WO2004009222A1

WO2004009222A1 - Spiral membrane element, reverse osmosis membrane module, and reverse osmosis membrane device

Info

Publication number: WO2004009222A1
Application number: PCT/JP2003/007393
Authority: WO
Inventors: Yuya Sato; Makio Tamura
Original assignee: Organo Corporation
Priority date: 2002-07-18
Filing date: 2003-06-11
Publication date: 2004-01-29
Also published as: CN1320948C; TWI239262B; AU2003242262A1; TW200401664A; CN1642625A; KR20050025154A; JP2004050005A; MY137069A

Abstract

A spiral membrane element, comprising a bag-like separating membrane wound, together with a raw water spacer, on the outer peripheral surface of a permeated water collecting tube, the raw water spacer further comprising first wire materials and second wire materials extending from the inflow side to the outflow side of raw water in a gently meandering curved shape, wherein the first wire materials extend along one membrane face of the separating membrane and form one raw water passages between the adjacent first wire materials, and the second wire materials extend along the other membrane face of the separating membrane and form the other raw water passages between the adjacent second wire materials, and the first and second wire materials are partly overlapped with each other and joined to each other at the overlapped positions.

Description

Description ^ Spiral type membrane element, reverse osmosis membrane module and reverse osmosis membrane device

The present invention relates to a spiral membrane element, a reverse osmosis membrane module, and a reverse osmosis membrane device capable of performing a stable water flow treatment for a long period of time without pretreatment even for raw water having high turbidity such as industrial water. Things. Background art

Conventionally, as a method for obtaining seawater desalination, ultrapure water, and water for various manufacturing processes, a spiral membrane element using a reverse osmosis membrane (RO membrane) or nanofiltration membrane (NF membrane) as a permeable membrane has been used. A method for separating ionic components and low molecular components from raw water is known. As illustrated in Fig. 9, a spiral membrane element that has been generally used in the past has a reverse osmosis membrane 91 superimposed on both sides of a permeated water spacer 92 and bonded on three sides. To form a bag-shaped membrane 93, and attach the opening of the bag-shaped membrane 93 to the permeated water collecting pipe 94, and spy on the outer peripheral surface of the permeated water collecting pipe 94 together with the mesh-shaped raw water spacer 95. It is formed by winding in a ral shape. The raw water 96 is supplied from one end face 9a of the spiral membrane element 90, flows along the raw water spacer 95, and flows from the other end face 9b of the spiral membrane element 90. It is discharged as concentrated water 98. In the process of flowing along the raw water spacer 95, the raw water 96 passes through the reverse osmosis membrane 91 to become permeated water 97, and this permeated water 97 flows along the permeated water spacer 92. It flows into the inside of the permeated water collecting pipe 94 and is discharged from the end of the permeated water collecting pipe 94. In this way, the raw water sensor 95 disposed between the wound bag-like membranes 93 serves A road will be formed.

When seawater desalination, ultrapure water, and water for various production processes are obtained using such a spiral-wound membrane element, pretreatment is usually performed for the purpose of removing turbidity of raw water. The reason for performing this pretreatment is that the thickness of the raw water sensor of the spiral type membrane element is usually 1 mm or less in order to make the contact area between the raw water and the reverse osmosis membrane as large as possible while securing the raw water flow path. It is so thin that turbidity is accumulated in the raw water space in the raw water flow path, and the raw water flow path is easily blocked. For this reason, the turbidity in the raw water is removed in advance to avoid an increase in the differential pressure of water flow and a decrease in the amount of permeated water and the quality of permeated water due to the accumulation of turbidity, and to ensure stable operation for a long period of time. Pretreatment devices used for such a purpose include, for example, coagulation sedimentation treatment, filtration treatment, membrane treatment, etc., and installation thereof increases installation costs and operation costs. In addition, there is a problem that a large installation area is required. For this reason, a spiral-type membrane element with a structure that can secure the raw water flow path with a thin raw water spacer like the conventional example and maintain the same level of desalination as the conventional one and that does not accumulate turbidity has been proposed. In this way, industrial water and tap water can be supplied without pre-treatment, simplifying the system, reducing the installation area, and reducing costs, resulting in extremely high industrial utility value.

