JP2017113735A - Operation method of separate membrane filtration device and water purification device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an operation method of a separate membrane filtration device and a water purification device for maintaining water generation amount of a separate membrane as high as possible without using a chemical solution in the separate membrane filtration device for purifying raw water by a separate membrane or the water purification device for purifying tap water or ground water by the separate membrane.SOLUTION: An operation method of a separate membrane filtration device having: a filtration operation process including a step for separating permeable water from raw water by a separate membrane module with a separate membrane filtration device and a step for discharging the permeable water from a permeable water discharging master line connected to a filtration side of the separate membrane module; and a cleaning operation process including a step for stopping filtration of a separate film module and a reverse pressure cleaning step for supplying reverse pressure cleaning water from a filtration side to a raw water side of the separate film module at flux of 1.1×10m/m/sec. is conducted. Water generation performance of the separate membrane module can maintain high without using a chemical solution.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a separation membrane filtration device that purifies raw water with a separation membrane, and a method for operating a water purification device that purifies tap water, groundwater, and the like with a separation membrane.

  Conventionally, a separation membrane filtration device using a separation membrane has been provided in order to remove impurities and microorganisms contained in river water, tap water, groundwater, sewage treated water, etc., and obtain water such as industrial water and domestic water. Yes. Separation membrane filtration devices take various forms depending on the use of raw water to be treated and water after treatment. For example, in general households, a water purifier equipped with a separation membrane is provided to remove turbidity derived from piping from tap water or groundwater.

  By filtering raw water through a separation membrane, turbidity, organic matter, etc. contained in the raw water accumulate on the membrane surface, resulting in membrane clogging. Membrane clogging is a phenomenon that occurs even in the treatment of raw water that appears to be relatively clean, such as tap water. As the clogging of the membrane proceeds, the water production capacity of the separation membrane decreases, or filtration itself becomes impossible. In order to maintain the performance of the separation membrane, it is necessary to wash the separation membrane. Examples of the cleaning method for the separation membrane include chemical cleaning in which chemicals such as acid, alkali, and chlorine are periodically added, and physical cleaning such as back pressure cleaning, air cleaning, and shaking cleaning.

  Patent Document 1 proposes a method in which a separation membrane module is filled with a chlorine-based chemical solution and allowed to stay for a predetermined time, then the chemical solution is discharged, the interior is washed with water, and the separation membrane module is further back-pressure washed. Yes.

JP 2007-130523 A

  As exemplified in Patent Document 1, when a separation membrane module is washed with a chemical solution, many of them require several hours for washing. Since the filtration operation is stopped during washing, there is a problem that the separation membrane module cannot be used for several hours.

  Furthermore, in the domestic water purifier, there has been a problem that it is difficult to apply the chemical cleaning because it is necessary to regularly replenish the chemical and it is difficult to discharge the waste water containing the chemical as it is.

  The present invention relates to a separation membrane filtration device that purifies raw water with a separation membrane, and a method for operating a water purification device that purifies tap water, groundwater, etc. with a separation membrane. Provided is a method for cleaning a separation membrane module which is maintained at a high level.

In order to solve the above problems, the present invention has the following configurations (means) (1) to (11).
(1) A method for operating a separation membrane filtration device, the step of separating permeate from raw water by a separation membrane module provided in the separation membrane filtration device, and the permeation connected to the filtration side of the separation membrane module A step of discharging from the water discharge line; a step of stopping filtration of the separation membrane module; and from the filtration side of the separation membrane module to the raw water side, 1.1 × 10 ⁻⁴ m ³ / A method for operating a separation membrane filtration apparatus, comprising: a back pressure cleaning step for supplying back pressure cleaning water at a flux of m ² / sec or more.
(2) A method for operating a separation membrane filtration device, the step of separating permeate from raw water by a separation membrane module provided in the separation membrane filtration device, and the permeation connected to the filtration side of the separation membrane module A step of discharging from the water discharge line; a step of stopping filtration of the separation membrane module; and a gas supply pipe into the separation membrane module through a gas supply pipe at 1.0 × 10 ⁻¹ Nm ^3. A cleaning operation process including an air cleaning step for supplying air at a speed of at least / m ² / sec.
(3) A method for operating a separation membrane filtration device, the step of separating permeate from raw water by a separation membrane module provided in the separation membrane filtration device, and the permeation connected to the filtration side of the separation membrane module A step of discharging from the water discharge line; a filtration operation step including: a step of stopping filtration of the separation membrane module; and a reverse pressure washing step of supplying back pressure washing water from the filtration side of the separation membrane module to the raw water side And an air washing step for supplying gas through the gas supply pipe in the separation membrane module, and at least one of the following conditions i) or ii) in the washing operation step: Method of separation membrane filtration device that operates to satisfy the above. i) The counter pressure cleaning water flux of the counter pressure cleaning step is 1.1 × 10 ⁻⁴ m ³ / m ² / sec or more. ii) The gas supply rate of the air washing step is 1.0 × 10 ⁻¹ Nm ³ / m ² / sec or more.
(4) The method for operating the separation membrane filtration device according to any one of (1) to (3), wherein the separation membrane module includes a hollow fiber membrane as a separation membrane. .
(5) The operation method of the separation membrane filtration device according to any one of (1) to (4), wherein the separation membrane filtration device is provided in each of a raw water supply line for supplying raw water and a permeated water discharge line. A pressure gauge is provided, and a flow meter is provided in the permeate discharge line, and the separation membrane module to be cleaned in the cleaning operation step is measured using at least one of the measured values of the pressure gauge and the flow meter. The operation method of the separation membrane filtration apparatus to control.
(6) A method for operating the water purification apparatus, the step of supplying raw water to the water purification apparatus from the raw water supply source using the raw water supply main line, and one or more of a plurality of separation membrane modules provided in the water purification apparatus A step of separating permeate from the raw water by the separation membrane module, and a step of discharging the permeate from a permeate discharge main line connected to the filtration side of all the separation membrane modules. A step of filtering the raw water with at least one of the plurality of separation membrane modules, stopping filtration of the raw water with at least one of the separation membrane modules, and at least part of the permeate. was fed filtered through line filtration side of the separation membrane module has been stopped, the raw water side from the filtration side of the separation membrane module, 1.1 × 10 ^-4 m ³ How the operation of the water purification device including a counter pressure washing step for supplying at m 2 ^/ sec or more flux, a cleaning operation step including, a.
(7) A method of operating the water purification apparatus, the step of supplying raw water from the raw water supply source to the water purification apparatus using the raw water supply main line, and one or more of a plurality of separation membrane modules provided in the water purification apparatus A step of separating permeate from the raw water by the separation membrane module, and a step of discharging the permeate from a permeate discharge main line connected to the filtration side of all the separation membrane modules. A step of stopping the filtration of the raw water with at least one of the separation membrane modules including a gas supply pipe among the plurality of separation membrane modules, and using the gas supply pipe in the separation membrane module , water purification instrumentation having an air cleaning step of supplying a gas at ^{1.0 × 10 -1 Nm 3 / m} 2 / sec or faster, and cleaning operation process including the The method of operation.
(8) A method for operating the water purification apparatus, the step of supplying raw water to the water purification apparatus from the raw water supply source using the raw water supply main line, and one or more of a plurality of separation membrane modules provided in the water purification apparatus A step of separating permeate from the raw water by the separation membrane module, and a step of discharging the permeate from a permeate discharge main line connected to the filtration side of all the separation membrane modules. A step of filtering the raw water with at least one of the plurality of separation membrane modules, stopping filtration of the raw water with at least one of the separation membrane modules having a gas supply pipe, and the permeated water At least a part is sent to the filtration side of the separation membrane module that has stopped filtration through the permeate discharge main line, and the separation membrane module A cleaning operation step comprising: a back pressure cleaning step for supplying from the excess side to the raw water side; and an air cleaning step for supplying gas using the gas supply pipe in the separation membrane module, and the cleaning The operation method of the water purifier which is operated so that at least one of the following i) or ii) is satisfied in the operation process. i) The counter pressure cleaning water flux of the counter pressure cleaning step is 1.1 × 10 ⁻⁴ m ³ / m ² / sec or more. ii) The gas supply rate of the air washing step is 1.0 × 10 ⁻¹ Nm ³ / m ² / sec or more.
(9) The operation method of the water purification apparatus according to (6) or (8), wherein the water purification apparatus includes three or more separation membrane modules, and the separation membrane module performs filtration in the back pressure washing step. The operation method of the water purifier which operates so that a number may become larger than the number of the said separation membrane modules which stop filtration.
(10) The water purification apparatus operating method according to any one of (6) to (9), wherein the separation membrane module includes a hollow fiber membrane as a separation membrane.
(11) The operation method of the water purification apparatus according to any one of (6) to (10), wherein the water purification apparatus is connected to the raw water supply main line and the separation membrane module, and the raw water supply line The separation membrane module and the permeate discharge line connected to the permeate discharge main line are each provided with a pressure gauge, and the permeate discharge line is provided with a flow meter, and the separation to be cleaned in the cleaning operation step The operation method of a water purifier which controls a membrane module using the measured value of at least any one of the said pressure gauge and the said flowmeter.

