JP2006110464A - Membrane treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a membrane treatment apparatus having a means for inexpensively and surely detecting the occurrence of membrane break. <P>SOLUTION: A treated water outlet nozzle 12a of a hollow fiber membrane module 1 is connected to a membrane break detecting part 50 through a treated water pipe 41. When a break is present in a hollow fiber membrane 4, pressurized air from a compressor C passes through the break and flows in a treated water chamber 12, and further passes between an electrode 51 and an elbow 70 in the membrane break detecting part 50 through the pipe 41. When a bubble is present in the treated water, the current and voltage between the electrode 51 and the elbow 70 are changed at the time when the bubble passes between the electrode 51 and elbow 70. The membrane break is detected by this change pattern. A vertically guiding section 72 is provided in the elbow 70, and the electrode 51 is provided on the downstream side of this vertically guiding section 72. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a membrane treatment apparatus such as a hollow fiber membrane separation apparatus equipped with a membrane for filtering water to be treated, and more particularly to a membrane treatment apparatus provided with means for detecting membrane breakage. Specifically, the present invention relates to a film processing apparatus in which film breakage detection in a film processing apparatus is performed by detecting bubbles.

  As a technique for detecting the breakage of the film in the film processing apparatus, a technique has been proposed in which bubbles leaking from the broken portion in the air backwash process are detected by visual observation, an ultrasonic sensor, a particle meter, a turbidimeter, and a photoelectric sensor.

  For example, Japanese Patent Application Laid-Open No. 2001-269551 discloses a method for detecting a breakage of a hollow fiber membrane in a water purification apparatus using an ultrasonic current meter. In the membrane breakage detection method of the publication, the treated water chamber is filled with treated water, and pressurized gas is blown into the circulating water chamber. When the hollow fiber membrane is broken, the pressurized gas moves from the broken portion through the hollow fiber membrane to the treated water chamber, and further flows out from the treated water pipe connected to the treated water chamber. By detecting the gas passing through the treated water pipe using an ultrasonic current meter provided in the treated water pipe, the breakage of the hollow fiber membrane is detected.

  Japanese Patent Laid-Open No. 2000-126563 discloses that a housing is partitioned into a raw water chamber and a treated water chamber by a hollow fiber membrane, and an air reservoir is provided in a treated water discharge pipe connected to the treated water chamber of the housing. In the hollow fiber membrane filtration device, pressurized air is supplied into the raw water chamber, and the pressurized air accumulates in the air reservoir from the broken portion of the hollow fiber membrane through the treated water chamber and the treated water discharge pipe. A method for confirming breakage of a hollow fiber membrane by detecting accumulated air visually or with a water level gauge is disclosed.

Further, in JP-A-2003-144866, the inside of a hollow fiber membrane module is partitioned by a hollow fiber membrane into an upper raw water chamber and a lower treated water chamber, and a hollow fiber membrane breakage detection unit is provided above the raw water chamber. In a hollow fiber membrane module type filtration device to which a bubble evacuation pipe having a transparent tube is connected, air that has been press-fitted into the treated water chamber during backwashing of air bubbles from the treated water chamber through the broken portion of the hollow fiber membrane and the raw water chamber. A technology is disclosed in which a membrane breakage is determined by passing through a hollow tube for detecting breakage of a hollow fiber membrane provided in a tube pull-out and detecting the air passing through the transparent tube visually or with a photoelectric sensor.
JP 2001-269551 A JP 2000-126563 A JP 2003-144866 A

  When air bubbles mixed in the liquid flowing through the flow path and flowing through the flow path are detected by a sensor, if the sensor is arranged near the inner surface of the flow path, the air bubbles flow near the center of the tubular flow path. May not be detected.

  An object of the present invention is to provide a membrane processing apparatus capable of reliably detecting a bubble flowing together with a liquid in a flow path and detecting a film breakage.

  The membrane treatment apparatus according to claim 1 is a membrane for filtering a liquid to be treated, a means for circulating a gas or gas-liquid mixture on one side separated by the membrane, and the membrane for detecting breakage of the membrane. And a bubble detector for detecting bubbles on the other side separated by a flow path in which a liquid that has permeated through the film flows, provided in a downward portion facing the flow path, and The channel is characterized in that the bubbles are collected in the upper part of the channel.

  The membrane treatment apparatus according to claim 2 is a membrane for filtering a liquid to be treated, means for circulating a gas or gas-liquid mixture on one side separated by the membrane, and the membrane for detecting the breakage of the membrane. A membrane detector having a bubble detector for detecting bubbles on the other side separated by a horizontal pulling channel through which the liquid that has permeated the membrane flows. It is provided in the downward direction part which faces the flow path of the flow path downstream from the part where the bubbles are collected in the upper part in the flow path.

