second insertion operation, the third insertion operation is performed by insertion, that is, after all the raw water in the raw water chamber has been permeated. , Stop the air supply and seal the air filling process of the raw water chamber, and diagnose whether there is membrane damage according to the pressure change of the raw water chamber in the air sealing process.

Invention effect

According to the present invention, raw water with high turbidity can be easily produced, and the detection sensitivity of membrane damage can be improved. In addition, since high-turbidity raw water can be generated by existing equipment, it is not necessary to install new turbidity sources or equipment, and the initial equipment cost is not consumed. The operating cost is also low, and membrane damage can be reliably detected.

In addition, even without changing equipment or rebuilding equipment, it is possible to reliably detect membrane damage in a membrane filtration process at low cost by utilizing the strengths of the direct method and the indirect method.

Description of drawings

Fig. 1 is the structural diagram of the membrane filtration device that uses embodiment 1 of the present invention namely external pressure type hollow wire membrane module;

Fig. 2 is a flowchart showing the membrane damage detection sequence of the membrane filtration device of the present embodiment;

Fig. 3 is a flowchart showing other membrane damage detection procedures of the membrane filtration device of the present embodiment;

Fig. 4 is a diagram illustrating the method of judging the presence or absence of membrane damage and the damage state of the present embodiment;

Fig. 5 is the structural view of the membrane filtration device using the embodiment 2 of the present invention, that is, the internal pressure type hollow wire membrane module;

Fig. 6 is the structural diagram of the membrane filtration device of embodiment 3 of the present invention;

Fig. 7 is a flowchart showing the membrane damage detection sequence of the membrane filtration device of the present embodiment;

8 is a structural diagram of a part of the membrane filtration device of Embodiment 4 of the present invention;

Fig. 9 is a structural diagram of a membrane filtration device for an external pressure type hollow fiber membrane module according to Embodiment 5 of the present invention;

10 is a flowchart illustrating the membrane damage detection sequence of Example 5;

Fig. 11 is the configuration diagram of the third insertion operation in embodiment 5;

Fig. 12 is the structural diagram of the membrane filtration device of embodiment 6 of the present invention;

13 is a flowchart illustrating the membrane damage detection sequence of Example 6;

Fig. 14 is the experimental characteristic diagram of membrane filtration device;

Fig. 15 is an experimental characteristic diagram of a membrane filtration device.

In the picture:

1—membrane module; 2—raw water supply device; 3—filtered water tank; 4—wash water supply device; 5—air supply device; 6—raw water supply pipe; 7—filtered water pipe; 9—exhaust branch pipe; 10—air Branch pipe; 11—filtration membrane; 12—raw water chamber; 13—permeable water chamber (filtered water chamber); 14—fixed wall; 15, 16, 22, 23—opening and closing valve; 19—turbidity detection device; 24 —branch pipe; 30—turbidity detector; 32—diagnostic equipment; 34—control equipment; 36—raw water branch pipe; 37—through water pipe; 40—membrane filtration treatment equipment; 42—normal filtration mode; 44—membrane damage Detection mode; 51—filtering process; 52—backwashing process; 53—rinsing process; 54—stripping process; 55—permeation, detection process; 56—disposal process; Process II; 62—backwashing process.

Detailed ways

Various embodiments of the present invention are described with reference to the accompanying drawings.

【Example 1】

Embodiment 1 of the present invention will be described with reference to FIG. 1 to FIG. 4 . Fig. 1 is a structural diagram of the membrane filtration treatment equipment of this embodiment.

The present embodiment has shown the example that uses the hollow fiber membrane module of external pressure type, and as shown in Figure 1, the main structural element of membrane filtration treatment equipment 40 has N membrane module 1a～1n, raw water supply device 2, filter water tank 3, A washing water supply device 4 and an air supply device 5 .

The membrane module 1a is provided with a permeation chamber 13a (also referred to as a filter chamber 13a) and a permeation chamber 13a' above and below, and a raw water chamber 12a is disposed between the permeation chamber 13a and the permeation chamber 13a'. In the raw water chamber 12a, a filter membrane 11a equipped with thousands of hollow fiber membranes is installed, and both ends of the hollow fiber membranes are opened to the permeation chamber 13a and the permeation chamber 13a'. The permeable chamber 13a and the raw water chamber 12a, and the permeable chamber 13a' and the raw water chamber 12a are separated by the fixed wall 14a and the fixed wall 14a' respectively. 'Between through.

An air branch pipe 10a is connected below the raw water chamber 12a, and the air branch pipe 10a is connected to the air supply pipe 10 through the on-off valve 17a, and the air supply pipe 10 is connected to the air supply device 5. The air branch pipe 10a is provided with a branch pipe, that is, a raw water branch pipe 36a. The raw water branch pipe 36a is connected to the raw water supply pipe 6 through the on-off valve 16a, and the raw water supply pipe 6 is connected to the raw water supply device 2 .

A discharge branch pipe 9a is connected above the raw water chamber 12a, and the discharge branch pipe 9a is connected to the discharge pipe 9 through an on-off valve 15a. A permeated water pipe 37 a having a turbidity detection device 19 a is connected to the upper permeated chamber 13 a, and the permeated water pipe 37 a is connected to the filtered water pipe 7 . The filtered water pipe 7 guides filtered water to the filtered water tank 3 through the on-off valve 22, and the branch pipe 24 branched from the filtered water pipe 7 with the on-off valve 23 is connected to the washing water supply device 4, and the washed water supply device 4 is connected to the filtered water tank. 3 connections.

Although the structure of the membrane module has been described by taking the membrane module 1a as an example, the other membrane modules 1b to 1n have the same structure. The supply pipe 6 is connected, the air branch pipes 10a-10n are connected to the air supply pipe 10 from the air supply device 5, the discharge branch pipes 9a-9n are connected to the discharge pipe 9, and the permeated water pipes 37a-37n are connected to the filtered water pipe 7. The on-off valve 22 is provided on the downstream side of the junction of the filtered water pipe 7 and the permeated water pipe 37n.

The turbidity detection devices 19a-19n are connected to the diagnostic equipment 32 through signal lines or wirelessly, the diagnostic equipment 32 is connected to the control equipment 34, and the control equipment 34 is connected to the raw water supply device 2, the washing water supply device 4, the air supply device 5 and the valves. Closed valves 15,16,17,19,22,23 are connected.

The normal operation of the membrane filtration treatment facility 40 configured in this way will be described. The running operation is shown in the normal filtering mode 42 in FIG. 2 , and three steps of filtering step 51 , backwashing step 52 , and rinsing step 53 (also called washing step 53 ) are repeated.