On the other hand, various proposals have been made to improve the structure of a conventional mesh-like raw water spacer in order to prevent the raw water flow path from being blocked by turbidity of the spiral membrane element. JP-A-64-47404 discloses a spiral membrane element that uses a raw water spacer that is corrugated and has a meandering waveform. This meandering wave-shaped raw water spacer is not practical because it is difficult to mold and the flow path is likely to be crushed when spirally wound.

Japanese Unexamined Patent Publication No. 9-297970 describes that the first wire and the second wire And a structure in which a raw water spacer is arranged so that the first wire or the second wire is parallel to the longitudinal direction of the permeated water collecting pipe. ing. According to the raw water system having this structure, the raw water flows almost linearly in a direction parallel to the longitudinal direction of the permeated water collecting pipe, so that the pressure loss is low, and the linear velocity of the raw water is increased. Although it is difficult for turbidity to accumulate, the wire present in the direction perpendicular to the longitudinal direction of the water collection pipe blocks the flow path of raw water, so that turbidity accumulates in the wire and block the raw water flow path. Wake up.

Japanese Patent Application Laid-Open No. H10-1566152, as shown in Fig. 8, consists of a wire extending in a zigzag manner from the inflow side X to the outflow side Y of raw water, and the wires face each other. A first wire rod 81 extending along the membrane surface of one of the separation membranes 80, and a second wire rod 82 extending along the membrane surface of the other separation membrane, Between the adjacent first wires and between the adjacent second wires, the raw water flow continuously extending along the membrane surface of the separation membrane from the inflow side to the outflow side of the raw water. The first wire rod and the second wire rod partially overlap with each other at 81 b and 82 a, and a raw water sensor having a structure to be joined at the overlapping portion is formed. It has been disclosed. According to the raw water spacer having this structure, although the blockage of the raw water flow path due to the turbidity is suppressed as compared with a conventional raw water spacer having a lattice structure, the first wire rod in FIG. The stagnation of raw water near the corner C of 81 cannot be eliminated even if it is affected by the flow of high flow velocity at the protruding portion B of the second wire rod 82. For this reason, the accumulation of turbidity also occurs during long-term use.

As described above, among the conventionally proposed raw water sensors, those having a mesh structure composed of the first wire and the second wire have a part of the corner in the raw water flow path. Or there is a part that becomes a bending point, During use for a long period of time, turbidity accumulates, and a rise in the differential pressure of water flow is unavoidable, leading to the omission of the conventional pretreatment of raw water. There is no present. From the viewpoint of forming a flow path without bending points while securing a raw water flow path, a structure formed of only a wire extending linearly or substantially linearly from the inflow side to the outflow side of the raw water. Although the structure is the most suitable, it is difficult to manufacture industrially because it is not a structure that connects wires.

Accordingly, an object of the present invention is to provide a spiral-type membrane element in which turbidity hardly accumulates even when raw water having high turbidity such as industrial water is supplied without pretreatment, and which enables stable water passage treatment over a long period of time. A reverse osmosis membrane module and a reverse osmosis membrane device are provided.

Disclosure of the invention

Under these circumstances, the present inventors have conducted intensive studies and as a result, have found that a spiral-type membrane element in which a bag-shaped separation membrane is wound on the outer peripheral surface of a permeated water collecting pipe together with a raw water spacer, the The turbidity accumulates mainly at the intersections and bends where the wires of the raw water spacer intersect. Therefore, the wires do not intersect and no bends are formed. Then, they found that the accumulation of suspended matter in the raw water spacer was significantly suppressed, and completed the present invention.

That is, the present invention (1) is a spiral-wound membrane element formed by winding a bag-shaped separation membrane on the outer peripheral surface of a permeated water collecting pipe together with a raw water sensor, wherein the raw water sensor comprises: It is composed of a first wire and a second wire extending in a meandering shape with a gentle curve from the inflow side to the outflow side of the raw water, wherein the first wire is one of the opposing ones of the separation membranes. While extending along the membrane surface, one raw water flow path is formed between adjacent first wires, and the second wire is formed. Extends along the other opposing membrane surface of the separation membrane, forms another raw water flow path between adjacent second wires, and the first wire and the second wire are It is an object of the present invention to provide a spiral-type membrane element in which portions overlap and are joined at the overlapping portion. By adopting such a configuration, the raw water flows from the inflow side to the outflow side while gently meandering or almost linearly between the wire rods meandering in a gentle curve along the membrane surface. Therefore, the accumulation of turbidity in the raw water flow path is greatly suppressed.

