JP2000271457A - Operation of spiral type membrane element and spiral type membrane module and spiral type membrane module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low cost, easily washable and highly reliably spiral type membrane element, and a method for operating a spiral type membrane module. SOLUTION: The spiral type membrane element 1 is constituted by covering a spiral shaped membranes element consisting of a plurality of independent or continuous envelope-like membranes wound in the outer peripheral surface of a water collection tube 2 via raw water spacers with a separation membrane, and further covering the resultant assembly with an outer peripheral part flow path material. The raw water 51 with air bubbles generated with a diffuser 102 is fed to the spiral type membrane element 1 in a pressure container 10. A portion of the raw water in the raw water 51 flows in the axis direction along the outer peripheral part of the spiral type membrane element 1, and is discharged from a raw water outlet 15 of the pressure container 10, and is then returned to a raw water tank 200 via a piping 17a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spiral-type membrane element, a method for operating a spiral-type membrane module, and a spiral-type membrane used in a membrane separation device such as a low-pressure reverse osmosis membrane separation device, an ultrafiltration device and a microfiltration device. About the module.

[0002]

2. Description of the Related Art In recent years, a membrane separation technique has been applied to a water purification technique, and a membrane separation technique has been applied as a pretreatment of a reverse osmosis membrane separation system used for seawater desalination and the like.
As a type of membrane used for such membrane separation, a microfiltration membrane or an ultrafiltration membrane capable of obtaining a high amount of permeated water is widely used, but recently, an ultra-low pressure of 10 kgf / cm ² or less has been used. Reverse osmosis membranes that provide a permeate volume have also been developed.

[0003] As a form of a membrane element used for membrane separation, a hollow fiber membrane element is often used in view of a membrane area per unit volume (volume efficiency). However, the hollow fiber membrane element has a disadvantage that the membrane is easily broken, and if the membrane is broken, the raw water mixes with the permeated water and the separation performance is reduced.

On the other hand, there is a spiral type membrane element as a form of a membrane element capable of increasing a membrane area. This spiral type membrane element has an advantage that separation performance can be maintained and reliability is high as compared with a hollow fiber membrane element.

FIG. 16 is a partially cutaway perspective view of a conventional spiral membrane element, and FIG. 17 is an external perspective view of the conventional spiral membrane element.

As shown in FIG. 16, a spiral-type membrane element 21 is composed of an envelope-shaped membrane (bag) by stacking separation membranes 26 on both surfaces of a permeated water spacer (permeate flow path material) 25 and bonding three sides thereof. Film) 23, and the envelope-shaped film 2
3 is attached to the water collecting pipe 22 formed of a perforated hollow pipe, and is wound spirally around the outer peripheral surface of the water collecting pipe 22 together with the net-shaped (net-shaped) raw water spacer 24 (raw water liquid passage material). Is done.

The raw water spacer 24 is provided for forming a flow path through which raw water passes between the envelope membranes 23. If the thickness of the raw water spacer 24 is small, the filling efficiency of the separation membrane 26 is increased, but clogging with the suspended substance occurs. Therefore, usually, the thickness of the raw water spacer 24 is about 0.7 mm to 3.0 m.
m.

A spiral membrane element using a zigzag corrugated raw water spacer (so-called corrugated spacer) for treating raw water containing a large amount of suspended substances, such as river water, has already been known.

As shown in FIG. 17, the outer peripheral surface of the spiral type membrane element 21 is covered with an exterior material 27 made of FRP (fiber reinforced plastic), a shrinkable tube or the like.
Packing holders 28 called anti-telescopes are respectively attached to both ends.

FIG. 18 is a sectional view showing an example of a conventional method of operating a spiral type membrane element. As shown in FIG. 18, the pressure vessel (pressure-resistant vessel) 30 is composed of a cylindrical case 31 and a pair of end plates 32a and 32b. A raw water inlet 33 is formed on one end plate 32a, and a concentrated water outlet 35 is formed on the other end plate 32b. A permeated water outlet 34 is provided at the center of the other end plate 32b.

A spiral type membrane element 21 having a packing 37 attached near one end of the outer peripheral surface is mounted in a cylindrical case 31, and both open ends of the cylindrical case 31 are sealed with end plates 32a and 32b, respectively. I do. One open end of the water collecting pipe 22 is fitted to the permeated water outlet 34 of the end plate 32b, and an end cap 36 is attached to the other open end.

During the operation of the spiral type membrane element 21, the raw water 51 is introduced into the first liquid chamber 38 from the raw water inlet 33 of the pressure vessel 30. As shown in FIG.
Is supplied from one end face side of the spiral membrane element 21. The raw water 51 flows in the axial direction along the raw water spacer 24, and is discharged as concentrated water 53 from the other end surface side of the spiral membrane element 21. As the raw water 51 flows along the raw water spacer 24, the permeated water 52 that has passed through the separation membrane 26 is collected along the permeated water spacer 25 by the water collecting pipe 2.
2 and discharged from the end of the water collecting pipe 22.

The permeated water 52 is supplied to the pressure vessel 30 shown in FIG.
Is taken out from the permeated water outlet 34 to the outside. Further, the concentrated water 53 is taken out of the second liquid chamber 39 in the pressure vessel 30 through the concentrated water outlet 35 to the outside.

[0014]

When the membrane element is operated, the membrane is clogged by suspended substances in the raw water, and the membrane flux is reduced. Therefore, although clogging is removed by performing chemical cleaning or the like to recover the membrane flux, the labor and cost required for chemical cleaning poses a problem. Therefore, in order to prevent clogging, for example, in a hollow fiber membrane element, backwashing with permeated water or air is periodically performed.

However, in the conventional spiral-type membrane element 21, the following problems occur when backwashing is performed.

FIG. 19 is a partially cutaway perspective view showing a backwashing operation in a conventional spiral membrane element.
As shown in FIG. 19, permeated water 52 is introduced from the end of the water collecting pipe 22. Since the outer peripheral surface of the envelope film 23 wound around the water collecting pipe 22 is covered with the exterior material 27, the water collecting pipe 22
The permeated water 52 derived from the outer peripheral surface of the spiral membrane element 21 passes through the envelope-shaped membrane 23, flows in the axial direction inside the spiral membrane element 21 along the raw water spacer 24, and is discharged from the end of the spiral membrane element 21. You. Therefore, even if the backwashing is performed, contaminants such as turbid substances causing clogging of the membrane are easily captured by the raw water spacer 24 before being discharged from the end of the spiral membrane element 21. There is a problem that it is not sufficiently removed.

Further, a gap existing between the inner peripheral surface of the cylindrical case 31 of the pressure vessel 30 of FIG. 18 and the spiral membrane element 21 becomes a dead space S, and a stagnation (fluid pool) of fluid occurs. Spiral type membrane element 21
When used for a long period of time, the fluid remaining in the dead space undergoes metamorphosis. In particular, when the fluid is a liquid containing an organic substance, germs such as microorganisms propagate, and the germs may decompose the organic substance to generate a bad smell or decompose the separation membrane. Leads to a decrease in

Further, in the conventional spiral type membrane element 21, raw water is supplied from one end of the spiral type membrane element 21 and discharged from the other end.
A packing holder 28 is required to prevent the envelope-shaped film 23 wound in 2 from being deformed into a bamboo shoot shape.
In addition, a pressure difference occurs between the raw water inflow side and the concentrated water outlet side due to the pressure loss due to the raw water spacer 24 and the pressure loss due to clogging, and the spiral membrane element 21 is deformed. In order to prevent this deformation, the outer peripheral surface of the envelope-like film 23 wound around the water collecting pipe 22 is covered with an exterior material 27 such as an FRP or a shrinkable tube. These increase component costs and manufacturing costs.

Further, it is necessary to obtain a sufficient film surface linear velocity in order to prevent the formation of cake due to contaminants in raw water, and for that purpose, a sufficient flow rate on the concentration side is required. When the flow rate on the concentration side is increased, the recovery rate per spiral type membrane element is reduced, and the pump for supplying the raw water is large, and the system cost is very large.

An object of the present invention is to provide a spiral-type membrane element and a method for operating a spiral-type membrane module which can be reduced in cost, are easy to clean, and have high reliability.

Another object of the present invention is to provide a spiral-type membrane module which can be reduced in cost, is easy to clean, and has high reliability.

[0022]

According to a first aspect of the present invention, there is provided a method for operating a spiral type membrane element, wherein a plurality of independent or continuous envelope-shaped membranes are formed on an outer peripheral surface of a perforated hollow tube. A spiral-shaped membrane element wound around a material, an outer peripheral portion of the spiral-shaped membrane element is covered with a liquid-permeable material, and an outer peripheral surface of the liquid-permeable material is wholly or partially formed with an outer peripheral passage. A method of operating a spiral type membrane element covered with a material, wherein bubbles are continuously or intermittently diffused into a liquid in contact with an outer peripheral portion of the spiral type membrane element.

According to the spiral membrane element operating method of the present invention, air bubbles are formed in the liquid in contact with the outer peripheral portion of the spiral membrane element, so that an air flow is formed on the outer peripheral portion of the spiral membrane element. Is done. This makes it possible to suppress the contaminants in the liquid from adhering to the film surface of the spiral-type membrane element and at least the outer peripheral portion. Further, it is possible to remove contaminants attached to the film surface and at least the outer peripheral portion of the spiral type membrane element.

Thus, in the spiral membrane element, stable operation can be continuously performed for a long time.

Further, in the above-mentioned method of operating the spiral membrane element, since the whole amount is filtered, no dead space is formed in the space between the spiral membrane element and the pressure vessel, and the spiral membrane element and the pressure No fluid remains in the gap between the container and the container. Therefore, even when used for separating a fluid containing an organic substance, problems such as propagation of various germs such as microorganisms, generation of offensive odor due to decomposition of the organic substance, and decomposition of the separation membrane do not occur, and high reliability can be obtained.

Further, the stock solution is supplied from at least the outer peripheral side of the spiral type membrane element, and pressure is applied to the spiral type membrane element from all directions and no pressure which causes displacement in the axial direction is applied. The envelope-shaped membrane wound around the empty tube does not deform into a bamboo shoot. This eliminates the need for a packing holder and an exterior material, thereby reducing parts costs and manufacturing costs. In addition, since the whole amount is filtered, a high recovery rate can be obtained without using a large pump for supplying the stock solution. Thereby, the system cost is reduced.

Further, since pressure is applied to the spiral membrane element from all directions, the spiral membrane element does not deform even if the supply pressure of the stock solution is increased. Therefore, high pressure resistance can be obtained.

