JP4829916B2 - Membrane separation device and filtration membrane cleaning method for membrane separation device - Google Patents

Description

  The present invention relates to a membrane separation device for filtering a liquid to be treated containing suspended substances and a filtration membrane cleaning method for the membrane separation device.

  Conventionally, a membrane separation device is known as one of filtration devices for filtering a liquid to be treated containing suspended substances such as sewage and industrial wastewater.

  Such a membrane separation device includes a plurality of membrane elements in which filtration membranes for filtering a liquid to be treated containing suspended substances are stretched on both surfaces, and the plurality of membrane elements are arranged at predetermined intervals so that the filtration membranes face each other. Are arranged side by side.

The membrane separation apparatus having the above configuration distributes the liquid to be treated by flowing the liquid to be treated from the outside to the inside of the membrane element, and supplies the fluid to the membrane element from the inside of the membrane element. By flowing fluid through the filtration membrane toward the outside, the suspended membrane adhering to the filtration membrane is removed to clean the filtration membrane (see, for example, Patent Document 1).
JP 2003-210947 A

  By the way, the membrane separation apparatus having the above configuration is configured to supply a fluid to the membrane element and circulate the fluid through the filtration membrane from the inside of the membrane element to the outside when removing suspended substances attached to the filtration membrane. Therefore, in each membrane element, the filtration membrane bulges to the outside of the membrane element due to the fluid circulation pressure.

  Therefore, if the interval between the plurality of membrane elements is too narrow, when the filtration membrane of each membrane element bulges to the outside, suspended substances adhering to the outer surface of the filtration membrane are separated from the filtration membrane (swelling membrane) of the adjacent membrane element. In some cases, suspended substances cannot be removed reliably and efficiently. On the other hand, if the interval between the plurality of membrane elements is set wide in consideration of the bulging amount of the filtration membrane in order to ensure the reliable removal of the suspended solids, the size of the apparatus is inevitably increased.

  Therefore, the present invention provides a membrane separation device capable of reliably and efficiently removing suspended substances attached to the filtration membrane of each membrane element, even if the interval between the plurality of membrane elements is reduced to reduce the size. It is an object of the present invention to provide a filtration membrane cleaning method for a membrane separator.

  The membrane separation apparatus according to the present invention includes a plurality of membrane elements each provided with a filtration membrane for filtering a liquid to be treated containing suspended substances, and the plurality of membrane elements are arranged at predetermined intervals so that the filtration membranes face each other. The liquid to be processed is circulated through the filtration membrane from the outside toward the inside of the membrane element to filter the liquid to be processed, while the fluid is supplied to the membrane element and the outside from the inside of the membrane element. In the membrane separation device configured to remove the suspended substances attached to the filtration membrane by causing the fluid to flow toward the filtration membrane, the timing of supplying the fluid to the membrane element is different between adjacent membrane elements. It is comprised by these.

  Further, the filtration membrane cleaning method of the membrane separation apparatus according to the present invention includes a plurality of membrane elements each provided with a filtration membrane for filtering the liquid to be treated containing suspended substances, and the plurality of membrane elements are arranged between the filtration membranes. The liquid to be treated is filtered by passing the liquid to be treated through the filtration membrane from the outside toward the inside of the membrane element, while supplying the fluid to the membrane element. In the filtration membrane cleaning method of a membrane separation device configured to remove suspended substances attached to the filtration membrane by flowing fluid through the membrane from the inside to the outside, the fluid for the membrane element Is characterized in that the timing of the supply differs between adjacent membrane elements.

  According to both the above inventions, since the timing of supplying the fluid to the membrane element is different between adjacent membrane elements, even if the fluid is supplied to the membrane element, the suspended substance may be sandwiched between the filtration membranes of the adjacent membrane elements. In addition, the suspended substances can be removed from the filtration membrane reliably and efficiently.

  That is, in both the above-mentioned inventions, when the filtration membrane of one membrane element of an adjacent membrane element swells as a result of the timing of supplying fluid to the adjacent membrane element, the filtration membrane of the other membrane element swells. While the filter membrane of one membrane element is maintained in a straight state without being bulged, the filter membrane of the other membrane element is in a bulged state.

  As described above, the membrane separation apparatus having the above-described configuration reduces the interval between the plurality of membrane elements because the opposing filtration membrane does not bulge out simultaneously when removing suspended substances attached to the filtration membrane. The device can be reduced in size, and even if the interval is narrowed in this way, the suspended matter is not sandwiched between the opposite filtration membranes when the filtration membrane is cleaned. Can be efficiently removed.