  A membrane treatment apparatus according to claim 3 is a membrane for filtering a liquid to be treated, a means for circulating a gas or gas-liquid mixture on one side separated by the membrane, and the membrane for detecting breakage of the membrane. In the film processing apparatus having a bubble detector for detecting bubbles on the other side separated by a horizontal pulling channel through which the liquid that has passed through the membrane flows, a liquid is placed in the middle of the horizontal pulling channel. A vertical pulling portion that flows upward is provided, and the bubble detector is provided in a downward portion facing the horizontal pulling channel on the downstream side of the vertical pulling portion. .

  According to a fourth aspect of the present invention, there is provided the membrane processing apparatus according to the third aspect, wherein the upward portion facing the flow path from the horizontal pulling portion upstream of the vertical pulling portion to the vertical pulling portion is curved along the liquid flow direction. It is characterized by that.

  The membrane treatment apparatus according to claim 5 is a membrane for filtering a liquid to be treated, a means for circulating a gas or gas-liquid mixture on one side separated by the membrane, and the membrane for detecting the breakage of the membrane. In the film processing apparatus having a bubble detector for detecting bubbles on the other side separated by a vertical pulling channel through which the liquid that has permeated the membrane flows upward is provided in the middle of the vertical pulling channel, A horizontal pulling portion in which the liquid flows sideways is provided, and the bubble detector is provided in a downward portion facing the flow path on the terminal side of the horizontal pulling portion.

  According to a sixth aspect of the present invention, there is provided the membrane processing apparatus according to the fifth aspect, wherein the horizontal pulling portion is connected to the upper end of the upstream vertical pulling portion on the upstream side of the horizontal pulling portion, and extends to the side therefrom. A second laterally extending portion that extends in a direction opposite to the extending direction of the first laterally extending portion; and a second laterally extending portion that is continuous with the extending direction end of the first laterally extending portion. A third laterally extending portion that extends in a direction parallel to the extending direction of the first laterally extending portion, and the distal end of the third laterally extending portion is the laterally extending portion. The bubble detector is provided in a downward portion facing the flow path on the end side of the second lateral pulling portion, which is continuous with the downstream vertical pulling portion on the downstream side. It is.

  The film processing apparatus according to a seventh aspect is the film processing apparatus according to the sixth aspect, wherein the upstream vertical pulling portion and the downstream vertical pulling portion are arranged coaxially, and the length of the first horizontal pulling portion and the third horizontal pulling portion are The length is substantially equal.

  The film processing apparatus according to an eighth aspect of the present invention is the film processing apparatus according to the fifth aspect, wherein the horizontal pulling portion is connected to the upper end of the upstream vertical pulling portion on the upstream side of the horizontal pulling portion and extends laterally therefrom. The lower end of the downstream vertical pulling portion downstream of the horizontal pulling portion is connected to the end of the portion.

  According to a ninth aspect of the present invention, there is provided the membrane processing apparatus according to the fifth aspect, wherein the horizontal pulling portion is connected to an upper end of the upstream vertical pulling portion on the upstream side of the horizontal pulling portion, and extends to the side therefrom. And a second laterally extending portion extending in a direction opposite to the extending direction of the first laterally extending portion, and extending from the distal end of the first laterally extending portion. The end of the second horizontal pulling portion is connected to the downstream vertical pulling portion on the downstream side of the horizontal pulling portion, and the bubble is formed in a downward portion facing the flow path on the terminal side of the second horizontal pulling portion. A detector is provided.

  A film processing apparatus according to a tenth aspect is characterized in that, in any one of the second, fifth, and ninth aspects, the length of the laterally drawn flow path is 0.6 m or more.

  The film processing apparatus according to claim 11 is the film processing apparatus according to any one of claims 1 to 10, wherein the bubble detector is a pair of electrodes arranged so as to be in contact with the liquid in the flow path. The apparatus includes a power source that applies a constant voltage to the electrodes, a measurement unit that measures a current flowing between the electrodes, and a determination unit that determines a film rupture from a pattern of changes in the measured current value, as a film breakage detection unit. It is characterized by having.

  The film processing apparatus according to a twelfth aspect is the film processing apparatus according to any one of the first to tenth aspects, wherein the bubble detector is a pair of electrodes arranged so as to be in contact with the liquid in the flow path. The apparatus, as a film breakage detection means, a power source that supplies a constant current between the electrodes, a measurement unit that measures a voltage generated between the electrodes, and a determination for determining film breakage from a pattern of changes in the measured voltage value Part.

  A film processing apparatus according to a thirteenth aspect is the film processing apparatus according to any one of the first to tenth aspects, wherein the bubble detector is a pair of electrodes arranged so as to be in contact with the liquid in the flow path. The apparatus includes, as a film breakage detection means, means for measuring the conductivity of the liquid to be treated between the electrodes, and a determination unit for determining film breakage from the measured change pattern of conductivity. It is.

  A film processing apparatus according to a fourteenth aspect is the membrane processing apparatus according to any one of the eleventh to thirteenth aspects, wherein one of the pair of electrodes is a flow path member and the other is separated from the flow path member via an insulating member. It is the needle-shaped electrode currently provided.