A method for operating a spiral-type membrane element according to a second aspect of the present invention is a spiral-type membrane in which a plurality of independent or continuous envelope-like membranes are wound around the outer peripheral surface of a perforated hollow tube via a stock solution flow path material. Of the spiral membrane element, wherein the outer peripheral portion of the spiral membrane element is covered with a liquid permeable material, and the outer peripheral surface side of the liquid permeable material is wholly or partially covered with the outer peripheral channel material. An operation method in which ultrasonic vibration is continuously or intermittently applied to a liquid in contact with an outer peripheral portion of a spiral membrane element.

According to the method for operating a spiral membrane element according to the present invention, by applying ultrasonic vibration to the liquid in contact with the outer peripheral portion of the spiral membrane element, the contaminants in the liquid are dispersed, and the spiral membrane element is dispersed. It is possible to prevent the contaminant from adhering to the film surface and at least the outer peripheral portion of the element. Further, since the spiral membrane element also vibrates, it becomes possible to peel off the contaminants attached to the membrane surface and at least the outer peripheral portion of the spiral membrane element.

Thus, in the spiral membrane element, stable operation can be continuously performed for a long period of time.

Further, in the method for operating the spiral-type membrane element described above, since the entire amount is filtered, no dead space is formed in the space between the spiral-type membrane element and the pressure vessel, and the spiral-type membrane element and the pressure are prevented. No fluid remains in the gap between the container and the container. Therefore, even when used for separating a fluid containing an organic substance, problems such as propagation of various germs such as microorganisms, generation of offensive odor due to decomposition of the organic substance, and decomposition of the separation membrane do not occur, and high reliability can be obtained.

Further, a stock solution is supplied from at least the outer peripheral side of the spiral membrane element, and pressure is applied to the spiral membrane element from all directions, and no pressure that causes displacement in the axial direction is applied. The envelope-shaped membrane wound around the empty tube does not deform into a bamboo shoot. This eliminates the need for a packing holder and an exterior material, thereby reducing parts costs and manufacturing costs. In addition, since the whole amount is filtered, a high recovery rate can be obtained without using a large pump for supplying the stock solution. Thereby, the system cost is reduced.

Further, since pressure is applied to the spiral membrane element from all directions, the spiral membrane element does not deform even if the supply pressure of the stock solution is increased. Therefore, high pressure resistance can be obtained.

A method for operating a spiral membrane module according to a third aspect of the present invention is a method for operating a spiral membrane module comprising one or a plurality of spiral membrane elements housed in a pressure vessel. Includes a spiral membrane element in which a plurality of independent or continuous envelope membranes are wound around the outer peripheral surface of a perforated hollow tube via a raw liquid flow path material, and the outer peripheral portion of the spiral membrane element is liquid permeable. The outer peripheral surface side of the liquid permeable material is entirely or partially covered with the outer peripheral channel material, and continuously or intermittently diffuses bubbles into the liquid in the pressure vessel. .

According to the method of operating the spiral membrane module according to the present invention, the air bubbles are scattered in the liquid in the pressure vessel, so that the diffused air is formed on the outer periphery of the spiral membrane element. This makes it possible to suppress the contaminants in the liquid from adhering to the film surface of the spiral-type membrane element and at least the outer peripheral portion. Further, it is possible to remove contaminants attached to the film surface and at least the outer peripheral portion of the spiral type membrane element.

In addition, in the above-mentioned method of operating the spiral membrane module, since the whole amount is filtered, no dead space is formed in the space between the spiral membrane element and the pressure vessel, and the spiral membrane element and the pressure No fluid remains in the gap between the container and the container. Therefore, even when used for separating a fluid containing an organic substance, problems such as propagation of various germs such as microorganisms, generation of offensive odor due to decomposition of the organic substance, and decomposition of the separation membrane do not occur, and high reliability can be obtained.

Further, a stock solution is supplied from at least the outer peripheral side of the spiral membrane element, and pressure is applied to the spiral membrane element from all directions, and no pressure that causes displacement in the axial direction is applied. The envelope-shaped membrane wound around the empty tube does not deform into a bamboo shoot. This eliminates the need for a packing holder and an exterior material, thereby reducing parts costs and manufacturing costs. In addition, since the whole amount is filtered, a high recovery rate can be obtained without using a large pump for supplying the stock solution. Thereby, the system cost is reduced.

Further, since pressure is applied to the spiral membrane element from all directions, the spiral membrane element does not deform even if the supply pressure of the stock solution is increased. Therefore, high pressure resistance can be obtained.

During operation, bubbles may be scattered in the stock solution while supplying the stock solution from at least the outer peripheral side of the spiral membrane element, and the permeate may be taken out from at least one open end of the perforated hollow tube. In this case, contaminants in the stock solution are captured at least at the outer peripheral portion of the spiral membrane element.

Here, by diffusing bubbles in the undiluted solution, a diffused air flow is formed on the outer periphery of the spiral membrane element. This makes it possible to suppress the contaminants in the undiluted solution from adhering to the membrane surface of the spiral membrane element and at least the outer peripheral portion, and to the inside of the spiral membrane module, particularly, to the membrane surface of the spiral membrane element. In addition, it is possible to remove at least contaminants attached to the outer peripheral portion.

Further, at the time of washing, the washing liquid is introduced from at least one open end of the perforated hollow tube, and the washing liquid derived from the outer peripheral surface of the perforated hollow tube is discharged from at least the outer peripheral portion of the spiral membrane element. Bubbles may be diffused into the cleaning liquid while the cleaning is performed.

At the time of washing, a washing solution is introduced from at least one open end of the perforated hollow tube to perform backwashing. The cleaning liquid derived from the outer peripheral surface of the perforated hollow tube passes through the envelope-shaped membrane, flows along the raw liquid flow path material, and is discharged from at least the outer peripheral portion of the spiral membrane element. Thereby, the contaminants trapped on the membrane surface of the spiral membrane element and at least on the outer peripheral portion are separated from the spiral membrane element. Since the spiral membrane element is prevented from spreading between the envelope membranes at the outer periphery by the liquid permeable material and the outer peripheral passage material, at the time of backwashing, the spiral membrane element is provided on the membrane surface and at least the outer periphery. A flow path for discharging the attached contaminants to the outside is secured. For this reason, the separated contaminants are discharged to the outside together with the cleaning liquid. Therefore, the contaminants trapped on the membrane surface and at least the outer peripheral portion of the spiral membrane element can be uniformly removed, and a constant amount of permeate can be constantly maintained during operation.

Here, by diffusing bubbles in the cleaning liquid, a diffused air flow is formed around the outer periphery of the spiral membrane element. Thereby, it becomes possible to more effectively peel off the contaminants attached to the inside of the spiral membrane module, in particular, to the membrane surface and at least the outer peripheral portion of the spiral membrane element, and the peeled contaminants become spiral membranes. Adhesion to the film surface of the element and at least the outer peripheral portion can be suppressed.

During flushing, bubbles may be scattered in the stock solution or the washing liquid while flowing the stock solution or the washing solution in the axial direction along the outer periphery of the spiral membrane element. Thereby, the contaminants adhered to the inside of the spiral type membrane module, in particular, to the membrane surface and at least the outer peripheral portion of the spiral type membrane element can be easily peeled off, and the peeled contaminants can be easily and reliably discharged to the outside. Can be discharged.

When the operation is stopped, bubbles may be scattered in the undiluted solution or the cleaning solution present in the pressure vessel. In this case, a diffused air flow is formed on the outer peripheral portion of the spiral membrane element. Thereby, it becomes possible to suppress the contaminants in the undiluted solution or the cleaning solution from adhering to the membrane surface and at least the outer peripheral portion of the spiral membrane element,
It is possible to remove contaminants adhered to the inside of the spiral membrane module, particularly to the membrane surface and at least the outer peripheral portion of the spiral membrane element.

A method for operating a spiral-type membrane module according to a fourth aspect of the present invention is a method for operating a spiral-type membrane module comprising one or more spiral-type membrane elements housed in a pressure vessel. Includes a spiral membrane element in which a plurality of independent or continuous envelope membranes are wound around the outer peripheral surface of a perforated hollow tube via a raw liquid flow path material, and the outer peripheral portion of the spiral membrane element is liquid permeable. The outer peripheral surface side of the liquid permeable material is entirely or partially covered with the outer peripheral channel material, and continuously or intermittently applies ultrasonic vibration to the liquid in the pressure vessel. .

According to the method of operating the spiral membrane module according to the present invention, by applying ultrasonic vibration to the liquid in the pressure vessel, contaminants in the liquid are dispersed, and the membrane surface of the spiral membrane element and At least the contaminant can be prevented from adhering to the outer peripheral portion. Also,
Since the spiral membrane element also vibrates, it becomes possible to peel off contaminants attached to the membrane surface and at least the outer peripheral portion of the spiral membrane element.

Thus, in the spiral membrane element, a stable operation can be continuously performed for a long time.

Further, in the method for operating the spiral-type membrane module described above, since the whole amount is filtered, no dead space is formed in the space between the spiral-type membrane element and the pressure vessel, and the spiral-type membrane element and the pressure are not changed. No fluid remains in the gap between the container and the container. Therefore, even when used for separating a fluid containing an organic substance, problems such as propagation of various germs such as microorganisms, generation of offensive odor due to decomposition of the organic substance, and decomposition of the separation membrane do not occur, and high reliability can be obtained.

Further, since a stock solution is supplied from at least the outer peripheral side of the spiral membrane element, pressure is applied to the spiral membrane element from all directions, and no pressure that causes displacement in the axial direction is applied. The envelope-shaped membrane wound around the empty tube does not deform into a bamboo shoot. This eliminates the need for a packing holder and an exterior material, thereby reducing parts costs and manufacturing costs. In addition, since the whole amount is filtered, a high recovery rate can be obtained without using a large pump for supplying the stock solution. Thereby, the system cost is reduced.

Since pressure is applied to the spiral membrane element from all directions, the spiral membrane element does not deform even if the supply pressure of the stock solution is increased. Therefore, high pressure resistance can be obtained.

In operation, ultrasonic vibration may be applied to the stock solution while supplying the stock solution from at least the outer peripheral side of the spiral membrane element, and the permeate may be taken out from at least one open end of the perforated hollow tube. In this case, contaminants in the stock solution are captured at least at the outer peripheral portion of the spiral membrane element.