  As a specific aspect, the fluid may be alternately supplied to an odd-numbered membrane element group and an even-numbered membrane element group in a parallel order of a plurality of membrane elements. In this way, suspended substances can be favorably removed while simplifying the piping system for the membrane element.

  As described above, according to the membrane separation device and the filtration membrane cleaning method of the membrane separation device according to the present invention, even if the interval between the plurality of membrane elements is reduced and the size is reduced, the membrane elements adhere to the filtration membrane of each membrane element. It is possible to achieve an excellent effect that the suspended solids can be removed reliably and efficiently.

  Hereinafter, a membrane separation apparatus and a filtration membrane cleaning method of the membrane separation apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings.

  As shown in FIGS. 1 and 2, the membrane separation apparatus according to the present embodiment filters a filtration tank 10 that stores a liquid W to be processed containing suspended substances and a liquid W to be processed that is stored in the filtration tank 10. And a plurality of membrane elements 20.

  As shown in FIG. 2, the filtration tank 10 is configured to be able to store the liquid to be processed W, and is supplied with the liquid to be processed W including a suspended substance before filtration. The filtration tank 10 according to the present embodiment is open at the top, so that a plurality of membrane elements 20 (membrane module M to be described later) immersed in the liquid to be treated W can be pulled straight up. . A submerged pump 100 is disposed in the filtration tank 10. The submerged pump 100 is connected to a pipe P ′ for discharging the liquid W to be treated to the bottom of the filtration tank 10. Thereby, the liquid W to be processed pumped up by the submerged pump 100 is discharged to the bottom of the filtration tank 10, and the liquid W in the filtration tank 10 is stirred by the liquid flow caused by the discharge.

  The submerged pump 100 is operated continuously or intermittently during the filtration of the liquid W to be treated in the filtration tank 10 by the membrane elements 20. Thereby, the membrane separation apparatus 1 according to the present embodiment prevents the suspended substance from being precipitated in the filtration tank 10 during the filtration of the membrane elements 20..., And the concentration of the suspended substance in each membrane element 20. The liquid W to be processed is filtered.

  In the present embodiment, the pipe P directly connected to the submerged pump 100 is provided with a three-way valve V. The three-way valve V is led to the bottom of the filtration tank 10 described above and is treated. The pipe P ′ for discharging W to the bottom of the filtration tank 10 and the pipe P ″ for discharging the liquid W to be processed to the outside are connected. Thereby, by switching the flow path of the three-way valve V, a state in which the liquid to be processed W in the filtration tank 10 is agitated by one submerged pump 100 and a state in which the liquid to be processed W is forcibly discharged. It can be switched to. In addition, the filtration tank 10 which concerns on this embodiment also has the rotary blade type stirring apparatus 101, and stirs the stored to-be-processed liquid W by both the said liquid flow and the stirring apparatus 101. Yes.

  And the liquid tank 10 is provided in the filtration tank 10 which concerns on this embodiment, and the to-be-processed liquid W is supplied based on the detection result of the liquid level sensor LG. That is, in order to compensate for the drop in the liquid level accompanying the filtration of the liquid W to be processed, the liquid W is supplied based on the detection of the liquid level sensor LG so as to keep the inside of the filtration tank 10 at a constant liquid level. It has become.

  1, the plurality of membrane elements 20 are supported by the element rack 250 and modularized (hereinafter, the plurality of membrane elements 20 that are modularized are referred to as membrane modules M).

  As shown in FIG. 3, each membrane element 20 is provided with filtration membranes 201, 201 for filtering the liquid W to be treated on both sides. More specifically, each of the membrane elements 20... Includes an element main body 200 serving as a base, and filtration membranes 201 and 201 stacked on the outer surface of the element main body 200. The element main body 200 is provided with a cylindrical connecting portion 202 for connecting piping (an odd numbered piping system and an even numbered piping system, which will be described later) through which the processing liquid filtered through the filtration membranes 201, 201 is circulated. A flow passage 203 is formed to connect the both sides of the element body 200 on which the filtration membranes 201 and 201 are laminated to the connection portion 202.

  The element main body 200 according to the present embodiment is formed in a plate shape. In the present embodiment, the element main body 200 is formed in a quadrangular shape (rectangular shape), and the connecting portion 202 is provided on one end surface in the longitudinal direction. Accordingly, the flow passage 203 is formed in a T shape so as to penetrate one end face of the element body 200 and both faces where the filtration membranes 201 and 201 are laminated. That is, the flow passage 203 includes a first hole 203a extending inward from one end surface of the element body 200, and a second hole 203b penetrating both surfaces of the element body 200 so as to intersect the first hole 203a. It consists of and.