In the filtration step 51, the on-off valves 16a to 16n and the on-off valve 22 are opened, the other on-off valves are closed, the raw water supply device 2 is operated, and the raw water containing turbidity is supplied to each membrane module through the raw water branch pipes 36a to 36n. 1a~1n. Raw water captures and removes turbidity on the surfaces of the filter membranes 11a to 11n on the side of the raw water chambers 12a to 12n, and permeates into the inside of the filter membranes. The raw water passing through the filter membrane becomes clear permeated water, and the permeated water is merged at the filtered water pipe 7 through the permeated water pipes 37a-37n connected to the permeated chambers 13a-13n. The combined filtered water is stored in the filtered water tank 3 in a certain amount, and most of them are supplied as clean water as tap water. After the filtering step 51 has been operated for a set time, the backwashing step 52 is entered.

In the backwashing step 52, the raw water supply device 2 is stopped, the on-off valves 15a to 15n, the on-off valves 17a to 17n, and the on-off valve 23 are opened, and the other on-off valves are closed to make the air supply device 5 and the washing water supply device 4 Work. Pressurized air is supplied to the raw water chambers 12a-12n of the membrane modules 1a-1n through the air branch pipes 10a-10n by the operation of the air supply device 5, and is discharged from the upper discharge branch pipes 9a-9n. In addition, by the operation of the washing water supply device 4, a certain amount of filtered water stored in the filtered water tank 3 is supplied to the permeated water chambers 13a to 13n of the membrane modules 1a to 1n, and the filtered water from the inside of the filter membranes 11a to 11n It passes through to the side of the raw water chamber, and is discharged from the discharge branch pipes 9a to 9n together with the air.

The air supplied to the raw water chambers 12a to 12n strips off the turbidity captured and adhered to the surface of the membrane, and the washing water permeating from the inside of the membrane to the raw water chambers 12a to 12n promotes the removal of the turbidity mixed in the membrane. Capture and peel off of turbid matter attached to the membrane surface on the raw water chamber 12 side. The detached turbidity, together with the air and permeated washing water, is combined at the discharge pipe 9 as the washing discharge, and is discharged outside the pipe.

In the flushing process 53, after the backwashing process 52 is completed, the air supply device 5 and the washing water supply device 4 are stopped, the on-off valves 15a-15n and the on-off valves 16a-16n are opened, and other on-off mechanisms are closed to make the raw water supply device 2 jobs. The raw water supplied to the raw water chambers 12a-12n does not pass through the filter membranes, and is discharged from the discharge branch pipes 9a-9n to wash the raw water chambers 12 and the membrane surface while removing the remaining air in the raw water chambers 12.

From the filtering step 51 to the rinsing step 53 constitutes one cycle, and after the rinsing step 53 is completed, it enters into the filtering step 51 of the next cycle. These operation operations are referred to as a normal filtering mode, and the control device 34 instructs the required time of each process and the timing of operation, stop, and opening and closing of various mechanisms.

The membrane damage detection method will be described with reference to FIG. 2 and FIG. 3 . FIG. 2 is a flow chart showing whether the normal filter mode 42 is periodically switched to the membrane damage detection mode 44 under the command of the control device 34 to determine the presence or absence of damage and the membrane damage module.

The membrane damage detection mode 44 is switched at the stage when the filtration process 51 of the normal filtration mode 42 is completed, and the peeling process 54 is implemented.

In the stripping step 54, the raw water supply device 2 is stopped from the operating state of the filtration step 51, the on-off valves 16a-16n are closed, the on-off valves 15a-15n, and the on-off valves 17a-17n are opened, and the air supply device 5 is operated. Pressurized air is supplied to the raw water chambers 12a to 12n of the respective membrane modules through the air branch pipes 10a to 10n by the operation of the air supply device 5 . Although the raw water chamber 12 is full of water, since the upper on-off valves 15a to 15n are opened, the rising air is discharged from the discharge branch pipes 9a to 9n. This ascending air flow has the effect of peeling off the turbidity adhering to the surfaces of the filter membranes 11a-11n of the raw water chambers 12a-12n, and uniformly mixing the peeled turbidity into the remaining raw water.

According to the inventor's experimental conclusions, the air cleaning in the peeling process can be 30 seconds or less. Although the raw water in the raw water chamber 12 has been reduced by a volume corresponding to the accumulated water in the fixed walls 14a to 14n and the air branch pipes 10a to 10n, most of the raw water remains and becomes highly turbid. This ratio is approximately the ratio of the amount of permeated water in the filtration step to the volume of the raw water chamber.

In the permeation and detection step 55, the on-off valves 15a to 15n are closed and the other on-off valves are opened to continue the air supply to pressurize the highly turbid raw water to permeate through the filter membranes 11a to 11n. If a part of the filtration membrane is damaged, the highly turbid raw water leaks directly from the damaged part, and the turbidity of the permeated water of the damaged membrane module as a whole increases.

On the other hand, as the permeation proceeds, the air layer in the raw water chamber increases the permeation portion of the highly turbid raw water. When the lower portion of the air layer is lower than the damaged portion, air bubbles are mixed into the permeated water, and turbidity including air bubbles is discharged from the permeated water chamber together with the permeated water. A turbidity detection device 19 is provided near the permeated water chamber 13 of each module to detect the presence or absence and change of turbidity.

In the turbidity detection device 19, sensors such as ultrasonic, photoelectric, acoustic, and electrical resistance are used. The detection values of the turbidity detection devices 19a-19n are input into the diagnostic equipment 32 such as a computer, and the membrane modules are compared and evaluated to determine whether it is the turbidity inherent in the raw water or the turbidity containing air bubbles, thereby assessing the degree of damage. Diagnostic evaluation, predictive evaluation of damage location due to delayed discharge of turbid matter including air bubbles.

Evaluation of turbidity inherent in raw water and determination of turbidity including air bubbles can be realized by the method shown in FIG. 4 as an example. In the example shown in FIG. 4, the turbidity of the permeated water is used as an index for judgment.

The turbidity of a normal membrane module without damage does not change over time, and the turbidity of the permeated water of a damaged membrane module is initially the same as that of a normal membrane module, or slightly higher than that. Turbidity raw water flows out and increases slowly. When the lower part of the air layer reaches the damaged position, air bubbles start to flow out, and the turbidity increases rapidly. The presence or absence of damage can be ascertained from this initial change in turbidity, and the location and degree of damage can be evaluated based on the time A for a sudden change in turbidity and the tendency of increase after the sudden change.

As an indicator of turbidity, in addition to the turbidity measured by the sensor, the number of particles, the attenuation, reflection, and scattering of light or ultrasonic waves, electricity, and current values can also be used. The diagnosis device 32 outputs indications of the presence or absence of damage, a damage alarm, a damage module, the degree of damage, and a predicted position, and outputs an operation command for the membrane filtration treatment device 40 to the control device 34 .