Further, in the present invention (2), the meandering shape with the gentle curve is a shape having regularity without a bending point, and the ratio (H / L) of the amplitude H to the wavelength L is 0.02 to 2 and the wavelength is 1 to 100 wavelengths per meter of one wire rod. (The adoption of such a configuration makes it possible to meet the application or use conditions.) The present invention (3) is characterized by including the spiral-type membrane element. (By adopting such a configuration, the same effects as those of the invention can be obtained, and the module can be easily carried into a water treatment facility, and can be attached to a treatment line in the same form. The present invention (4) is characterized in that It is an object of the present invention to provide a reverse osmosis membrane device characterized by comprising an osmosis membrane module, wherein the reverse osmosis membrane device of the present invention is used for desalination of seawater, ultrapure water, and water for various production processes. Raw water with high turbidity such as water for use and water can be supplied without pretreatment, which simplifies the system, reduces the installation area, and reduces the cost. The industrial utility value is extremely high.

FIG. 1 is a diagram showing a raw water sensor according to the present embodiment. 2 (A) is a view taken along line A--A of FIG. 1, (B) is a view taken along line B--B of FIG. 1, and FIG. 3 is a view of FIG. FIG. 4 is an enlarged perspective view of a portion, wherein FIG. 4 (A) is a diagram showing a first wire constituting a raw ice spacer, and FIG. 4 (B) is a second diagram constituting a raw water spacer. FIG. 5 is a view showing a wire rod, FIG. 5 is a view showing a raw water sensor in another embodiment, and FIG. 6 is an example of a structure of a reverse osmosis membrane module in the embodiment. FIG. 7 is a diagram showing an example of a reverse osmosis membrane device according to an embodiment of the present invention. FIG. 8 is a diagram for explaining a conventional zigzag raw water spacer. 1 is a schematic view of a conventional reverse osmosis membrane module. BEST MODE FOR CARRYING OUT THE INVENTION

In the present invention, the raw water spacer includes a plurality of first wires and a plurality of second wires extending in a meandering shape with a gentle curve from the inflow side to the outflow side of the raw water. The cross-sectional shape of the first wire and the second wire is not particularly limited, and examples thereof include a circle, a triangle, and a rectangle. The first wire and the second wire have the same dimensions and the same cross-sectional shape.

As the shape meandering with a gentle curve, for example, there is no meandering shape having no curved point and all curved lines except the inflection point. An inflection point is an angular portion formed by a straight line and a straight line and having an angle. In addition, the corners include those in which the corners are cut or the corners are slightly rounded. Therefore, the meandering shape with a gentle curve does not include the so-called zigzag shape as shown in FIG. In addition, examples of the curved portion include a semi-circular shape that always has the same radius of curvature, a shape in which the radius of curvature changes continuously such as a partial arc of a circle and a sin curve, and the like. In the case of a semi-circular shape that always has the same radius of curvature, or a partial arc of a circle, the curve of this curve The rate radius is 10 mi! ~ 1000 thighs, preferably 20 ~ 500 thighs. If the radius of curvature is less than 100 thighs, the flow of raw water tends to stagnate, and turbidity will accumulate over a long period of use. It becomes difficult. In addition, the meandering shape with a gentle curve is, for example, a regular shape having a repetitive shape having a predetermined size of wavelength and amplitude, or the wavelength or amplitude gradually changes in the longitudinal direction of the water collection pipe or in a direction perpendicular thereto. Irregular shapes may be used, but regular shapes are preferred in that they are easy to manufacture.

A preferred form of a meandering shape with a gentle curve will be described with reference to FIGS. FIG. 1 is a diagram showing a raw water spacer according to this embodiment, FIG. 2 (A) is a diagram viewed along the line A—A in FIG. 1, and (B) is a line B—B in FIG. Fig. 3 is a perspective view showing a part of Fig. 1 in an enlarged scale, Fig. 4 (A) is a diagram showing a first wire constituting a raw water spacer, (B) ) Is a diagram showing the second wire constituting the raw water spacer. In the figure, the shape of raw water spacer-1 has regularity with no bending point, the curved part has a gentle meandering shape with continuously changing radius of curvature, and the wavelength L is 10 to 10 0 Marauder, preferably 20 to 500 marauder, amplitude H is 2 to 200 mm, preferably 10 to 100 thigh, and the ratio of amplitude H to wavelength L (H / L ) Is from 0.02 to 2, preferably from 0.05 to less than 0.5. In this case, the wavelength is 1 to L0 wavelength per lm of one wire. If the ratio of the amplitude H to the wavelength L (H / L), and the amplitude H and the wavelength L are within the above numerical ranges, the raw water flows from the inflow side to the outflow side while gently meandering in the raw water flow path or almost linearly. This will prevent turbidity from accumulating in the raw water flow path and make it possible to manufacture raw water spacers.