  In addition, the inclination | tilt angle of a horizontal pulling flow path and a horizontal pulling part is not limited to a horizontal direction, If a bubble is collected by the upper part in a flow path, you may be inclined slightly. Further, the inclination angle of the vertical pulling channel and the vertical pulling portion is not limited to the vertical direction.

  The film processing apparatus according to claim 1, wherein when bubbles that have passed through the broken film flow in the flow path together with the liquid, the bubbles rise by forming the flow path so that the bubbles gather at the upper part of the flow path. Since the air bubbles gather at the upper part in the flow path, the air bubbles can be reliably detected by providing a bubble detector at the upper part of the inner surface of the flow path.

  3. The film processing apparatus according to claim 2, wherein when bubbles that have passed through the broken film flow in the horizontal pulling channel together with the liquid, the bubbles rise and gradually gather at the upper part of the inner surface of the channel. Air bubbles can be reliably detected by providing a bubble detector at the upper part of the inner surface of the flow channel on the downstream side of the part gathered at the upper part.

  In the film processing apparatus according to claim 3, in the case where bubbles that have passed through the broken membrane flow in the horizontal pulling channel together with the liquid, if a vertical pulling portion is provided in the middle of the horizontal pulling channel, the upstream horizontal pulling portion Centrifugal force acts when the liquid flows over the vertical pulling portion, and bubbles are collected in the upper part of the flow path. For this reason, bubbles can be reliably detected by providing a bubble detector at the upper part of the inner surface of the horizontal pulling channel on the downstream side of the vertical pulling portion.

  As described in claim 4, when the upward portion facing the flow path from the upstream side horizontal flow path to the vertical pulling portion is curved along the liquid flow direction, the flow of the liquid becomes smooth and bubbles due to centrifugal force are generated. Separation is promoted.

  In the film processing apparatus according to the fifth aspect, the air bubbles that have passed through the broken film flow upward along with the liquid in the longitudinal pulling channel. Since the horizontal pulling portion is provided in the middle of the vertical pulling channel, the bubbles rise and gather on the upper side of the horizontal pulling portion while the bubbles and the liquid flow through the horizontal pulling portion. Therefore, bubbles can be efficiently detected by providing a bubble detector in a downward portion facing the flow path on the end side of the horizontal pulling portion.

  In the film processing apparatus of the sixth aspect, the second horizontal pulling portion can be disposed so that the second horizontal pulling portion projects in both the left and right directions with respect to the vertical pulling portion. For this reason, the right and left weight balance of the horizontal pulling portion can be achieved, and the support structure of the horizontal pulling portion is simplified.

  In particular, as in claim 7, when the upstream and downstream longitudinal pulls are installed coaxially, by making the length of the first horizontal pulling portion and the length of the second horizontal pulling portion substantially equal, The right and left weight balance of the horizontal pulling portion is balanced, and the support structure of the horizontal pulling portion is simplified.

  However, as in claim 8 or 9, only one or two lateral pulling portions may be provided.

  As described in claim 10, by setting the length of the laterally extending portion to 0.6 m or more, the bubbles are sufficiently floated.

  In the film processing apparatus according to any one of claims 11 to 13, when the film is ruptured, air bubbles flow from one side of the film through the ruptured portion to the other side, and the liquid on the other side. Bubbles are mixed in. Then, the electric resistance of the liquid changes as the bubbles pass through the electric resistance detection unit. Therefore, film breakage can be detected from this change in electrical resistance.

  In the membrane processing apparatus according to claims 11 to 13, a pair of electrodes is disposed in the flow path, and bubbles are caused to flow between the electrodes when the membrane breaks. When bubbles flow in between the electrodes, the electrical resistance between the electrodes changes as compared with the case where only the liquid flows between the electrodes. Therefore, the occurrence of film breakage can be detected based on this change in electrical resistance.

  Since the change in the electrical resistance of the liquid can be detected with a simple device, the equipment cost is low.

  In order to detect the change in resistance of the liquid, a constant voltage may be applied between the pair of electrodes, and the current value between the electrodes may be detected.

  Alternatively, a constant current may be passed between the electrodes to detect a change in voltage between the electrodes (claim 12). Furthermore, a change in conductivity between the electrodes may be detected, and the change in conductivity may be used as an index value for a change in the electrical resistance of the liquid.

  In order to determine the breakage of the film from the change in current value, voltage value, or conductivity, the gas, gas-liquid mixture is circulated through the film processing apparatus having the broken film, and the change pattern of the voltage, current, or conductivity. This change pattern is stored in the storage means, and the pattern of voltage, current, or conductivity is detected by circulating a gas or gas-liquid mixed solution through a film processing apparatus whose membrane breakage has not been confirmed. Is convenient to compare with the change pattern stored in the storage means.