In the treatment process 56 , the control device 34 executes the next operation of the membrane filtration treatment device 40 based on the output information of the diagnosis device 32 . When no damage occurs, the filter is switched to the normal filtration mode 42 , and the operation is performed from the backwashing step 52 . When damage occurs and the damaged membrane module is determined, for example, when it is determined that the membrane module 1b is damaged, after closing the locking on-off valves 15b, 16b, 17b, switch to the normal filtration mode 42, from reverse The washing process 52 is carried out and the running operation is performed. Although not shown in the figure, the closing and locking of the damaged membrane module can also be carried out by the on-off valve arranged on the permeate water pipe, which does not affect the operation of the normal filtration mode 42 of other normally damaged membrane modules, and module replacement can be implemented and repair operations. The closing lock is released after replacement and repair operations.

In this way, according to the membrane damage detection method of this embodiment, it is possible to temporarily generate high-turbidity raw water without supplying new turbidity, and to perform detection with improved leakage sensitivity of permeated water, because it is possible to change from a certain time period to one containing air bubbles. Turbidity, so the extent of damage and its location can be determined.

Fig. 3 has shown the detection value of the turbidity detecting devices 19a-19n in the filtration step 51 of the normal filtration mode 42, it is judged whether the insertion processing of the membrane damage detection is necessary in the diagnostic equipment 32, and the case where the insertion processing is judged to be necessary Below, the flow of temporarily executing the membrane damage detection mode 44 is displayed by the control device 34 .

When the detection values of the turbidity detection devices 19a to 19n are higher than the set values, or the determined detection values are different from other detection values, it is determined that insertion is necessary. The processing sequence in the membrane damage detection mode 44 is the same as that shown in FIG. 2 .

In the membrane damage detection mode 44, since the generation of filtered water is interrupted, if it is determined that no membrane damage occurs, although its operation is useless, according to this membrane damage inspection method, it can be provided because it is executed when necessary. Efficient membrane filtration operation.

[Example 2]

Fig. 5 is a diagram showing Example 2 for an internal pressure type hollow fiber membrane module. This example has the same configuration as the embodiment shown in FIG. 1 , but the structure of the membrane module and a part of the piping are different.

Taking the membrane module 1a as an example, the structure of the membrane module of this embodiment will be described. Raw water chambers 12a, 12a' are arranged up and down, and a permeated water chamber 13a is provided therebetween. The permeated water chamber 13 is provided with a filter membrane 11a composed of a plurality of hollow fiber membranes, and both ends of the hollow fiber membranes are opened to the raw water chamber 12a and the raw water chamber 12a'. The permeable chamber 13a and the raw water chamber 12a, and the permeable chamber 13a and the raw water chamber 12a' are separated by the fixed wall 14a and the fixed wall 14a' respectively, and the liquid passes through the built-in filter membrane 11a and passes through the permeable chamber 13a and the raw water chamber 13a, 13a' pass through.

A permeated water pipe 37a is connected above the permeated water chamber 13a, and the permeated water pipe 37a is connected to the filtered water pipe 7 through the turbidity detection device 19a. A discharge branch pipe 9a is connected to the upper raw water chamber 12a, and the discharge branch pipe 9a is connected to the discharge pipe 9a through an on-off valve 15a. The raw water chamber 12a' below is connected with a raw water branch pipe 36a and an air branch pipe 10a. The raw water branch pipe 36a is connected to the raw water supply pipe 6 through an on-off valve 16a, and the air branch pipe 10a is connected to the air supply pipe 10 through an on-off valve 17a. . The other membrane modules 1b to 1n also have the same structure.

In such a membrane module configuration, the normal filtration mode 42 and the membrane damage detection mode 44 can be implemented in the order described for the external pressure type shown in FIG. 1 . However, in the internal pressure type, there are cases where the air supply device 5 is not permanently installed. In this case, the air supply device 5 does not use a compressor but uses an air cylinder to reduce equipment cost. The air cylinder can be supplied with pressurized air only by opening the on-off valve, which can greatly reduce the running cost.

Generally speaking, compared with the external pressure type, the internal pressure type has a smaller volume on the side of the raw water chamber, and can realize the separation and mixing of turbidity with less air volume. In addition, by applying the membrane damage detection mode shown in FIG. 3, since the frequency of use of air can be reduced, it is sufficient to use an air cylinder. In addition, the pressure in the cylinder is monitored, and when the pressure is lower than a predetermined pressure, the diagnostic device 32 may output an instruction display and an alarm for cylinder replacement.

In the example shown in FIG. 5 , a turbidity detector 30 is installed on the filtered water pipe 7 , and the detection value of the turbidity detector 30 is output to a diagnostic device 32 . The turbidity detector 30 is a laser-type high-sensitivity turbidity meter or particle sensor that measures the turbidity to 3 to 4 decimal places or the number of tens of fine particles. Because such detection mechanisms are expensive, multiple modules are allocated to one setup.

On the other hand, the turbidity detection devices 19a to 19n are cheap devices with low detection accuracy. According to such a detection method, the turbidity detector 30 monitors the filtered water of the membrane filtration treatment facility 40 as a whole, and the turbidity detection devices 19a to 19n respectively manage the permeated water of each membrane module. Thereby, according to the state of the turbidity of raw water, even when the abnormality of the permeated water cannot be sensed by the turbidity detecting devices 19a to 19n, it can be sensed by the highly accurate turbidity detector 30 .

A membrane damage detection method in the case of using the turbidity detector 30 and the turbidity detection device 19 in combination will be described. In the diagnosis device 32, when the change trend of the measured value of the turbidity detector 30 or the measured value above the preset value is reached, it is judged that damage has occurred on the membrane module of the membrane filtration processing device 40. According to FIG. The insert processing shown in 3 executes the membrane damage detection mode 44 . Highly turbidized raw water is produced in each membrane module according to the membrane damage detection mode 44, and the turbidity state of the permeated water is measured by the turbidity detection devices 19a to 19n.

The membrane module corresponding to the turbidity detection device 19 whose measurement value becomes abnormal is determined as a damaged membrane. The operation operation after determination is the same as the sequence explained in FIG. 3 . For the turbidity detection devices 19a to 19n used in this embodiment, if the number of membrane modules is N, the ratio of the turbidity concentration of the high-turbidity raw water in the membrane damage detection mode 44 to the raw water supplied by the raw water supply device 2 is When M is used, the detection sensitivity D of the turbidity detector 30 can be D×N×M, and a very cheap method is applied. Therefore, a damaged membrane module can be easily identified without incurring equipment costs.

[Example 3]

FIG. 6 is a diagram illustrating Example 3 when the membrane damage detection mode is executed. Although this embodiment has the same structure as the embodiment shown in FIG. Valve 25. The on-off valve 25 is arranged on the filtered water pipe 7 downstream of the permeated water confluence in the direction opposite to the on-off valve 22, and the filtered water passing through the on-off valve 25 is discharged out of the pipe.

In this structure, the membrane damage detection mode 44 is implemented in the order shown in FIG. 7 . Switching to the membrane damage detection mode 44, the contents of the peeling, permeation, detection, and treatment steps 56 in the mode are the same as those in FIGS. 2 and 3, but the difference is that the filtered water switching step I61 and the filtered water switching step are added. II63 and backwashing process 62.