The raw water spacer 1 in the present embodiment includes a plurality of first wires 11 and a plurality of second wires extending in the above-described shape from the inflow side X to the outflow side Y of the raw water. As shown in FIG. 2, the first wire rod 11 extends along one of the opposite film surfaces 21 of the separation films 20 and the adjacent first rod material 11 as shown in FIG. One raw water channel 23 is formed from the inflow side X to the outflow side Y in a meandering shape with a gentle curve between the wires 1 1 and 1 1, and the raw water flows through this one raw water channel 23 It flows along the flow path formed on the membrane surface of the membrane 21. The second wire rod 12 extends along the other opposing membrane surface 22 of the separation membrane 20, and forms a meandering shape with a gentle curve between the adjacent second wire rods 12, 12. The other raw water flow path 24 is formed toward the outflow side Y, and the raw water also flows through the other raw water flow path 24 along the flow path formed on the membrane surface of the membrane 22. The flow in the raw water flow path formed by the one raw water flow path 23 and the other raw water flow path 24 does not have a bending point or a part of a corner that hinders the flow in the flow path direction. The flow will be straight or nearly straight. In FIG. 3 and FIG. 4, reference numeral 231 indicates a flow in one raw water flow path, and reference numeral 241 indicates a flow in the other raw water flow path.

In addition, as shown in FIGS. 1 and 3, the projecting portions 11a, 11a on one side of the gentle curve of the first wire 11 It overlaps with the projections 12a, 12a- 'on the other side of the curve and is joined at this overlap. In addition, the protrusion 11b, lib- 'on the other side of the gentle curve of the first wire rod 11 is the protrusion 12b, 1b on one side of the gentle curve of the second wire rod 12. 2 b-'overlapped and joined at this overlap. Therefore, as shown in FIG. 4, the distance between the adjacent first wires 11 and 11 and the distance between the adjacent second wires 12 and 12, that is, the flow path width V in FIG. In form, it is equal to twice the amplitude H. Therefore, if the amplitude width H is determined, the flow path width V is determined.

Another preferred form of meandering with a gentle curve will be described with reference to FIG. FIG. 5 is a view showing a raw water spacer in another embodiment. In Fig. 5, the points that are different from the raw water spacers in Fig. 1 are mainly explained. That is, in FIG. 5, the difference from FIG. 1 is that the distance between adjacent first wires 51 and 51 and the distance between adjacent second wires 52 and 52, that is, the flow path The point is that the width V is equal to the amplitude H. The first wire rod 51 and the second wire rod 52 are provided with lower projections 51 a and 52 a and gentle upper curves 51 b and 52 b in FIG. Then, the middle part of the protrusion 51 a, 51 b in the gentle curve of the first wire 51 and the middle part of the protrusion 52 a, 52 b in the gentle curve of the second wire 52 are formed. Intersect and overlap. The lower protrusion 51a of the first wire 51 and the upper protrusion 52b of the second wire 52 overlap each other. Furthermore, the upper protrusion 51b of the first wire and the lower protrusion 52a of the second wire 52 overlap each other. These overlapping portions are joined to each other, thereby forming an integrated raw water sensor 1a. In the spiral-type membrane element using the raw water space 1a as well, although the flow path width V is half the width of that in FIG. 1, similarly, the adjacent first wire rod 5 1 One raw water flow path is formed from the inflow side X to the outflow side Y in a shape meandering with a gentle curve between, 51 and meandering between the adjacent second wires 52, 52 with a gentle curve In the shape, the other raw water flow path is formed from the inflow side X to the outflow side Y. The flow in the raw water flow path formed by the one raw water flow path and the other raw water flow path tends to meander as compared to the raw water flow path 1 in FIG. Not to the point of accumulation.