  According to the operation method of the separation membrane filtration device and the water purification device according to the present invention, it becomes possible to maintain the water production amount of the separation membrane as high as possible without using the chemical solution, and to shorten the stop time caused by the chemical solution cleaning. Even if it is difficult to apply chemical cleaning such as household water purifiers or small-scale water purifiers, the performance of the separation membrane can be improved.

The flowchart of an example is shown in 1st Embodiment of the water purifier which concerns on this invention. The flowchart at the time of carrying out washing | cleaning driving | operation of the separation membrane module of 1st Embodiment of the water purifier which concerns on this invention is shown. The flowchart of another preferable one aspect | mode (2nd Embodiment) of the water purifier which concerns on this invention is shown. The flowchart at the time of carrying out washing | cleaning operation of the separation membrane module using another preferable one aspect | mode (2nd Embodiment) of the water purifier which concerns on this invention is shown. The flowchart of another preferable one aspect | mode (3rd Embodiment) of the water purifier which concerns on this invention is shown. The flowchart at the time of carrying out the washing | cleaning driving | operation of the separation membrane module using another another preferable aspect (3rd Embodiment) of the water purifier which concerns on this invention is shown. The flowchart of another preferable one aspect (4th Embodiment) of the water purifier which concerns on this invention is shown.

(1) Device configuration (1.1) Separation membrane filtration device and water purification device The separation membrane filtration device and the water purification device according to the present invention both comprise a separation membrane module, and filter the raw water with the separation membrane module to obtain permeated water. It is a device for. The separation membrane filtration device in the present invention is a device including one or more separation membrane modules, and the raw water to be treated is not particularly limited. Moreover, the water purifier in this invention takes piping structure as shown in FIGS. 1-7, is equipped with two or more separation membrane modules, and the raw water used as a process target is an apparatus for which tap water, groundwater, etc. are used preferably. . Although the effect of the invention in the water purification apparatus will be described with reference to FIGS. 1 to 7, the same cleaning effect as that of the water purification apparatus can be obtained in the separation membrane filtration apparatus. In addition, since the separation membrane filtration apparatus should just have at least one separation membrane module, the tap water supply main line (raw water supply main line) mentioned later and a permeated water discharge main line are not essential.

(1.2) Separation membrane module 1
The water purifier concerning this invention is provided with the some separation membrane module 1 as shown in FIG. The separation membrane module 1 includes a separation membrane in a container, and has a structure in which the liquid to be filtered and the permeate are not mixed by the separation membrane. The separation membrane module 1 has one or more entrances and exits for each of the filtrate and permeate, and the side where the filtrate is present is referred to as the primary side, and the side where the permeate is present is referred to as the secondary side.

  The separation membrane disposed in the separation membrane module 1 removes turbidity contained in tap water. Examples of the separation membrane include an MF membrane and a UF membrane. Different types of separation membranes may be arranged in the plurality of separation membrane modules, or the same type of separation membrane may be arranged in all the separation membrane modules.

(1.3) Pipe flow path shape around separation membrane module 1 In the water purification apparatus according to the present invention, tap water that is raw water passes through a tap water supply main line 3 that is a raw water supply main line and is connected to each separation membrane module 1. Is supplied to the primary side of the separation membrane module 1 through the tap water supply line 4 which is the raw water supply line. The permeated water filtered by each separation membrane module 1 is collected in the permeated water discharge main line 5 through the permeated water discharge line 6 connected to the secondary side of each separation membrane module 1 and discharged to the water faucet. The structure is taken.

  The tap water supply main line 3 or the tap water supply line 4 is provided with at least one liquid feeding control means 7. A specific example of the liquid feeding control means 7 is a liquid feeding pump. Since all the tap water supply lines 4 are arranged in parallel to the tap water supply main line 3, the liquid feeding control means 7 is on the tap water supply main line 3 and from all the tap water supply lines 4. Is also preferably arranged on the upstream side, since the arrangement effect of one liquid feeding control means can be exerted on all the separation membrane modules 1.

  Each separation membrane module 1 is connected to a module lower discharge line 13 so that water can be discharged from the lower part. The module lower discharge line 13 is preferably connected to the bottom surface of the separation membrane module 1 because of excellent dischargeability, and is preferably a straight pipe to the discharge port because the discharged matter does not stay. A part of the module lower discharge line 13 may be shared with the tap water supply line 4.

(1.4) Pipe switching valve The permeated water discharge main line 5 includes at least one permeated water discharge main switching valve 9. In order to effectively perform the back pressure cleaning method described later, it is preferable that the permeated water discharge main switching valve 9 is disposed on the downstream side of the permeated water discharge lines 6 of all the separation membrane modules 1.

  A tap water supply switching valve 11 is provided on the tap water supply line 4 of each separation membrane module 1. Further, a module lower discharge switching valve 15 is provided on the module lower discharge line 13. When a part of the line is shared, it is necessary to provide a switching valve in addition to the shared part.

