JP2009233650A - Operation control method of membrane filtration apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of damage detection of a membrane module by which the detection precision of membrane damage and the safety of filtrate water are improved, and an operator can easily comprehend situations. <P>SOLUTION: A membrane filtration apparatus comprises: damage detection sensors, provided in the piping of the filtrate water on the downstream side of the respective membrane modules, for detecting a foreign matter in the filtrate water; an inflow valve provided to shut off raw water on the upstream side of the membrane module; a controller for controlling the opening/closing of the inflow valve and receiving the measured value of the damage detection sensors; and a display means for displaying the measured value of the damage detection sensors and the control result of the controller. The controller compares the measured value of the damage detection sensors with a preset determination value, displays an alarm when the measured value is equal to or larger than the determination value, determines that it is a damage when the duration of exceeding the determination value reaches the set time period, and shuts off the raw water by the inflow valve. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an operation control method for a membrane filtration apparatus installed for separating and removing turbidity and pathogenic protozoa contained in raw water.

  Membrane filtration devices can remove almost 100% of fine particles larger than the pore size of the installed membrane and are easy to maintain and manage, so the introduction to water purification facilities is increasing. The membrane is processed in module units. In the case of a hollow fiber membrane, thousands of hollow fibers are incorporated in the membrane module. In the water purification facility, a unit is constituted by a plurality of membrane modules, and the membrane modules are controlled.

  Since the membrane filtration apparatus is repeatedly subjected to operations such as filtration, backwashing, and chemical washing, the membrane module may be damaged. If damaged, turbidity will be mixed into the treated water, so a system that can detect the damage of the membrane module online with high accuracy is necessary in order to always supply safe and safe purified water.

  There are the following methods for detecting damage to the membrane module. As described in [Patent Document 1], there is a device that detects the turbidity of filtrate water, detects a value of turbidity of a predetermined value or more for a predetermined time or more, and determines damage in a subsequent pressure holding test. In addition, as described in [Patent Document 2], there is an apparatus that detects damage to a film by installing an optical sensor in a transparent pipe. As described in [Patent Document 3], there is an apparatus in which an ultraviolet ray device is installed at the rear stage of a membrane filtration device and ultraviolet rays are irradiated when the membrane is damaged.

JP 2000-279770 A JP 2000-342937 A JP 2007-98338 A

  The membrane damage detection apparatus described in [Patent Document 1] may increase the turbidity of filtered water even in a normal membrane when the raw water quality varies, for example, when the turbid particle size in the raw water is small. In addition, the operator cannot grasp that it is in the primary determination state, and the response may be delayed.

  In the damage detection apparatus described in [Patent Document 2], since an optical sensor is installed in a transparent pipe, ambient light may reach the sensor, which may cause erroneous detection.

  In the water treatment apparatus described in [Patent Document 3], it is possible to irradiate ultraviolet rays when the membrane is damaged, but it is desirable to stop the filtration at the time of damage in order to improve safety.

  The purpose of the present invention is to prevent false detection of the damage detection sensor, and automatically stop the operation when determining damage, so that the detection accuracy and the safety of filtered water can be improved, and the membrane module is easily damaged by the operator. It is to provide a detection method.

  Another object of the present invention is to provide an operation control method for a membrane filtration device that can improve detection accuracy and safety of filtered water for automatically stopping operation when determining damage.

  In order to achieve the above-mentioned object, the present invention compares a measured value with a preset judgment value, displays an alarm when the measured value is equal to or greater than the judgment value, and continues for a duration exceeding the judgment value. When the set time is reached, it is judged as damaged and the raw water is closed by the inflow valve.

  In addition, the control device determines that the damage has occurred when the measured value exceeds the determination value for a continuation time and the measurement value of at least one other damage detection sensor is smaller than the determination value. Is to be closed.

  The display means changes the display of at least one of the color, shape, numerical value, and sentence of the damage detection sensor for each determination result according to the determination of the normal level, alarm level, and raw water cutoff level of the control device. It is.