The thickness of the raw water spacer is the sum of the diameter of the first wire and the diameter of the second wire, or slightly smaller than that, and is in the range of 0.4 to 3.0 mm. If the thickness is less than 0.4 thigh, the pressure difference in water flow will increase, and the accumulation of turbidity will easily occur. On the other hand, if the thickness exceeds 3.Omni, spiral In this case, the film area per element becomes too small, which is not practical. Although the flow width V in the raw water spacer is not particularly limited, when the configuration shown in FIG. 1 is employed, the amplitude is twice as large as the amplitude H. When the configuration shown in FIG. It has the same dimensions as H. The material of the raw water supplier is not particularly limited, but polypropylene and polyethylene are preferred in terms of moldability and cost. The method for producing the raw water spacer is not particularly limited, and a known method can be applied. However, a molded product using a mold is preferable in terms of cost and precision.

The spiral membrane element of the present invention is formed by winding a bag-shaped separation membrane on the outer peripheral surface of a permeated water collecting pipe together with the raw water spacer. The winding may be performed by winding one bag-shaped separation membrane, or by winding a plurality of bag-shaped separation membranes. The spiral type membrane element of the present invention can be used for a membrane separation device such as a microfiltration device, an ultrafiltration device and a reverse osmosis membrane separation device. Examples of the reverse osmosis membrane include a normal reverse osmosis membrane having a high removal rate of 90% or more against sodium chloride in saline, and a nanofiltration membrane or a loose reverse osmosis membrane having a low desalination rate. Although the nanofiltration membrane and the loose reverse osmosis membrane have desalination performance, they have lower desalination performance than ordinary reverse osmosis membranes, and particularly have a performance of separating hardness components such as Ca and Mg. The nanofiltration membrane and loose reverse osmosis membrane are sometimes called NF membrane. The reverse osmosis membrane module of the present invention is not particularly limited as long as it has the spiral type membrane element. For example, a reverse osmosis membrane module having a structure shown in FIG. 6 can be mentioned. As shown in FIG. 6, a bag-shaped reverse osmosis membrane 61 is wound around the outer peripheral surface of the permeated water collecting pipe 60 in a spiral shape together with a raw water spacer, and the upper part thereof is covered with an exterior body 62. . In order to prevent the reverse osmosis membrane 61 wound in a spiral form from protruding, a telescopic stop 64 having several radial ribs 63 is attached to both ends. You. The permeated water collecting pipe 60, the reverse osmosis membrane 61, the outer body 62, and the telescopic stopper 64 form one spiral membrane element 65, and each permeated water collecting pipe 60 is connected to a connector ( (Not shown), and a plurality of spiral membrane elements 65 are loaded in the housing 66. A gap 67 is formed between the outer periphery of the spiral membrane element 65 and the inner periphery of the housing 66, and the gap 67 is closed by a brine seal 68. A raw water inflow pipe (not shown) for flowing raw water into the housing is provided at one end of the housing 66, and a treated water pipe (not shown) communicating with the permeated water collecting pipe 60 at the other end. A non-permeated water pipe (not shown) is attached, and a reverse osmosis membrane module 69 is composed of the housing 66, its internal parts and piping (nozzle).