  The permeated water discharge main switching valve 9, the tap water supply switching valve 11, and the module lower discharge switching valve 15 each have at least a function of narrowing the flow path, and have a function of completely blocking the flow path. Particularly preferred.

  These switching valves 9, 11, 15 and liquid feeding control means 7 are connected to the control device 101.

(2) Filtration operation (2.1) Pipe flow path at the time of filtration operation The water purifier concerning this invention filters the tap water normally using the some separation membrane module 1. FIG. The piping situation during the filtration operation will be described with reference to FIG. In the case where there are a plurality of components, the reference numerals are affixed with alphabets a, b, c,... For easy understanding of the comparison with the drawings, but the arrangement relationship is not limited.

  First, the tap water supply switching valves 11a and 11b are fully opened and the module lower discharge switching valves 15a and 15b are fully closed. Thereby, tap water is supplied to each of the separation membrane modules 1a and 1b, and the whole amount is filtered by the separation membrane. Further, the permeated water discharge main switching valve 9 is fully opened, and the permeated water obtained from the separation membrane modules 1 a and 1 b is discharged from the water tap through the permeated water discharge main line 5.

(2.2) Conditions at the time of filtration operation The flux and pressure of tap water supplied to the separation membrane module 1 during filtration are required for the water production capacity and membrane area of the separation membrane module 1 and the water purification device. It may be determined appropriately from the amount of water produced. However, in consideration of the pressure resistance of the separation membrane module 1 and the surrounding piping, it is preferable to set the pressure condition so as not to break. When the supply tap water flux or pressure is insufficient only with the water pressure, the liquid supply control means 7 may be used to increase the flow rate. Moreover, with the operation of the water purifier, the separation membrane module 1 may become clogged with turbidity, resulting in a decrease in water production capacity. When the amount of fresh water required for the water purifier is insufficient, the liquid feeding control means 7 may be used to increase the pressure to increase the flux, or the clogging may be eliminated by using a cleaning method as described later. .

(3) Backwash operation (3.1) Pipe flow path during backwash operation The turbidity contained in tap water accumulates in the separation membrane module 1 by continuously performing the filtration operation. This suspended matter is deposited so as to block the pores of the separation membrane, and the water production capacity of the separation membrane is reduced. In order to recover the water production capacity of the separation membrane, it is necessary to stop the filtration operation and wash the separation membrane module 1. In the operation method of the water purifier of the present invention, the reverse pressure cleaning is performed by switching the piping by the switching valve.

  Hereinafter, the pipe switching when the separation membrane module 1a is washed will be described with reference to FIG.

  First, only the tap water supply switching valve 11a is fully closed so that tap water is supplied only to the separation membrane module 1b. Further, the permeated water discharge main switching valve 9 is fully closed and the module lower discharge switching valve 15a is opened. Then, the permeated water obtained by the separation membrane module 1b does not go to the water faucet, and reaches the secondary side of the separation membrane module 1a by going back the permeated water discharge main line as shown by a thick arrow in FIG. The permeated water at this time is defined as backwash water for convenience. Backwash water is pushed from the secondary side of the separation membrane to the primary side, and is discharged through the module lower discharge line 13a together with turbidity accumulated in the separation membrane module 1a.

  In addition, when the separation membrane module of the separation membrane filtration device is back-pressure washed, as a method to cover the back-pressure washing water, the permeated water of the other separation membrane module is directly back-pressure washed as the piping configuration similar to the water purification device. It may be supplied as water, or a storage tank for storing at least part of the permeated water is provided. When the filtration operation is stopped, the permeated water is extracted from the storage tank with a pump or the like, and the secondary of the separation membrane module You may use as a reverse pressure washing water from the side. In addition, although it abbreviate | omits about the detailed apparatus structure of a separation membrane filtration apparatus, it is also preferable to take the control method similar to the control method of a water purifier which is mentioned later.

(3.2) Flow rate conditions during backwashing operation When backwashing is performed, there is a correlation between the flow of backwash water and the cleaning effect. However, the amount of back pressure washing water to be supplied varies depending on the size of the separation membrane module 1 and the width of the membrane surface to be washed. For this reason, in the present invention, an index for further enhancing the cleaning effect is defined as a flux. In order to express the cleaning effect more strongly, the back pressure cleaning flux is 5.7 × 10 ⁻⁵ m ³ / m ² / sec or more, preferably 1.1 × 10 ⁻⁴ m ³ / m ² / sec or more. More preferably, it is 2.3 × 10 ⁻⁴ m ³ / m ² / sec or more. In order to achieve these fluxes, the output of the liquid feeding control means 7 may be varied.

Even if the flux is too high, the improvement of the cleaning effect will reach its peak, or excessive back pressure washing water will be supplied to the separation membrane, resulting in a disadvantage that it will be economically disadvantageous. . In view of these disadvantages, the back pressure washing flux is 1.2 × 10 ⁻³ m ³ / m ² / sec or less, more preferably 1.0 × 10 ⁻³ m ³ / m ² / sec or less. Good.

(3.3) Pressure condition at the time of back pressure washing | cleaning operation When performing back pressure washing | cleaning, you may control the pressure of back pressure washing water. The more pressure is applied, the more effective the backwash water removes the turbidity in the membrane surface or inside the separation membrane. However, the separation membrane module 1 and the separation membrane, each member constituting the apparatus, water pipes, etc. Control to prevent damage. As a pressure concerning the secondary side of the separation membrane module 1a, it is 150 kPa or more, More preferably, it is 250 kPa or more, 600 kPa or less, More preferably, it is 500 kPa or less.

(3.4) Detailed provisions of high-speed back pressure cleaning In the operation method of the water purification apparatus of the present invention, when back pressure cleaning is performed at a predetermined flux density, back pressure cleaning is performed at a predetermined flux density or higher. It may be all the time during the cleaning or a part of the time. The flux density may be controlled so as to change stepwise or smoothly. Regarding the pressure, the counter pressure washing water may be fed at a constant pressure or may be varied within the above-mentioned preferred range. As the control means, the output of the liquid feeding control means 7 may be changed, or the opening degree of any one of the switching valves 9, 11, 15 in the apparatus system may be adjusted.

(3.5) Implementation time of back pressure cleaning In the operation method of the water purification apparatus of the present invention, the length of time for continuously performing back pressure cleaning is 15 seconds or more, preferably 30 seconds or more, 180 seconds or less, Preferably it is 120 seconds or less. If it is less than 15 seconds, the turbidity accumulated by the backwash water will not be sufficiently discharged, and if it is longer than 180 seconds, the usable time will be shortened. It becomes economically disadvantageous.

  The start and end of the back pressure washing operation may be switched manually by each switching valve, or may be automatically controlled by the control device 101. Examples of the automatic control method include starting cleaning when the continuous operation time exceeds a certain time, starting cleaning when a predetermined time is reached, and the like. Even if the cleaning start condition is satisfied, it is also preferable to perform control so that the back pressure cleaning operation is not started in a state where any of the water faucets is open. When the user opens the water tap, it may be controlled to temporarily stop or forcibly end the back pressure cleaning.