  In addition, the control device obtains an average value of the measurement values of the damage detection sensor, displays an alarm when the absolute value of the difference between the measurement value and the average value is equal to or greater than the first determination value, and the absolute value is greater than the first determination value. Is greater than the second determination value, it is determined that there is damage and the inflow valve is closed.

  In addition, the control device displays an alarm when the absolute value of the difference between the measured value and the average value is greater than or equal to the determination value, and determines that the damage has occurred when the duration exceeding the determination value reaches a set time. The valve is closed.

  The display means displays the measurement value, average value, and judgment value of the damage detection sensor, and the color of the damage detection sensor for each judgment result according to the judgment of the normal level, alarm level, and raw water cutoff level of the control device. , Shape, numerical value, or at least one of the sentences is changed.

  Also, the initial value of the measurement value of the damage detection sensor is stored in the control device, and compared with the current value of the measurement value of the damage detection sensor. It is determined and displayed on the display means.

  In addition, an ultraviolet ray device for irradiating the filtered water with ultraviolet rays according to a signal from the control device is provided, and the control device displays an alarm on the display means and outputs a signal for irradiating the ultraviolet ray device with ultraviolet rays.

  The damage detection sensor is provided with a window where light passes through and does not leak filtered water at the opposite position of the piping, and is equipped with a light emitting element outside the window and a light receiving element on the other side. Is sent to the control device.

  According to the present invention, it is possible to issue a warning for the detection of the damage of the membrane module by the first determination, stop the operation at the time of the damage by the second determination, and improve the detection accuracy and the safety of filtered water.

  Embodiments of the present invention will be described with reference to the drawings.

  A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a configuration diagram of the membrane filtration device according to the first embodiment.

  In the membrane modules 1-1 to 1-4, an MF membrane (microfiltration membrane), a UF membrane (ultrafiltration membrane), and the like are incorporated, and turbidity and fine particles in the raw water are removed. A raw water pump 2 is installed upstream of the membrane module 1, and raw water is supplied to the membrane module 1 by the raw water pump 2 through a pipe. Between the membrane module 1 and the raw water pump 2, inflow valves 3-1 to 3-4 such as motor valves and electromagnetic valves are installed. For example, when the inflow valve 3-1 is closed, the filtration of the membrane module 1-1 is stopped. it can.

  The filtered water filtered by the membrane module 1 is temporarily stored in the filtered water tank 4 installed on the downstream side of the membrane module 1. In the middle of the pipe connecting the membrane module 1 and the filtrate water tank, a pipe provided with the backwash pump 5 is connected. When the backwash pump 5 is activated, the filtrate water in the filtrate water tank 4 is 2 of the membrane module 1. The turbidity supplied from the next side and accumulated on the film surface is peeled off. In FIG. 1, piping for backwash drainage and valves necessary for switching between filtration and backwashing are omitted.

  Damage detection sensors 6-1 to 6-4 are installed in the piping of filtrate water downstream of the membrane modules 1-1 to 1-4. The damage detection sensor 6 includes a light-emitting element such as a laser diode and a light-receiving element such as a photodiode, and can measure the amount of light that is blocked by mixing fine particles or bubbles into the filtered water, thereby detecting damage to the film. .

  A flow meter 7 is installed in the pipe between the damage detection sensor 6 and the filtrate water tank 4 to measure the filtration flow rate of the membrane filtration device. Measurement signals from the damage detection sensor 6 and the flow meter 7 are transmitted to the control device 8.

  The control device 8 outputs a signal to the raw water pump 2 and the backwash pump 5 and operates at a flow rate set based on the signal from the flow meter 7. The control device 8 controls the opening and closing of the inflow valves 3-1 to 3-4, and individually stops the filtration of the membrane modules 1-1 to 1-4 as necessary. The input signal and output signal of the control device 8 are input to the display means 9 such as a liquid crystal display, and the operating conditions, the state of film damage detection, and the like are displayed.