When treating raw water with the reverse osmosis membrane module 69 having such a structure, the raw water is injected by using a pump from one end of the housing 66, but as shown by the arrow in FIG. The first spiral type membrane element 65 passes between the radial ribs 63 of the first telescope 64 and enters the first spiral type membrane element 65, and some raw water is supplied to the raw water space between the membranes of the spiral type membrane element 65. After passing through the raw water flow path defined by the sagittal, it reaches the next spiral membrane element 65, and the other raw water permeates through the reverse osmosis membrane 61 and becomes permeated water, and the permeated water is a permeated water collecting pipe 60 The water is collected. In this way, the raw water passes through the spiral membrane element 65 one after another, and the raw water that has not passed through the reverse osmosis membrane is concentrated from the other end of the housing 66 as a concentrated water containing a high concentration of turbidity and ionic impurities. The permeated water that has been taken out and has passed through the reverse osmosis membrane is taken out of the housing 66 through the permeated water collecting pipe 60 as permeated water. In addition, the reverse osmosis membrane module of the present invention may be one in which a plurality of spiral type membrane elements are mounted as shown in FIG. 6, or one in which a spiral type membrane element is mounted, for example. The reverse osmosis membrane device of the present invention is not particularly limited. For example, at least one or more of the reverse osmosis membrane modules, raw water supply means such as a pump, raw water inflow piping, concentrated water outflow piping, and permeated water outflow piping are provided. It is. Raw water directly supplied to the reverse osmosis membrane device of the present invention includes industrial water, tap water and recovered water. The turbidity of the raw water is not particularly limited, but even if the turbidity is as high as about 2 degrees, no increase in the differential pressure of water due to the blockage of the turbidity occurs. In addition, when raw water contains coarse particles such as sand particles in the raw water, it includes treated water that has been passed through a coarse filter in advance and water to which a dispersant for preventing scale fouling has been added. The addition of the dispersant can further suppress the accumulation of suspended matter on the membrane surface of the raw water substrate. Examples of the dispersant include commercially available products “hypersperse MSI300J” and “hypersperse MDC200” (both manufactured by ARGO SCIENTIFIC). According to the reverse osmosis membrane device of the present invention, it is possible to omit the installation of a pretreatment device, such as a coagulation sedimentation process, a filtration process, and a membrane process, which has been conventionally used for removing suspended matter in raw water. . For this reason, an epoch-making effect is achieved in that the system can be simplified, the installation area can be reduced, and the cost can be reduced. An example of the reverse osmosis membrane device according to the embodiment of the present invention will be described with reference to FIG. In FIG. 7, the reverse osmosis membrane device 70 has a raw water supply device 71, a first reverse osmosis membrane module 70A and a second reverse osmosis membrane module 70B arranged in this order. 7 1 and the upstream reverse osmosis module 7 OA are connected by raw water supply piping 7 2, and the upstream reverse osmosis membrane module 7 OA and the downstream reverse osmosis module 70 B Primary permeated water outflow pipe 73, which is supplied as water to be treated in the downstream equipment, is connected to the reverse reverse osmosis membrane module 70B. Equipped with return pipe 75 returning to 72. Also, concentrated water outflow piping 7 6 It has. The first-stage reverse osmosis membrane module 70A is a reverse osmosis membrane device according to the present invention which does not cause accumulation of turbidity, and the second-stage reverse osmosis membrane module 70B is a conventional reverse osmosis membrane device.

Next, a method of treating raw water using the reverse osmosis membrane device 70 of the present embodiment will be described. First, raw water is supplied to the pre-stage reverse osmosis membrane module 7OA by raw water supply means 71. The raw water is treated by the reverse osmosis membrane module 7 OA in the former stage, and the primary concentrated water is obtained from the concentrated water outlet pipe 76 and the primary permeated water is obtained from the primary permeated water outlet pipe 73. Next, the primary permeate is treated in the reverse reverse osmosis membrane module 70 B to obtain secondary permeate from the permeate discharge pipe 74, and the secondary concentrated water is returned from the return pipe 75 ′ to the raw water supply pipe 7. Returned to 2. This secondary concentrated water is obtained by concentrating the permeated water already desalinated by the first-stage reverse osmosis membrane module 70OA in the second-stage reverse osmosis membrane module 70B, and has lower conductivity than the raw water. For this reason, it is possible to circulate the entire amount of the secondary concentrated water, and the water recovery rate can be improved. Further, the reverse osmosis membrane device 70 is a reverse osmosis membrane module capable of greatly suppressing the accumulation of turbidity in the present invention, instead of the pretreatment device used only for turbidity removal used in the conventional type device. Since the first stage is used, the reverse osmosis membrane is essentially used in two stages. Since the pretreatment apparatus in the conventional apparatus does not have a desalination function, the reverse osmosis membrane apparatus 70 has much better permeation water quality than the conventional reverse osmosis membrane apparatus.

(Example)

Example 1

Industrial water having a turbidity of 2 degrees and an electrical conductivity of 200 mS / m was passed through a reverse osmosis membrane module A having the following specifications, and a 200-hour endurance operation was performed under the following operating conditions. The performance evaluation of reverse osmosis membrane module A was conducted at the initial stage of operation and at the time of 2000 hours. Was measured. After 2000 hours, the reverse osmosis membrane module was disassembled, and the state of adhesion of suspended matter in the raw water flow path was observed. Table 1 shows the measurement results, and Table 2 shows the results of visual observations of the raw water flow channels. In Table 1, the water pressure difference and the permeate conductivity are values converted at 25 ° C.

