JP5932272B2 - Membrane filtration device, operation method and damage detection device - Google Patents

Description

  Embodiments described herein relate generally to a membrane filtration device, an operation method, and a damage detection device.

  In the field of water treatment, a membrane filtration device for membrane filtration of suspended substances in water using a filtration membrane is widely used. In such a membrane filtration device, a membrane filtration step for separating suspended substances from water is performed for a predetermined time, and then a physical washing step such as backwashing is performed, thereby causing fouling-causing substances such as suspended substances attached to the filtration membrane. Has been removed. By performing this physical cleaning step, it is possible to recover the filtration performance to some extent, but there is a problem that fouling that is difficult to remove progresses with the time of membrane filtration. Conventionally, a technique for washing the filtration membrane using a chemical solution and a technique for backwashing the filtration membrane using hot water have been proposed for this problem.

  In addition, as described above, the filtration membrane is operated by repeating filtration and physical cleaning, but there is a risk of deterioration and damage with the years of use. Therefore, conventionally, a technique for detecting a damaged state of a filtration membrane using a pressurized gas has been proposed, and damage detection is performed at a timing when the flow of water is stopped in a process such as after cleaning.

JP 2009-274221 A JP 2007-130588 A JP 2007-130532 A Japanese Patent Laid-Open No. 2003-210949

  However, the conventional technique using a chemical solution for cleaning the filtration membrane has problems such as an increase in environmental burden and the deterioration of the filtration membrane due to the chemical solution. In addition, the running cost required for the chemical solution is increased, and the equipment cost is high because the equipment is made of a material resistant to the chemical solution. On the other hand, the conventional technology that uses hot water for washing the filtration membrane has little environmental impact and little influence on the deterioration of the filtration membrane, but the energy for heating increases according to the amount of water for washing. Is desired.

  Further, as described above, the damage detection of the filtration membrane is performed at a timing different from the membrane filtration step and the physical cleaning step and after the water flow is stopped, so that the detection time for damage detection is directly related to the processing efficiency. Be involved.

The membrane filtration device according to the embodiment includes a membrane module, a treated water tank, a heating unit, a treated water supply unit, a pressurized air supply unit, and a damage detection unit. The membrane module has a filtration membrane that divides the interior into a primary side region and a secondary side region, and the raw water supplied from the primary side region is membrane-filtered by the filtration membrane and discharged as treated water from the secondary side region. To do. The treated water tank stores treated water discharged from the membrane module. The heating means heats the treated water to a predetermined temperature. The treated water supply means is connected to the secondary side region of the membrane module by piping, and supplies the treated water heated by the heating means to the secondary side region of the membrane module through the piping when the membrane module is cleaned. The pressurized air supply means supplies pressurized air into the pipe after stopping the supply of treated water to the secondary region of the membrane module. The damage detection means detects damage to the filtration membrane based on the leakage amount of the pressurized air supplied from the pressurized air supply means from the secondary side region to the primary side region of the membrane module. Further, the treated water supply means sets the flow rate of the treated water supplied to the secondary region of the membrane module to less than the flow rate of treated water discharged during membrane filtration , and the flow rate of the membrane module in 5 to 10 seconds with pressurized air. The flow rate is pumped to the secondary area .

FIG. 1 is a block diagram schematically showing the configuration of the membrane filtration device according to the embodiment. FIG. 2 is a flowchart showing the procedure of the operation method of the membrane filtration device 100. Drawing 3 is a figure for explaining the membrane filtration process of a membrane filtration device. FIG. 4 is a diagram for explaining the backwashing process of the membrane filtration device. FIG. 5 is a diagram showing an example of changes in membrane differential pressure. FIG. 6 is a diagram for explaining the combined backwashing step (first step) of the membrane filtration device. FIG. 7 is a diagram for explaining the combined backwashing step (second step) of the membrane filtration device. FIG. 8 is a diagram showing an example of changes in the membrane differential pressure. FIG. 9 is a graph showing an example of damage detection processing. FIG. 10 is a diagram schematically illustrating another configuration of the membrane filtration device.