  The filtration membranes 201, 201 are formed in a shape corresponding to the element body 200, and in this embodiment, are formed in a quadrangular shape (rectangular shape). For the filtration membranes 201 and 201, a polymer membrane or the like that does not include a support can be employed. However, in this embodiment, a nonwoven fabric composed of a synthetic resin is used as a support and is coated with a resin. Those having micropores (for example, micropores having an average pore diameter of 0.4 μm) are employed. As such filtration membranes 201 and 201, for example, Yumicron membranes manufactured by GS Yuasa Corporation can be used. The filtration membranes 201 and 201 having such an average pore diameter are called microfiltration membranes from the definition of JIS K 3802.

  The filtration membranes 201 and 201 have their outer peripheral ends attached to the element body 200, and the opening of the second hole 203b is located in the region surrounded by the attached portion. The attachment of the filtration membranes 201 and 201 to the element main body 200 may be thermal welding using a hot plate or welding using ultrasonic waves, but the strength of the filtration membranes 201 and 201 at the attachment portion is reduced. Considering this, it is preferable to stick the filter membranes 201 and 201 to the element body 200 without melting them. That is, when the non-woven fabric that is the support for the filtration membranes 201 and 201 is melted when the filtration membranes 201 and 201 are heat-welded to the element main body 200, the portion becomes thin and the strength is reduced. In adhering the filtration membranes 201, 201, it is preferable not to melt the nonwoven fabric that is the support for the filtration membranes 201, 201.

  And it is preferable that the filtration membranes 201 and 201 are pasted so as to be replaceable, and for example, they may be pasted on the element body 200 by the method described in JP-A-2006-231139. That is, it is preferable that the outer peripheral end of the element body 200 made of thermoplastic resin is formed on a smooth surface, and the filtration membranes 201 and 201 are joined to the smooth surface, and the filtration membrane 201, More preferably, the filtration membranes 201 and 201 are joined to the element body 200 by pressurizing 201 with a temperature-controlled hot plate. Thus, when heat-welding the filtration membranes 201 and 201 and the element main body 200, the hot plate is below the melting point of the filtration membranes 201 and 201 (nonwoven fabric as a support) and above the Vicat softening temperature of the element main body 200. Control is sufficient. Furthermore, it is preferable to control the temperature of the hot plate below the deflection temperature under load of the nonwoven fabric.

  In the membrane element 20 according to this embodiment, a mesh 204 is interposed between the element body 200 and the filtration membranes 201 and 201, and a gap is formed between the element body 200 and the filtration membranes 201 and 201. Thus, a fluid (a processing liquid obtained by filtering the liquid W to be processed) can be smoothly distributed. As the mesh 204 is interposed as described above, the element body 200 according to the present embodiment has a region (region where the mesh 204 is interposed) surrounded by the outer peripheral end portion to which the filtration membranes 201 and 201 are attached. It is formed to be recessed from the outer peripheral end. Thereby, even if the mesh 204 is interposed, the area | region which opposes the mesh 204 of the filtration membranes 201 and 201 does not bulge, but becomes flat.

  Returning to FIG. 1, the element rack 250 is configured to hold each membrane element 20 in a predetermined position. The element rack 250 according to the present embodiment includes an upper frame 251 framed in a square shape in plan view, a lower frame 252 formed in a square shape in plan view, a corner portion of the upper frame 251, and a corner portion of the lower frame 252. Are connected to each other, and holding means (not shown) for holding the membrane elements 20 in a predetermined posture on the lower frame 252 is provided.

  The membrane separation apparatus 1 according to the present embodiment is provided with a bracket 254 for hooking a hook of a lifting means described later on the upper frame 251 of the element rack 250. Since the element rack 250 according to the present embodiment is framed so that the upper frame 251 has a rectangular shape in plan view, the bracket 254 is provided on a pair of transverse beams 251a and 251a that constitute the upper frame 251 and face each other. It has been. In addition, since the element rack 250 (upper frame 251) according to the present embodiment is formed in a rectangular shape in plan view, brackets 254 are provided on the pair of transverse beams 251a and 251a at both ends in the longitudinal direction.