  The damage detection method according to the first embodiment will be described with reference to the flowchart of FIG.

  In step 1, the control device 8 receives the measurement signals of the damage detection sensors 6-1 to 6-4 and compares these measurement values with a preset first determination value A. Here, the measured value may be determined by an absolute value. If the measured value is less than or equal to the determination value A, it is determined as a normal level and the process ends. For example, when the measured value of the damage detection sensor 6-1 is greater than or equal to the determination value A, the control device 8 determines a warning level in step 2 and gives a signal for displaying a warning to the display means 9.

  In step 3, the control device 8 compares the measured value with the second determination value B. The determination value B is set to a value larger than the determination value A. For example, when the measurement value of the damage detection sensor 6-1 is equal to or less than the determination value B, the alarm level is determined and the process ends. When the measured value of the damage detection sensor 6-1 is greater than or equal to the determination value B, it is determined that the membrane module 1-1 is at the raw water cutoff level due to damage.

  In step 4, the control device 8 gives a signal for indicating the closing of the inflow valve 3-1 to the inflow valve 3-1, and gives a signal for displaying the damage to the display means 9 and ends. The control device 8 executes the flow shown in FIG. 2 at set intervals and monitors the state of the membrane module.

  The display means 9 displays whether the membrane module is at a normal level, an alarm level, or a raw water cutoff level based on a signal from the control device 8. The display means 9 changes at least one of the measured value, the sensor color, the shape, the comment text, and the blinking of the display in accordance with the above three levels. By changing the display according to the level, the operator can easily confirm the presence or absence of film damage.

  The flow shown in FIG. 2 may be executed during filtration. Since the damage detection sensor 6 used in the present embodiment can detect fine particles and bubbles, when bubbles accumulated in the pipe pass through the damage detection sensor 6 when switching from filtration to backwashing or backwashing to filtration, Even if the module itself is normal, it may be judged as damaged. For this reason, the flow shown in FIG. 2 is executed during the filtration except immediately after the switching of the filtration, and the detection accuracy can be improved in this way.

  According to the present embodiment, the detection of the damage of the membrane module can be issued by the first determination, and the operation can be stopped when the damage is determined by the second determination, so that the detection accuracy and the safety of the filtered water can be improved. Further, since the display changes according to the determination result, the operator can easily grasp the situation.

  In Example 1, for example, when the turbid particle size in the raw water becomes smaller than the membrane pore size of the membrane module due to fluctuations in the raw water quality, fine particles may be mixed into the filtered water even if it is normal, and it is erroneously detected as damage. There is a fear. In that case, the flow shown in FIG. 3 may be executed. The flow in FIG. 3 is the same as the flow in FIG. 2, but step 3-2 is added between step 3 and step 4 in the flow shown in FIG. 3.

For example, when the measurement value of the damage detection sensor 6-1 is greater than or equal to the determination value B, the control device 8 proceeds to step 3-2. In step 3-2, the control device 8 compares the measurement values of the other damage detection sensors 6-2 to 6-4 with the determination value A. When one or more of the measurement values of the other damage detection sensors 6-2 to 6-4 are equal to or higher than the determination value A, it is determined that the damage is derived from the raw water quality, and the process is terminated as an alarm level. When the measured values of the other damage detection sensors 6-2 to 6-4 are all equal to or less than the determination value A, the control device 8 determines that the membrane module 1-1 is damaged and controls the inflow valve 3-1. A closing signal is given to the inflow valve 3-1, and a signal for displaying damage is given to the display means 9, and the process is terminated.

  According to the present embodiment, the detection of the damage to the membrane module is issued with the first determination, and the operation can be stopped at the time of the damage with the second determination, so that the detection accuracy and the safety of the filtered water can be improved. Moreover, since the damage detection sensor is installed for every membrane module and each is compared, the false detection derived from raw | natural water quality can be prevented.

  A third embodiment of the present invention will be described with reference to FIG. The membrane filtration device of this example is configured in the same manner as in Example 1, and the method for detecting membrane damage by the control device 8 is different.