Here, by applying ultrasonic vibration to the undiluted solution, it is possible to disperse the contaminants in the undiluted solution and to prevent the contaminants from adhering to the membrane surface and at least the outer peripheral portion of the spiral membrane element. become. In addition, since the spiral membrane element also vibrates, it becomes possible to peel off contaminants attached to the inside of the spiral membrane module, particularly to the membrane surface and at least the outer peripheral portion of the spiral membrane element.

At the time of washing, the washing liquid is introduced from at least one open end of the perforated hollow tube, and the washing liquid derived from the outer peripheral surface of the perforated hollow tube is discharged from at least the outer peripheral portion of the spiral membrane element. Ultrasonic vibration may be applied to the cleaning liquid while the cleaning is performed.

At the time of washing, a washing solution is introduced from at least one open end of the perforated hollow tube to perform backwashing. The cleaning liquid derived from the outer peripheral surface of the perforated hollow tube passes through the envelope-shaped membrane, flows along the raw liquid flow path material, and is discharged from at least the outer peripheral portion of the spiral membrane element. Thereby, the contaminants trapped on the membrane surface of the spiral membrane element and at least on the outer peripheral portion are separated from the spiral membrane element. Since the spiral membrane element is prevented from spreading between the envelope membranes at the outer periphery by the liquid permeable material and the outer peripheral passage material, at the time of backwashing, the spiral membrane element is provided on the membrane surface and at least the outer periphery. A flow path for discharging the attached contaminants to the outside is secured. For this reason, the separated contaminants are discharged to the outside together with the cleaning liquid. Therefore, the contaminants trapped on the membrane surface and at least the outer peripheral portion of the spiral membrane element can be uniformly removed, and a constant amount of permeate can be constantly maintained during operation.

Here, by applying ultrasonic vibration to the cleaning liquid, contaminants adhering to the inside of the spiral membrane module, in particular, to the membrane surface and at least the outer peripheral portion of the spiral membrane element can be more effectively peeled off. And it is possible to suppress the detached contaminants from adhering to the film surface and at least the outer peripheral portion of the spiral-type membrane element.

Further, at the time of flushing, ultrasonic vibration may be applied to the stock solution or the cleaning liquid while flowing the stock solution or the cleaning liquid in the axial direction along the outer peripheral portion of the spiral membrane element. Thereby, inside the spiral type membrane module,
In particular, the contaminants adhered to the membrane surface and at least the outer peripheral portion of the spiral-type membrane element can be easily separated, and the separated contaminants can be easily and reliably discharged to the outside.

Further, when the operation is stopped, ultrasonic vibration may be applied to the stock solution or the cleaning solution existing in the pressure vessel. This makes it possible to suppress contaminants in the stock solution or the cleaning solution from adhering to the membrane surface and at least the outer peripheral portion of the spiral membrane element, and to adhere to the membrane surface and at least the outer peripheral portion of the spiral membrane element. It becomes possible to peel off contaminants.

In the method for operating the spiral membrane module according to the third and fourth aspects of the present invention, during the operation, a part of the stock solution is continuously or intermittently removed in the axial direction along the outer periphery of the spiral membrane element. It may be taken out of the sink pressure vessel. In this case, a part of the contaminants in the undiluted solution and the contaminants separated from the membrane surface and at least the outer peripheral portion of the spiral membrane element can be easily and reliably discharged to the outside of the spiral membrane module, It is possible to further suppress the contaminants in the stock solution from adhering to the membrane surface and at least the outer peripheral portion of the spiral membrane element. From the above, a more stable operation can be continuously performed in the spiral membrane module for a long period of time.

Further, the undiluted solution taken out of the pressure vessel may be returned to the supply side again. In this case, since the undiluted solution discharged outside is circulated, the supplied undiluted solution can be recovered as a permeate at a theoretically 100% recovery rate.

A spiral membrane module according to a fifth aspect of the present invention is a spiral membrane module in which one or a plurality of spiral membrane elements are housed in a pressure vessel having a stock solution inlet and a stock solution outlet. The element includes a spiral membrane element formed by winding a plurality of independent or continuous envelope membranes on the outer peripheral surface of a perforated hollow tube via a raw liquid flow path material, and the outer peripheral portion of the spiral membrane element is a liquid. The outer peripheral portion of the spiral membrane element is covered with a liquid permeable material, the outer peripheral surface side of the liquid permeable material is wholly or partially covered with an outer peripheral channel material, and the inside of the pressure vessel is The apparatus is provided with an air diffuser for dispersing bubbles in the liquid and a circulation system for returning the undiluted liquid taken out of the pressure vessel from the undiluted liquid outlet to the undiluted liquid inlet.

In the spiral membrane module according to the present invention, air bubbles are continuously or intermittently scattered into the stock solution or the cleaning solution in the pressure vessel by the air diffuser. As a result, a diffused air flow is formed around the spiral membrane element in the spiral membrane module,
It is possible to remove contaminants attached to the membrane surface and at least the outer peripheral portion of the spiral membrane element.
Further, it is possible to prevent the contaminants in the undiluted solution or the cleaning solution and the separated contaminants from adhering to the film surface of the spiral membrane element and at least the outer peripheral portion.

Further, during operation, the flow of the stock solution is formed in the axial direction along the outer peripheral portion of the spiral membrane element, so that some of the contaminants in the stock solution and the separated contaminants can be easily and surely removed. It is possible to discharge to the outside of the spiral membrane module, and it is possible to further suppress the contaminants in the stock solution and the separated contaminants from adhering to the membrane surface and at least the outer peripheral portion of the spiral membrane element. .

From the above, stable performance is realized in the spiral type membrane module.

Further, since a circulation system is provided for returning the undiluted solution taken out of the pressure vessel from the undiluted solution outlet to the undiluted solution inlet, the supplied undiluted solution is theoretically used as a permeate.
% Recovery rate.

Further, since the whole amount is filtered, no dead space is formed in the gap between the spiral membrane element and the pressure vessel, and the fluid remains in the gap between the spiral membrane element and the pressure vessel. No accumulation occurs. Therefore, even when used for separating a fluid containing an organic substance, problems such as propagation of various germs such as microorganisms, generation of offensive odor due to decomposition of the organic substance, and decomposition of the separation membrane do not occur, and high reliability can be obtained.

Further, the undiluted solution is supplied from at least the outer peripheral side of the spiral membrane element, and pressure is applied to the spiral membrane element from all directions and no pressure that causes displacement in the axial direction is applied. The envelope-shaped membrane wound around the empty tube does not deform into a bamboo shoot. This eliminates the need for a packing holder and an exterior material, thereby reducing parts costs and manufacturing costs. In addition, since the whole amount is filtered, a high recovery rate can be obtained without using a large pump for supplying the stock solution. Thereby, the system cost is reduced.

Since pressure is applied to the spiral membrane element from all directions, the spiral membrane element does not deform even if the supply pressure of the stock solution is increased. Therefore, high pressure resistance can be obtained.

A spiral-type membrane module according to a sixth aspect of the present invention is a spiral-type membrane module in which one or a plurality of spiral-type membrane elements are housed in a pressure vessel. A plurality of envelope-like membranes independent or continuous on the outer peripheral surface of the tube include a spiral membrane element that is wound via a raw liquid flow path material, and the outer peripheral portion of the spiral membrane element is covered with a liquid permeable material, An outer peripheral surface side of the liquid permeable material is entirely or partially covered with an outer peripheral channel material, and an ultrasonic oscillator for applying ultrasonic vibration to the liquid in the pressure vessel is provided.

In the spiral type membrane module according to the present invention, ultrasonic vibration is continuously or intermittently applied to the stock solution or cleaning solution in the pressure vessel by the ultrasonic oscillator. Thereby, the spiral type membrane element vibrates,
It is possible to remove contaminants adhered to the inside of the spiral membrane module, in particular, to the membrane surface and at least the outer peripheral portion of the spiral membrane element. Further, it is possible to prevent the contaminants in the undiluted solution or the cleaning solution and the separated contaminants from adhering to the film surface of the spiral membrane element and at least the outer peripheral portion. From the above, stable performance is realized in the spiral membrane module.

Further, since the entire amount is filtered, no dead space is formed in the gap between the spiral membrane element and the pressure vessel, and the fluid remains in the gap between the spiral membrane element and the pressure vessel. No accumulation occurs. Therefore, even when used for separating a fluid containing an organic substance, problems such as propagation of various germs such as microorganisms, generation of offensive odor due to decomposition of the organic substance, and decomposition of the separation membrane do not occur, and high reliability can be obtained.

Further, the undiluted solution is supplied from at least the outer peripheral side of the spiral membrane element, and pressure is applied to the spiral membrane element from all directions and no pressure that causes displacement in the axial direction is applied. The envelope-shaped membrane wound around the empty tube does not deform into a bamboo shoot. This eliminates the need for a packing holder and an exterior material, thereby reducing parts costs and manufacturing costs. In addition, since the whole amount is filtered, a high recovery rate can be obtained without using a large pump for supplying the stock solution. Thereby, the system cost is reduced.

Since pressure is applied to the spiral membrane element from all directions, the spiral membrane element does not deform even if the supply pressure of the stock solution is increased. Therefore, high pressure resistance can be obtained.

[0074]

FIG. 1 is a partially cutaway perspective view showing a spiral type membrane element according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing an example of the envelope-shaped membrane of the spiral membrane element shown in FIG. 1, and FIG. 3 is a cross-sectional view showing another example of the envelope-shaped membrane of the spiral membrane element shown in FIG. is there.

Spiral type membrane element 1 shown in FIG.
Includes a spiral-shaped membrane element 1a formed by winding a plurality of independent envelope-shaped membranes 3 or a plurality of continuous envelope-shaped membranes 3 on the outer peripheral surface of a water collecting pipe 2 composed of a perforated hollow pipe. . Raw water spacers (raw liquid flow path material) between the envelope films 3 to prevent the envelope films 3 from adhering to each other and to reduce the film area, and to form a flow path for raw water.
4 has been inserted.

The outer peripheral surface of the spiral membrane element 1a is covered with a separation membrane 9 which is a liquid permeable material. As the separation membrane 9, a microfiltration membrane or an ultrafiltration membrane is used.

As the microfiltration membrane, a polymer organic membrane such as polyolefin, polysulfone, polypropylene, polyethylene, polystyrene, polyacrylonitrile, cellulose acetate and the like can be used. As the ultrafiltration membrane, polysulfone, polypropylene, polystyrene,
A high molecular organic film such as polyacrylonitrile, cellulose acetate, or polyethylene can be used.