  The element rack 250 (holding means) can install a plurality of membrane elements 20 arranged in parallel as unit units U1, U2, U3. That is, the element rack 250 is configured so that one unit unit U1 or two or more unit units U1, U2, U3 can be installed according to the filtration capacity of the membrane separation apparatus 1, and in this embodiment, The unit units U1, U2, U3 can be installed in three upper and lower stages, and these three unit units U1, U2, U3 are modularized to form the membrane module M as described above.

  The plurality of membrane elements 20 constituting the unit units U1, U2, U3 are arranged such that the adjacent membrane elements 20 are opposed to each other with a predetermined interval as shown in FIG. The membrane elements 20 of each unit unit U1, U2, U3 in the vertical direction are arranged in a line in the vertical direction. That is, the plurality of unit units U1, U2, U3 arranged in the vertical direction are arranged so that the filtration membranes 201, 201 of the membrane elements 20 adjacent in the vertical direction are substantially flush with each other.

  The interval between the plurality of membrane elements 20 constituting each unit U1, U2, U3 is set in consideration of the bulging amount of the filtration membranes 201, 201 when a fluid is supplied to the membrane elements 20. That is, the distance between adjacent membrane elements 20 with the filtration membranes 201 and 201 facing each other is such that the amount of bulging outward of both of the pair of opposed filtration membranes 201 and 201 between adjacent membrane elements 20. A pair of filtration membranes 201, 201 that are narrower than the distance obtained by adding a predetermined amount of suspended matter (cake layer K) deposited on each of the pair of filtration membranes 201, 201 and that face each other adjacent membrane elements 20. Is set wider than the distance obtained by adding the estimated amount of suspended matter (cake layer) deposited on each of the pair of filtration membranes 201 and the allowance.

Here, when the interval between the membrane elements 20 is expressed by a mathematical expression, it is expressed as follows. In the following mathematical formula (1), X is the distance between the membrane elements 20, A is the amount of swelling of one filtration membrane 201, 201, and B is to be deposited on one filtration membrane 201, 201. The amount of deposition, C, is a margin.
A + B × 2 + C <X <A × 2 + B × 2 (1)

  Note that the bulging amount of the filtration membranes 201 and 201 will be described later with respect to the conditions (for example, outer shape and thickness, effective filtration area, fluid passage resistance, etc.) regarding the filtration membranes 201 and 201 laminated on the element body 200. Calculated based on the pressure of the fluid circulated at the time of cleaning of the filtration membrane 201, the expected accumulation amount of the suspended substance is the filtration capacity (filtration amount) per unit time of the apparatus, and the liquid W to be treated. Based on the content of the suspended solids and the time for performing the filtration process (for example, when the filtration process and cleaning of the filtration membrane 201 are performed continuously, the time from the start of the filtration process to the cleaning). Calculated. Further, the allowance may be a numerical value that satisfies the above formula (1), that is, C <A, and is set as small as possible by setting C <(A ÷ 3) to (A ÷ 2), for example. Is preferred.

  The membrane separation device 1 is configured such that the timing of supplying fluid for removing suspended substances attached to the filtration membranes 201 and 201 differs between adjacent membrane elements 20. In the present embodiment, in each unit unit U1, U2, U3, the odd number No. in the parallel order of the plurality of membrane elements 20. 1, No. 1 3, No. 5... Membrane element group (hereinafter referred to as odd-number membrane element group) On and even number No. 5. 2, no. 4, no. 6... Are configured to supply fluid alternately to the membrane element groups 6 (hereinafter referred to as even-numbered membrane element groups) En.

  Here, in addition to a piping system for achieving this fluid supply (hereinafter referred to as a fluid supply piping system), a piping system (hereinafter referred to as a drainage system) for filtering and discharging the liquid W to be treated in the filtration tank 10. The liquid piping system) will be described.

  As shown in FIG. 2, a drainage piping system 40 for discharging the liquid W to be treated in the filtration tank 10 is fluidly connected to the membrane elements 20 of each unit unit U1, U2, U3. Yes. Each of the membrane elements 20 is fluidly connected to a fluid supply piping system 30 that supplies a fluid for removing suspended substances attached to the filtration membranes 201 and 201.

  In the present embodiment, the fluid supply piping system 30 and the drainage piping system 40 are configured by a piping system configured integrally with a part of the piping. That is, the membrane separation apparatus 1 according to the present embodiment includes a connection piping system 50 connected to each of the membrane elements 20 and the connection piping system 50 connected to each other. It is configured with a combined piping system 60 configured to suck the processing liquid W and store the filtered processing liquid W ′ and to supply the filtered processing liquid W ′ to each membrane element 20. Has been.