  This embodiment will be described with reference to the control flow of FIG. In step 10, the control device 8 receives the measurement signals from the damage detection sensors 6-1 to 6-4, and compares the measurement value with a preset determination value α. Here, the measured value may be determined by an absolute value.

  When each measured value is less than or equal to the determination value α, it is determined that the level is normal and the process ends. For example, when the measured value of the damage detection sensor 6-1 is equal to or greater than the determination value α, the control device 8 determines that the alarm level is reached, and gives a signal for displaying an alarm to the display unit 9 in step 11.

  In step 12, the control device 8 obtains a continuation time during which the measurement value of the damage detection sensor 6-1 has reached the alarm level, and compares the continuation time t with a preset determination time T. When the duration t is equal to or shorter than the determination time T, the control device 8 determines the alarm level and ends. When the duration t is equal to or longer than the determination time T, the control device 8 determines that the membrane module 1-1 is at the raw water cutoff level due to damage. The control device 8 gives a signal for closing the inflow valve 3-1 to the inflow valve 3-1, and a signal for displaying the damage to the display means 9, and ends. The control device 8 executes the flow shown in FIG. 4 at set intervals and monitors the state of the membrane module.

  According to the present embodiment, the detection of the damage of the membrane module is issued by the sensor value determination, and the operation can be stopped by determining the damage by the determination of the duration of the sensor value. It can be improved.

  In Example 3, when the fluctuation | variation of raw | natural water quality, for example, when the turbid particle diameter in raw | natural water is smaller than the membrane pore diameter of a membrane module, even if normal, microparticles | fine-particles may mix in filtered water. In such a case, the flow shown in FIG. 5 may be executed.

  In the flow shown in FIG. 5, step 12-2 is provided between step 12 and step 13 of the flow shown in FIG.

  In step 13, for example, if the duration t during which the measured value of the damage detection sensor 6-1 has reached the alarm level is equal to or longer than the determination time T, the process proceeds to step 12-2. In step 12-2, the control device 8 compares the measurement values of the other damage detection sensors 6-2 to 6-4 with the determination value α. When one or more of the measured values of the other damage detection sensors 6-2 to 6-4 are equal to or greater than the determination value α, it is determined that the damage is derived from the raw water quality, and the alarm level is determined and the process ends. When the measured values of the other damage detection sensors 6-2 to 6-4 are all equal to or less than the determination value α, the control device 8 determines that the membrane module 1-1 is at the raw water cutoff level due to damage, and the inflow valve A signal for closing 3-1 is given to the inflow valve 3-1, and a signal for displaying damage is given to the display means 9, and the process is terminated.

  According to the present embodiment, the detection of the damage to the membrane module can be alerted by determining the sensor value, and it can be determined that the sensor value is determined to be damaged by determining the duration of the sensor value. it can. Furthermore, since the damage detection sensor is installed for every membrane module and each is compared, the false detection originating in raw | natural water quality can be prevented, and detection accuracy can be improved.

  A fifth embodiment of the present invention will be described with reference to FIG. The membrane filtration device of this example is configured in the same manner as in Example 1, and the method for detecting membrane damage by the control device 8 is different.

  This embodiment will be described with reference to the control flow of FIG. In step 20, the control device 8 obtains an average value of the measurement values of the damage detection sensors 6-1 to 6-4. The average value is calculated for all active sensors. The control device 8 causes the display means 9 to display the average value.

  In step 21, the control device 8 obtains a difference C between one measured value in the damage detection sensor 6 and the average value as described above, and takes the absolute value (| C |) of C to obtain the first determination value. Compare a. If the absolute value | C | is smaller than the determination value a, the control device 8 determines that the level is normal and ends. For example, when the absolute value | C | obtained from the measurement value of the damage detection sensor 6-1 is equal to or greater than the determination value a, the control device 8 determines that the alarm level is present, and displays a warning on the display unit 9 in step 22. Give a signal to send.