The outer peripheral surface of the separation membrane 9 is covered with an outer peripheral channel material 5 made of a net. As the material of the net,
Polymer materials such as polyolefin, polysulfone, polypropylene, polyethylene, polystyrene, polyacrylonitrile, and cellulose acetate; inorganic materials such as ceramic;
Metal, synthetic rubber, fiber, or the like can be used.

The pore size of the microfiltration membrane is 0.01 μm or more and 1
It is preferably 0 μm or less. The pore size of the ultrafiltration membrane is preferably from 20,000 to 0.01 μm. Further, it is preferable that the net used as the outer peripheral channel material 5 has a mesh size of 4 mesh or more and 100 mesh or less.

The pore size of the microfiltration membrane or ultrafiltration membrane used as the separation membrane 9 and the number of meshes of the net used as the outer peripheral flow path member 5 are selected according to the quality of the raw water.

In the spiral type membrane element 1 shown in FIG. 1, a microfiltration membrane having a pore diameter of 0.4 μm made of polyolefin such as ethylene vinyl alcohol is used as the separation membrane 9. Further, an ultrafiltration membrane made of polysulfone may be used as the separation membrane 9. Further, a 50 mesh net made of PET (polyethylene terephthalate) is used as the outer peripheral channel material 5.

Incidentally, in addition to the outer peripheral surface of the spiral membrane element 1a, the end face of the spiral membrane element 1a may be covered with the separation membrane 9.

As shown in FIG. 2 and FIG.
Is formed by superposing two separation membranes 7 on both sides of a permeated water spacer (permeated liquid flow path material) 6 and bonding three sides thereof, and the opening of the envelope-shaped membrane 3 is formed on the outer periphery of the water collecting pipe 2. Attached to the surface. 10 kgf / c for the separation membrane 7
Low pressure reverse osmosis membranes, ultrafiltration membranes, microfiltration membranes, etc., operated at m ² or less are used.

In the example of FIG. 2, a plurality of envelope-shaped membranes 3 are formed by independent separation membranes 7, respectively. In the example of FIG.
A plurality of envelope membranes 3 are formed by folding a continuous separation membrane 7.

If the thickness of the raw water spacer 4 is larger than 0.5 mm, it becomes difficult to capture contaminants in the raw water at least at the outer peripheral portion of the spiral membrane element 1. On the other hand, when the thickness of the raw water spacer 4 is smaller than 0.1 mm, the envelope films 3 are likely to come into contact with each other, and the film area is reduced.
Therefore, the thickness of the raw water spacer 4 is preferably 0.1 mm or more and 0.5 mm or less.

As shown in FIG. 1, the outer peripheral channel material 5 is formed in a lattice shape so that a plurality of wires 61 and 62 intersect at right angles. The thickness of the wire 61 is set to be larger than the thickness of the wire 62. This makes it easier for the raw water 51 to flow between the wires 61 almost linearly in a direction parallel to the wires 61.

Further, as shown in FIG.
Are arranged such that the wire 61 is parallel to the axial direction of the water collecting pipe 2. Therefore, the raw water is the spiral membrane element 1
It becomes easy to flow in the axial direction at the outer peripheral portion of a.

When the thickness t of the outer peripheral flow path member 5 is larger than 30 mm, the volume efficiency of the spiral membrane element 1 with respect to the pressure vessel storing the spiral membrane element 1 is reduced. On the other hand, the thickness t of the outer peripheral channel material 5 is 0.6 m.
If it is smaller than m, the flow rate of raw water for discharging contaminants attached to at least the outer peripheral portion of the spiral membrane element 1 during backflow cleaning of permeated water is reduced. Therefore, the thickness of the outer peripheral channel material 5 is 0.6 mm or more and 30 m or more.
m or less.

The porosity in the thickness direction of the outer peripheral flow path member 5 is set, for example, to 20% or more and 60% or less. Thereby, sufficient strength of the outer peripheral channel member 5 can be secured while reducing the resistance of the raw water that moves the contaminant in the axial direction during the backwashing. The vertical and horizontal pitches of the mesh of the outer peripheral channel member 5 are, for example, 3 mm or more and 30 mm or less.
Thus, the raw water can be sufficiently supplied between the envelope-shaped membranes 3 while preventing the outer peripheral surface of the spiral membrane element 1a from contacting the pressure vessel and narrowing the flow path of the raw water.

The whole of the outer peripheral separation membrane 9 may be covered with the outer peripheral channel material 5, or a part of the region may be covered with the outer peripheral channel material 5.

FIG. 4 is a schematic cross-sectional view showing an example of a method for operating the spiral membrane element and the spiral membrane module according to the present invention. As shown in FIG. 4, the pressure vessel (pressure-resistant vessel) 10 includes a cylindrical case 11 and a pair of end plates 12a and 12b. One end plate 12a
Has a raw water inlet 13 formed therein, and the other end plate 12b has a raw water outlet 15 formed therein. Also, the other end plate 12b
Is provided with a permeated water outlet 14 at the center thereof.

The spiral membrane element 1 shown in FIG. 1 is housed in a cylindrical case 11, and both open ends of the cylindrical case 11 are sealed by end plates 12a and 12b, respectively. One end of the water collecting pipe 2 is fitted to the permeated water outlet 14 of the end plate 12b, and an end cap 16 is attached to the other end. Thus, a spiral-type membrane module in which one spiral-type membrane element 1 is loaded in the pressure vessel 10 is configured. A pipe 19 is connected to the raw water inlet 13 of the end plate 12a, and a pipe 20 and a pipe 21 are further connected to the pipe 19.
00 is connected. The pipe 19 is connected to a pressure pump 101 via a valve 18a. The pipe 20 is provided with a valve 18b. Piping 21 is a valve 18d
Is connected to the air diffuser 102 via the. in this case,
An air supply device such as a compressor is used as the air diffuser 102. The raw water outlet 15 of the end plate 12b is connected to a pipe 17 and further connected to a pipe 17a. Piping 1
7 is provided with a valve 18c. In addition, piping 17
a is connected to the raw water tank 200.

As shown in FIG. 4, when the spiral membrane element 1 is operated, the valve 18a of the pipe 19 and the valve 18c of the pipe 17 are opened, and the valve 18b of the pipe 20 is opened.
Close. After the raw water 51 taken from the raw water tank 200 is pressurized by the pressure pump 101, the raw water 51 is introduced into the pressure vessel 10 through the raw water inlet 13 of the pressure vessel 10. here,
The valve 18d of the pipe 21 is opened, and air bubbles (air) scattered by the air diffuser 102 are introduced into the pressure vessel 10. Thus, air bubbling is performed inside the spiral membrane module.

The raw water 51 supplied into the pressure vessel 10
Some of the raw water flows in the axial direction along the outer peripheral portion of the spiral-wound membrane element 1, and flows from the raw water outlet 15 to the pipe 17.
Is discharged to the outside through Further, this part of the raw water is returned to the raw water tank 200 via the pipe 17a.

On the other hand, the remaining raw water 51 flows along the outer peripheral flow path member 5 of the spiral membrane element 1, and the separation membrane 9 flows from at least the outer peripheral side of the spiral membrane element 1.
And penetrates between the envelope-shaped membranes 3 along the raw water spacers 4. In the example of FIG. 4, raw water 51 enters between the envelope-shaped membranes 3 from the outer peripheral side and both end sides of the spiral membrane element 1. The permeated water that has passed through the separation membrane 7 is transferred to the permeated water spacer 6.
Flows into the inside of the water collecting pipe 2 along. Thereby, the permeated water 52 is taken out from the permeated water outlet 14 of the pressure vessel 10.

In this case, since the outer peripheral surface of the spiral membrane element 1 a is covered with the separation membrane 9, a contaminant such as a turbid substance larger than the pore diameter of the separation membrane 9 is removed from at least the outer periphery of the spiral membrane element 1. Caught in the department. That is,
Only contaminants smaller than the pore size of the separation membrane 9
Break in. Therefore, the load on the separation membrane 7 constituting the envelope-shaped membrane 3 is reduced.

In this embodiment, air bubbling is performed inside the spiral membrane element, and a part of raw water flows in the axial direction along the outer periphery of the spiral membrane element 1. A diffused flow (a gas-liquid mixed flow) is formed. Thereby, it is possible to suppress the contaminant from settling and adhering to the film surface of the spiral membrane element 1 and at least the outer peripheral portion, and to adhere to the film surface of the spiral membrane element 1 and at least the outer peripheral portion. It becomes possible to peel off contaminants. Furthermore, by forming the flow of the raw water in the axial direction, a part of the contaminants in the raw water 51 and the contaminants separated from the film surface and at least the outer peripheral portion of the spiral type membrane element 1 can be easily and surely removed. It becomes possible to discharge to the outside of the element 1. Thus, stable operation can be continuously performed for a long time.

Further, since part of the raw water discharged from the raw water outlet 15 to the outside is circulated, the permeated water 52 can be obtained from the supplied raw water 51 at a theoretically 100% recovery rate.

Here, the valve 18d of the pipe 21 may be opened continuously or intermittently. This makes it possible to continuously or intermittently perform air bubbling in the spiral membrane module.

When air bubbling is performed intermittently, the opening and closing of the valve 18d may be controlled by a timer. Alternatively, measuring devices such as an operation pressure gauge, a transmembrane pressure gauge, and a permeated water flow meter are installed in a membrane separation device in which a spiral type membrane module is incorporated, and the opening and closing of the valve 18d is controlled according to signals from these measuring devices. May be.

For example, since the flow rate of the permeated water of the spiral membrane element 1 decreases with the contaminants adhering to the membrane surface, the outer peripheral portion, etc. of the spiral membrane element 1, the flow rate of the permeated water is measured by the permeated water flow meter. The change is measured, and a signal is sent when a change is found in the permeate flow rate to open the valve 18d. Thereby, the membrane surface of the spiral membrane element 1,
The contaminants adhering to the outer peripheral portion and the like can be separated, and a stable permeate flow rate can be maintained.

The flow of raw water may be intermittently formed in accordance with air bubbling by opening and closing valve 18c in accordance with opening and closing of valve 18d.