  The connection piping system 50 is provided for each unit unit U1, U2, U3. In the present embodiment, the plurality of membrane elements 20 in each of the unit units U1, U2, U3 are divided into the odd-numbered membrane element group On and the even-numbered membrane element group En as described above. The system 50 constitutes an even-numbered membrane element group En and odd-numbered piping systems 50a, 50b, 50c connected to the membrane elements 20 (No. 1, No. 3, No. 5) constituting the odd-numbered membrane element group On. And even-numbered piping systems 55a, 55b, 55c connected to the membrane elements 20 (No. 2, No. 4, No. 6).

  The odd number piping system 50a, 50b, 50c and the even number piping system 55a, 55b, 55c differ only in whether the connected membrane element 20 ... belongs to the odd number membrane element group On or the even number membrane element group En. Both have the same configuration.

  That is, as shown in FIG. 4, the odd-numbered piping systems 50a, 50b, and 50c are composed of a single pipe (hereinafter referred to as odd-numbered group piping) 51 connected to the merged piping system 60 (main piping 302 described later), The plurality of branch pipes 52 are branched from the odd group pipe 51 and connected to the connection portions 202 of the membrane elements 20 (No. 1, No. 3, No. 5...). In this embodiment, since the membrane module M is pulled up from the filtration tank 10, the odd-numbered group piping 51 is constituted by a flexible hose so as to allow this vertical movement. In addition, a first valve V1 constituted by a two-way valve (open / close valve) for opening and closing the flow path is provided at an intermediate position of the odd group pipe 51 (odd pipe systems 50a, 50b, 50c) ( (See FIG. 2).

  The even-numbered piping systems 55a, 55b, and 55c are branched from one piping (hereinafter referred to as even-numbered group piping) 56 connected to the merged piping system 60 (main piping 302) and the even-numbered group piping 56. Each of the membrane elements 20 (No. 2, No. 4, No. 6...) Is connected to a connecting portion 202 of a plurality of branch pipes 57. In this embodiment, since the membrane module M is pulled up from the filtration tank 10, the even-numbered group pipe 56 is constituted by a flexible hose so as to allow this vertical movement. Further, a second valve V2 constituted by a two-way valve (open / close valve) for opening and closing the flow path is provided at an intermediate position of the even group pipe 56 (even pipe systems 55a, 55b, 55c) ( (See FIG. 2).

  Returning to FIG. 2, in the membrane separation apparatus 1 according to the present embodiment, as described above, since the connection piping system 50 is provided for each of the unit units U1, U2, U3, the odd-numbered piping systems 50a, 50b, 50c and Unit units U1, U2, and U3 are assigned to even-numbered piping systems 55a, 55b, and 55c, respectively. In the present embodiment, regarding the unit unit U1, an odd number piping system 50a and an even number piping system 55a are provided. That is, by opening and closing the first valve V1 and the second valve V2 of the odd-numbered piping systems 50a, 50b, and 50c and the even-numbered piping systems 55a, 55b, and 55c, the flow of the liquid to be processed W or the fluid (processing liquid W ′) The shutoff can be controlled independently.

  The fluid supply piping system 30 of the merged piping system 60 (the portion constituting the fluid supply piping system 30 together with the connection piping system 50) stores the processing liquid W ′ as a fluid obtained by filtering the liquid W to be processed. The liquid tank T, the pressure pump 300, the liquid tank T and the pressure pump 300 are connected, the supply pipe 301 for supplying the processing liquid W ′ to the pressure pump 300, and the processing liquid W discharged from the pressure pump 300. The main pipe 302 is formed so as to be able to return to the liquid tank T.

  A swirl pump, a swirl pump, a magnet pump, a vane pump, or the like can be adopted as the pressure feed pump 300. In this embodiment, a swirl pump is employed. In the pumping pump 300, the discharge pressure of the processing liquid W 'is set to a pressure at which the processing liquid W' can be supplied to at least one unit unit U1 among the three unit units U1, U2, U3. That is, in the pressure pump 300, the treatment liquid W ′ supplied to any one of the unit units U1, U2, U3 (a plurality of membrane elements 20...) Passes through the filtration membranes 201 and 201 from the inside of each membrane element 20. Thus, the discharge pressure is set to be able to circulate outside. In the present embodiment, the processing liquid W ′ is alternately supplied to the odd-numbered piping systems 50a, 50b, and 50c and the even-numbered piping systems 55a, 55b, and 55c. The discharge pressure is set so that the processing liquid W ′ can be supplied to any one of the odd-numbered piping systems 50a, 50b, and 50c and the even-numbered piping systems 55a, 55b, and 55c of one unit unit U1.