(4) Air cleaning operation (4.1) Air cleaning piping flow path, supply method, air cleaning gas The cleaning device according to the present invention supplies gas into the separation membrane module 1 as shown in FIG. It is also preferable to take such a device configuration.

  The cleaning apparatus of the second embodiment shown in FIG. 3 includes a gas supply main line 31 that supplies gas from a gas supply source into the apparatus, and branches from the gas supply main line 31 to at least one separation membrane module 1. The gas supply line 33 connected to is provided. The gas supply main line 31 and the gas supply line 33 are grasped as gas supply pipes for supplying gas. It is preferable that the gas supply lines 33 are provided for all the separation membrane modules 1 in the apparatus because the gas can be supplied to all the separation membrane modules 1 for cleaning.

  The gas supply line 33 may be connected anywhere in the separation membrane module 1 as long as gas can be supplied into the separation membrane module 1. The gas supplied into the separation membrane module 1 peels off turbidity on the surface of the separation membrane while flowing vertically upward. Therefore, if the gas is supplied to the lower side when the separation membrane module 1 is installed, the gas cleaning effect is more effective. Since it is exhibited, it is preferable. In order to discharge the gas supplied into the separation membrane module 1, a module upper discharge line 35 is provided at a location corresponding to the primary side of the separation membrane module 1 and vertically above the installation.

  Further, a gas supply switching valve 37 is provided on the gas supply line 33, and a module upper discharge switching valve 39 is provided on the module upper discharge line 35. Each switching valve has at least a function of narrowing the flow path, and it is particularly preferable that the switching valve has a function of completely blocking the flow path.

  The gas supply source is not particularly limited as long as it can stably supply gas. For example, a gas cylinder, an air pump, etc. are mentioned.

  The composition of the gas is not particularly limited, but it is preferable to use air from the viewpoint of cost and ease of supply. When sucking ambient air with an air pump, it is preferable to filter the contaminants before introducing them into the apparatus. Hereinafter, an operation of cleaning the separation membrane module 1 by supplying air into the apparatus and cleaning the separation membrane module 1 is referred to as air cleaning.

(4.2) Air supply flow rate conditions during air cleaning operation When performing air cleaning, there is a correlation between the height of the cleaning effect and the flux of the supplied gas. However, the amount of gas to be supplied varies depending on the size of the separation membrane module 1, the width of the gas flow path, and the width of the membrane surface to be cleaned. Therefore, in the present invention, as an index for further enhancing the cleaning effect, the gas supply flow rate is obtained by standardizing the gas supply flow rate with the flow passage cross-sectional area (m ² ) on the primary side of the separation membrane module 1.

The volume of gas is expressed in Nm ³ (normal rice) normalized for each condition of temperature, pressure, and humidity. 1 Nm ³ indicates that the gas has a volume of 1 cubic meter at 0 ° C., 101.325 kPa, and a relative humidity of 0%. The gas supply flux for expressing the cleaning effect more strongly is 1.0 × 10 ⁻¹ Nm ³ / m ² / sec or more, more preferably 1.4 × 10 ⁻¹ Nm ³ / m ² / sec or more. There should be.

When the gas supply flux is too large, not only does the cleaning effect reach a peak, but there are also concerns such as membrane breakage due to excessive oscillation of the membrane, and drying of the membrane due to increased contact with the gas. In view of these concerns, the gas supply flux is 7.0 × 10 ⁻¹ Nm ³ / m ² / sec or less, more preferably 3.5 × 10 ⁻¹ Nm ³ / m ² / sec or less.

(4.3) Gas supply pressure during air cleaning The supply pressure may be controlled during gas supply. When the gas supply pressure is too low, the cleaning effect due to film shaking or the like is weakened. Therefore, the gas supply pressure is 100 kPa or more, preferably 200 kPa or more. On the other hand, if the gas supply pressure is too high, the gas supply pressure is 600 kPa or less, preferably 500 kPa or less because there is a risk of damage to the separation membrane and separation membrane module 1, each pipe or water pipe, and the risk of shortening the life. There should be.

(4.4) Water supply to the primary side of the separation membrane module 1 at the time of air washing Even if the gas supply flux is within the optimum flow rate range, the supply gas is used to supply water on the primary side of the separation membrane module 1. It may be extruded and discharged out of the separation membrane module 1. From the viewpoint of sufficiently obtaining the effect of swinging the separation membrane by the supply gas or not drying the separation membrane, it is preferable that water in the separation membrane module 1 remains as much as possible.

  The gas supply flux may be set so that the water in the separation membrane module 1 is not easily discharged out of the system, but air cleaning is performed while simultaneously supplying gas and water to the primary side of the separation membrane module 1. Also good. Examples of the water supply method at this time include providing a separate water supply line in the gas supply line 33 and partially opening the tap water supply switching valve 11 of the separation membrane module 1 to be air-washed. The water supply method may combine a plurality of means.

(4.5) Detailed provisions of high-speed air cleaning When air cleaning is performed under predetermined conditions in the operation method of the water purifier of the present invention, air cleaning is performed under predetermined conditions at all times during cleaning. It may be a part of time. The gas supply flux may be controlled so as to change stepwise or smoothly. As for the gas supply pressure, the liquid may be fed at a constant pressure or may be varied within the above-mentioned preferred range. As the control means, the supply speed from the gas supply source may be varied, or the opening degree of the gas supply switching valve 37 may be adjusted.

  There is no particular limitation on the size of the bubbles to be introduced. You may provide the apparatus which introduces microbubbles, such as a microbubble.

(4.6) Air cleaning execution time In the operation method of the water purification apparatus of the present invention, the length of time for which the air cleaning is continuously performed is 5 seconds or more, preferably 15 seconds or more, and 120 seconds or less, preferably 90 Less than a second. The turbidity accumulated by the air washing water is not sufficiently discharged in 5 seconds or less, the usable time is shortened in 90 seconds or more, the user of the water purification apparatus suffers inconvenience, and the time for the separation membrane to contact the gas is long. Therefore, the concern that the separation membrane is dried increases.

  The start and end of the air cleaning operation may be switched manually by each switching valve, or may be automatically controlled by the control device 101. Examples of the automatic control method include starting cleaning when the continuous operation time exceeds a certain time, starting cleaning when a predetermined time is reached, and the like. Even if the cleaning start condition is satisfied, it is also preferable to perform control so that the air cleaning operation is not started when any of the water taps is open. When the user opens the water tap, the air cleaning may be controlled to be interrupted or forcibly terminated.