  In addition, by using the flow path member as an electrode as in the fourteenth aspect, the film breakage detecting means can be installed in a small space. In addition, by making the electrode needle-like, fluctuations in current or voltage when bubbles are brought into contact with the electrode become significant, so that film breakage detection becomes sharp.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic view of a film processing apparatus according to an embodiment of the present invention, and FIG. 2 is a block diagram of the film breakage detecting apparatus of FIG. In FIG. 1, four hollow fiber membranes are used for the sake of clarity, but in reality, a large number of hollow fiber membranes are arranged.

  A plurality of hollow fiber membranes 4 are bundled and arranged in the casing 2 of the internal pressure type hollow fiber membrane module 1. The lower and upper ends of the bundle of hollow fiber membranes 4 are bound by sealing materials 6 and 8 made of synthetic resin or the like, respectively. The sealing materials 6 and 8 are, for example, in a disk shape, and the outer peripheral surface or outer peripheral edge thereof is in watertight contact with the inner surface of the casing 2. A raw water chamber 10 is formed on the lower side of the lower sealing material 6, a circulating water chamber 14 is formed on the upper side of the upper sealing material 8, and the treated water chamber 12 is formed between both the sealing materials 6 and 8. Is formed.

  The upper end side of the hollow fiber membrane 4 penetrates the sealing material 8, and the opening 4 a at the upper end faces the circulating water chamber 14. Similarly, the lower end side of the hollow fiber membrane 4 penetrates the sealing material 6, and the opening 4 b at the lower end faces the raw water chamber 10.

On the side of the raw water chamber 10 of the casing 2, a raw water inlet nozzle 10a and a gas inlet nozzle 10b are provided. Raw water inlet nozzle 10a is raw water pipe 21, via the raw water valve V ₁ and the raw water pump P are connected to the raw water tank 20. From the point between the raw water nozzle 10a and the raw water valve V ₁ of the raw water pipe 21, discharge pipe 24 is branched with a drain valve V _2. Gas inlet nozzle 10b is connected to a compressor C via a gas pipe 27 having a valve V _3.

A circulating water outlet nozzle 14 a is provided on the circulating water chamber 14 side of the casing 2. The circulation water outlet nozzle 14a is connected to the raw water tank 20 through a circulating water pipe 31 having a circulating water valve V _4. From the point between the circulation water outlet nozzle 14a of the circulating water pipe 31 and the circulating water valve V _4, a vent pipe 33 provided with a vent valve V ₅ is branched.

  A treated water outlet nozzle 12 a is provided on the treated water chamber 12 side of the casing 2. The treated water outlet nozzle 12 a is connected to the membrane breakage detection unit 50 via the treated water pipe 41, and the membrane breakage detection unit 50 is connected to the treated water tank 40 via the treated water pipe 42. Although FIG. 1 shows the case of the internal pressure type, the present invention is not limited to this and can also be implemented by the external pressure type.

  As shown in FIG. 2, in the membrane breakage detection unit 50, a metal elbow 70 as a channel member bent in a crank shape is provided between the pipes 41 and 42. The elbow 70 has an upstream side pulling portion 71 in which the pipe 41 is connected in a straight line, and a vertical pulling portion 72 in which the lower end is connected to the upstream side pulling portion 71 and the upper end is connected to the downstream side pulling portion 73. The upward surface 74 of the flow path inner surface from the upstream lateral pulling portion 71 to the vertical pulling portion 72 is curved in a substantially arc shape along the flow direction. The needle-like electrode 51 is provided on the downward facing portion (ceiling portion) 76 of the inner surface of the flow channel facing the downstream side pulling portion 73 via the electrical insulating material 77. The needle electrode 51 slightly protrudes from the inner surface of the flow path.

  If bubbles are contained in the liquid flowing in the pipe 41 and the horizontal pulling portion 71, the bubbles gradually rise based on the specific gravity difference. When this liquid flows along the curved upward surface 74, centrifugal force acts, and the low specific gravity bubbles receive a force separating from the upward surface 74, and the rising is promoted. For this reason, most of the bubbles in the liquid that have passed through the vertical pulling portion 72 flow along the inner surface 75 on the upper side of the vertical pulling portion 72 and the ceiling portion 76 of the downstream side horizontal pulling portion 73, and the bubbles are electroded. It starts to flow around 51.

  Next, a mechanism for detecting bubbles flowing in the vicinity of the electrode 51 will be described with reference to FIGS.

  As shown in FIG. 3, a power source 52 that applies a voltage to the electrode 51 and the elbow 70 and a measurement unit 53 that measures the current, voltage, or conductivity between the electrode 51 and the elbow 70 in order to detect film breakage. And a storage unit 55 that stores changes over time in current, voltage, or conductivity, and a determination unit 56 that determines the generation of bubbles from a pattern of changes over time in current, voltage, or conductivity.

  In addition, it is preferable that the material of the electrode 51 and the elbow 70 is platinum or stainless steel so as not to be affected by the pH of the treated water.