  The main pipe 302 is for the odd group pipes 51 of the odd pipe systems 50a, 50b, and 50c of the connection pipe system 50 and the even group of the even pipe systems 55a, 55b, and 55c provided for the unit units U1, U2, and U3. A pipe 56 is fluidly connected. The main pipe 302 according to the present embodiment is located downstream of the connection point of the odd group pipe 51 of the odd pipe systems 50a, 50b, and 50c and the even group pipe 56 of the even pipe systems 55a, 55b, and 55c. The first flow path Ra that returns to the liquid tank T and the second flow path Rb led to the filtration tank 10 are branched to open and close the flow paths in the first flow path Ra and the second flow path Rb, respectively. Are provided with a third valve V3 and a fourth valve V4. Thereby, by switching the opening and closing of the third valve V3 and the fourth valve V4, the fluid (process liquid W ′) sent out by the pressure feed pump 300 is returned to the liquid tank T, and the state is supplied to the filtration tank 10. Switchable.

  The drainage piping system 40 of the merged piping system 60 (the part constituting the draining piping system 40 together with the connection piping system 50) is negatively pressurized by the vacuum pump 400 and the vacuum pump 400. A vacuum tank 401, a suction pipe 402 fluidly connecting the even-numbered group pipe 56 and the odd-numbered group pipe 51 and the vacuum tank 401, and a vacuum so as to guide the filtered processing liquid W ′ to the vacuum tank 401. A return pipe 403 for returning the processing liquid W ′ in the tank 401 to the liquid tank T is provided.

  The drainage piping system 40 according to the present embodiment is formed by configuring a part of the fluid supply piping system 30 (the supply piping 301 and the main piping 302) as one configuration. For the vacuum pump 400 according to the present embodiment, a water seal type is adopted. The vacuum pump 400 is connected to a branch pipe 410 branched from the supply pipe 301 so that the processing liquid W ′ is supplied as water sealing water. A fifth valve V5 composed of a two-way valve (open / close valve) that opens and closes the flow path is provided in the middle of the branch pipe 410. By opening / closing the fifth valve V5, water is supplied to the vacuum pump 400. It is possible to switch between a state of supplying water for sealing and a state of stopping the supply. A pipe 411 for returning the processing liquid W ′ to the liquid tank T is connected to the discharge port of the vacuum pump 400. In the vacuum pump 400, the pipe 412 connected to the upper part of the vacuum chamber 401 is connected to the suction port, and the air in the vacuum chamber 401 is extracted from the upper part during driving to make the inside negative pressure. ing.

  The vacuum tank 401 draws in the processing liquid W ′ from the even group piping 56 and the odd group piping 51 connected to the membrane elements 20 when the vacuum pump 400 is set to a negative pressure (vacuum). It is supposed to be stored at. The vacuum tank 401 includes a pressure gauge PG for measuring the internal pressure, a pressure release valve VR for returning the inside to the atmospheric pressure when discharging the stored processing liquid W ′, and a liquid for the stored processing liquid W ′. A liquid level sensor LG or the like for detecting the position is provided.

  The suction pipe 402 has one end connected directly or indirectly to the vacuum chamber 401 and the other end connected to the odd group pipe 51 and the even pipes 55a and 55b of the odd pipes 50a, 50b, and 50c. , 55c are connected directly or indirectly to the even group piping 56. The suction pipe 402 according to this embodiment has one end connected to a return pipe 403 between a later-described seventh valve V7 and a vacuum chamber 401, and the other end connected to the main pipe 300 for an odd group. The pipe 51 and the even-numbered group pipe 56 are connected on the downstream side. As a result, the suction pipe 402 is connected to the vacuum chamber 401 via the return pipe 403, and the odd group pipe 51 and the even pipe system 55a of the odd pipe systems 50a, 50b and 50c via the main pipe 302. , 55b, 55c are connected to the even group piping 56. The suction pipe 402 is provided with a sixth valve V6 constituted by a two-way valve (open / close valve) for opening and closing the flow path at an intermediate position. When “is sucked into the vacuum chamber 401, the flow path is opened while the processing liquid W ′ is not sucked into the vacuum tank 401, that is, when the processing liquid W ′ is circulated in the fluid supply piping system 30. The flow path is closed.