After filtration for a certain period of time, backwashing with permeated water 52 is performed from the permeate side. FIG. 5 is a partially cutaway perspective view showing the backwashing operation in the spiral membrane element 1 of FIG. At the time of backwashing, the valve 1
8a, the valve 18c of the pipe 17 and the valve 18d of the pipe 21 are closed, and the valve 18b of the pipe 20 is opened. In this state, the permeated water 52 is introduced from the permeated water outlet 14 into the water collecting pipe 2 as washing water. The permeated water 52 during backwashing is
The contaminants that pass through the envelope-shaped membrane 3 from the water collecting pipe 2 and adhere to the membrane surface, the raw water spacer 4 and the like are separated, and flow along the raw water spacer 4 at least toward the outer peripheral portion. Further, the contaminants trapped on at least the outer peripheral portion of the spiral membrane element 1 are easily separated by the permeated water 52.
The separated contaminants, together with the permeated water 52, enter the raw water inlet 13
Is discharged to the outside through the pipe 20.

After the above backwashing, flushing with raw water is performed. That is, the valve 18 b of the pipe 20 is closed and the valve 18 a of the pipe 19 is opened, and the raw water 51 is supplied from the raw water inlet 13 through the
Is opened. As a result, the raw water 51 flows linearly in the axial direction along the outer peripheral channel member 5, and the separated contaminants and permeated water are discharged from the raw water outlet 15 to the outside via the pipe 17. In addition, contaminants remaining on the membrane surface of the spiral membrane element 1, the raw water spacer 4, the outer peripheral portion, and the like are separated from the spiral membrane element 1 and discharged to the outside. As a result, the membrane flux is remarkably recovered compared to before the backwashing. In this case, the raw water discharged to the outside by the flushing is supplied to the raw water tank 20 via the pipe 17a.
Returned to 0.

According to the above-mentioned cleaning method, the contaminants adhering to the membrane surface of the spiral type membrane element 1, the raw water spacer 4, the outer peripheral portion and the like, in particular, the separation membrane 9 can be easily discharged to the outside along the outer peripheral flow path member 5. And can be discharged reliably and reliably.
Can be suppressed from increasing. Thereby,
It is possible to always maintain a stable amount of permeated water.

The above spiral type membrane element 1
In (2), since the outer peripheral portion is covered with the outer peripheral portion flow path member 5, handling (handling) is improved.

Further, since the dead space such as the dead space S shown in FIG. 18 is not formed in the space between the spiral type membrane element 1 and the pressure vessel 10 by the above-described filtration mode, various bacteria such as microorganisms can be formed. There is no problem of odor propagation, generation of offensive odor due to decomposition of organic matter, decomposition of separation membrane, etc., and high reliability can be obtained.

Further, since pressure is applied to the spiral membrane element 1 from all directions, the spiral membrane element 1
No deformation problem occurs, and the packing holder and the exterior material become unnecessary. Thereby, component costs and manufacturing costs are reduced.

The pressurizing pump 10 for supplying raw water 51
There is no need to use a large one. Thereby, the system cost is reduced.

In the backwashing, the permeated water 52 is first introduced into the water collecting pipe 2, and the permeated water 52 derived from the outer peripheral surface of the water collecting pipe 2 causes the outer peripheral portion of the spiral type membrane element 1, Although the flushing with the raw water is performed after the contaminants captured by the raw water spacer 4 and the like are separated, the permeated water 52 may be introduced into the water collecting pipe 2 after the flushing with the raw water. According to this cleaning method, most of the contaminants trapped in the outer peripheral portion of the spiral membrane element 1 are removed by flushing, and the permeated water 52 is further introduced, whereby the outer peripheral portion of the spiral membrane element 1 and the membrane surface are removed. In addition, contaminants remaining in the raw water spacer 4 and the like can be removed. Therefore, also in this case, the same cleaning effect as described above can be obtained.
Alternatively, flushing with raw water may be performed in parallel with the introduction of the permeated water 52 into the water collecting pipe 2. Also in this case, the same cleaning effect as described above can be obtained.

Furthermore, in the above description, the spiral membrane element in which one spiral membrane element 1 is loaded in the pressure vessel 10 has been described. However, the spiral membrane element and the spiral membrane module shown in FIG. The operation method can be applied to a spiral membrane module in which a plurality of spiral membrane elements are loaded in a pressure vessel, as described below.

FIG. 6 is a schematic sectional view showing another example of the method of operating the spiral membrane element and the spiral membrane module according to the present invention.

The configuration of the spiral membrane module shown in FIG. 6 is the same as the configuration of the spiral membrane module shown in FIG. 4 except for the following points.

As shown in FIG. 6, the pressure vessel 100 includes a cylindrical case 111 and a pair of end plates 120a and 120b. A raw water inlet 13 is formed at the bottom of the cylindrical case 111, and a raw water outlet 15 is formed at the top. The raw water outlet 15 is also used for air release. Also,
A permeated water outlet 14 is provided at the center of the end plates 120a and 120b.

A plurality of spiral membrane elements 1 in which the water collecting pipes 2 are connected in series by an interconnector 116 are housed in a cylindrical case 111, and both open ends of the cylindrical case 111 are connected to end plates 120a and 120b, respectively. Sealed. Water collecting pipe 2 of spiral type membrane element 1 at both ends
Are connected to the end plates 12 through the adapter 115, respectively.
0a and 120b are fitted to the permeated water outlets 14. Thus, a spiral-type membrane module in which the plurality of spiral-type membrane elements 1 are loaded in the pressure vessel 100 is configured.

As shown in FIG. 6, when the spiral type membrane module is operated, the valve 18a of the pipe 19 and the valve 18c of the pipe 17 are opened and the valve of the pipe 20 is opened as in the operation of the spiral type membrane module shown in FIG. Close 18b. After the raw water 51 taken from the raw water tank 200 is pressurized by the pressurizing pump 101, the raw water 51 is introduced into the pressure vessel 100 from the raw water inlet 13 of the pressure vessel 100. Here, the valve 18d of the pipe 21 is opened, and the air bubbles (air) scattered by the air diffuser 102 are introduced into the pressure vessel 100. Thus, air bubbling is performed inside the spiral membrane module.

Raw water 5 supplied inside pressure vessel 100
A part of the raw water flows axially along the outer peripheral portions of the plurality of spiral membrane elements 1, and is discharged to the outside from a raw water outlet 15 through a pipe 17. Further, the raw water is returned to the raw water tank 200 via the pipe 17a.

On the other hand, the remaining raw water 51 flows along the outer peripheral channel material 5 in each spiral type membrane element 1,
At least from the outer peripheral part side, it permeates the separation membrane 9 and penetrates between the envelope-shaped membranes 3 along the raw water spacer 4. The permeated water that has passed through the separation membrane 7 flows into the water collecting pipe 2 along the permeated water spacer 6, and the permeated water outlets 14 at both ends of the pressure vessel 100.
The permeated water 52 is taken out from the tank.

In this case, each spiral membrane element 1
Since the outer peripheral surface of the spiral membrane element 1a is covered with the separation membrane 9, contaminants larger than the pore diameter of the separation membrane 9 are captured at least at the outer peripheral part of each spiral membrane element 1. Therefore, each spiral membrane element 1
The load on the separation membrane 7 constituting the envelope-shaped membrane 3 is reduced.

In addition, air bubbling is performed inside the spiral membrane element, and the flow of raw water is formed in the axial direction along the outer periphery of each spiral membrane element 1. An airflow is formed. Thereby, it is possible to prevent the contaminant from settling and adhering to the film surface and at least the outer peripheral portion of each spiral type membrane element 1, and to prevent the contaminant from adhering to the film surface and at least the outer peripheral portion of each spiral type membrane element 1. The attached contaminants can be removed. Further, due to the flow of the raw water, a part of the contaminants in the raw water 51 and the contaminants separated from at least the outer surface and the film surface of each spiral membrane element 1 are easily and reliably discharged to the outside of the spiral membrane module. It becomes possible. Thus, stable operation can be continuously performed for a long time.

Further, since a part of the raw water discharged from the raw water outlet 15 to the outside is circulated by the circulation system constituted by the pipe 17a, the permeated water 52 can be obtained from the raw water 51 at a theoretically 100% recovery rate. It becomes possible.

In this case, since the spiral membrane module is loaded with a plurality of spiral membrane elements 1, the processing capacity of the spiral membrane module is large.
The permeated water 52 can be obtained efficiently.

After filtration for a certain period of time, backwashing with permeated water 52 is performed from the permeation side. At the time of backwashing, pipe 1
The valve 18a of the pipe 9, the valve 18c of the pipe 17, and the valve 18d of the pipe 21 are closed, and the valve 18b of the pipe 20 is opened. In this state, permeated water 52 is introduced from the permeated water outlets 14 at both ends of the pressure vessel 100 into the water collecting pipe 2 of the spiral membrane element 1 as washing water. In each spiral membrane element 1, the permeated water 52 penetrates through the envelope-shaped membrane 3 from the water collection pipe 2, peels off contaminants attached to the membrane surface, the raw water spacer 4, etc., and at least the outer periphery along the raw water spacer 4. Flowing towards. Further, the contaminants trapped at least at the outer peripheral portion of each spiral membrane element 1 are easily separated by the permeated water 52. The separated contaminants are discharged to the outside via the pipe 20 together with the permeated water 52.

After the backwashing described above, the valve 1
8a and the valve 18c of the pipe 17 are opened to perform flushing with raw water. Thereby, the separated contaminants and the remaining permeated water 52 are discharged from the raw water outlet 15 to the outside of the spiral membrane module via the pipe 17 together with the raw water. In this case as well, flushing with raw water is performed before or after backwashing, or flushing with raw water in parallel with backwashing, as in the case of washing the spiral membrane element and the spiral membrane module shown in FIG. Do. The raw water discharged to the outside by the flushing is supplied to the raw water tank 20 via the pipe 17a.
Returned to 0.

According to the above-mentioned cleaning method, contaminants adhering to the membrane surface of the spiral type membrane element 1, the raw water spacer 4, the outer peripheral portion and the like, especially the separation membrane 9, can be easily discharged to the outside along the outer peripheral flow path material 5. And can be discharged reliably and reliably.
Can be suppressed from increasing. Thereby,
It is possible to always maintain a stable amount of permeated water.

In the above spiral type membrane module, no dead space is formed in the gap between each spiral type membrane element 1 and the pressure vessel 100 due to the above-mentioned filtration mode, so that germs such as microorganisms can be propagated. There is no problem such as generation of offensive odor and decomposition of the separation membrane due to decomposition of organic substances, and high reliability can be obtained.

Further, in each spiral type membrane element 1, since pressure is applied from all directions, the problem of deformation of the spiral type membrane element 1 does not occur, and the packing holder and the exterior material become unnecessary. Thereby, component costs and manufacturing costs are reduced.