  Embodiments of a membrane filtration device, an operation method, and a damage detection device according to the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 is a block diagram schematically showing the configuration of the membrane filtration device according to this embodiment. As shown in the figure, the membrane filtration apparatus 100 includes a raw water tank 11, a raw water pump 12, a membrane module 13, a treated water tank 14, a flow meter 15, a backwash pump 16, and a hot water wash pump 17. , A hot water unit 18, an air compressor 19, a gas pressure gauge 20, and a gas flow meter 21.

  The raw water tank 11 stores raw water supplied from a supply source (not shown). The raw water pump 12 is a supply pump that supplies the raw water stored in the raw water tank 11 to the membrane module 13. The raw water pump 12 is connected to the primary region of the membrane module 13 via a filtration inlet valve V1.

  The membrane module 13 has a filtration membrane (not shown) that divides the interior into a primary side region and a secondary side region, and membrane-filters the raw water supplied from the primary side region with a filtration membrane. Discharged as treated water. A filtration outlet valve V2 is installed in the secondary region of the membrane module 13, and a common line L1 is formed by a pipe connecting the filtration outlet valve V2 and the secondary region of the membrane module 13. . The treated water discharged from the secondary region of the membrane module 13 flows through the common line L1 and reaches the treated water tank 14 via the filtration outlet valve V2.

  A drain valve V <b> 3 for discharging the retentate in the membrane module 13 to the outside of the membrane filtration device 100 is provided in the primary region of the membrane module 13. An air scrubbing valve V7 for introducing pressurized air is provided in the primary region of the membrane module 13.

  The filtration membrane used in the membrane module 13 is for turbidity such as a microfiltration membrane and an ultrafiltration membrane, and may be a module type pressure type or an immersion type that separates the membrane by suction. In the present embodiment, an example using a pressurized external pressure microfiltration membrane will be described. In the membrane module 13, the filtration membrane is held at a free end where one end is not fixed, or is held with both ends fixed and a sufficient margin in the middle. It is assumed that it can swing.

  The treated water tank 14 stores treated water discharged from the membrane module 13 via the common line L1. The flow meter 15 is provided on the shared line L1, and measures the flow rate of water flowing through the shared line L1. Note that, based on the flow rate measured by the flow meter 15, the execution timing of each step described later can be automatically controlled by the membrane filtration device 100.

  The backwash pump 16 is connected to the common line L1 through the backwash valve V4, and the membrane module 13 uses a part of the treated water stored in the treated water tank 14 through the common line L1 as backwash water. To the secondary region of

  The warm water washing pump 17 supplies a part of the treated water stored in the treated water tank 14 to the warm water unit 18. The hot water unit 18 is a heating device that heats the treated water guided by the hot water washing pump 17 to a predetermined temperature. The hot water unit 18 is connected to the common line L1 through the hot water washing valve V5, and supplies hot water heated to a predetermined temperature to the secondary side region of the membrane module 13 through the common line L1.

  The hot water unit 18 includes, for example, a hot water tank that temporarily stores the treated water guided by the hot water washing pump 17, a heater that heats the treated water stored in the hot water tank to a predetermined temperature, and the like. The treated water is kept as warm water. Moreover, the membrane filtration apparatus 100 is good also as a structure which heats the piping which connects the warm water washing pump 17 and the warm water washing valve V5, without using a warm water tank. In FIG. 1, the piping system extending from the backwash valve V4 to the shared line L1 and the piping system extending from the hot water cleaning valve V5 to the shared line L1 are shared. In addition, a configuration in which a piping system that reaches the common line L1 may be provided individually.

  The air compressor 19 is an air compressor, and supplies pressurized air to the membrane module 13 via the pressure reducing valve V6. Here, the output side of the pressure reducing valve V6 is connected to the primary region of the membrane module 13 via the air scrubbing valve V7. The pressurized air supplied from the air compressor 19 is introduced into the primary region of the membrane module 13 via the air scrubbing valve V7. The output side of the pressure reducing valve V6 is connected to the common line L1 via the damage detection valve V8, and the pressurized air supplied from the air compressor 19 through the common line L1 is supplied to the membrane module 13. It is configured to be introduced into the secondary side region.

  A gas pressure gauge 20 and a gas flow meter 21 are provided in the piping system between the output side of the pressure reducing valve V6 and the damage detection valve V8. The gas pressure gauge 20 measures the pressure of pressurized air supplied from the air compressor 19 to the secondary region of the membrane module 13. The gas flow meter 21 measures the flow rate of pressurized air supplied from the air compressor 19 to the secondary region of the membrane module 13.