In the filtered water switching process I61, before the peeling process 54 or the permeation and detection process 55 is performed, the control device 34 executes the control of closing the on-off valve 22 and opening the on-off valve 25 . Through this switching operation, the permeated water from each membrane module in the permeation and detection step 55 is not sent to the filtered water tank 3 but is discharged outside the system. The backwashing process 52 is a state where the on-off valve 22 is closed and the on-off valve 25 is opened, and other operations are performed the same as the backwashing process 52 described in the embodiment shown in FIG. 1 . After performing this backwashing process 52 for a predetermined time, the filtered water switching process II63 which switches to closing the on-off valve 25 and opening the on-off valve 22 is implemented. In this embodiment, after the filtered water switching process II63 is performed, the process returns to the rinsing and washing process 53 of the normal filtration mode 42 .

In this way, all the turbidity leaked from the damaged membrane module can be taken into the filtered water tank 3, and safe and clear filtered water can be maintained.

【Example 4】

In the filtration process 51 of the normal filtration mode 42, the measured values of any of the turbidity detection devices 19a to 19n show a tendency to be higher than a predetermined value or gradually increase, and FIG. 8 shows a case where there is a possibility of abnormality or damage. Example 4 below.

Fig. 8 illustrates the surroundings of the membrane module 1b. The membrane module 1b shown in Figure 8 is provided with an on-off valve 18b on the permeable water pipe 7b, and the branch pipe 7b' is connected between the on-off valve 18b and the turbidity detection device 19b and the on-off valve 18b' is arranged. The branch pipe 7b 'The point of connection with the discharge water pipe 9 is different from that of the embodiment shown in FIG. 6 . Other membrane modules also have the same structure as the membrane module 1b.

Membrane damage detection mode 44 is implemented with the flow shown in FIG. 3, but according to the flow shown in FIG. For this purpose, other normal membrane modules continue to perform normal filtration mode. In the membrane module 1b, in the peeling step 54, the on-off valves 16b and 18b are closed, the on-off valves 15b and 17b are opened, and the air supply device 5 is operated to peel off the attached turbidity to generate raw water with high turbidity. In the permeation and detection step 55, the on-off valve 15b is closed, and the on-off valve 18b' is opened to permeate the high-turbidity raw water, and the turbidity state of the permeated water is measured by the turbidity detection device 19b. In the case where the measured value showed the same change as the damaged film shown in FIG. 4 , it was judged that the film was damaged. Since the membrane module has also been determined, the normal filtration mode will not be performed in the future, and replacement and repair work will be carried out.

According to such a procedure, it is possible to accurately detect damage to a specific membrane module without interrupting the normal production of filtered water by the membrane module. In addition, it is only necessary to supply air to a certain membrane module, so that the running cost can be reduced.

In the foregoing, each embodiment has been described, but the peeling step 54 of the film damage detection mode 44 is performed as cleaning in air, but backwashing water may be temporarily supplied during air cleaning. In addition, although air is used in the permeation and detection process 55, raw water may be supplied. Furthermore, in each of the embodiments, the raw water and flush water supply devices are pumps, and the opening and closing valves are solenoid valves or air-operated valves.

【Example 5】

Embodiment 5 of the present invention will be described with reference to FIG. 9 to FIG. 11 . Fig. 9 is a structural diagram of the membrane filtration device of this embodiment.

This embodiment has shown the example of using the hollow fiber membrane module of external pressure type, as shown in Figure 9, membrane filtration processing equipment 40 is made up of membrane module 1, raw water supply device 2, filter tank 3, washing water supply device 4 and air The supply device 5 is a main component.

The upper part of the membrane module 1 is provided with a filtered water chamber 13, and the lower part is provided with a raw water chamber 12. The raw water chamber 12 is provided with a filter membrane with thousands of hollow fiber membranes. One end side of the hollow fiber membrane is installed to open to the filtered water chamber 13. The raw water chamber 12 and the filtered water are separated by the filter membrane 11 and the fixed wall 14. Room 13. Therefore, the liquid can pass through between the raw water chamber 12 and the filtered water chamber 13 through the built-in filter membrane 11 .

Connect the supply pipe 70 below the raw water chamber 12, one end of the supply pipe 70 is connected with the raw water supply device 2 through the on-off valve 22, and the other end is connected with the air supply device 3 through the on-off valve 23, and the raw water can be supplied by the raw water supply device 2, Air is supplied from the air supply device 3 .

A discharge pipe 71 provided with an on-off valve 28 is connected above the raw water chamber 12 . The filtered water chamber 13 is connected to the washing water supply device 4 through the on-off valve 29 , and the washing supply device 4 is connected to the filtered water tank 3 through the washing water pipe 72 . In addition, the filtered water chamber 13 is connected to the turbidity monitoring device 21 , and the filtered water is guided to the upper part of the filter tank 3 through the filtered water pipe 7 provided with the on-off valve 27 . Filter tank 3 is connected with clean water pipe 73 .

The normal operation of the membrane filtration treatment facility 40 configured in this way will be described. Operation operation As shown in the normal filtration mode 42 of FIG. 10 , three steps of the filtration step 51 , the backwash step 52 , and the rinse step 53 are repeatedly performed.

In the filtration step 51 , the on-off valve 22 and the on-off valve 27 are opened, the other on-off valves are closed, the raw water supply device 2 is operated, and the raw water containing turbidity is supplied to the membrane module through the supply pipe 70 . The supplied raw water captures and removes turbidity on the surface of the filter membrane 11 on the side of the raw water chamber 12, and permeates into the inside of the filter membrane. The raw water that has passed through the filter membrane becomes clear filtered water, which is stored in a certain amount in the filtered water tank 3 through the filtered water pipe 7 connected to the filter chamber 13, and the overflowed filtered water is subjected to disinfection treatment through the purified water pipe 73, etc. into clean water.

After the filtering process 51 runs for a set time, it enters the backwashing process 52 . In the backwash step 52, the raw water supply device 2 is stopped, the on-off valve 23, the on-off valve 28, and the on-off valve 29 are opened, the other on-off valves are closed, and the air supply device 5 and the washing water supply device 4 are operated. Pressurized air is supplied to the raw water chamber 12 of the membrane module 1 through the supply pipe 70 by the operation of the air supply device 5 and is discharged from the upper discharge pipe 71 . In addition, by the operation of the washing water supply device 4, a certain amount of filtered water stored in the filtered water tank 3 is supplied to the filtered water chamber 13 of the membrane module 1 through the washed water pipe 72 as the washed water, and the filtered water from the filter membrane 11 The inside permeates to the side of the raw water chamber, and is discharged from the discharge pipe 71 together with the air.