The pressurizing pump 10 for supplying raw water 51
There is no need to use a large one. Thereby, the system cost is reduced.

In the operation method of the spiral membrane element and the spiral membrane module shown in FIGS. 4 and 6, a part of the raw water taken out from the raw water outlet 15 at the time of operation and the raw water used for flushing at the time of washing are connected to the piping. It is returned to the raw water tank 200 via 17a,
These raw waters may be discharged without being circulated.

In the method of operating the spiral membrane element and the spiral membrane module shown in FIGS. 4 and 6, the case where air bubbling is performed during the operation of the spiral membrane element and the spiral membrane module has been described. Air bubbling may be performed at other times.

For example, air bubbling may be performed during backwashing. Alternatively, when the operation is stopped, air bubbling may be performed in a state where the raw water 51 or the washing water (permeated water 52) is sealed in the spiral membrane module. Further, when the operation is stopped, air bubbling may be performed when the membrane surface is flushed using the raw water 51 or the washing water (permeated water 52). In these cases, the same effects as described above can be obtained.

FIG. 7 is a schematic sectional view showing still another example of the method of operating the spiral membrane element and the spiral membrane module according to the present invention. The spiral-type membrane module shown in FIG.
Has the same configuration as the spiral type membrane module shown in FIG.

In the spiral type membrane module shown in FIG. 7, the air diffusion device 102, the pipe 21 and the valve 18d are not provided unlike the spiral type membrane module shown in FIG. Is provided with an ultrasonic oscillator 103.

As shown in FIG. 7, when the spiral membrane element 1 is operated, the valve 18a of the pipe 19 is opened,
Valve 18b of pipe 20 and valve 18c of pipe 17
Close. After the raw water 51 taken from the raw water tank 200 is pressurized by the pressure pump 101, the raw water 51 is introduced into the pressure vessel 10 through the raw water inlet 13 of the pressure vessel 10. here,
Ultrasonic oscillator 1 provided in cylindrical case 11 of pressure vessel 10
With 03, the ultrasonic vibration is applied to the raw water 51 and the spiral membrane element 1 inside the pressure vessel 10 via the pressure vessel 10.

The raw water 51 introduced into the pressure vessel 10
Flows along the outer peripheral channel material 5 of the spiral membrane element 1, passes through the separation membrane 9 from at least the outer peripheral side of the spiral membrane element 1, and penetrates between the envelope membranes 3 along the raw water spacer 4. I do. In the example of FIG. 7, raw water 51 enters between the envelope-shaped membranes 3 from the outer peripheral side and both end sides of the spiral membrane element 1. The permeated water that has passed through the separation membrane 7 flows into the water collecting pipe 2 along the permeated water spacer 6. Thereby, the permeated water 52 is taken out from the permeated water outlet 14 of the pressure vessel 10.

In this case, since the outer peripheral surface of the spiral membrane element 1a is covered with the separation membrane 9, contaminants larger than the pore diameter of the separation membrane 9 are captured at least in the outer peripheral section of the spiral membrane element 1. You. That is, only contaminants smaller than the pore diameter of the separation membrane 9 enter between the envelope-shaped membranes 3.
Therefore, the load on the separation membrane 7 constituting the envelope-shaped membrane 3 is reduced.

Further, since ultrasonic vibration is applied to the raw water 51 inside the spiral type membrane module by the ultrasonic oscillator 103, contaminants in the raw water 51 are dispersed. This makes it possible to suppress the contaminants in the raw water 51 from adhering to the inside of the spiral membrane module, particularly to the membrane surface and at least the outer peripheral portion of the spiral membrane element 1. In addition, since the ultrasonic vibration is also applied to the spiral membrane element 1, it is possible to peel off the contaminants attached to the membrane surface and at least the outer peripheral portion of the spiral membrane element 1. From the above, stable operation can be continuously performed for a long period of time.

After filtering for a certain period of time, backwashing with permeated water 52 is performed from the permeate side. At the time of cleaning, the ultrasonic oscillator 103 is stopped, and backflow cleaning and flushing with raw water are performed by a method similar to the method of cleaning the spiral membrane element and the spiral membrane module shown in FIG. In this case, as described above, flushing with raw water is performed before or after backwashing,
Alternatively, flushing is performed in parallel with backwashing.

According to the above-described cleaning method, contaminants adhering to the membrane surface of the spiral type membrane element 1, the raw water spacer 4, the outer peripheral portion, etc., particularly the separation membrane 9, can be easily discharged to the outside along the outer peripheral portion flow path member 5. And can be discharged reliably and reliably.
Can be suppressed from increasing. Thereby,
It is possible to always maintain stable permeated water.

Further, since no dead space is formed in the space between the spiral membrane element 1 and the pressure vessel 10 by the above-described filtration mode, propagation of various bacteria such as microorganisms, generation of offensive odors by decomposition of organic substances, Problems such as decomposition of the separation membrane do not occur, and high reliability can be obtained.

Since pressure is applied to the spiral membrane element 1 from all directions, the spiral membrane element 1
No deformation problem occurs, and the packing holder and the exterior material become unnecessary. Thereby, component costs and manufacturing costs are reduced.

In addition, since the whole amount is filtered, the raw water 51
It is not necessary to use a large pump for supplying pressure. Thereby, the system cost is reduced.

During the operation, the raw water may be partially taken out from the raw water outlet 15 by opening the valve 18c of the pipe 17. In this case, the flow of raw water can be formed at the outer peripheral portion of the spiral membrane element 1. As a result, the sedimentation of pollutants in the raw water 51 is suppressed while the raw water 5
Part of the contaminants in 1 and the separated contaminants can be discharged to the outside of the pressure vessel 10. Further, the raw water partially discharged to the outside may be returned to the raw water tank 200 via the pipe 17a and circulated.

In the above description, the ultrasonic oscillator 103 is provided on the outer peripheral portion of the cylindrical case 11 of the pressure vessel 10. However, the ultrasonic oscillator 103 may be provided on the end plate 12a or the end plate 12b of the pressure vessel 10. Good. Also in this case, it is possible to apply ultrasonic vibration to the raw water 51 and the spiral membrane element 1 via the pressure vessel 10. Alternatively, ultrasonic vibration may be directly applied to the raw water 51 or the spiral membrane element 1.

Further, in the above description, the spiral membrane element in which one spiral membrane element 1 is loaded in the pressure vessel 10 has been described, but the spiral membrane element and the spiral membrane module shown in FIG. The operation method can be applied to a spiral membrane module in which a plurality of spiral membrane elements are loaded in a pressure vessel, as described below.

FIG. 8 is a schematic sectional view showing still another example of the method of operating the spiral membrane element and the spiral membrane module according to the present invention.

The configuration of the spiral membrane module shown in FIG. 8 is the same as the configuration of the spiral membrane module shown in FIG. 6 except for the following points.

In the spiral type membrane module shown in FIG. 8, the air diffusion device 102, the pipe 21 and the valve 18d are not provided unlike the spiral type membrane module shown in FIG. Is provided with an ultrasonic oscillator 103. As described above, the ultrasonic oscillator 103 may be provided on the end plate 12a or the end plate 12b of the pressure vessel 100. Alternatively, the pressure vessel 100
The ultrasonic vibration may be directly applied to the raw water 51 or the spiral membrane element 1 without going through.

As shown in FIG. 8, during operation of the spiral type membrane module, the valve 18a of the pipe 19 is opened, and the valve 18b of the pipe 20 and the valve 18c of the pipe 17 are closed. After the raw water 51 taken from the raw water tank 200 is pressurized by the pressurizing pump 101, the raw water 51 is introduced into the pressure vessel 100 from the raw water inlet 13 of the pressure vessel 100. Here, ultrasonic vibration is applied to the raw water 51 and each spiral membrane element 1 inside the pressure vessel 100 via the pressure vessel 100 by the ultrasonic oscillator 103.

In each spiral type membrane element 1,
The raw water 51 flows along the outer peripheral flow path material 5, permeates the separation membrane 9 from at least the outer peripheral side, and penetrates between the envelope-shaped membranes 3 along the raw water spacer 4. The permeated water that has passed through the separation membrane 7 flows into the water collecting pipe 2 along the permeated water spacer 6,
From the permeated water outlet 14 at both ends of the pressure vessel 100, the permeated water 5
2 is taken out.

In this case, each spiral membrane element 1
Since the outer peripheral surface of the spiral membrane element 1a is covered with the separation membrane 9, contaminants larger than the pore diameter of the separation membrane 9 are captured at least at the outer peripheral part of each spiral membrane element 1. Therefore, each spiral membrane element 1
The load on the separation membrane 7 constituting the envelope-shaped membrane 3 is reduced.

In addition, since the ultrasonic oscillator 103 applies ultrasonic vibration to the raw water 51 inside the spiral membrane module, contaminants in the raw water 51 are dispersed. This makes it possible to suppress the contaminants in the raw water 51 from adhering to the inside of the spiral membrane module, particularly to the membrane surface and at least the outer peripheral portion of each spiral membrane element 1. Further, since ultrasonic vibration is also applied to each spiral membrane element 1, it is possible to remove contaminants attached to the membrane surface and at least the outer peripheral portion of each spiral membrane element 1. From the above, stable operation can be continuously performed for a long period of time.

Further, since the spiral membrane module is loaded with a plurality of spiral membrane elements 1, the processing capacity of the spiral membrane module is large, and the permeated water 52 can be obtained efficiently.

After filtration for a certain period of time, backwashing with permeated water 52 is performed from the permeate side. In this case, the ultrasonic oscillator 103 is stopped, and backwashing and flushing with raw water are performed by the same method as the method for cleaning the spiral membrane element and the spiral membrane module shown in FIG.

According to the above-mentioned cleaning method, contaminants adhering to the membrane surface of each spiral type membrane element 1, raw water spacer 4, outer peripheral portion, etc., particularly the separation membrane 9, are discharged to the outside along the outer peripheral channel member 5. It is possible to discharge easily and reliably, and it is possible to suppress an increase in the resistance of the separation membrane 9. Thereby, a stable amount of permeated water can always be maintained.

In the above spiral type membrane module, no dead space is formed in the gap between each spiral type membrane element 1 and the pressure vessel 100 by the above-mentioned filtration mode, so that germs such as microorganisms can be propagated. There is no problem such as generation of offensive odor and decomposition of the separation membrane due to decomposition of organic substances, and high reliability can be obtained.