  In addition, the membrane filtration apparatus 100 shall not be restricted to the structure shown in FIG. For example, when raw water is supplied from the outside of the membrane filtration device 100, the raw water tank 11 and the raw water pump 12 may be removed from the configuration of the membrane filtration device 100. Further, when pressurized air is supplied from the outside of the membrane filtration device 100, the air compressor 19 and the pressure reducing valve V6 may be removed from the configuration of the membrane filtration device 100. Moreover, when not measuring the flow volume of the water which flows into the common line L1, it is good also as a structure which remove | eliminated the flowmeter 15 from the structure of the said membrane filtration apparatus 100. FIG.

  Next, an example of the operation method of the membrane filtration apparatus 100 will be described. FIG. 2 is a flowchart showing the procedure of the operation method of the membrane filtration device 100. As shown in the figure, the operation method of the membrane filtration apparatus 100 includes a “membrane filtration step” for membrane filtration of raw water, a “backwash step” for backwashing the membrane module 13 with treated water, hot water and pressurization. It includes a “combination backwashing step” for backwashing the membrane module 13 using air together, and a “damage detection step” for detecting damage to the filtration membrane.

  Here, the membrane filtration step and the backwashing step are alternately repeated. The transition from the membrane filtration step to the backwashing step is usually performed every predetermined time, but may be automatically performed based on the flow rate of the treated water measured by the flow meter 15. After performing the predetermined number of times (or after a predetermined time has elapsed), the combined back washing step is performed. The combined back washing process includes a first process and a second process, and a damage detection process is performed integrally with the execution of the second process. Hereinafter, each process shown in FIG. 2 will be described.

<Membrane filtration process>
First, the membrane filtration step of the membrane filtration device 100 will be described with reference to FIG. Here, FIG. 3 is a figure for demonstrating the membrane filtration process of the membrane filtration apparatus 100, and the valve of an open state is represented by white painting, and the valve of a closed state is represented by black painting (henceforth, FIG. 4, FIG. 6 and FIG. 7 are the same).

  In the membrane filtration step, as shown in FIG. 3, the raw water in the raw water tank 11 is introduced into the primary region of the membrane module 13 by opening the filtration inlet valve V1 and the filtration outlet valve V2 and operating the raw water pump 12. To do. At this time, all other valves are closed. The raw water introduced into the membrane module 13 is subjected to membrane filtration by a filtration membrane and then discharged to the treated water tank 14 as treated water.

  When the fouling-causing substances such as suspended substances begin to adhere to the primary side surface of the filtration membrane (hereinafter referred to as the primary side surface) with the passage of time in the membrane filtration process, the membrane differential pressure increases and the filtration capacity gradually increases. It will drop to. Therefore, a back washing process is performed at a predetermined timing, and the membrane module 13 is washed by back washing with treated water.

<Backwash process>
FIG. 4 is a diagram for explaining the backwashing process of the membrane filtration device 100. First, the operation of the raw water pump 12 is stopped, and the filtration inlet valve V1 and the filtration outlet valve V2 are closed. Next, the drainage valve V3 and the backwash valve V4 are opened and the backwash pump 16 is operated to introduce the treated water stored in the treated water tank 14 from the secondary side region of the membrane module 13 as backwash water. . Next, the air scrubbing valve V7 is opened, and the air compressor 19 is put into an operating state, thereby starting the air scrubbing that physically swings the filtration membrane with the pressurized air supplied from the primary side region of the membrane module 13. To do. By introducing this backwash water, the fouling-causing substance adhering to the primary side surface of the filtration membrane is peeled off and discharged to the outside of the membrane filtration device 100 through the drain valve V3. Further, the fouling-causing substance can be more easily separated from the filtration membrane by swinging the filtration membrane by supplying pressurized air. In the present embodiment, the air scrubbing is started after the supply of the treated water is started, but not limited to this, the supply of the treated water may be started after the air scrubbing is started, The supply of treated water and air scrubbing may be started simultaneously. Thereby, the fouling cause substance adhering to the filtration membrane can be removed to some extent.