  In step 23, the control device 8 compares the absolute value | C | with the second determination value b. The determination value b is set to a larger value than the determination value a. When the absolute value | C | is equal to or less than the determination value b, it is determined as the alarm level and the process is terminated. When the absolute value | C | is equal to or greater than the determination value b, the control device 8 determines that the membrane module 1-1 is at the raw water cutoff level due to damage.

  In step 24, the control device 8 gives a signal for closing the inflow valve 3-1 to the inflow valve 3-1, and a signal for displaying the damage to the display means 9, and ends. The control device 8 executes the flow shown in FIG. 6 at set intervals, and monitors the state of the membrane module.

  The control device 8 stores data of initial values (L0) of the measured values of the damage detection sensors 6-1 to 6-4, compares the data with the current values (L), and when L <Β × L0, the sensor Is displayed on the display means 9. For this reason, maintenance of the sensor can be performed appropriately, and a decrease in detection sensitivity due to deterioration of the sensor or dirt on the piping can be prevented. Here, Β should be set to about 0.1 to 0.7. As a result of replacing some of the damage detection sensors 6, the detection sensitivity may be recovered and the measured value may increase or decrease. Therefore, a correction formula is incorporated in the calculation of the average value of the measured values so that it can be corrected in advance. It is good to leave.

  According to the present embodiment, it is possible to issue a warning for the detection of the damage of the membrane module by the first determination, stop the operation at the time of the damage by the second determination, and improve the detection accuracy and the safety of filtrate water. Moreover, since the damage detection sensor is installed for every membrane module and each is compared, the false detection derived from raw | natural water quality can be prevented. In addition, since the display is changed according to the determination result, the operator can easily grasp the situation.

  FIG. 7 shows a control flow of the sixth embodiment of the present invention. In this embodiment, step 22-2 is provided instead of step 23 of the fifth embodiment.

  In step 22-2, the control device 8 obtains, for example, a duration time during which the damage detection sensor 6-1 has reached the alarm level, and compares the duration time t1 with a preset determination time T1. When the duration t1 is equal to or shorter than the determination time T1, the control device 8 determines the alarm level and ends. When the duration t1 is equal to or longer than the determination time T1, the control device 8 determines that the membrane module 1-1 is at the raw water cutoff level due to damage. The control device 8 gives a signal for closing the inflow valve 3-1 to the inflow valve 3-1 and a signal for displaying the damage to the display means 9 and ends. The control device 8 executes the flow shown in FIG. 7 at set intervals and monitors the state of the membrane module.

  According to the present embodiment, the detection of the damage to the membrane module is issued by the sensor level judgment, and the operation can be stopped by judging the damage by judging the duration of the sensor value, thereby improving the detection accuracy and the safety of filtrate water. it can. Moreover, since the damage detection sensor is installed for every membrane module and each is compared, the false detection derived from raw | natural water quality can be prevented.

  A seventh embodiment of the present invention is shown in FIG. The present embodiment is configured in the same manner as the embodiment shown in FIG. 1, but in this embodiment, ultraviolet irradiation devices 10-1 to 10-4 are installed downstream of the damage detection sensors 6-1 to 6-4. is doing. The ultraviolet irradiation device 10 is controlled on-off by the control device 8. By irradiating ultraviolet rays, even when the membrane modules 1-1 to 1-4 are damaged, pathogenic viruses and the like mixed in the filtered water can be rendered harmless. The ultraviolet irradiation device may be installed in the filtered water tank 4.

  The control device 8 is operated by any one of the control methods described in the first to sixth embodiments. When the measurement values of the damage detection sensors 6-1 to 6-4 are at the alarm level, the control device 8 turns on the ultraviolet irradiation devices 10-1 to 10-4 corresponding to the membrane modules 1-1 to 1-4. To. The safety of filtered water can be secured by irradiating ultraviolet rays at the alarm level. In addition, when it determines with damage, since filtration will be stopped, the ultraviolet irradiation devices 10-1 to 10-4 are turned off.