  FIG. 4 shows a constant voltage type film breakage detection circuit diagram in which a dry battery is used as a constant voltage source and a change in the current flowing between the electrode 51 and the elbow 70 is amplified and detected by a transistor. Yes.

An elbow 70 is connected to the base of the NPN transistor T and is used as an electrode. The collector of the transistor T is connected to the electrode 51 via resistors R ₂ and R ₁ . The emitter of the transistor T is connected to the cathode of the dry battery 68. The anode of the battery 68 is connected to a point between said resistors R ₁ and R _2. Voltmeter V is provided to measure the voltage drop across the resistor R _2. A constant voltage is applied from the dry battery 68 between the elbow 70 and the electrode 51. When only water flows through the elbow 70, the current value between the elbow 70 and the electrode 51 is constant, but when the bubbles pass through the elbow 70, the current value decreases. This current change is amplified by the transistor T, a collector current changes in the transistor T, the voltage across the resistor R ₂ that is detected by the voltmeter V varies. From the change in the detection voltage of the voltmeter V, the passage of bubbles in the elbow 70 is detected. In particular, in the detection mechanism shown in FIGS. 3 and 4, since the value of the current flowing through the electrode 51 changes greatly when the bubble contacts the needle electrode 51, the bubble can be detected sensitively.

  Next, the operation content when the film breakage detection method is a constant voltage method will be described. The power source 52 applies a constant voltage between the electrode 51 and the elbow 70. With this applied voltage, a current corresponding to the electrical resistance of the treated water flows between the electrode 51 and the elbow 70. When bubbles exist in the water, the current between the electrode 51 and the elbow 70 changes when the bubble passes between the electrode 51 and the elbow 70.

  The measuring unit 53 measures the current value between the electrode 51 and the elbow 70.

  Next, the current value change pattern stored in the storage unit 55 and the current value change pattern of the current value measured by the measurement unit 53 are compared with each other by the determiner 56 to determine the presence or absence of film breakage.

  When the film breakage detection is set to the constant current method, the power source 52 applies a voltage so that a constant current flows between the electrode 51 and the elbow 70. When bubbles exist in the water, the voltage between the electrode 51 and the elbow 70 changes when the bubble passes between the electrode 51 and the elbow 70. The measuring unit 53 measures the voltage value between the electrode 51 and the elbow 70. Next, the change pattern of the voltage value stored in the storage unit 55 and the temporal change pattern of the voltage value measured by the measurement unit 53 are compared with each other by the determiner 56 to determine the presence or absence of film rupture.

  When the film breakage detection is the conductivity detection method, the power source 52 applies a predetermined voltage between the electrode 51 and the elbow 70, and causes a current to flow between the electrode 51 and the elbow 70. When bubbles exist in the water, the conductivity between the electrode 51 and the elbow 70 changes when the bubble passes between the electrode 51 and the elbow 70. This change is measured by the measurement unit 53, and then the conductivity change pattern stored in the storage unit 55 is compared with the measured conductivity change pattern with time by the determiner 56 to determine the presence or absence of film breakage. Is done.

  The flow of water or gas during normal operation and cleaning operation of the membrane processing apparatus configured as described above is as follows.

[During normal operation]
During normal operation, the valves V ₁ and V ₄ are opened, the other valves (V ₂ , V ₃ , V ₅ ) are closed, and the raw water pump P is operated. Raw water raw water tank 20 is the raw water pipe 21, the raw water pump P, through the valve _{V 1,} and flows from the raw water inlet nozzle 10a to the raw water chamber 10. The raw water in the raw water chamber 10 flows into the hollow fiber membrane 4 from the opening 4b at the lower end of the hollow fiber membrane 4, and a part of this raw water passes through the hollow fiber membrane 4 and flows into the treated water chamber 12, The remainder flows into the circulating water chamber 14 from the opening 4 a at the upper end of the hollow fiber membrane 4.
The treated water in the treated water chamber 12 flows out from the treated water outlet nozzle 12 a and is sent to the treated water tank 40 through the treated water pipe 41, the membrane breakage detection device 50 and the pipe 42.
Circulating water in the circulation water chamber 14 flows out from the circulation water outlet nozzle 14a, the circulating water pipe 31, is water in the raw water tank 20 via a valve V _4.

[Washing with mixed water]
When washing the membrane treatment apparatus with gas-water mixing water, in the state of the normal operation, and the valve V ₃ is opened, to operate the compressor C. Thereby, the pressurized gas from the compressor C passes through the inside of the hollow fiber membrane 4 together with the raw water supplied by the raw water pump P, and the hollow fiber membrane 4 is washed.
The mixture of the gas and raw water that has passed through the inside of the hollow fiber membrane 4 flows into the circulating water chamber 14 and is discharged out of the system through the drain pipe 33.

[Cleaning with gas]
To perform cleaning with gas in the mixing cleaning operation of the water and gas, stop the raw water pump P, and the state of the valve V ₁ was closed. Thereby, the hollow fiber membrane 4 is washed with the mixed water of the raw water and the pressurized gas remaining in the hollow fiber membrane 4 and in the raw water chamber 10.