(5) Simultaneous reverse-air operation (5.1) Outline of simultaneous reverse-air operation When the gas supply piping is connected to the separation membrane module 1, the separation membrane module 1 is cleaned by combining reverse pressure cleaning and air cleaning. May be. When combined with back pressure cleaning and air cleaning, the suspended matter suspended in the membrane is easily peeled off from the membrane surface by back pressure cleaning, and a synergistic effect is exhibited in which the effect of removing the suspended matter by air cleaning is enhanced. This effectively removes and discharges turbidity in a short time. Back pressure cleaning and air cleaning may be performed sequentially, but it is preferable to perform both at the same time because the cleaning effect is further enhanced. The back pressure cleaning and the air cleaning may be performed simultaneously during the entire cleaning process, or may be performed simultaneously during only a part of the time.

(5.2) Piping flow path at the time of simultaneous reverse idling operation Piping for cleaning the separation membrane module 1 which is the second embodiment of the cleaning device in combination with back pressure cleaning and air cleaning will be described below with reference to FIG. The flow path will be described.

  First, the piping is switched so that the separation membrane module 1a can be back-pressure washed using the permeated water of the separation membrane module 1b. Only the tap water supply switching valve 11a is fully closed, and the permeated water discharge main switching valve 9 is fully closed. Further, the gas supply switching valve 37a is opened to perform air cleaning. The module lower discharge switching valve 15a is opened for back pressure cleaning only, but when combined with air cleaning, the cleaning wastewater is discharged from the module upper discharge line 35a by the supply gas, so the upper discharge switching valve 39a. Open and perform back pressure cleaning.

(5.3) Selection of cleaning means for increasing the speed of back pressure cleaning and air cleaning At this time, by setting at least one of the cleaning conditions of back pressure cleaning and air cleaning as described above, the cleaning effect is further enhanced. be able to. As to which of the back pressure cleaning and the air cleaning is to be enhanced, a method in which the cleaning effect is further enhanced may be selected from the type and content of turbid components in tap water and the method of blocking the separation membrane. Further, a method such as alternating cleaning methods that enhance the effect may be used. Cleaning may be carried out under the above-described conditions of both reverse pressure cleaning and air cleaning.

(5.4) Supplement on water supply replenishment into the separation membrane module 1 at the time of air washing The separation membrane is supplied while simultaneously supplying gas and water to the primary side of the separation membrane module 1 described in the method of air washing. As the water supply method in the washing method, back pressure washing water pushed out from the secondary side of the separation membrane module 1 to the primary side by the back pressure washing performed simultaneously can be preferably used. Similarly to the case where only air cleaning is performed, when the amount of water supply is insufficient only with the counter pressure cleaning water, it may be combined with other means.

(6) Back pressure cleaning method in which the number of backwash water supply modules is larger than the number of modules to be cleaned when there are three or more separation membrane modules 1 (6.1) From the number of cleaning modules when performing high speed back pressure cleaning Advantages of increasing the number of backwash water supply modules (illustrated in three modules: see Figs. 5 and 6)
The water purification apparatus according to the present invention preferably includes three or more separation membrane modules 1. An example of a third embodiment of a water purifier having three separation membrane modules 1 is shown in FIG. 5 and the merit in carrying out back pressure cleaning using such a water purifier will be described.

  In a water purification apparatus having two separation membrane modules 1, when one of them is backwashed under the above-mentioned conditions, the other separation membrane module 1 can perform backpressure washing so that the prescribed backpressure washing flux can be satisfied. It is necessary to supply water. Here, when the separation membrane module 1 that supplies the reverse pressure washing water is also clogged, and the sufficient fresh water generation capacity is not maintained, the output of the liquid feeding control means 7 is increased and the reverse pressure washing is performed. Measures such as earning water supply can be taken. However, there is a concern that the separation membrane module 1 or the surrounding piping may be damaged due to the further blockage of the separation membrane module 1 or the excessive application of pressure due to the securing of the back pressure washing water.

  On the other hand, in the water purification apparatus having three separation membrane modules 1 as shown in FIG. 5, when one separation membrane module 1a is back-pressure washed under the above-mentioned conditions, the two separation membrane modules 1b and 1c are used in reverse. Pressure wash water can be supplied. Since the load per one separation membrane module 1 that supplies the backwash water is reduced, there is an advantage that the separation membrane module 1 can be delayed or the life of the separation membrane module 1 can be extended. Similarly, in a water purification apparatus including three or more separation membrane modules 1, washing is performed such that the number of separation membrane modules 1 that supply back-pressure washing water is larger than the number of separation membrane modules 1 to be washed. This is preferable because it reduces the load on the separation membrane module 1 that supplies the backwash water and the surrounding piping.

  Hereinafter, the flow path when backwashing one separation membrane module 1, which is an example of the third embodiment of the cleaning apparatus, with the backwash water of the two separation membrane modules 1 will be described with reference to FIG. 6.

  Only the tap water supply switching valve 11a is fully closed so that tap water is supplied to the separation membrane modules 1b and 1c. Further, the permeated water discharge main switching valve 9 is fully closed, and the module lower discharge switching valve 15a is opened. Then, the permeated water obtained by the separation membrane modules 1b and 1c reaches the secondary side of the separation membrane module 1a up the permeated water discharge main line as shown by the thick arrows in FIG. Is discharged from the separation membrane module 1a through the module lower discharge line 13a.

  The apparatus illustrated in FIG. 5 does not include a gas supply line, but may be an apparatus configured to include a gas supply line. At this time, air cleaning may be performed as described above, or a combination of back pressure cleaning and air cleaning may be performed.

  (6.2) When there are four or more separation membrane modules 1 (such as a piping configuration), a suitable number of modules

  The water purifier according to the present invention may include four or more separation membrane modules 1. For example, in a water purifier having four separation membranes, the back pressure washing water for one separation membrane module 1 may be supplied from three separation membrane modules 1 or one while supplying from two separation membrane modules 1 The separation membrane module 1 may be connected to a water tap so that filtered water can be obtained from the water tap even while the separation membrane module 1 is being washed.

  By increasing the number of separation membrane modules 1, there is an advantage that a backup method for troubles such as breakage of the separation membrane module 1 can be prepared. On the other hand, there are also disadvantages such as complicated control system and high cost of the water purifier itself. The number of separation membrane modules 1 of the water purification device is preferably designed based on the balance between the water production performance required for the water purification device, the type and concentration of turbidity in tap water, and the size of each separation membrane module 1.

(7) Separation membrane shape and material In the separation membrane module provided in these membrane filtration separation devices or water purification devices, the shape of the separation membrane is not particularly limited, and is a flat membrane, hollow fiber membrane, tubular type A membrane or any other shape can be used as appropriate, but a hollow fiber membrane can be preferably used because it has a merit that a membrane area per unit device area can be increased. In the present invention in which reverse pressure washing is performed to pass liquid from the secondary side to the primary side of the separation membrane, or air washing in which air is blown into the primary side of the separation membrane module, the separation membrane module is a hollow fiber membrane. The module is preferable because the effect can be more exhibited.

  The material of the membrane is not particularly limited, but at least selected from the group consisting of polyacrylonitrile, polyphenylene sulfone, polyphenylene sulfide sulfone, polyvinylidene fluoride, polypropylene, polyethylene, polysulfone, polyvinyl alcohol, cellulose acetate, ceramics, and other inorganic materials It is preferable that 1 type is included.