Further, since pressure is applied to all the spiral membrane elements 1 from all directions, the problem of deformation of the spiral membrane element 1 does not occur, and the packing holder and the exterior material are not required. Thereby, component costs and manufacturing costs are reduced.

Further, since the whole amount is filtered, the raw water 5
It is not necessary to use a large pressure pump 101 for supplying 1. Thereby, the system cost is reduced.

In operation, the raw water may be partially taken out from the raw water outlet 15 by opening the valve 18c of the pipe 17. In this case, the flow of raw water can be formed at the outer peripheral portion of each spiral membrane element 1. As a result, the sedimentation of pollutants in the raw water 51 is suppressed while the raw water 5
Part of the contaminants in 1 and the separated contaminants can be discharged to the outside of the pressure vessel 10. Further, the partial raw water may be returned to the raw water tank 200 via the pipe 17a and circulated.

In the method of operating the spiral membrane element and the spiral membrane module shown in FIGS. 7 and 8, the case where ultrasonic vibration is applied during the operation of the spiral membrane element and the spiral membrane module has been described. Alternatively, ultrasonic vibration may be applied other than during operation.

For example, ultrasonic vibration may be applied during backwashing. Alternatively, when the operation is stopped, the raw water 51 or the washing water (permeated water 5) is stored in the spiral membrane module.
Ultrasonic vibration may be applied in a state where 2) is sealed.
Further, the operation may be stopped, and ultrasonic vibration may be applied when the membrane surface is flushed using the raw water 51 or the washing water (permeated water 52). In these cases, the same effects as described above can be obtained.

The operation of the spiral membrane element and the spiral membrane module according to the present invention as shown in FIGS. 4 and 6 to 8 is not limited to the spiral membrane element shown in FIG. It is also applicable to elements.

FIG. 9 is a front view showing a spiral type membrane element according to another embodiment of the present invention. In FIG. 9, the illustration of the outer peripheral channel material is omitted.

The spiral type membrane element 1 shown in FIG.
In, both ends of the spiral membrane element 1a are sealed with a resin layer 40. In the spiral membrane element 1 shown in FIG. 9B, one end of the spiral membrane element 1a is sealed with a resin layer 40.

In the spiral type membrane element 1 shown in FIGS. 9A and 9B, the number of working steps at the time of manufacturing is increased, but a space for supplying raw water to both ends or one end of the spiral type membrane element 1 is not required. Become. Therefore, the pressure vessel can be miniaturized, and the spiral membrane module in which the spiral membrane element 1 is housed in the pressure vessel can be miniaturized.

By arranging the end of the spiral membrane element 1 sealed with the resin layer 40 on the raw water inlet side of the pressure vessel, the end surface of the spiral membrane element 1 is moved by the dynamic pressure of the raw water when the raw water is introduced. Dirt can be prevented from adhering.

FIG. 10 is a partially cutaway perspective view showing a spiral type membrane element according to still another embodiment of the present invention. FIG. 11 is a cross-sectional view showing an example of the envelope-shaped membrane of the spiral membrane element shown in FIG. 10, and FIG. 12 is a cross-sectional view showing another example of the envelope-shaped membrane of the spiral membrane element shown in FIG. is there. FIG. 13 is a partially cutaway front view of the spiral membrane element of FIG.

Spiral type membrane element 1 shown in FIG.
Includes a spiral-shaped membrane element 1a formed by winding a plurality of independent envelope-shaped membranes 3 or a plurality of continuous envelope-shaped membranes 3 on the outer peripheral surface of a water collecting pipe 2 composed of a perforated hollow pipe. . Raw water spacers (raw liquid flow path material) between the envelope films 3 to prevent the envelope films 3 from adhering to each other and to reduce the film area, and to form a flow path for raw water.
4 has been inserted.

As shown in FIGS. 11 and 12, the envelope-shaped membrane 3 is provided on both sides of a permeated water spacer (permeated liquid channel material) 6.
The separation membrane 7 is formed by overlapping and bonding three sides, and the opening of the envelope-shaped membrane 3 is attached to the outer peripheral surface of the water collecting pipe 2. 10 kgf for the separation membrane 7
/ Cm pressure reverse osmosis membrane operated at ² or less, ultrafiltration membrane,
A microfiltration membrane or the like is used.

In the example of FIG. 11, a plurality of envelope-shaped membranes 3 are formed by independent separation membranes 7, respectively. In the example of FIG. 12, a plurality of envelope-shaped membranes 3 are formed by folding a continuous separation membrane 7.

Further, the outer peripheral surface of the spiral membrane element 1a is covered with a net 8 which is a liquid permeable material. As a material of the net 8, a synthetic resin such as polyolefin, polysulfone, polypropylene, polyester, polyethylene, polystyrene, polyacrylonitrile, or polyamide, or a metal such as stainless steel or iron can be used.

The net 8 preferably has a size of 3 mesh or more and 200 mesh or less. Thereby, the swelling of the spiral membrane element 1a due to the back pressure at the time of backwashing can be reliably suppressed, and the raw water can be sufficiently supplied into the spiral membrane element 1a from the outer peripheral side during operation.

Spiral type membrane element 1 shown in FIG.
In this case, the net 8 is made of tricot cloth impregnated with epoxy resin. This net 8
Is 50 mesh, the pitch of the warp and the weft is 0.5 mm, and the diameter of the warp and the weft is 0.15 mm.

The end face of the spiral membrane element 1a may be covered with the net 8 in addition to the outer peripheral face of the spiral membrane element 1a.

As shown in FIG. 13, three portions of the net 8 covering the outer peripheral surface of the spiral membrane element 1a are coated with resin 81 along the circumferential direction at equal intervals, whereby the net 8 is formed. It is fixed to the outer peripheral surface of 1a at three places. The number of locations where the resin 81 is applied is not particularly limited since it depends on the back pressure generated during backwashing. However, if the number of locations where the resin 81 is applied is greater than three, contamination of the outer peripheral portion of the spiral membrane element 1a during backflow cleaning is made. Substances are less likely to be removed. Therefore, for example, in a spiral membrane element 1a having a length of 944 cm, it is preferable to fix about three places with the resin 5a.

The outer peripheral surface of the net 8 is covered with the outer peripheral channel material 5. The material and dimensions of the outer peripheral channel member 5 are the same as those of the outer peripheral channel member 5 shown in FIG.

The entire outer peripheral net 8 may be covered with the outer peripheral flow path member 5, or a part of the area may be covered with the outer peripheral flow path member 5.

Spiral type membrane element 1 shown in FIG.
1 is operated by the operation method of the spiral membrane element and the spiral membrane module shown in FIGS. 4 and 6 to 8, for example, similarly to the spiral membrane element shown in FIG. 1. In this case, since the outer peripheral surface of the spiral membrane element 1a is covered with the net 8, contaminants such as turbid substances larger than the pore diameter of the net 8 are captured at least at the outer peripheral section of the spiral membrane element 1. . That is, only contaminants smaller than the pore diameter of the net 8 enter between the envelope-shaped membranes 3. Therefore, the load on the separation membrane 7 constituting the envelope-shaped membrane 3 is reduced.

Spiral type membrane element 1 shown in FIG.
When the operation method of the spiral membrane element and the spiral membrane module shown in FIG. 4 or FIG. 6 is applied, air blown into the raw water 51 from the air diffuser 102 causes air to flow in the spiral membrane module. Bubbling is performed. Thereby, it is possible to prevent the contaminants in the raw water 51 from settling and adhering to the membrane surface of the spiral membrane element 1 and at least the outer peripheral portion thereof, and to prevent the contaminants from adhering to the membrane surface of the spiral membrane element 1 and at least the outer periphery thereof. It becomes possible to peel off contaminants attached to the part.

On the other hand, when the spiral membrane element and the spiral membrane module operating method shown in FIG. 7 or FIG. 8 are applied to the spiral membrane element 1 shown in FIG. Ultrasonic vibration is applied to the raw water 51 and the spiral membrane element 1 in the membrane module. Thereby, it is possible to prevent the contaminants in the raw water 51 from adhering to the inside of the spiral membrane element, particularly to the membrane surface and at least the outer peripheral portion of the spiral membrane element 1, and to prevent the spiral membrane element 1 from being attached. It becomes possible to remove contaminants attached to the film surface and at least the outer peripheral portion.

FIG. 14 is a partially cutaway perspective view showing the operation of the spiral type membrane element 1 shown in FIG. 10 during backwashing. At the time of cleaning the spiral membrane element 1 shown in FIG. 10, backwashing and flushing with raw water are performed by the same method as the spiral membrane element cleaning method shown in FIG. Also in this case, as described above, flushing with raw water is performed before or after backwashing, or flushing with raw water and backwashing are performed in parallel.

According to such a cleaning method, the film surface of the spiral type membrane element 1, the raw water spacer 4, the outer peripheral portion, etc.
In particular, the contaminants adhering to the net 8 can be easily and reliably discharged to the outside along the outer peripheral channel material 5, and an increase in the resistance of the net 8 can be suppressed. Thereby, a stable amount of permeated water can always be maintained.

Further, in the spiral membrane element 1 shown in FIG. 10, since the outer peripheral portion is covered with the outer peripheral portion flow path member 5, handling (handling) is improved.

Further, since the outer peripheral surface of the spiral membrane element 1a is covered with the net 8, the spiral membrane element 1a
Even if the back pressure generated during the backwashing by the contaminants trapped on the outer peripheral portion of the outer peripheral portion a becomes large, the spiral membrane element 1a is prevented from bulging by the net 8 on the outer peripheral portion, and the envelope membrane 3 is removed.
The distance between them does not increase. Therefore, damage to the membrane due to the bulging of the envelope membrane 3 is prevented, and contaminants in the raw water 51 do not leak into the permeated water 52.

In particular, since the net 8 is fixed to the outer peripheral portion of the spiral membrane element 1a at a plurality of locations, the spiral membrane element 1a is reliably prevented from bulging even when the back pressure during backwashing is high. .

Further, since no dead space is formed in the gap between the spiral membrane element 1 and the pressure vessel, problems such as propagation of various bacteria such as microorganisms, generation of offensive odor due to decomposition of organic matters, decomposition of the separation membrane, and the like. It does not occur and high reliability is obtained.

Since pressure is applied to the spiral membrane element 1 from all directions, the spiral membrane element 1
No deformation problem occurs, and the packing holder and the exterior material become unnecessary. Thereby, component costs and manufacturing costs are reduced.