  According to the present embodiment, since the ultraviolet ray is irradiated at the alarm stage before the membrane module is determined to be damaged, the safety of filtered water can be improved.

  FIG. 9 shows a cross-sectional view of the damage detection sensor described in the first to seventh embodiments. Transmission windows 92-1 and 92-2 are provided in part of the filtrate water pipe 91. The filtrate water pipe 91 is a filtrate water pipe shown in FIG. 1 or FIG.

  The transmission window 92 has a sealed structure that transmits light but does not leak filtrate. A light emitting element 93 such as a laser diode is disposed outside the transmission window 92-1, and a light receiving element 94 such as a photodiode is disposed outside the transmission window 92-2. The light emitting element 93 and the light receiving element 94 are installed facing each other, and the light from the light emitting element 93 is received by the light receiving element 94 to measure the entry of fine particles, bubbles, etc. into the filtered water.

  The light emitting element 93 and the light receiving element 94 are fixed to the filtrate pipe 91 by a light emitting element fixing tool 95 and a light receiving element fixing tool 96, respectively. The light emitting element fixture 95 and the light receiving element fixture 96 have a structure that blocks light from the outside to the transmission window 92, and the light receiving element 94 can receive the light of the light emitting element 93. When fine particles are mixed in the filtered water, the amount of light received by the light receiving element 94 changes. The measurement value of the amount of received light is transmitted to the control device 8.

  In FIG. 9, power supply and measurement signal wiring are omitted. If the damage detection sensor breaks down due to a malfunction of the light emitting element 93 or the light receiving element 94, the light emitting element fixing tool 95 and the light receiving element fixing tool 96 can be removed, and the parts can be replaced. it can.

  According to the present embodiment, even when the damage detection sensor is broken down or the detection sensitivity is lowered, it can be repaired or exchanged without stopping the operation of the membrane filtration device, so that the detection accuracy and the safety of filtrate water can be improved.

  As described above, according to each embodiment, the first detection can give an alarm for damage detection of the membrane module, and the second determination can stop the operation at the time of damage, improving the detection accuracy and the safety of filtered water. it can. Moreover, since the damage detection sensor is installed for every membrane module and each is compared, the false detection derived from raw | natural water quality can be prevented. In addition, since the display changes depending on the determination result, the operator can easily grasp the situation. Moreover, since the detection sensor is installed outside the pipe, it can be replaced without stopping the membrane filtration device.

It is a block diagram of the membrane filtration apparatus which is Example 1 of this invention. It is a flowchart which shows an example of the control flow of a membrane filtration apparatus. It is a control flow figure of the membrane filtration apparatus which is Example 2 of this invention. It is a control flowchart of the membrane filtration apparatus which is Example 3 of this invention. It is a control flow figure of the membrane filtration apparatus which is Example 4 of this invention. It is a control flow figure of the membrane filtration apparatus which is Example 5 of this invention. It is a control flow figure of the membrane filtration apparatus which is Example 6 of this invention. It is a block diagram of the membrane filtration apparatus which is Example 7 of this invention. It is a cross-sectional view of the damage detection sensor which is Example 8 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Membrane module 2 Filtration pump 3 Inflow valve 4 Filtration water tank 5 Backwash pump 6 Damage detection sensor 7 Flowmeter 8 Control device 9 Display means 10 Ultraviolet irradiation device 91 Filtration water pipe 92 Transmission window 93 Light emitting element 94 Light receiving element 95 Light emitting element Fixing device 96 Light receiving element fixing device

Claims (10)