The air supplied to the raw water chamber 12 strips off the turbidity captured and attached to the surface of the membrane, and the washing water permeating from the inside of the membrane to the raw water chamber 12 removes the turbidity entering the membrane at the same time during the permeation process. The membrane surface on the 12th side promotes the removal of captured and attached turbidity. The detached turbidity is discharged from the discharge pipe 71 to the outside of the membrane module system together with air and permeated washing water as washing water.

After the backwashing step 52 is completed, the washing process 53 stops the air supply device 3 and the washing water supply device 5, opens the on-off valve 22 and the on-off valve 28, and closes other on-off valves to activate the raw water supply device 2. The raw water supplied to the raw water chamber 12 does not pass through the filter membrane, and is discharged from the discharge pipe 71 to clean the raw water chamber 12 and the membrane surface on the side of the raw water chamber, and remove the remaining air in the raw water chamber 12 at the same time.

It is a cycle from the filtering process 51 to the washing process 53, and after the washing process 53 is finished, it enters the filtering process 51 of the next cycle. These operations are called the normal operation mode, and the time required for each process input from the input device 60, the operation and stop of each supply device, and the operation time of each on-off valve are instructed from the diagnostic device 50 to the control device 70 and executed. . The diagnosis device 50 has a timer function, counts the execution time of each processing step and determines to enter the next step and the next cycle.

The membrane damage detection method will be described below. In the normal operation mode, the turbidity state of the filtered water in the filtration step 51 is measured by the turbidity monitoring device 21, and if the measured value is abnormal, it can be determined that the membrane is damaged. However, it is very difficult to clearly determine membrane damage based on the measurement sensitivity of the turbidity monitoring device 21, the concentration of raw water, the specifications of the membrane module, and the like.

The turbidity monitoring device 21 is an ultra-high-sensitivity turbidity meter that can display 0.0001 degrees to 4 decimal places, and a membrane module with 10,000 hollow lines is based on the turbidity of raw water, which is usually 1 degree in river surface water. For example, when calculating the filtered water concentration when one hollow line is damaged, it is 0.0001 degrees based on a simple calculation. If the damaged part is easy to leak in consideration of the no-membrane impedance, the turbidity change will be at the fourth decimal place. In the turbidity monitoring device 21 targeting a plurality of membrane modules, the change is further reduced, and detection becomes very difficult.

The membrane damage detection in the present embodiment is performed in the normal operation mode based on the measurement value of the turbidity monitoring device 21 or the setting information input from the input device 60 . The operation of the insertion is from the indirect method, the combination of the indirect method and the direct method, and from the combination to the direct method, which are respectively called the first insertion operation mode 100, the second insertion operation mode 110, and the third insertion operation mode. 120. Its sequence and content are shown in Figure 10.

According to the interrupt execution command of the diagnosis device 50, the first interrupt operation mode is entered, and the membrane filtration treatment device 40 is operated by the control device 70 according to a preset sequence.

In the first plug-in operation mode 100, in the filtration process 51 of the normal operation mode 42, or after the filtration process 51, first perform: open the on-off valve 23 and the on-off valve 28, close other on-off valves, and make the air supply device 5. High turbidity step 101 of working for a predetermined time. Pressurized air is supplied to the raw water chamber 12 through this turbidity increasing step 101 . Although the raw water chamber 12 is full of water, the rising air is discharged from the discharge pipe 71 because the upper on-off valve 28 is opened. This ascending air flow has the effect of stripping the turbidity captured and attached to the surface of the filter membrane 11 of the raw water chamber 12, and uniformly mixing the detached turbidity with the remaining raw water. According to the experimental conclusions of the present inventors, the air cleaning in the step 101 of increasing turbidity can be 1 minute or less.

Although the raw water in the raw water chamber 12 has decreased by a volume corresponding to the accumulated water in the fixed wall 14 and the discharge pipe 71, most of it remains in the raw water chamber 12 and becomes high turbidity water. The ratio is approximately the ratio of the amount of filtered water in the filtration step 51 to the volume of the raw water chamber. For example, when a membrane module with a membrane area of 25m ² and a raw water chamber volume of 10L is operated for 1 hour at a filtration flow rate of 2m/d, the turbidity of high turbidity water becomes about 200 times that of raw water. Although the high turbidity step 101 may not be empty washing, the on-off valve 28 and the on-off valve 29 are opened, and the washing water supply device 4 is operated for a predetermined time to generate high turbidity water, but the turbidity due to the dilution of the washing water Low, the effect is not obvious.

In the high turbidity water filtration step 101 , the on-off valve 22 and the on-off valve 27 are opened to operate the raw water supply device 2 as in the normal filtration step 51 . Through this operation, high turbidity water is filtered for the first time, and when membrane damage occurs, the turbidity contained in the filtered water increases.

In the determination step A103, the presence or absence of damage is determined based on the measurement value of the turbidity monitoring device 21, and the next operation is instructed based on the determination result. For example, if the difference between the measurement value of the turbidity monitoring device 21 of the filtration process 51 in the previous normal operation mode 42 and the measurement value of the high turbidity water filtration process 102 is α, three reference values are set to α 1< When α 2<α 3, if α<α 1, it is determined that there is no damage, and the normal operation mode 42 is returned. If α1<α<α2, it is determined that the possibility of damage is high, and the second interrupt operation mode 110 described later is executed. In the case of α>α3, it is clearly determined that damage has occurred, the membrane filtration processing device 40 is stopped, and an alarm and damage occurrence information are output to the output device 80.

The reference value can be set as follows: α1 is the number of digits at the same level as the measured value of the turbidity monitoring device 21, α2 is changed by 1 digit, and α3 is changed by 2 digits. The high turbidity water filtration process 102 is set to the operating conditions under which the influence of high turbidity water is expressed on the filtered water, for example, the time for filtering about half of the high turbidity water (half of the volume of the raw water chamber), or the flow rate of filtered water .

In the first interrupt operation mode 100, if it is determined that there is no membrane damage, the filtered water obtained in the high turbidity water filtration process 102 is judged to be as safe as the normal operation mode 42 and used as purified water, so there will be no The problem of reduced water production efficiency.

In addition, as the source of supply to the raw water chamber 12 of the high turbidity water filtration process 102, by replacing the raw water with air, the generated high turbidity water can be filtered without diluting it, so the turbidity of the filtered water can be further improved at the time of damage. sensitivity. In addition, if the flow rate of the filtered flow is set low in the high turbidity water filtration step 102, the sensitivity of the turbidity of the filtered water can be increased and the change time can be further continued, which has the effect of improving the detection accuracy when the membrane is damaged.

When it is determined in the first interrupt operation mode 100 that the possibility of membrane damage is high, the second interrupt operation mode 110 is executed. In the second interrupt operation mode 110 , the on-off valve 23 and the on-off valve 27 are opened, the air supply device 5 is operated, and an air supply and filtration step 111 is performed in which the filtration process is performed using the pressure of air. As the air supply filtering process 111 proceeds, the volume of the air layer formed in the upper part of the raw water chamber 12 by the supplied air increases, and the raw water layer decreases. When the lower part of the air layer is lower than the damaged position, the filtered water from the raw water layer and the leaked air from the damaged part flow into the filtered water chamber 13 , and the filtered water mixed with air and liquid flows into the filtered water pipe 7 .