  In the present invention, reverse pressure cleaning and air cleaning are performed at a high fluid supply rate. It is preferable that the film has high strength because the cleaning effect is enhanced while the film may be broken. If the separation membrane is a hollow fiber membrane, the membrane strength is preferably 4.9 N or more, and more preferably 9.8 N or more.

(8) Control of washing operation using pressure gauge and flow meter (8.1) Installation location of pressure gauge and flow meter The separation membrane module 1 of the water purifier relating to the present invention is the fourth implementation of the washing device of FIG. As shown in an example of the embodiment, a module primary pressure measuring means (pressure gauge) 51 is provided on the tap water supply line 4, and a module secondary pressure measuring means (pressure gauge) 53 is provided on the permeate discharge line 6. It is preferable.

  Further, these pressure measuring means are interlocked with the control device 101, and the control device reads the measurement values of at least one pressure measuring means, calculates the degree of blockage of the separation membrane module 1, and separates it as a cleaning target. Control to determine the membrane module 1 is preferable because wear and damage of the separation membrane module 1 due to wasteful cleaning can be suppressed.

  Furthermore, it is preferable that the separation membrane module 1 of the water purifier according to the present invention includes module permeate flow rate measuring means (flow meter) 55 on the permeate discharge line 6. Similarly to the pressure measuring means, this is preferably controlled so as to determine the separation membrane module 1 to be cleaned in conjunction with the control device 101.

  The module primary pressure measuring means 51 is preferably arranged at a position as close as possible to the connecting portion between the tap water supply line 4 and the separation membrane module 1. Furthermore, it is preferable that the piping from the module primary side pressure measurement means 51 to the separation membrane module 1 is a straight line. With such a configuration, it is possible to suppress the deviation of the measured value due to the pipe pressure loss as much as possible. However, when the water purifier also includes a gas supply line, the module primary pressure measuring means 51 is preferably arranged on the upstream side of the connection portion between the gas supply line 33 and the tap water supply line 4. Thereby, it can prevent that the measured value of a pressure measurement means shift | deviates with supply gas.

  Similarly, the module secondary side pressure measuring means 53 is preferably arranged at a position as close as possible to the connecting portion between the permeate discharge line 6 and the separation membrane module 1. Furthermore, it is preferable that the piping from the module secondary side pressure measurement means 53 to the separation membrane module 1 is a straight line.

  When both the module permeate flow rate measuring means 55 and the module secondary side pressure measuring means 53 are arranged on the permeate discharge line 6, the module secondary side pressure measuring means 53 is normally connected to the separation membrane module 1. It is preferable to be arranged close to the part. However, this is not the case when the module permeated water flow rate measuring means 55 does not have a structure that generates pressure loss such as a rotor and gears.

(8.2) Cleaning operation control method from pressure gauge and flow meter readings When the separation membrane module 1 is closed, the permeate flow rate decreases with respect to the pressure on the primary side of the separation membrane module 1. 1 and the pressure on the primary side of the separation membrane module 1 is naturally increased, and the transmembrane pressure difference between the primary side and the secondary side of the separation membrane module 1 is increased. Therefore, it is preferable to control the separation membrane module 1 as a cleaning target when the measurement result of the pressure measuring unit or the flow rate measuring unit is equal to or higher than the threshold if the pressure is measured, and is equal to or lower than the threshold if the flow rate.

  In many cases, the water purifier according to the present invention provides a plurality of separation membrane modules 1 to the filtration operation at the same time. Therefore, the separation membrane module 1 is often closed at a substantially similar speed. When there are a plurality of separation membrane modules 1 that straddle the above-mentioned threshold value, the plurality of separation membrane modules 1 may be washed sequentially.

(8.3) Control method for recording pressure gauge and flow meter readings to inform the life of the separation membrane module 1 The control device of the water purification apparatus according to the present invention records the measurement results of the pressure measuring means and the flow measuring means. A control device that can be used is preferable. The initial pressure and flow rate at which operation is started with the new separation membrane module 1 is recorded, and the extent to which the initial pressure and flow rate values have been recovered by cleaning the separation membrane module 1 is calculated. When the cleaning does not return to a predetermined flow rate and pressure even after repeating a certain number of times or more, it may be set as a replacement time of the separation membrane module 1 and a function of informing the user so that it can be seen.

(9) Combination with other purifying means (RO, adsorbent, UV sterilization) The water purifying apparatus according to the present invention may further include means for purifying tap water separately at the preceding stage or the subsequent stage. Examples of the tap water purification means include separation membranes, adsorbents such as activated carbon, and sterilization with ultraviolet rays and ozone.

  Based on the above-mentioned embodiment, the implemented content and the result are enumerated below.

<Reference example: Outline of hollow fiber membrane module, new water production performance>
The hollow fiber membrane module “HFU-2020 (manufactured by Toray Industries, Inc.)” was disassembled, and the hollow fiber membrane contained in the container was taken out. This hollow fiber membrane was processed into an appropriate length, and was accommodated in a cylindrical container having an inner diameter of 100 mm and a length of 550 mm, and adhered to the container with an epoxy resin to obtain a separation membrane module 1. Pure water was supplied for 10 minutes so that a hydrostatic pressure of 17 kPa was applied to the separation membrane module 1, and the water production capacity was derived from the permeated water obtained by external pressure total filtration.
Result: The initial water-making capacity of the separation membrane module 1 was 3.07 × 10 ⁻⁹ m ³ / m ² / sec / Pa.

<Comparative Example 1: Module water-making performance after passing turbidity tap water>
The hollow fiber membrane module described in the reference example is used as the separation membrane module 1 of the water purifier shown in FIG. 1, and tap water containing fine particles of iron (III) oxide as turbidity is used on the primary side of the separation membrane module 1. The supply pressure was adjusted to 250 kPa and filtration was continued for 8 hours continuously. Thereafter, the water production capacity of the separation membrane module 1 was measured in the same manner as described in the reference example without performing any reverse pressure washing or air washing.
Results: The water production capacity was 4.44 × 10 ⁻¹⁰ m ³ / m ² / sec / Pa, which was 15% of the water production capacity of the reference example.

<Comparative example 2>
Two hollow fiber membrane modules described in the reference example were used as the separation membrane module 1 of the water purifier shown in FIG. 1, and tap water containing fine particles of iron (III) oxide as turbidity was filtered. After adjusting the supply pressure on the primary side of the separation membrane module 1 to 250 kPa and filtering for 9 minutes, the filtration is stopped and the pipe flow path is switched as shown in FIG. Back pressure washing was performed for 1 minute while adjusting to 5 × 10 ⁻⁵ m ³ / m ² / sec. After that, the counter pressure washing was stopped and the filtration was resumed. The cycle of 9 minutes filtration and 1 minute counter pressure washing was repeated 48 times, and the operation for a total of 8 hours was carried out. The measurement was performed in the same manner as described above.
Result: The water production capacity was 6.00 × 10 ⁻¹⁰ m ³ / m ² / sec / Pa, which was 20% of the water production capacity of the reference example.