  The return pipe 403 may be directly piped from the vacuum tank 401 to the liquid tank T. However, in the present embodiment, as described above, a part of the fluid supply pipe system 30 is connected to the drain pipe system 40. Therefore, the vacuum chamber 401 and the supply pipe 301 are fluidly connected, and the supply pipe 301 and the main pipe 302 are part of the return pipe 403. In the present embodiment, the return pipe 403 is provided with a seventh valve V7 constituted by a two-way valve (open / close valve) that opens and closes the flow path between the vacuum chamber 401 and the supply pipe 301. Accordingly, the flow path is opened when the processing liquid W ′ in the vacuum chamber 401 is discharged, and the flow path is closed when the processing liquid W ′ is stored in the vacuum tank 401.

  The membrane separation apparatus 1 according to the present embodiment is configured to perform the maintenance of the membrane module M (removal of suspended substances attached to the filtration membranes 201, 201) while the membrane module M is pulled up from the filtration tank 10. It has become. Accordingly, as shown in FIGS. 1 and 2, the membrane separation apparatus 1 according to the present embodiment includes a pulling means 70 for pulling up the membrane module M from the filtration tank 10 and a pulling means 70 in addition to the above configuration. And a collecting means 80 for collecting suspended substances removed from the pulled up membrane module M (filtration membranes 201 and 201).

  The pulling means 70 is configured to raise and lower the membrane module M. In this embodiment, a winch is adopted. The winch 70 includes a drum (not shown) for winding the rope 71 such as a wire rope or a chain, and a motor (not numbered) for driving the drum to rotate. A connecting means 72 for connecting to the membrane module M (element rack 250) is provided. In the present embodiment, a hook is employed for the connecting means 72, and the hook is connected to a bracket 254 provided on the upper frame 251 of the element rack 250. Accordingly, when the drum 71 is driven to rotate and the strip 71 is wound up, the membrane module M (membrane element 20...) Is lifted from the filtration tank 10 (liquid W to be treated), and the winding of the strip 71 with respect to the drum is released. The membrane module M (membrane element 20...) Is immersed in the filtration tank 10 (processed liquid W).

  In the present embodiment, as described above, the element rack 250 of the membrane module M is formed in a rectangular shape in plan view, and the distance between the pair of horizontal beams 251a and 251a provided with the bracket 254 is wide. Two sets 70 are provided corresponding to the arrangement of the horizontal beams 251a and 251a.

  The recovery means 80 includes a tray 81 for receiving suspended substances removed from the filtration membranes 201, 201 of the membrane module M (membrane element 20 ...), and a container 82 for recovering the suspended substances received by the tray 81. And.

  Since the membrane separation apparatus 1 according to the present embodiment is configured to pull up the membrane module M from the filtration tank 10 directly above, the tray 81 is configured to be able to travel in the lateral direction and lifted. It moves between a position directly below the membrane module M and a position deviated from the position immediately below it. The tray 81 can be opened and closed at the bottom, and the suspended material received by the opening of the bottom can be dropped downward. Furthermore, the bottom of the tray 81 is made of a mesh material so that the suspended suspended matter can be drained.

  The container 82 is configured to be able to run and is disposed directly below the tray 81 at a position off the position directly above the filtration tank 10. Then, the suspended matter from the tray 81 may be directly received by the container 82 with respect to the container 82, but in this embodiment, a flexible container (so-called flexible container bag) F is disposed in the container 82. The suspended matter is received by the flexible container bag F in the container 82.

  The membrane separation apparatus 1 according to the present embodiment has the above-described configuration. Next, the operation of the membrane separation apparatus 1 will be described.

  First, as shown in FIG. 2, the membrane module M is immersed in the filtration tank 10, and the submerged pump 100 and the stirring device 101 are operated to stand by in a state where the liquid W in the filtration tank 10 is stirred. The vacuum pump 400 is operated after the third valve V3, the fourth valve V4, and the seventh valve V7 are closed while maintaining this state. Then, the vacuum chamber 401 has a negative pressure, and the membrane elements 20 connected to the vacuum chamber 401 via the suction pipe 402, the main pipe 302, and the odd-numbered pipe systems 50a, 50b, and 50c (an odd-numbered film element group On). And the liquid to be treated in the filtration tank 10 from each of the membrane elements 20 (even film element group En) connected to the vacuum tank 401 via the suction pipe 402, the main pipe 302, and the even pipe systems 55a, 55b, and 55c. W (a high-concentration liquid W in which suspended substances are stirred) is sucked. As a result of this suction, the liquid W to be processed passes through the filtration membranes 201 and 201 of the membrane elements 20... And is guided into the vacuum chamber 401 as a filtered processing liquid W ′.