[Detection of film breaks]
In order to detect membrane breakage, prior to the detection operation, a membrane module in which membrane breakage has been confirmed is first installed as shown in FIG. 1, and the normal operation is performed to fill the membrane module with water. Perform “cleaning with mixed water”.
When the membrane module in which the membrane breakage is present is washed with the air / water mixed water, a part of the pressurized gas from the compressor C passes through the broken portion of the hollow fiber membrane 4 to become bubbles, and the treated water chamber 12. This bubble passes through the membrane breakage detection device 50 via the treated water pipe 41.
The conductivity between the electrode 51 and the elbow 70 changes when the bubble passes through the film breakage detection device 50. That is, when air bubbles enter between the electrode 51 and the elbow 70, the electrical resistance between the electrode 51 and the elbow 70 increases. Therefore, when a constant voltage is applied between the electrode 51 and the elbow 70 from the constant voltage power source, the current value between the electrode 51 and the elbow 70 decreases, and when a bubble passes between the electrode 51 and the elbow 70, the electrode 51 The current value between the elbows 70 is restored.

  FIG. 5 (b) shows an example of a waveform diagram obtained by converting the current change accompanying the bubble passage into the voltage change. The storage unit 55 stores this voltage change pattern. For example, the voltage change as shown in FIG. 5B is binarized and converted into a pulse waveform, and the average value of the frequency and period of the pulse is stored.

  In order to detect a membrane breakage of a membrane module incorporated in an actual water treatment apparatus, the membrane module is washed with air / water mixed water, and a voltage change accompanying a current change between the electrode 51 and the elbow 70 is measured. If there is no film rupture, the voltage is normally constant as shown in FIG. 5 (a), and the determination unit 56 determines that there is no film rupture.

  When the change pattern is detected, the determination unit compares the detected change pattern with the stored change pattern to determine whether or not the film is broken. For example, if the period and frequency of the pulse pattern obtained by binarizing the voltage change are within a predetermined range determined based on the stored average value, it is determined that there is a film rupture. It is determined that there is no film breakage.

  In addition, since the determination of membrane breakage is made by comparing the change patterns in this way, even if there is a voltage change due to disturbance such as fluctuations in raw water quality, it is not judged that the membrane is broken, and the judgment accuracy is extremely high. Become.

  In this description, a change is measured by passing a current between the electrode 51 and the elbow 70 from a constant voltage power source. However, a constant current is passed between the electrode 51 and the elbow 70 by a constant current power source, and applied in accordance with passage of bubbles. A voltage change may be measured, and film breakage may be determined from the change pattern.

  Moreover, the electrical conductivity between the electrode 51 and the elbow 70 may be measured, and the film breakage may be determined based on the change pattern of the electrical conductivity.

  After the completion of the membrane rupture detection step, if there is a membrane rupture, the hollow fiber membrane 4 in the membrane module 1 is replaced, and then the normal operation is resumed.

  The above embodiment is an example of the present invention, and the present invention is not limited to the above embodiment. For example, in the above embodiment, the cleaning operation and the film breakage detection operation are separated from each other, but the film breakage detection device 50 may be turned ON during the cleaning operation to detect the presence or absence of the film breakage.

  In the above embodiment, the compressor C is connected to the raw water chamber 10 and gas is introduced into the hollow fiber membrane 4. However, the compressor C is connected to the treated water chamber 12 and is disposed outside the hollow fiber membrane 4. Gas back-flushing may be performed by introducing gas. In this case, by providing the membrane breakage detection device 50 in the circulating water pipe 31, for example, the membrane breakage can be detected.

  In the above embodiment, the membrane module 1 is an internal pressure type hollow fiber module, but may be an external pressure type hollow fiber module. Also in this case, the compressor may be provided on the raw water side and the membrane breakage detecting device may be provided on the treated water side. Conversely, the compressor may be provided on the treated water side, and the membrane breakage detecting device may be provided on the raw water side.

  In the above embodiment, there is one membrane module 1, but there may be two or more. When there are a plurality of membrane modules, one compressor C and one membrane breakage detection device 50 may be provided for each module, or they may be shared. The membrane break detection procedure for each membrane module when the compressor C and the membrane break detection device 50 are shared is, for example, as follows.

  The pressurized gas from the compressor C is introduced only into the first membrane module, and the presence or absence of membrane rupture is detected by the membrane rupture detection device. After the membrane rupture detection of the first membrane module is completed, the introduction of the pressurized gas to the first membrane module is stopped, and then the pressurized gas is introduced only into the second membrane module. The presence or absence of film breakage is detected. Similarly, the membrane breakage of the third membrane module to the last membrane module is sequentially detected.

  When the occurrence of film breakage is detected, for example, a warning lamp in the management room blinks, and the maintenance manager is notified of which film module has broken. Upon receiving the notification, the maintenance manager stops the operation of the membrane module in which the membrane breakage occurs, replaces the membrane module with a new one, and resumes normal operation. Repair the membrane module that has been broken and reuse it.