<Example 1>
The same operation as in Comparative Example 2 was performed except that the back pressure washing flux was adjusted to 1.1 × 10 ⁻⁴ m ³ / m ² / sec.
Result: The water production capacity after 8 hours of operation was 1.46 × 10 ⁻⁹ m ³ / m ² / sec / Pa, which was 48% of the water production capacity of the reference example.

<Example 2>
The same operation as in Comparative Example 2 was performed except that the back pressure washing flux was adjusted to 2.3 × 10 ⁻⁴ m ³ / m ² / sec.
Result: The water production capacity after 8 hours of operation was 1.60 × 10 ⁻⁹ m ³ / m ² / sec / Pa, which was 52% of the water production capacity of the reference example.

<Example 3>
The same operation as in Comparative Example 2 was performed except that the back pressure washing flux was adjusted to 1.0 × 10 ⁻³ m ³ / m ² / sec.
Result: The water production capacity after 8 hours of operation was 1.64 × 10 ⁻⁹ m ³ / m ² / sec / Pa, which was 54% of the water production capacity of the reference example.

<Example 4>
The same operation as in Comparative Example 2 was performed except that the back pressure washing flux was adjusted to 1.2 × 10 ⁻³ m ³ / m ² / sec.
Result: The water production capacity after 8 hours of operation was 1.66 × 10 ⁻⁹ m ³ / m ² / sec / Pa, which was 54% of the water production capacity of the reference example.

<Example 5>
The same operation as in Comparative Example 2 was performed except that the back pressure washing flux was adjusted to 1.4 × 10 ⁻³ m ³ / m ² / sec.
Result: The water production capacity after the operation for 8 hours was 1.68 × 10 ⁻⁹ m ³ / m ² / sec / Pa, which was 55% of the water production capacity of the reference example.

<Comparative Example 3>
Two hollow fiber membrane modules described in the reference example were used as the separation membrane module 1 of the water purifier shown in FIG. 3, and tap water containing fine particles of iron (III) oxide as turbidity was filtered. After adjusting the supply pressure on the primary side of the separation membrane module 1 to 250 kPa and filtering for 9 minutes, the filtration was stopped and the piping flow path was switched, and the air washing flux was 5.0 × 10 ⁻² Nm Air cleaning was performed for 1 minute while adjusting to ³ / m ² / sec. Thereafter, the air washing is stopped and the filtration is restarted, and the cycle of 9-minute filtration and 1-minute air washing is repeated 48 times. After a total of 8 hours of operation, the water production capacity of the separation membrane module 1 is described in the reference example. Was measured in the same manner.
Result: The water production capacity was 5.44 × 10 ⁻¹⁰ m ³ / m ² / sec / Pa, which was 18% of the water production capacity of the reference example.

<Example 6>
The same operation as in Comparative Example 3 was performed except that the air washing flux was adjusted to 1.0 × 10 ⁻¹ Nm ³ / m ² / sec.
Result: The water production capacity after 8 hours of operation was 1.24 × 10 ⁻⁹ m ³ / m ² / sec / Pa, 41% of the water production capacity of the reference example.

<Example 7>
The same operation as Comparative Example 3 was performed except that the air washing flux was adjusted to 1.4 × 10 ⁻¹ Nm ³ / m ² / sec.
Result: The water production capacity after 8 hours of operation was 1.36 × 10 ⁻⁹ m ³ / m ² / sec / Pa, which was 44% of the water production capacity of the reference example.

<Example 8>
The same operation as in Comparative Example 3 was performed except that the air washing flux was adjusted to 3.5 × 10 ⁻¹ Nm ³ / m ² / sec.
Result: The water production capacity after 8 hours of operation was 1.43 × 10 ⁻⁹ m ³ / m ² / sec / Pa, which was 47% of the water production capacity of the reference example.

<Example 9>
The same operation as Comparative Example 3 was performed except that the air washing flux was adjusted to 7.0 × 10 ⁻¹ Nm ³ / m ² / sec.
Result: The water production capacity after 8 hours of operation was 1.46 × 10 ⁻⁹ m ³ / m ² / sec / Pa, which was 48% of the water production capacity of the reference example.

<Example 10>
The same operation as Comparative Example 3 was performed except that the air washing flux was adjusted to 8.5 × 10 ⁻¹ Nm ³ / m ² / sec.
Results: The water production capacity after 8 hours of operation was 1.45 × 10 ⁻⁹ m ³ / m ² / sec / Pa, 47% of the water production capacity of the reference example.

<Comparative example 4>
Two hollow fiber membrane modules described in the reference example were used as the separation membrane module 1 of the water purifier shown in FIG. 3, and tap water containing fine particles of iron (III) oxide as turbidity was filtered. After adjusting the supply pressure on the primary side of the separation membrane module 1 to 250 kPa and filtering for 9 minutes, the filtration is stopped and the piping flow path is switched as shown in FIG. Back pressure washing was started while adjusting to 5 × 10 ⁻⁵ m ³ / m ² / sec. Immediately after that, air cleaning was started while adjusting the air cleaning flow rate to be 5.0 × 10 ⁻² Nm ³ / m ² / sec, and back pressure cleaning and air cleaning were simultaneously performed for 1 minute. After that, the washing was stopped and the filtration was resumed. The cycle of 9-minute filtration and 1-minute air washing was repeated 48 times, and after a total of 8 hours of operation, the water production capacity of the separation membrane module 1 was described in the reference example. It measured similarly.
Result: The water production capacity was 9.28 × 10 ⁻¹⁰ m ³ / m ² / sec / Pa, which was 30% of the water production capacity of the reference example.

<Example 11>
The same operation as in Comparative Example 3 was performed except that the back pressure washing flux was adjusted to 1.1 × 10 ⁻⁴ m ³ / m ² / sec.
Result: The water production capacity after the operation for 8 hours was 1.93 × 10 ⁻⁹ m ³ / m ² / sec / Pa, which was 63% of the water production capacity of the reference example.

<Example 12>
The same operation as in Comparative Example 3 was performed except that the air washing flux was adjusted to 1.0 × 10 ⁻¹ Nm ³ / m ² / sec.
Result: The water production capacity after 8 hours of operation was 1.85 × 10 ⁻⁹ m ³ / m ² / sec / Pa, which was 60% of the water production capacity of the reference example.

<Example 13>
Comparison was made except that the counter pressure cleaning flux was adjusted to 1.1 × 10 ⁻⁴ m ³ / m ² / sec and the air cleaning flux was adjusted to 1.0 × 10 ⁻¹ Nm ³ / m ² / sec. The same operation as in Example 3 was performed.
Result: The water production capacity after the operation for 8 hours was 2.06 × 10 ⁻⁹ m ³ / m ² / sec / Pa, which was 67% of the water production capacity of the reference example.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably. In addition, the material, shape, dimension, numerical value, form, number, arrangement location, and the like of each component in the above-described embodiment are arbitrary and are not limited as long as the present invention can be achieved.