Since the turbidity monitoring device 21 measures air bubbles in the liquid as turbidity, it is not particularly limited, and sensors such as ultrasonic waves, photoelectricity, sound, and resistance can be used. Judgment step B112 obtains the inflection point of the measured value of the turbidity monitoring device 21 and its appearance time, and then the rising speed of the measured value after the inflection, diagnoses the membrane damage position and the size of the damage based on these calculated values, and stops the membrane filtration processing device 40 , and output to the output device 80 to display an alarm or its diagnosis result. And, regardless of the possibility of membrane damage, the third interrupt operation mode 120 is executed when an inflection point of the measured value is identified or the measured value rises in the air supply filtration step.

In the third interrupt operation mode 120 , after filtering all the raw water in the raw water chamber 12 , an air-filling step 121 of stopping the air supply and sealing the raw water chamber 12 is implemented. FIG. 11 shows the apparatus configuration of the air filling step 121 .

The difference with the device structure shown in FIG. 9 is that a flow monitoring device 26 for filtered water is provided on the filtered water pipe 7 between the membrane module 1 and the on-off valve 27, and a flow monitoring device 26 is provided between the membrane module 1 and the on-off valve 28. The pressure monitoring device 25 is arranged on the discharge pipe 71 of the exhaust pipe.

In the second interrupt operation mode 110 , the on-off valve 23 and the on-off valve 27 are opened to obtain filtered water from the air from the air supply device 5 . If the air is continuously supplied, all the raw water in the raw water chamber 12 is filtered and disappears, and becomes an air layer. At this time, the measurement value of the flow rate monitoring device 26 becomes 0, and it is judged that the raw water chamber 12 is completely replaced with air, and the on-off valve 23 is closed to stop the air supply device 5 . This step is called an air filling step 121 .

In the air sealing step 121, the on-off valve 27 is opened, and when the membrane is damaged, the air in the raw water chamber 12 leaks from the damaged part and is discharged from the filtered water pipe 7, and the pressure of the enclosed air decreases. In the case of a normal membrane without damage, the air in the raw water chamber 12 does not leak to the filtered water chamber 13 side, and the air pressure does not change. In the determination step C122, the diagnosis device 50 diagnoses the presence or absence of damage and the degree of damage based on the pressure measurement value of the pressure monitoring device 25 having the raw water chamber 12 as a measurement object.

The presence or absence of damage can be diagnosed by whether the pressure drops, and the degree of damage can be diagnosed by the pressure drop speed which varies corresponding to the damage area. These diagnostic results are output and displayed on the output device 80 . In addition, when the pressure does not drop, it can be diagnosed that the turbidity monitoring device 21 is abnormal or the like.

In this way, in the third cut-off operation mode 120, even if there is a possibility of membrane damage in the first cut-off operation mode 100, if the presence or absence and degree of damage of the membrane in the second cut-off operation mode 110 are unclear, It can be grasped correctly, without worry, and can improve safety. In addition, since the insertion operation in which the membrane module is filled with pressurized air is the final mode, the stress applied to the filter membrane can be suppressed as much as possible.

[Example 6]

Embodiment 6 of the present invention will be described with reference to FIG. 12 and FIG. 13 . Fig. 12 is a structural diagram of the membrane filtration device of this embodiment.

The difference from Embodiment 5 shown in FIG. 9 is that a turbidity monitoring device 24 for measuring the turbidity concentration of supplied raw water is installed on the upstream side of the raw water supply device 2, and a flow rate monitoring device for filtered water is installed on the filtered water pipe 7. 26.

In this embodiment, based on the measurement value of the turbidity monitoring device 24, etc., the production state of high turbidity water is grasped, and the presence or absence of membrane damage can be determined in advance based on the generated high turbidity water, and an effective plug-in operation mode is set.

First, the volume V of the raw water chamber 12 of the applicable membrane module 1, the number of hollow threads, the inner and outer diameters, etc., the necessary heights required for the measurement sensitivity of the turbidity monitoring device 21 and the degree of damage of the measurement object are determined in advance. The turbidity water (for example, turbidity target value Dm) is set in the diagnosis device 50 by the input device 60 . The turbidity target value Dm can be easily calculated using a fluid formula, and can be set using the experimental results of a membrane module in an assumed damaged state.

In the diagnostic device 50, the raw water turbidity d of the turbidity monitoring device 24, the filtered water volume q of the flow rate monitoring device 26, the operating time setting value tm of the filtration process step stored in the diagnostic device 50 under normal operation, etc. are used, The formation turbidity value Du of high turbidity water is calculated by formula 1 and formula 2.

(Formula 1)

Du＝k·d·q·tm/V …(1)

Here, k (=~1.0) is a high turbidity conversion coefficient.

In addition, in the diagnostic device 50 , the filtration treatment time tn required to bring the turbidity value Du of the high-turbidity water to the target value Dm is obtained from Equation 2.

(Formula 2)

tn＝Dm·V/k·d·q …(2)

Fig. 13 shows the sequence and contents of the interrupt operation in this embodiment. In the case of performing the same interrupt operation command as in Embodiment 5, the diagnosis device 50 executes the normal operation mode 42, and in the determination step 104, if Dm≤Du, under predetermined conditions, the normal operation After the filtration process 51, it enters into the 1st interrupt operation mode 100. If Dm>Du, the operation is changed at the ratio C (=tn/tm) of the required filtration processing time tn and the set value tm.

For example, when the ratio C is below the set value Cm (<1.0~5.0), the target high turbidity water can be obtained if the filtration treatment time is extended, so the normal operation before the interrupt operation is changed. The time of the filtration process 51 is changed from tm to tn, and the first interrupt operation mode 100 is entered after the filtration processing time tn.

In the case of C>Cm, it is determined that the target high turbidity water cannot be obtained even if the time of the filtration step 51 is prolonged, and the first interrupt operation mode 100 is not executed, and the second interrupt operation mode 110 is implemented. In this case, the third interrupt operation mode 120 confirms that the measured value changed to the turbidity monitoring device 21 in the second interrupt operation mode 110 is implemented when an inflection point or an increase tendency due to leaked air bubbles is not clear. The output information to the output device 80 in the determination step B112 and the determination step C122 in the second interrupt operation mode 110 and the third interrupt operation mode 120 is the same as that in the fifth embodiment. In addition, the change information of the first interrupt operation 100 is also output and displayed on the output device 80 .

According to such a procedure, the turbidity of the membrane module 1 can be effectively used to detect membrane damage. In addition, when the expected effect cannot be obtained even by trapping turbidity, although stress is applied to the filter membrane, it is possible to ensure safety by early detection necessary for the water purification process by implementing the filter method from the air supply. Effect.