The pressurizing pump 10 for supplying raw water 51
There is no need to use a large one. Thereby, the system cost is reduced.

It should be noted that also in the above, FIGS.
As described above in the operation method of the spiral membrane element and the spiral membrane module shown in FIG.
In addition to the operation, air bubbling or ultrasonic vibration may be applied at the time of backwashing, at the time of operation stop, or at the time of flushing.

Further, the spiral membrane element and the method for operating the spiral membrane module according to the present invention are as follows.
It may be applied to a spiral membrane element 1 using a part of the permeated water spacer 6 as a net as shown in FIG. In such a spiral membrane element 1, the permeated water spacer 6 inserted in one envelope-shaped membrane 3 is used.
Is extended so as to protrude outside from the outer peripheral side of the envelope-shaped membrane 3, and the extended portion of the permeated water spacer 6 is wound around the outer peripheral surface of the spiral membrane element 1 a as a net 8. The space between the permeate spacer 6 projecting from the outer peripheral side of the envelope-shaped membrane 3 to the outside and the envelope-shaped membrane 3 is sealed with a resin 6a.

In this case, the swelling of the spiral membrane element 1a due to the back pressure at the time of backwashing can be prevented by the extended permeated water spacer 6 while suppressing the cost of additional parts due to the separate provision of the net 8.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view of a spiral membrane element according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an example of an envelope-shaped membrane of the spiral membrane element shown in FIG.

FIG. 3 is a cross-sectional view showing another example of the envelope-shaped membrane of the spiral membrane element shown in FIG.

FIG. 4 is a schematic sectional view showing an example of an operation method of the spiral membrane element and the spiral membrane module according to the present invention.

FIG. 5 is a partially cutaway perspective view showing a backwash operation in the spiral membrane element of FIG. 4;

FIG. 6 is a schematic cross-sectional view showing another example of the method of operating the spiral membrane element and the spiral membrane module according to the present invention.

FIG. 7 is a schematic cross-sectional view showing still another example of the method of operating the spiral membrane element and the spiral membrane module according to the present invention.

FIG. 8 is a schematic sectional view showing still another example of the method of operating the spiral membrane element and the spiral membrane module according to the present invention.

FIG. 9 is a front view of a spiral-type membrane element according to another embodiment of the present invention.

FIG. 10 is a partially cutaway perspective view of a spiral membrane element according to still another embodiment of the present invention.

FIG. 11 is a cross-sectional view showing an example of an envelope-shaped membrane of the spiral membrane element shown in FIG.

FIG. 12 is a cross-sectional view showing another example of the envelope-shaped membrane of the spiral membrane element of FIG.

FIG. 13 is a partially cutaway front view of the spiral membrane element of FIG. 10;

FIG. 14 is a partially cutaway perspective view showing a backwashing operation in the spiral membrane element of FIG. 10;

FIG. 15 is a cross-sectional view showing an example in which a permeated water spacer is used as a net.

FIG. 16 is a partially cutaway perspective view of a conventional spiral type membrane element.

FIG. 17 is an external perspective view of a conventional spiral membrane element.

FIG. 18 is a cross-sectional view showing an example of a conventional spiral-type membrane element operating method.

FIG. 19 is a partially cutaway perspective view showing a backwashing operation in a conventional spiral membrane element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spiral type membrane element 1a Spiral type membrane element 2 Water collecting pipe 3 Envelope type membrane 4 Raw water spacer 5 Outer flow path material 6 Permeated water spacer 7 Separation membrane 8 Net 9 Separation membrane 10, 100 Pressure vessel 13 Raw water inlet 14 Permeated water outlet Reference Signs List 51 Raw water 52 Permeated water 61, 62 Wire rod 81 Resin 101 Pressure pump 102 Air diffuser 103 Ultrasonic oscillator

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hajime Hisada 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation F-term (reference) 4D006 GA05 GA06 GA07 HA61 HA62 HA65 JA05B JA06A JA06B JA06C JA30A JA30B JA30C KA42 KC02 KC03 KC12 KC13 KC19 KE01Q KE03Q KE06P KE07P KE12P KE15P KE16P KE22Q KE24Q KE28Q MA03 MA22 MB22 MC18 MC22 MC23 MC24 MC39 MC62 PA01 PB04 PB24

Claims (16)

[Claims] 1. A method for operating a spiral-type membrane element, wherein the spiral-type membrane element is formed by winding a plurality of independent or continuous envelope-shaped membranes on an outer peripheral surface of a perforated hollow tube via a stock solution flow path material. A spirally wound spiral membrane element, an outer peripheral portion of the spiral membrane element is covered with a liquid permeable material, and an outer peripheral surface side of the liquid permeable material is wholly or partially covered with an outer peripheral channel material. A method for operating a spiral membrane element, wherein bubbles are continuously or intermittently scattered in a liquid in contact with an outer peripheral portion of the spiral membrane element. 2. A method for operating a spiral-type membrane element, wherein the spiral-type membrane element is formed by winding a plurality of independent or continuous envelope-shaped membranes on an outer peripheral surface of a perforated hollow tube via a stock solution flow path material. A spirally wound spiral membrane element, an outer peripheral portion of the spiral membrane element is covered with a liquid permeable material, and an outer peripheral surface side of the liquid permeable material is wholly or partially covered with an outer peripheral channel material. A method for operating a spiral-type membrane element, wherein ultrasonic vibration is continuously or intermittently applied to a liquid in contact with an outer peripheral portion of the spiral-shaped membrane element. 3. A method for operating a spiral-type membrane module comprising one or a plurality of spiral-type membrane elements housed in a pressure vessel, wherein the spiral-type membrane element is independent of an outer peripheral surface of a perforated hollow tube. Or a spiral membrane element formed by winding a plurality of continuous envelope membranes via a stock solution flow path material, and an outer peripheral portion of the spiral membrane element is covered with a liquid permeable material, The method of operating a spiral-wound membrane module, wherein the outer peripheral surface of the spiral membrane module is entirely or partially covered with an outer peripheral channel material, and bubbles are diffused into the liquid in the pressure vessel. 4. During operation, air bubbles are scattered in the stock solution while supplying the stock solution from at least the outer peripheral side of the spiral membrane element, and the permeate is discharged from at least one open end of the perforated hollow tube. The method for operating a spiral membrane module according to claim 3, wherein the spiral membrane module is taken out. 5. At the time of washing, a washing liquid is introduced from at least one open end of the perforated hollow tube, and a washing liquid derived from the outer peripheral surface of the perforated hollow tube is supplied to at least the outer periphery of the spiral membrane element. 5. The operating method for a spiral-type membrane module according to claim 3, wherein air bubbles are scattered in the cleaning liquid while being discharged from the section. 6. The flushing method according to claim 3, wherein bubbles are scattered in the stock solution or the cleaning solution while flowing the stock solution or the cleaning solution in the axial direction along the outer peripheral portion of the spiral membrane element. The operation method of the spiral membrane module according to any one of the above. 7. The method for operating a spiral-type membrane module according to claim 3, wherein bubbles are scattered in a stock solution or a cleaning solution existing in the pressure vessel when the operation is stopped. 8. A method for operating a spiral-wound membrane module comprising one or more spiral-wound membrane elements housed in a pressure vessel, wherein the spiral-wound membrane element is independent of an outer peripheral surface of a perforated hollow tube. Or a spiral membrane element formed by winding a plurality of continuous envelope membranes via a stock solution flow path material, and an outer peripheral portion of the spiral membrane element is covered with a liquid permeable material, Wherein the outer peripheral surface side of the is entirely or partially covered with an outer peripheral channel material, and continuously or intermittently applies ultrasonic vibration to the liquid in the pressure vessel. . 9. During operation, ultrasonic vibration is applied to the stock solution while supplying the stock solution from at least the outer peripheral side of the spiral membrane element, and the permeated solution is passed through at least one open end of the perforated hollow tube. The method for operating a spiral type membrane module according to claim 8, wherein the spiral type membrane module is taken out. 10. A cleaning liquid is introduced from at least one open end of the perforated hollow tube at the time of cleaning, and the cleaning liquid derived from the outer peripheral surface of the perforated hollow tube is supplied to at least the outer periphery of the spiral membrane element. The method for operating a spiral-type membrane module according to claim 8, wherein ultrasonic vibration is applied to the cleaning liquid while discharging the cleaning liquid from the section. 11. An ultrasonic vibration is applied to the stock solution or the cleaning solution while flowing the stock solution or the cleaning solution in the axial direction along the outer peripheral portion of the spiral membrane element during flushing. The operation method of the spiral membrane module according to any one of the above. 12. The method for operating a spiral-type membrane module according to claim 8, wherein ultrasonic vibration is applied to the stock solution or the cleaning solution existing in the pressure vessel when the operation is stopped. 13. An operation, wherein a part of the stock solution is continuously or intermittently flowed in the axial direction along the outer periphery of the spiral membrane element and taken out of the pressure vessel. 10. The method for operating the spiral membrane module according to 4 or 9. 14. The method for operating a spiral membrane module according to claim 13, wherein the stock solution taken out of the pressure vessel is returned to the supply side again. 15. A spiral type membrane module comprising one or a plurality of spiral type membrane elements housed in a pressure vessel having a stock solution inlet and a stock solution outlet, wherein the spiral type membrane element is a perforated hollow tube. A plurality of envelope-like membranes that are independent or continuous on the outer peripheral surface include a spiral membrane element wound around a raw liquid flow path material, and the outer peripheral portion of the spiral membrane element is covered with a liquid permeable material, The outer peripheral surface side of the liquid permeable material is wholly or partially covered with an outer peripheral channel material, and from the undiluted liquid outlet to the outside of the pressure vessel from an air diffuser for discharging bubbles in the liquid in the pressure vessel. A spiral type membrane module provided with a circulation system for returning the taken-out stock solution to the stock solution inlet. 16. A spiral-type membrane module comprising one or a plurality of spiral-type membrane elements housed in a pressure vessel, wherein the spiral-type membrane element is independent or continuous with an outer peripheral surface of a perforated hollow tube. A plurality of envelope-shaped membranes include a spiral-shaped membrane element wound around a stock solution flow path material, an outer peripheral portion of the spiral-shaped membrane element is covered with a liquid-permeable material, and an outer peripheral surface of the liquid-permeable material. A spiral-type membrane module, wherein the side is entirely or partially covered with an outer peripheral channel material, and an ultrasonic oscillator for applying ultrasonic vibration to the liquid in the pressure vessel is provided.