  By the way, it is known that when the fouling-causing substance on the filtration membrane is captured by the pore structure or the like on the surface of the filtration membrane, the fouling-causing substance cannot be easily removed by the backwashing process. For example, by performing a backwash process after the membrane filtration process, it is possible to reduce (recover) the membrane differential pressure increased in the membrane filtration process to some extent, but the remaining fouling-causing substances gradually As it accumulates, the recovery rate of the membrane differential pressure also gradually decreases.

  Here, FIG. 5 is a figure which shows the example of a change of the film | membrane differential pressure at the time of implementing a membrane filtration process and a backwash process alternately. In the figure, the membrane pressure difference (kPa) of the filtration membrane is shown on the vertical axis, and the elapsed time (number of repetitions) is shown on the horizontal axis. In the first to third membrane filtration steps, the amount of water per unit time for membrane filtration is the same condition.

  As shown in FIG. 5, in the membrane filtration step, the fouling-causing substance adheres to the primary side surface of the filtration membrane with the passage of time, so that the membrane differential pressure gradually increases. Therefore, when the backwash process is performed, the film differential pressure is reduced (recovered) by removing the fouling-causing substances. At this time, the smaller the difference ΔP (ΔP1 to ΔP3) between the recovered membrane differential pressure value and the reference membrane differential pressure P0, the higher the recovery rate.

  However, since fouling-causing substances remaining in the backwashing process accumulate, even if the backwashing process is repeatedly performed, the values of ΔP1 to ΔP3 gradually increase and the membrane differential pressure required for membrane filtration also increases. . Therefore, in the membrane filtration device 100 of the present embodiment, when ΔP exceeds a predetermined threshold, or after a predetermined time elapses, the combined backwashing process is performed at a predetermined timing, so that Remove ring-causing substances. Hereinafter, the combined back washing process will be described.

<Combination backwash process>
The combined backwashing step includes a “first step” for peeling off the fouling-causing substance adhering to the primary surface of the filtration membrane and a “second step” for removing the peeled fouling-causing substance. Prior to the execution of the first step, it is assumed that the treated water in the treated water tank 14 is introduced into the heated water unit 18 by temporarily operating the warm water cleaning pump 17 at a predetermined timing. . In the hot water unit 18, the introduced treated water is heated to a predetermined temperature and is kept warm as hot water. Here, the temperature of the hot water is not particularly limited as long as it is equal to or lower than the heat resistance of the filtration membrane, and may be, for example, in the range of 40 to 60 ° C., and the higher the temperature, the better.

  First, the 1st process of a combined backwash process is demonstrated using FIG. Here, FIG. 6 is a figure for demonstrating the 1st process of a combined backwash process. In the first step, first, the drain valve V3 and the hot water washing valve V5 are opened (other valves are closed), and the hot water washing pump 17 is in an operating state (the raw water pump 12 and the back washing pump 16 are in a stopped state). The warm water heated to a predetermined temperature is supplied from the warm water unit 18 to the secondary region of the membrane module 13. Next, the air scrubbing valve V7 is opened, and the air compressor 19 is put into an operating state, thereby starting the air scrubbing that physically swings the filtration membrane with the pressurized air supplied from the primary side region of the membrane module 13. To do.

  In this way, in the first step, the fouling-causing substance attached or trapped on the filtration membrane is easily peeled off by warming the filtration membrane with warm water. Further, the fouling-causing substance can be more easily separated from the filtration membrane by swinging the filtration membrane by supplying pressurized air. In this embodiment, the air scrubbing is started after the hot water supply is started. However, the present invention is not limited to this, and the hot water supply may be started after the air scrubbing is started. It is good also as a form which starts supply and air scrubbing simultaneously. Moreover, although the flow rate of the warm water supplied to the secondary region of the membrane module 13 by the warm water unit 18 is less than the flow rate of the treated water (membrane filtration flow rate) discharged by the membrane module 13 during the membrane filtration step, However, the function of washing is not hindered.

  Next, the 2nd process of a combined backwash process is demonstrated using FIG. Here, FIG. 7 is a figure for demonstrating the 2nd process of a combined backwash process. In the second step, first, the air scrubbing valve V7 is closed to stop the oscillation of the filtration membrane. Next, the hot water supply to the membrane module 13 is stopped by closing the hot water cleaning valve V5 and stopping the hot water cleaning pump 17. At this time, in the common line L1, the filtration outlet valve V2, the backwash valve V4, the hot water washing valve V5, and the damage detection valve V8 are closed and closed with the secondary region of the membrane module 13, so that the first step The hot water that was supplied in the state remains.