  In the membrane module damage detection method of a membrane filtration device that filters raw water with multiple membrane modules and obtains filtered water, damage that detects foreign matter in the filtered water provided in the filtered water piping downstream of each membrane module A detection sensor; an inflow valve provided to shut off raw water upstream of the membrane module; a control device for controlling the opening and closing of the inflow valve and receiving a measurement value of the damage detection sensor; and the damage detection Display means for displaying the measured value of the sensor and the control result of the control device, the control device compares the measured value of the damage detection sensor with a preset judgment value, and the measured value is the judgment Operation control of a membrane filtration device characterized by displaying an alarm above the value, determining that it is damaged when the duration exceeding the determination value reaches a set time, and closing the raw water with the inflow valve Law.   2. The control device according to claim 1, wherein the control device reaches a set time for which the measurement value exceeds the determination value, and the measurement value of at least one other damage detection sensor is smaller than the determination value. The operation control method for a membrane filtration device is characterized in that it is determined that there is damage and the inflow valve is closed.   The operation control method for a membrane filtration device according to claim 1 or 2, wherein the display means determines the color of the damage detection sensor for each determination result in accordance with the determination of the normal level, the alarm level, and the raw water cutoff level of the control device. An operation control method for a membrane filtration device, wherein the display of at least one of shape, numerical value and text is changed.   In the operation control method of a membrane filtration device that filters raw water with a plurality of membrane modules and obtains filtrate water, a damage detection sensor that detects foreign matter in filtrate water installed in the filtrate water piping of each membrane module, and the membrane An inflow valve that can shut off raw water installed for each membrane module on the upstream side of the module, a control device that controls opening and closing of the inflow valve, and receives a measurement value of the damage detection sensor, and a measurement value of the damage detection sensor Display means for displaying a control result of the control device, the control device obtains an average value of the measurement values of the damage detection sensor, and an absolute value of a difference between the measurement value and the average value is a first value. An alarm is displayed at one judgment value or more, a damage is judged at a second judgment value or more greater than the first judgment value, and the inflow valve is closed. Operation control method.   In the membrane module damage detection method of a membrane filtration device for filtering raw water through a plurality of membrane modules to obtain filtrate water, a damage detection sensor for detecting foreign matter in filtrate water in the filtrate water pipe of each membrane module, and the membrane module An inflow valve that can shut off raw water for each membrane module upstream, a control device that controls opening and closing of the inflow valve, and receives a measurement value of the damage detection sensor, a measurement value of the damage detection sensor, and the control device Display means for displaying the control result, and the control device obtains an average value of the measurement values of the damage detection sensor, and issues an alarm if the absolute value of the difference between the measurement value and the average value is greater than or equal to a determination value. An operation control method for a membrane filtration device, characterized in that, when the duration time that exceeds the determination value reaches a set time, it is determined as damage and the raw water is closed by the inflow valve.   6. The operation control method for a membrane filtration device according to claim 4 or 5, wherein the display means displays the measurement value, the average value, and the determination value of the damage detection sensor, and the control device normal level, alarm level, and raw water cutoff. An operation control method for a membrane filtration device, wherein at least one of the color, shape, numerical value and text of the damage detection sensor is changed for each determination result according to the level determination.   The operation control method for a membrane filtration device according to any one of claims 4 to 6, wherein an initial value of the measurement value of the damage detection sensor is stored in the control device and compared with a current value of the measurement value of the damage detection sensor. A method for detecting damage to a membrane module, comprising: determining that the sensor is abnormal when the current value is less than or equal to a predetermined value relative to the initial value, and displaying the sensor with the display means.   The operation control method for a membrane filtration device according to any one of claims 1 to 7, wherein the control device performs damage detection determination at the time of filtration of the membrane module.   9. The operation control method for a membrane filtration device according to claim 1, further comprising an ultraviolet device that irradiates filtered water with ultraviolet light according to a signal from the control device, wherein the control device displays an alarm on the display means. An operation control method for a membrane filtration device, wherein a signal for irradiating ultraviolet rays to the ultraviolet device is output.   10. The operation control method for a membrane filtration device according to claim 1, wherein the damage detection sensor is provided with a sealed window at a position where the pipes face each other so as to transmit light and prevent filtrate water from leaking. A method for controlling the operation of a membrane filtration device, comprising: a light emitting element on one side; a light receiving element on the other; and transmitting a measurement signal of the light receiving element to the control device.

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