(Reverse osmosis membrane module A)

With the structure shown in Fig. 1 and Fig. 2, amplitude H / wavelength L is 0.66, wavelength L is 15 awake, amplitude H is 10 hall, raw water channel width V is 20 bandages, thickness A raw water sensor A having a length of 1.0 mm was produced. Next, a spiral type membrane element A was produced using the raw water sensor A, and a reverse osmosis membrane module A having a structure as shown in FIG. 6 was produced. However, the reverse osmosis membrane module A was one module containing one spiral membrane element.

(Operating conditions)

The operation pressure is 0. Ί 5 MPa, concentrated water flow rate is 2. 7 m ³ / time, water temperature is at 2 5 ° C, 1 once every 8 hours, is attached in 6 0 seconds flushing (the concentrated water outlet pipe Fully open the valve to supply the raw water at a flow rate three times the flow rate of the raw water in the permeation treatment, and quickly supply it into the reverse osmosis membrane module to discharge the flushing wastewater from the concentrated water outflow pipe.

Example 2

The durability operation was performed for 2000 hours under the same operating conditions as in Example 1 except that the reverse osmosis membrane module A was replaced with a reverse osmosis membrane module B having the following specifications. Tables 1 and 2 show the performance evaluation results of reverse osmosis membrane module B.

(Reverse osmosis membrane module B)

Instead of the raw water spacer A, it has the structure shown in Fig. 5, where the amplitude H / wavelength L is 0.66, the wavelength L is 15 麵, the amplitude H is 10 mm, and the raw water channel width V Is 1 The reverse osmosis membrane module A was produced in the same manner as described above except that the raw water sensor B having a thickness of 1.0 was used.

Example 3

Industrial water with a turbidity of 2 degrees and a conductivity of 2 O mS / m is passed through the reverse osmosis membrane device with the following specifications and the flow shown in Fig. 7, and has a durability of 200 hours under the following operating conditions. I drove. Tables 1 and 2 show the performance evaluation results of the reverse osmosis membrane device. The results in Table 1 are for the reverse-stage reverse osmosis membrane device. (Reverse osmosis membrane device)

The reverse osmosis membrane module B used in Example 2 was used as the first-stage reverse osmosis membrane module, and the 8-inch element ES-10 (manufactured by Nitto Denko Corporation) was installed as the second-stage reverse osmosis membrane module. Were used. The raw water sensor used for this ES-10 is a grid mesh.

(Operating conditions)

Both the first and second reverse osmosis membrane modules have an operating pressure of 0.75 MPa, a concentrated water flow rate of 2.7 m ³ / hour, a water temperature of 25 ° C, and only the first reverse osmosis membrane module for 8 hours Flush for 60 seconds (same operation as in Example 1) once every time.

Example 4

The durability operation was performed for 2000 hours under the same operating conditions as in Example 1 except that the reverse osmosis membrane module A was replaced with a reverse osmosis membrane module C having the following specifications. Tables 1 and 2 show the performance evaluation results of reverse osmosis membrane module C.

(Reverse osmosis membrane module C)

In place of the raw water spacer A, it has the structure shown in Fig. 1, where the amplitude HZ wavelength L is 0.2, the wavelength L is 100, the amplitude H is 20 thighs, and the raw water channel width V is Four A reverse osmosis membrane module A was prepared in the same manner as above except that a raw water spacer C having a thickness of 0 mm and a thickness of 1.0 mm was used.

Comparative Example 1

The same as in Example 1 except that a known pretreatment device consisting of a membrane treatment was arranged at the front stage, and an 8-inch element ES-10 (manufactured by Nitto Denko Corporation) was used instead of the spiral type membrane element A. Made by the way. That is, industrial water having a turbidity of 2 degrees and a conductivity of 2 OmS / m was treated with a pretreatment device, and the treated water was further treated with a conventional commercially available reverse osmosis membrane module. The results are shown in Tables 1 and 2.

Comparative Example 2

The procedure was performed in the same manner as in Example 1 except that an 8-inch element ES-10 (manufactured by Nitto Denko Corporation) was used instead of the spiral membrane element A. That is, industrial water having a turbidity of 2 degrees and a conductivity of 2 OmS / m was directly treated with a conventional commercial reverse osmosis membrane module without treating with a pretreatment device. The results are shown in Tables 1 and 2. In Comparative Example 2, the water flow differential pressure increased extremely around 800 hours, and permeated water could not be obtained. Therefore, the operation was stopped at this time.