  Then, by opening the damage detection valve V8, the hot water remaining in the common line L1 is pumped to the secondary region of the membrane module 13 by the pressurized air supplied from the air compressor 19 at a stretch. By this pressure feeding, the fouling-causing substance on the primary side surface of the filtration membrane is peeled off and discharged to the outside of the membrane filtration device 100 through the drain valve V3.

  Here, the pressure of the pressurized air supplied in the second step is preferably a pressure equal to or higher than the membrane differential pressure in the membrane filtration step, and needs to be equal to or lower than the pressure resistance of the filtration membrane. Specifically, about 250 kPa is preferable for a film having a withstand voltage of 300 kPa. Further, the amount of hot water pumped to the secondary region of the membrane module 13 by pressurized air is preferably an amount that requires about 5 to 10 seconds for pumping under the above-described pressure. It is preferable that the shared line L1 is configured. In addition, since supply of pressurized air is used for damage detection in the subsequent damage detection process, it is assumed to continue for a predetermined time after the hot water in the common line L1 is pumped.

  Thus, in the combined backwashing step, in the first step, the fouling-causing substance is easily peeled off, and in the second step, the fouling-causing substance is generated using the hot water pressure pushed out by the pressurized air. Since the removal is performed, the fouling-causing substance can be removed from the filtration membrane more effectively than the backwashing process described above. Thus, for example, if the fourth membrane filtration step is performed after the third backwash step shown in FIG. 4 and the combined backwash step is performed, as shown in FIG. It is possible to recover the membrane differential pressure to a value equivalent to.

  Moreover, since the fouling-causing substance can be removed by using the hot water remaining in the common line L1 by supplying pressurized air in the second step, the cause of fouling is caused only by the hot water supplied from the hot water unit 18. Compared with the case where the substance is removed (backwashing), the amount of hot water used can be reduced. Thereby, energy required for warming water can be reduced.

<Damage detection process>
In the subsequent damage detection step, while the pressurized air is being supplied from the air compressor 19 to the secondary region of the membrane module 13 in the second step, the membrane module is operated by the gas pressure gauge 20 and the gas flow meter 21. The pressure (air pressure) and the flow rate (air flow rate) of the air supplied to 13 are measured. When the change of the air pressure and the air flow rate is stabilized, if the filtration membrane is damaged, air leaks from the secondary side region to the primary side region through the damaged part.

  Here, FIG. 9 is a graph showing an example of damage detection processing of the membrane filtration device 100. In the figure, the air flow rate (1 / min) is shown on the vertical axis, and the air pressure (kPa) is shown on the horizontal axis. In the same figure, the graph indicated by the alternate long and short dash line shows the air pressure-air flow rate characteristic in the damaged filtration membrane, and air leaks from the secondary side region to the primary side region through the damaged part. The air flow rate depends on the air pressure of the pressurized air. In addition, the graph shown by the solid line shows the air pressure-air flow rate characteristics of the undamaged filter membrane, and the air leaking from the secondary side region to the primary side region is the characteristic of the damaged filter membrane. Compared to a very small amount. For this reason, from the relationship between the air pressure of the pressurized air supplied to the membrane module 13 and the air flow rate, the membrane module 13 (filtration membrane is filtered based on the amount of air leaked from the secondary side region of the membrane module 13 to the primary side region. It is possible to determine whether or not damage has occurred.

  In the present embodiment, the amount of air leaked from the secondary region to the primary region of the membrane module 13 is specified from the air pressure-air flow rate characteristics of the pressurized air. It is good also as a form which specifies the amount of leaked air using other methods, such as detecting the bubble which leaked to 13 primary side area | regions.

  If damage to the membrane module 13 is not detected in the damage detection step, the damage detection valve V8 is closed, the air compressor 19 is stopped, and the water in the primary region of the membrane module 13 is drained from the drain valve V3. Then, the process returns to the membrane filtration step again. When damage to the membrane module 13 is detected in the damage detection step, the membrane module 13 is replaced with a new membrane module 13 and the process returns to the membrane filtration step.