In addition, usually without using a new source of turbidity, by effectively utilizing the turbidity in the membrane module, the sensitivity to the turbidity of filtered water can be improved, and whether or not membrane damage has occurred can be easily ascertained. If there is a possibility of membrane damage during this detection process, the detailed judgment of membrane damage is first performed using air, and since the stop of the process treatment is the final direct method, it is possible to minimize the decrease in water purification production efficiency .

FIG. 14 shows an example of the first interrupt operation mode 100 . The membrane module used is a large type suitable for an actual process described in Example 5. The damaged membrane was damaged by a hollow line approximately in the middle of the longitudinal direction, and the normal membrane module was compared with the result of the high-turbidity water supply filtration process. The turbidity of filtered water with damaged membranes varies greatly compared with normal membranes. In addition, the turbidity of the filtered water of the damaged membrane is also increased in the step of supplying air and raw water, and the damaged membrane can be easily confirmed and evaluated in the high turbidity water filtration step 102 . In addition, the influence of high turbidity water that damages the membrane on filtered water also appears in a short period of time when air and raw water are supplied.

In this way, by increasing the turbidity of the raw water chamber and filtering the high turbidity water, the filtered water is affected regardless of the location of the damage, and it can be known whether or not the membrane damage occurs can be ascertained in advance.

An example of the second interrupt operation mode 110 is shown in FIG. 15 . As in Example 5, it is the comparison result of the damaged membrane and the normal membrane in the air supply filtration process 111 in the flow rate of filtered water and the amount of air leaked from the filtered water. The filtered water flow rate decreases due to the reduction of the membrane filtration area while continuing to supply air. It is difficult to see the difference in the filtered water flow rate between the damaged membrane and the normal membrane, but the difference in the amount of leaked air can be clearly confirmed.

Normal membranes do not expose air even when the filtered water flow is zero. In the damaged film, air leakage occurs when the air layer reaches the vicinity of the middle of the damaged portion. Even if the air starts to leak out, since the raw water remains under the raw water chamber of the damaged part, it is filtered water that coexists with air and liquid until the raw water disappears. Such gas-liquid mixed water can be easily detected by sensors utilizing the principles of ultrasonic waves, photoelectricity, sound, and resistance.

In addition, the filtered water flow rate is measured by the water flow rate monitoring device 25, but all the raw water is removed from the damaged membrane, and the flow rate becomes zero regardless of whether the leakage air is discharged. From this, it can be seen that the water flow rate monitoring device 25 has not measured the air flow rate.

In addition, the raw water and washing water supply device is a pump, the air supply device is an air pump, and the on-off valve is a solenoid valve or an air-operated valve. In addition, these supply devices and on-off valves can automatically adjust the flow rate, especially the on-off valve that does not open and discharge at a stretch after the air supply filtration process and air sealing process in the second and third insertion operations. , can prevent stress from being applied to the filter membrane by operating within the specified time.

In addition, each embodiment is described for an external pressure type membrane module, but the present inventors have confirmed that the same effect can be obtained even in an internal pressure type membrane module, and can be applied to an internal pressure type membrane module without hindrance. .

Claims (25)

1. film filter, it possesses:

Former hydroecium, it supplies with former water by first open and close valve from former water feeder;

Film module, it sees through the former water of this former hydroecium by filter membrane;

See through the chamber, it stores the permeate water that has been seen through by this film module;

Discharge pipe, it is connected with described former hydroecium by second open and close valve;

Filtering trough, it is connected with the described chamber that sees through by turbid quality inspection survey device, the 3rd open and close valve;

Air feeder, it is connected with described former hydroecium by the 4th open and close valve;

Control appliance, it is controlled, make and close described first open and close valve and the 3rd open and close valve, open described second open and close valve and the 4th open and close valve, make described air feeder work, open described the 3rd open and close valve, close described second open and close valve, open the 3rd open and close valve or the 4th open and close valve, the film module of damage is judged in the variation of surveying the Device Testing value according to described turbid quality inspection, described first～the 4th open and close valve of the film module that is judged to be this damage is closed the control of locking.

2. film filter, it possesses:

Former hydroecium, it supplies with former water by first open and close valve from former water feeder;

Film module, it sees through the former water of this former hydroecium by filter membrane;

See through the chamber, it stores the permeate water that has been seen through by this film module;

Discharge pipe, it is connected with described former hydroecium by second open and close valve;

Filtering trough, it is connected with the described chamber that sees through by turbid quality inspection survey device, the 3rd open and close valve;

Air feeder, it is connected with described former hydroecium by the 4th open and close valve;

Control appliance, it is after open described the first, the 3rd open and close valve makes the filtered model of former water feeder work, implement the membrane damage detecting pattern, the membrane damage detecting pattern is carried out following two operations, one is a stripping process, stop described former water feeder, open described second open and close valve makes described air feeder work setting-up time; It is closed described second open and close valve and generates permeate water two for seeing through, detecting operation, surveys device by described turbid quality inspection and carries out based on the measured value that generates the turbid matter in the permeate water and judge that film module has not damaged.

3. film filter as claimed in claim 2, wherein,

Described membrane damage detecting pattern is carried out the operation of the film module of having determined to damage.

4. as each described film filter in the claim 1 to 3, wherein,

Described film filter possesses highly sensitive turbid matter detector at the leading portion of described filtering trough, judge under the situation of the damage that has produced film module at measured value, survey device based on described turbid quality inspection and judge the damage that has or not film module according to this turbid matter detector.

5. film filter as claimed in claim 2, wherein,

Be provided with described turbid quality inspection and survey the pipe arrangement that is used for filtered water is discharged to the outside that device is connected and has the 5th open and close valve, close described the 3rd open and close valve, open described the 5th open and close valve, described membrane damage detecting pattern are carried out the operation of the film module of having determined to damage.

6. film filter as claimed in claim 2, wherein,

Described membrane damage detecting pattern termly based on the turbid matter measurement mechanism in the filtered model to the measured value of permeate water and carry out.

7. as each described film filter in the claim 1～3,5,6, it possesses the 6th open and close valve of the film module disconnection that will be judged to be described damage.

8. film filter as claimed in claim 4, it possesses the 6th open and close valve of the film module disconnection that will be judged to be described damage.

9. the membrane damage detection method of a film filter, wherein,

Supply with former water from former water feeder to former hydroecium by first open and close valve, former water at this former hydroecium sees through the filter membrane of film module and surveys device by turbid quality inspection, the 3rd open and close valve is after being stored into the filtered model the filtering trough through the chamber, control by control appliance, make and close described first open and close valve and the 3rd open and close valve, open second open and close valve that is arranged on the discharge pipe that is connected with described former hydroecium, open the 4th open and close valve that is arranged on the pipe arrangement that connects described former hydroecium and air feeder, make described air feeder work, open described the 3rd open and close valve, close described second open and close valve, open described the 3rd open and close valve or the 4th open and close valve, the film module of damage is judged in the variation of surveying the Device Testing value according to described turbid quality inspection, and described first～the 4th open and close valve of the film module that is judged to be this damage is closed locking.