Comparative Example 3

The durability operation was performed for 2000 hours under the same operating conditions as in Example 1 except that the reverse osmosis membrane module A was replaced with a reverse osmosis membrane module D having the following specifications. Table 1 shows the results. The reverse osmosis membrane module D was one module containing one spiral type membrane element.

(Reverse osmosis membrane module D)

Instead of the raw water sensor A, the structure shown in FIG. 1 of JP-A-10-156152, that is, the structure shown in FIG. 8 described above, having a thickness of 1.0 mm , The angle of the bend point is 60 degrees, the distance between the bend points is 5 thighs of raw water spacer Except for using E, it was produced in the same manner as the reverse osmosis membrane module A.

Table 1 Water differential pressure 〖MPa] Permeate water volume [1 / min] Permeate water conductivity [mS / m] Initial operation 2000hr Initial operation 2000hr Initial operation 2000hr Example 1 0.015 0.021 18 15 0.40 0.55 Example 2 0.015 0.022 18 15 0.40 0.55 Example 3 0.020 0.020 20 20 0.03 0.03 Example 4 0.013 0.018 18 15 0.40 0.55 Comparative example 1 0.020 0.022 20 20 0.30 0.30 Comparative example 2 0.020 20 0.30

Comparative Example 3 0.020 0.075 19 8 0.35 1.90 Table 2

Visual observation result of raw water flow channel after 2000 hours Example 1. Slightly turbid adhesion

Example 2 Slightly turbid adhesion

Example 3 (previous stage R0) Almost no turbidity adhered

Example 3 (Second stage R0) No suspended matter attached

Example 4 Slightly turbid adhesion (less than Examples 1 and 2) Comparative Example 1 Almost no turbid adhesion

Comparative Example 2 Turbidity adhered as raw water flow path was completely blocked

Comparative Example 3 Suspended turbidity mainly at the inflection point In Examples 1 to 4, after 2000 hours, there was almost no increase in the differential water pressure, no decrease in the amount of permeated water, and high water quality of the permeated water Met. Comparative Example 1 shows a result comparable to that of the Example in the performance evaluation after 2000 hours. However, this requires the installation of a pre-treatment device, which requires extra space and cost. Therefore, Comparative Examples 2 and 3 are Comparative Examples 2 and 3, but Comparative Example 2 is one in which the adhesion of turbid matter is severe until the amount of permeated water becomes zero in about 800 hours. In 3), a significant increase in the pressure difference in water flow and a decrease in the amount of permeated water were observed at the time of 2000 hours, and it was presumed that the water could not be used in about 30000 to 40000 hours. Industrial applicability

According to the spiral membrane element of the present invention, the raw water gently or quasi-linearly meanders from the inflow side to the outflow side between the wires having a meandering shape with a gentle curve along the membrane surface. Flowing towards. For this reason, accumulation of turbid matter in the raw water flow channel is greatly suppressed. ADVANTAGE OF THE INVENTION According to the reverse osmosis membrane module and reverse osmosis membrane apparatus of this invention, installation of the pretreatment apparatus conventionally used for the purpose of clarification in raw water can be omitted. For this reason, it has a remarkable effect in that the system can be simplified, the installation area is reduced, and the cost is reduced. Furthermore, even if raw water with high turbidity such as industrial water is supplied without pretreatment, turbidity is hard to accumulate, and stable water treatment can be performed for a long period of time.

Claims

The scope of the claims

1. A spiral-type membrane element in which a bag-like separation membrane is wound around the outer surface of a permeated water collecting pipe together with a raw water spacer, and the raw water spacer is arranged from the raw water inflow side. It comprises a first wire and a second wire that extend in a meandering shape with a gentle curve toward the outflow side, and the first wire is attached to one of the opposed membrane surfaces of the separation membrane. And the first wire rod forms one raw water flow path between the adjacent first wire rods, and the second wire rod extends along the other opposing membrane surface of the separation membrane. A raw water flow path is formed between the second wires to be formed, and the first wire and the second wire are partially overlapped with each other and joined at the overlapping portion. ho

2. The meandering shape with the gentle curve has a regularity without a bending point, the ratio (H / L) of the amplitude H to the wavelength L is 0.02 to 2, and one The spiral type membrane element according to claim 1, wherein the wavelength is 1 to 100 wavelengths per lm of the wire.

3. A reverse osmosis membrane module comprising the spiral membrane element according to claim 1 or 2.

4. A reverse osmosis membrane device comprising the reverse osmosis membrane module according to claim 3.