  In the membrane filtration device 100, the membrane filtration step, backwashing step, and combined backwashing step (damage detection step) shown in FIG. 2 are automatically controlled to be performed in a predetermined order and timing. For example, the membrane filtration step 22 minutes → the back washing step 40 seconds is repeated, and once a day, instead of the back washing step, the first step of the combined back washing step is carried out for 2 minutes, and then the second step ( If damage to the filtration membrane is not detected by performing the damage detection step), the rotation may be returned to the repetition of the membrane filtration step 22 minutes → the back washing step 40 seconds. Moreover, although the implementation frequency of the combined backwashing step (damage detection step) can be set as appropriate according to the quality of the raw water and the operation method, for example, in the water purification treatment, the effect is about once a day. Can be demonstrated.

  As described above, according to the present embodiment, the fouling-causing substance adhering to the primary side of the filtration membrane can be efficiently removed by performing the combined back washing step. In addition, since the hot water flow rate supplied at the first step is smaller than the membrane filtration flow rate, and the hot water remaining in the pipe is pushed out by air pressure at the second step to exert a cleaning effect, the amount of hot water to be used can be reduced. Energy efficiency related to warming can be improved. In addition, since the membrane module 13 can be cleaned and damaged at the same time by performing damage detection on the filtration membrane at the same time when the membrane module 13 is cleaned with pressurized air (during the second step), the membrane Time other than the filtration step can be shortened, and the processing efficiency of the membrane filtration device 100 can be improved.

  Moreover, since warm water (treated water) is used for washing the filtration membrane, running costs and equipment costs can be reduced as compared with the case of washing with a chemical solution. Moreover, since warm water (treated water) is used for washing the filtration membrane, the environmental load can be reduced, and the influence on the deterioration of the filtration membrane can also be reduced.

  As mentioned above, although embodiment of this invention was described, the said embodiment was shown as an example and is not intending limiting the range of invention. The above embodiment can be implemented in various other forms, and various omissions, replacements, changes, additions, and the like can be made without departing from the scope of the invention. Moreover, the said embodiment and its deformation | transformation are included in the range of the invention, the summary, and the invention described in the claim, and its equal range.

  For example, in the above embodiment, the hot water obtained by heating the treated water to a predetermined temperature is used to peel off the fouling-causing substance trapped on the primary side surface of the filtration membrane. It is good also as a form which implements the said combined backwashing process using the treated water which is not. In this case, in the hot water unit 18 shown in FIG. 1, the treated water from the hot water washing pump 17 is supplied to the secondary region of the membrane module 13 as it is, so that the combined backwashing using the unheated treated water is performed. A process can be performed. Further, as the membrane filtration device 100a of another configuration example, as shown in FIG. 10, a configuration in which the hot water washing pump 17, the hot water unit 18, and the hot water washing valve V5 are removed from the configuration of the membrane filtration device 100 shown in FIG. It is good. In the membrane filtration device 100a of this configuration example, by performing the first step using the treated water supplied by the backwash pump 16, the treated water remaining in the common line L1 is passed through the membrane module 13 in the subsequent second step. Can be pumped to the secondary region.

  In addition, when treated water is used in the combined backwashing process, the fouling-causing substance is less likely to be peeled off than in the case of using warm water. It is preferable to make it longer. Also in this case, the flow rate of the treated water supplied to the secondary region of the membrane module 13 is smaller than the flow rate of the treated water discharged from the membrane module 13 during the membrane filtration step (membrane filtration flow rate). At most, it does not hinder the function of washing.

  Moreover, in the said embodiment, although it was set as the form which implement | achieves supply of the pressurized air which concerns on the air scrubbing of the membrane module 13 and the pumping of the warm water which remained in the common line L1, using the same air compressor 19, The configuration is not limited, and the air compressor 19 may be provided for each application.

  Moreover, in the said embodiment, although it was set as the structure which implements the air scrubbing which rocks a filtration membrane by supply of pressurized air in a combined backwashing process (1st process), not only this but air scrubbing is not performed. It is good also as a form.