1 Separation Membrane Module 3 Tap Water Supply Main Line (Raw Water Supply Main Line)
4 tap water supply line (raw water supply line)
5 Permeated water discharge main line 6 Permeated water discharge line 7 Liquid feed control means 9 Permeated water discharge main switching valve 11 Tap water supply switching valve 13 Module lower discharge line 15 Module lower discharge switching valve 31 Gas supply main line (gas supply piping)
33 Gas supply line (gas supply piping)
35 Module upper discharge line 37 Gas supply switching valve 39 Module upper discharge switching valve 51 Module primary side pressure measuring means (pressure gauge)
53 Module secondary pressure measurement means (pressure gauge)
55 Module permeate flow rate measuring means (flow meter)
101 Control device

Claims (11)

A method for operating a separation membrane filtration device, comprising:
A step of separating permeate from raw water by a separation membrane module provided in the separation membrane filtration device;
Discharging the permeate from a permeate discharge line connected to the filtration side of the separation membrane module;
A filtration operation process including:
Stopping filtration of the separation membrane module;
Back pressure washing step of supplying back pressure washing water at a flux of 1.1 × 10 ⁻⁴ m ³ / m ² / sec or more from the filtration side of the separation membrane module to the raw water side;
A cleaning operation process including:
A method for operating a separation membrane filtration apparatus. A method for operating a separation membrane filtration device, comprising:
A step of separating permeate from raw water by a separation membrane module provided in the separation membrane filtration device;
Discharging the permeate from a permeate discharge line connected to the filtration side of the separation membrane module;
A filtration operation process including:
Stopping filtration of the separation membrane module;
An air washing step of supplying gas at a rate of 1.0 × 10 ⁻¹ Nm ³ / m ² / sec or more through the gas supply pipe into the separation membrane module;
A cleaning operation process including:
A method for operating a separation membrane filtration apparatus. A method for operating a separation membrane filtration device, comprising:
A step of separating permeate from raw water by a separation membrane module provided in the separation membrane filtration device;
Discharging the permeate from a permeate discharge line connected to the filtration side of the separation membrane module;
A filtration operation process including:
Stopping filtration of the separation membrane module;
Back pressure washing step of supplying back pressure washing water from the filtration side of the separation membrane module to the raw water side;
An air washing step for supplying gas through the gas supply pipe in the separation membrane module;
A cleaning operation process including:
And operating the separation membrane filtration device so that at least one of the following conditions i) or ii) is satisfied in the washing operation step.
i) The backwash water flux in the backwash step is 1.1 × 10 ⁻⁴ m ³ / m ² / sec or more.
ii) The gas supply rate of the air cleaning step is 1.0 × 10 ⁻¹ Nm ³ / m ² / sec or more. A method for operating the separation membrane filtration device according to any one of claims 1 to 3,
A method for operating a separation membrane filtration device, wherein the separation membrane module comprises a hollow fiber membrane as a separation membrane. An operation method of the separation membrane filtration device according to any one of claims 1 to 4,
The separation membrane filtration device includes a pressure gauge in each of the raw water supply line for supplying raw water and the permeated water discharge line, and a flow meter in the permeated water discharge line,
A method for operating a separation membrane filtration device, wherein the separation membrane module to be cleaned in the cleaning operation step is controlled using a measured value of at least one of the pressure gauge and the flow meter. A method for operating a water purification device,
Supplying raw water from the raw water supply source to the water purifier using the raw water supply main line;
Separating the permeated water from the raw water by one or more of the separation membrane modules among a plurality of separation membrane modules provided in the water purifier;
Discharging the permeate from a permeate discharge main line connected to the filtration side of all the separation membrane modules;
A filtration operation process including:
Filtering the raw water with at least one of the separation membrane modules, and stopping filtering the raw water with at least one of the separation membrane modules;
At least a part of the permeated water is sent to the filtration side of the separation membrane module where filtration is stopped through the permeated water discharge main line, and 1.1 × 10 ⁻ from the filtration side of the separation membrane module to the raw water side. A back pressure washing step for supplying a flux of ⁴ m ³ / m ² / sec or more;
A cleaning operation process including:
A method for operating a water purification apparatus. A method for operating a water purification device,
Supplying raw water from the raw water supply source to the water purifier using the raw water supply main line;
Separating the permeated water from the raw water by one or more of the separation membrane modules among a plurality of separation membrane modules provided in the water purifier;
Discharging the permeate from a permeate discharge main line connected to the filtration side of all the separation membrane modules;
A filtration operation process including:
Stopping the filtration of the raw water with at least one of the separation membrane modules including a gas supply pipe among the plurality of separation membrane modules;
An air washing step of supplying gas at a rate of 1.0 × 10 ⁻¹ Nm ³ / m ² / sec or more using the gas supply pipe in the separation membrane module;
A cleaning operation process including:
A method for operating a water purification apparatus. A method for operating a water purification device,
Supplying raw water from the raw water supply source to the water purifier using the raw water supply main line;
Separating the permeated water from the raw water by one or more of the separation membrane modules among a plurality of separation membrane modules provided in the water purifier;
Discharging the permeate from a permeate discharge main line connected to the filtration side of all the separation membrane modules;
A filtration operation process including:
Filtering the raw water with at least one of the plurality of separation membrane modules, and stopping the filtration of the raw water with at least one of the separation membrane modules including a gas supply pipe; and
A reverse pressure washing step of feeding at least a part of the permeated water to the filtration side of the separation membrane module that has stopped filtration through the permeate discharge main line, and supplying the raw water side from the filtration side of the separation membrane module; ,
An air cleaning step for supplying gas using the gas supply pipe in the separation membrane module;
A cleaning operation process including:
And operating the water purifier so that at least one of the following conditions i) or ii) is satisfied in the washing operation step.
i) The backwash water flux in the backwash step is 1.1 × 10 ⁻⁴ m ³ / m ² / sec or more.
ii) The gas supply rate of the air cleaning step is 1.0 × 10 ⁻¹ Nm ³ / m ² / sec or more. It is a driving | operation method of the water purifier of Claim 6 or 8, Comprising:
The water purifier comprises three or more separation membrane modules,
The number of the separation membrane modules that perform filtration in the back pressure washing step is operated to be larger than the number of the separation membrane modules that stop the filtration.
Operation method of water purification equipment. It is a driving | operation method of the water purifier of any one of Claim 6 to 9,
The separation membrane module includes a hollow fiber membrane as a separation membrane,
Operation method of water purification equipment. It is a driving | running method of the water purifier of any one of Claim 6 to 10,
The water purifier includes pressure gauges in each of the raw water supply main line and the raw water supply line connected to the separation membrane module, and the permeate discharge line connected to the separation membrane module and the permeate discharge main line. And a flow meter is provided in the permeate discharge line,
A method for operating a water purifier, wherein the separation membrane module to be cleaned in the cleaning operation step is controlled using a measured value of at least one of the pressure gauge and the flow meter.

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