  In the above embodiment, the hollow fiber membrane is used as the membrane, but the membrane is not limited to this and may be, for example, a spiral membrane.

  FIG. 6 (a) is a longitudinal sectional view of a flow path member 86 used in a membrane treatment apparatus according to another embodiment of the present invention, and FIG. 6 (b) is a sectional view taken along line BB of FIG. 6 (a). It is.

  The flow path member 86 includes a first vertical pulling flow path 80 extending upward, a first horizontal pulling flow path 81 extending in a lateral direction, connected to an upper end of the first vertical pulling flow path 80, A second horizontal pulling channel 82 which is connected to the end of the first horizontal pulling channel 81 in the extending direction and extends above the first horizontal pulling channel 81 in a direction opposite to the extending direction; A third horizontal pulling channel 83 which is connected to the end of the flow channel 82 in the extending direction and whose upper side extends in a direction opposite to the extending direction of the second horizontal pulling channel 82; It has a second longitudinal pulling channel 84 that is continuous with the end in the extending direction and extends upward. A flange 85 is provided at each of the lower end of the vertical pulling channel 80 and the upper end of the vertical pulling channel 84.

  Water flows into the flow path member 86 from the first vertical pulling flow path 80 and flows in the order of the flow paths 81, 82, 83, and 84.

  Among the horizontal pulling channels 81, 82, 83, the second horizontal pulling channel 82 is the longest, and the bubbles in the water rise while flowing there, and collect on the ceiling surface of the second horizontal pulling channel 82. . Therefore, by providing the electrode 51 (not shown) on the downward portion (ceiling portion) S on the end side of the second horizontal pulling flow channel 82, it is possible to reliably detect bubbles.

In FIG. 6, the horizontal pulling channel is provided in three stages. However, as shown in FIG. 7, the horizontal pulling channel 91 may be provided in only one stage. As shown in FIG. , 93 may be provided in two stages. An electrode 51 (not shown) is provided on the upper surface portion S on the end side of the horizontal pulling flow channel 91 and the horizontal pulling flow channel 93.
In addition, the length of the horizontal pulling channel needs to be long enough for air bubbles to be sufficiently collected in the upper part of the inner wall of the pipe. The flow rate on the filtered water side during backwashing is 0.1 to 0.3 m / second, and the time required for air bubbles to be collected at the top due to the difference in specific gravity is about 2 seconds. The length (the length of the path from the start portion of the horizontal channel to the location where the electrode 51 is installed) is 0.2 to 0.6 m.

It is a schematic diagram of the film processing apparatus concerning an embodiment. It is sectional drawing of the film | membrane fracture | rupture detection part of FIG. It is a block diagram of the film | membrane fracture | rupture detection apparatus integrated in the film | membrane processing apparatus of FIG. It is a circuit diagram of the film | membrane breakage detection apparatus used in an Example. (A) is a figure which shows the time-dependent change of the voltage when the hollow fiber membrane is not cut | disconnected, (b) is a figure which shows the time-dependent change of the voltage when one hollow fiber membrane is cut | disconnected. (A) is the longitudinal cross-sectional view of the flow-path member 86 used for the film processing apparatus which concerns on another embodiment of this invention, (b) is the BB sectional drawing of the same (a). It is explanatory drawing of another horizontal drawing flow path. It is explanatory drawing of another horizontal pulling flow path.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal pressure type hollow fiber membrane module 2 Casing 4 Hollow fiber membrane 6,8 Sealing material 10 Raw water chamber 12 Treated water chamber 14 Circulating water chamber 20 Raw water tank 40 Treated water layer 50 Membrane breakage detection part 51 Electrode 70 Elbow 71 1st horizontal Pulling channel 72 Vertical pulling channel 73 Second horizontal pulling channel 80 First vertical pulling channel 81 First horizontal pulling channel 82 Second horizontal pulling channel 83 Third horizontal pulling channel 84 Second vertical pulling channel 86 Channel member 90 Membrane treatment device 91, 92, 93 Horizontal channel

Claims (14)