100, 100a Membrane filtration device 11 Raw water tank 12 Raw water pump 13 Membrane module 14 Treated water tank 15 Flow meter 16 Backwash pump 17 Hot water wash pump 18 Hot water unit 19 Air compressor 20 Gas pressure gauge 21 Gas flow meter V1 Filtration inlet valve V2 Filtration outlet valve V3 Drain valve V4 Backwash valve V5 Hot water wash valve V6 Pressure reducing valve V7 Air scrub valve V8 Damage detection valve

Claims (8)

A membrane having a filtration membrane that divides the interior into a primary side region and a secondary side region, and membrane-filtering the raw water supplied from the primary side region through the filtration membrane and discharging it as treated water from the secondary side region Module,
A treated water tank for storing treated water discharged from the membrane module;
Heating means for heating the treated water to a predetermined temperature;
Treated water connected to the secondary region of the membrane module by piping and supplying the treated water heated by the heating means to the secondary region of the membrane module through the piping when the membrane module is cleaned Supply means;
After stopping the supply of treated water to the secondary region of the membrane module, pressurized air supply means for supplying pressurized air into the pipe,
Of the pressurized air the compressed air supplied by the supply means, based on the amount of leakage into the primary side area from the secondary side area of the membrane module, and a damage detecting means for detecting damage to the filtration membrane ,
The treated water supply means is configured such that the flow rate of treated water supplied to the secondary region of the membrane module is less than the flow rate of treated water discharged at the time of the membrane filtration and is 5 to 10 seconds by the pressurized air. A membrane filtration device with a flow rate that is pumped to the secondary region of the module .   The membrane filtration device according to claim 1, wherein the pressurized air supply means pressure-feeds the treated water remaining in the pipe to the secondary region of the membrane module by the supply of the pressurized air.   The membrane according to claim 1, further comprising a swinging unit that swings the filtration membrane by supplying pressurized air from a primary region of the membrane module when the treated water is supplied by the treated water supply unit. Filtration device.   The membrane filtration device according to claim 3, wherein the pressurized air supply means and the swinging means use pressurized air supplied from the same air compressor. Pressure measuring means for measuring the pressure of the pressurized air supplied by the pressurized air supply means;
Flow rate measuring means for measuring the flow rate of pressurized air supplied by the pressurized air supply means;
With
The membrane filtration device according to claim 1, wherein the damage detection unit detects damage of the filtration membrane based on the pressure measured by the pressure measurement unit and the flow rate measured by the flow rate measurement unit.   The said pressurized air supply means supplies the said pressurized air with the pressure more than the membrane differential pressure at the time of the said membrane filtration, and below the pressure | voltage resistance of the said filtration membrane. Membrane filtration device. A membrane having a filtration membrane that divides the interior into a primary side region and a secondary side region, and membrane-filtering the raw water supplied from the primary side region through the filtration membrane and discharging it as treated water from the secondary side region A membrane filtration apparatus comprising a module, a treated water tank for storing treated water discharged from the membrane module, and a heating means for heating the treated water to a predetermined temperature,
A treated water supply step of supplying treated water heated by the heating means to the secondary side region via a pipe connected to the secondary side region of the membrane module when cleaning the membrane module;
After the supply of treated water to the secondary region of the membrane module is stopped, a pressurized air supply step for supplying pressurized air into the pipe,
Of the pressurized air supply step the pressurized air supplied by Based on the leakage amount to the primary side area from the secondary side area of the membrane module includes a damage detection step of detecting damage to the filtration membrane ,
In the treated water supply step, the flow rate of treated water supplied to the secondary region of the membrane module is less than the flow rate of treated water discharged at the time of the membrane filtration and is 5 to 10 seconds by the pressurized air. The operation method of the membrane filtration apparatus which makes the flow volume pumped to the secondary area of a module . A membrane having a filtration membrane that divides the interior into a primary side region and a secondary side region, and membrane-filtering the raw water supplied from the primary side region through the filtration membrane and discharging it as treated water from the secondary side region A module damage detection device,
After supplying the treated water heated by the heating means to the secondary region of the membrane module and backwashing the membrane module, supply pressurized air into the pipe used for backwashing, Pressurized air supply means for pressure-feeding the treated water remaining in the backwash to the secondary region of the membrane module;
Of the pressurized air the compressed air supplied by the supply means, based on the amount of leakage into the primary side area from the secondary side area of the membrane module, and a damage detecting means for detecting damage to the filtration membrane ,
The flow rate of the treated water supplied to the secondary side region of the membrane module is less than the flow rate of the treated water discharged during the membrane filtration , and the secondary side region of the membrane module in 5 to 10 seconds by the pressurized air. Damage detection device with flow rate to be pumped .

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