10. the membrane damage detection method of a film filter, it is supplying with former water from former water feeder to former hydroecium by first open and close valve, the former water of this former hydroecium sees through the filter membrane of film module and surveys device by turbid quality inspection, the 3rd open and close valve is after being stored into the filtered model the filtering trough through the chamber, has the membrane damage detecting pattern, described membrane damage detecting pattern is implemented the stripping process of setting-up time, this stripping process is to pass through control appliance, stop supply from the former water of described former water feeder, utilize described air feeder to discharge to the discharge pipe that is connected with described former hydroecium to former hydroecium air supply and with air, stripping film adheres to turbid matter, obtain high turbidity water's operation

Carry out seeing through, detecting operation, should see through, detect operation is to close second open and close valve, stops the discharge of air, generates permeate water, surveys device according to described turbid quality inspection the turbid matter status detection value of this permeate water is judged that film module has not damaged.

11. as the membrane damage detection method of claim 9 or 10 described film filters, wherein,

Be judged as under the situation of film module generation damage at the measured value of basis, carry out surveying the membrane damage detecting pattern of device based on described turbid quality inspection at the turbid matter detector of high sensitivity of described the 3rd open and close valve leading portion setting.

12. as the membrane damage detection method of claim 9 or 10 described film filters, wherein,

Damage is arranged on film module, determined to stop to supply with under the situation of damage film module to the former water of this film module.

13. the membrane damage detection method of film filter as claimed in claim 11, wherein,

Damage is arranged on film module, determined to stop to supply with under the situation of damage film module to the former water of this film module.

14. the membrane damage detection method of a film filter, wherein, described film filter possesses the film module that is divided into former hydroecium and filtration hydroecium by film, as common running, carries out following operation repeatedly:

Filter operation, its former water that will contain turbid matter is supplied with to described former hydroecium and the filtered water that obtains clarifying from described filtration hydroecium;

The back washing operation, it is supplied with filtered water and it is seen through to former hydroecium side to described filtration hydroecium, sees through in the process at this and peel off the turbid matter of catching on the face of described former hydroecium side, discharges outside film module as cleaning draining; And

Do the wash operation, it is supplied with former water to described former hydroecium and also directly discharges outside film module,

In the filtration operation of described common running or after filtering operation, insert and implement the first insertion running, described first inserts the running that running is following two operations of running, that is: high turbidity chemical industry preface, it is stripped in the former water of described former hydroecium the turbid matter of catching and generates the high turbidity water on the face of described former hydroecium side; And the high turbidity water filters operation, and it makes the high turbidity water that generates in this high turbidity chemical industry preface see through to described filtration hydroecium with the time set or the amount of setting,

The turbid qualitative change judgement film that filters according to described high turbidity water in the permeate water of operation has not damaged.

15. the membrane damage detection method of film filter as claimed in claim 14, wherein,

Be judged to be under the situation of no membrane damage in the result who implements the described first insertion running, removing described first inserts running and returns common running, be judged as under the situation of membrane damage, the insertion enforcement second insertion running is promptly turned round to former hydroecium air supply and is carried out filtered air and supply with the filtration operation, according to the faulted condition of the turbid qualitative change diagnosis film in the filtered water of described air supply filtration operation.

16. the membrane damage detection method of film filter as claimed in claim 15, wherein,

Under supplying with turbid matter state in the filtered water of filtering operation, described air can't diagnose under the situation of faulted condition of film, insert after running promptly operates at the former water that makes described former hydroecium and all see through by insert implementing the 3rd, stop air and supply with and seal the air inclosure operation of former hydroecium, the pressure of enclosing the former hydroecium of operation according to described air changes to diagnose whether membrane damage is arranged.

17. the membrane damage detection method of film filter as claimed in claim 14, wherein,

Described first to insert running be the running that the turbid matter state in the filtered water when turning round termly or is usually carried out, according to predefined high turbidity water's turbidity desired value with carry out slightly before common running the time former water chaotic degree, calculate the running time to described filtration operation, through computing duration of runs of described filtration operation after, carry out described first and insert running.

18. the membrane damage detection method of film filter as claimed in claim 17, wherein,

Duration of runs of the described filtration operation of having calculated under the situation more than the predefined time, by inserting, and insert the running entry into service from described second.

19. as the membrane damage detection method of claim 15 or 16 described film filters, its:

Gradually outside film module, discharge by described second air that inserts the described former hydroecium of running and the 3rd insertion running supply.

20. a film filter, wherein,

Possess:

Film module, it is filtered film and is divided into former hydroecium and filters hydroecium;

Former water feeder, it is connected with described former hydroecium by supply pipe;

Air feeder, it is connected with described former hydroecium; And

Filtering trough, it is connected with described filtration hydroecium by the filtration water pipe that is provided with turbid quality supervision view apparatus,

Insertion execution command according to diagnostic device, from described former water feeder to described film module supply with former water and the process of the filtration operation of the common running of filtering or filter operation after, from described air feeder to described former hydroecium air supply and after peeling off the turbid matter of described filter membrane surface, enforcement is supplied with first of former water from described former water feeder to described former hydroecium and is inserted running, judges the damage of described filter membrane according to the measured value of described turbid quality supervision view apparatus.

21. film filter as claimed in claim 20, wherein,

Be judged to be under the situation of no membrane damage in the result who implements the described first insertion running, remove described insertion running, return the common running of filtering operation, back washing operation repeatedly, doing the wash operation, be judged to be under the situation of membrane damage, enforcement is inserted running from described air feeder to described former hydroecium air fed second, judges the damage of described filter membrane according to the measured value of described turbid quality supervision view apparatus.

22. film filter as claimed in claim 21, wherein,

In the result who implements the described second insertion running is can't judge under the situation of membrane filtration damage, implement the 3rd and insert running, promptly the described former hydroecium of sealing after judging the air of being supplied with by described air feeder to be full of former hydroecium is judged the damage of described filter membrane based on the measured value of the pressure monitoring device of measuring described former hydroecium pressure.

23. film filter as claimed in claim 20, wherein,

Before implementing the described first insertion running, based on predefined high turbidity water's turbidity desired value with carry out described first insert before the running common running the time former water chaotic degree calculate necessary filtration time, in through the filtration operation behind the filtration time that has calculated, implement described first and insert running.

24. film filter as claimed in claim 23, wherein,

Inserting filtration time necessary in the running described first is under the situation more than the predefined time, implements to insert running from described air feeder to described former hydroecium air fed second.

25. as claim 21 or 22 described film filters, wherein,

Have and carrying out described second insertion running or the 3rd mechanism that inserts the air fed efflux time of the former hydroecium of running back adjustment.

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