A membrane for filtering the liquid to be treated;
Means for circulating a gas or gas-liquid mixture on one side separated by the membrane;
In a film processing apparatus having a bubble detector for detecting bubbles on the other side separated by the film for detecting breakage of the film,
A flow path through which the liquid that permeated the membrane flows is provided, the bubble detector is provided in a downward portion facing the flow path, and the flow path is configured so that the bubbles are collected in the upper part of the flow path. A membrane processing apparatus. A membrane for filtering the liquid to be treated;
Means for circulating a gas or gas-liquid mixture on one side separated by the membrane;
In a film processing apparatus having a bubble detector for detecting bubbles on the other side separated by the film for detecting breakage of the film,
A horizontal flow path through which the liquid that has permeated the membrane flows is provided;
The film processing apparatus according to claim 1, wherein the bubble detector is provided in a downward portion facing the flow path downstream of a portion where the bubbles are collected in an upper portion of the flow path. A membrane for filtering the liquid to be treated;
Means for circulating a gas or gas-liquid mixture on one side separated by the membrane;
In a film processing apparatus having a bubble detector for detecting bubbles on the other side separated by the film for detecting breakage of the film,
A horizontal pulling channel through which the liquid that has permeated the membrane flows is provided,
In the middle of the horizontal pulling channel, a vertical pulling part in which the liquid flows upward is provided,
The film processing apparatus according to claim 1, wherein the bubble detector is provided in a downward portion facing the horizontal pulling channel on the downstream side of the vertical pulling portion.   4. The membrane according to claim 3, wherein the upward portion facing the flow path from the horizontal pulling portion upstream of the vertical pulling portion to the vertical pulling portion is curved along the liquid flow direction. Processing equipment. A membrane for filtering the liquid to be treated;
Means for circulating a gas or gas-liquid mixture on one side separated by the membrane;
In a film processing apparatus having a bubble detector for detecting bubbles on the other side separated by the film for detecting breakage of the film,
A longitudinal flow path through which the liquid that has permeated the membrane flows upward is provided;
In the middle of the vertical pulling channel, a horizontal pulling part in which the liquid flows sideways is provided,
The film processing apparatus according to claim 1, wherein the bubble detector is provided in a downward portion facing the flow path on the terminal side of the lateral pulling portion. 6. The lateral pulling portion according to claim 5,
A first horizontal pulling portion that is continuous with the upper end of the upstream vertical pulling portion on the upstream side of the horizontal pulling portion and extends laterally therefrom;
A second laterally extending portion extending in a direction opposite to the extending direction of the first laterally extending portion, connected to an end in the extending direction of the first laterally extending portion;
A third laterally extending portion extending in a direction parallel to the extending direction of the first laterally extending portion, which is connected to the end of the second laterally extending portion in the extending direction;
The end of the third horizontal pulling portion is connected to the downstream vertical pulling portion downstream of the horizontal pulling portion,
The film processing apparatus, wherein the bubble detector is provided in a downward portion facing the flow path on the terminal side of the second lateral pulling portion. In claim 6, the upstream vertical pulling portion and the downstream vertical pulling portion are arranged coaxially,
The film processing apparatus characterized in that the length of the first horizontal pulling portion is substantially equal to the length of the third horizontal pulling portion. In claim 5, the horizontal pulling portion is connected to the upper end of the upstream vertical pulling portion upstream of the horizontal pulling portion, and extends laterally therefrom.
A membrane processing apparatus characterized in that a lower end of a downstream vertical pulling portion downstream of the horizontal pulling portion is connected to an end of the horizontal pulling portion. 6. The lateral pulling portion according to claim 5,
A first horizontal pulling portion that is continuous with the upper end of the upstream vertical pulling portion on the upstream side of the horizontal pulling portion and extends laterally therefrom;
A second laterally extending portion extending in a direction opposite to the extending direction of the first laterally extending portion, connected to an end in the extending direction of the first laterally extending portion;
With
The end of the second horizontal pulling portion is connected to the downstream vertical pulling portion downstream of the horizontal pulling portion,
The film processing apparatus, wherein the bubble detector is provided in a downward portion facing the flow path on the terminal side of the second lateral pulling portion.   The film processing apparatus according to any one of claims 2, 5 to 9, wherein a length of the horizontal pulling portion in which the horizontal pulling channel or the bubble detector is provided is 0.6 m or more. . In any one of Claims 1 thru | or 10, the said bubble detector is a pair of electrode arrange | positioned so that the liquid in this flow path may be contacted,
The film processing apparatus determines film breakage from a power supply that applies a constant voltage to the electrodes, a measurement unit that measures a current flowing between the electrodes, and a pattern of changes in the measured current value as a film breakage detection unit. A film processing apparatus comprising: a determination unit. In any one of Claims 1 thru | or 10, the said bubble detector is a pair of electrode arrange | positioned so that the liquid in this flow path may be contacted,
The film processing apparatus, as a film breakage detection means, breaks a film from a power source that supplies a constant current between the electrodes, a measurement unit that measures a voltage generated between the electrodes, and a pattern of change in the measured voltage value. A film processing apparatus comprising: a determination unit for determining. In any one of Claims 1 thru | or 10, the said bubble detector is a pair of electrode arrange | positioned so that the liquid in this flow path may be contacted,
The film processing apparatus includes, as film breakage detection means, means for measuring the conductivity of the liquid to be treated between the electrodes, and a determination unit for determining film breakage from the measured change pattern of conductivity. A membrane processing apparatus.   14. One of the pair of electrodes according to claim 11, wherein one of the pair of electrodes is a flow path member, and the other is a needle electrode separated from the flow path member via an insulating member. A membrane processing apparatus.

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