  When the liquid level sensor LG of the vacuum chamber 401 determines that a predetermined amount of the processing liquid W ′ has been stored, the pressure release valve VR of the vacuum chamber 401 is opened to bring the inside to an atmospheric pressure state. The suction of the liquid W to be processed from. Then, the first valve V1, the second valve V2, and the sixth valve V6 are closed and the third valve V3 and the seventh valve V7 are opened. The processing liquid W ′ is discharged into the liquid tank T.

  When the filtration of the liquid W to be treated is resumed, the pressure pump 300 is stopped, the first valve V1, the second valve V2, and the sixth valve V6 are opened, and the third valve V3 and the second valve V6 are opened. By closing the seven valve V7 and then closing the pressure release valve VR, the liquid W to be treated in the filtration tank 10 is sucked by the membrane elements 20. Will be drawn into. As described above, the membrane separation apparatus 1 according to the present embodiment filters the liquid W to be processed in the filtration tank 10 and stores it in the vacuum tank 401 and stores it in the vacuum tank 401 by switching between opening and closing of each valve. The processing liquid W ′ is switched to a state where the processing liquid W ′ is discharged to the liquid tank T as needed, and the liquid W to be processed is filtered intermittently.

  As the liquid W to be treated is filtered in this way, suspended substances are deposited on the filtration membranes 201, 201 of the membrane elements 20 ..., so when the filtration performance falls below a predetermined filtration performance. Suspended substances adhering to the filtration membranes 201 of each membrane element 20 are removed. Here, whether the pressure falls below the predetermined filtration performance is determined by the pressure state of the vacuum chamber 401. That is, when the filtration membranes 201 and 201 are not clogged or when clogging is small, the filtered processing liquid W ′ smoothly flows into the vacuum chamber 401, so that the pressure in the vacuum chamber 401 is extremely high. However, when the clogging of the filtration membranes 201 and 201 occurs, the liquid W ′ to be treated is difficult to flow into the membrane elements 20... And the pressure in the vacuum chamber 401 is extremely lowered. When the pressure state of the vacuum chamber 401 reaches a predetermined pressure (for example, 90 kPa (0.09 MPa)), suspended substances that reduce filtration performance are deposited on the filtration membranes 201 and 201 of the membrane elements 20. It comes to judge.

  As another determination method, there is a method of determining based on the filtration flow rate. When the filtration membranes 201 and 201 are not clogged or small, a predetermined amount (for example, the amount at which the above-described suction is stopped. Liquid) because the filtered processing liquid W ′ flows into the vacuum chamber 401 at a high speed. Judgment is made by the position sensor LG.) The time until storage is short, but when clogging occurs, the flow speed becomes slow, so that time becomes long. When this time reaches a predetermined value (for example, 10 minutes), it is determined that the suspended matter is deposited on the filtration membranes 201 and 201 so as to reduce the filtration performance. This determination method can increase the accuracy when the vacuum pump 400 having high suction performance is employed as compared with the determination method based on the pressure state. This is because the change in pressure in the vacuum chamber 401 decreases as the suction performance of the vacuum pump 400 increases. When the change is reduced, depending on the accuracy of the pressure gauge PG, it cannot be detected that the pressure gauge PG has reached a predetermined value, or a large error is included even if it can be detected. The suction performance of the vacuum pump 400 is often enhanced to improve the processing speed.

  When it is determined that the suspended substances are deposited on the filtration membranes 201 and 201 in this way, the filtration membranes 201 and 201 of the membrane module M (membrane element 20...) Are cleaned.

  In the present embodiment, as described above, since the lifting means 70 is provided, the membrane module M is pulled up from the filtration tank 10, and the tray 81 of the recovery means 80 is located directly below the membrane module M. Then, the treatment liquid W ′ is supplied to each membrane element 20... And the filtration membrane 201 of each membrane element 20.

  Specifically, in the initial stage, the first valve V1, the second valve V2, the fourth valve V4, the fifth valve V5, the sixth valve V6, and the seventh valve V7 are closed, and then the pressure pump 300 Operates. Then, the treatment liquid W ′ stored in the liquid tank T is guided to the main pipe 302 by the pressure pump 300 and then returned to the liquid tank T, that is, the supply pipe 301, the pressure pump 300, and the main pipe 302. Then, the processing liquid W ′ in the liquid tank T is circulated at a predetermined pressure.

  In this state, the first valve V1 and the second valve V2 are alternately opened and closed, so that the membrane elements 20 (No. 1, No. 3, No. 5) of the odd-numbered membrane element group On and the even-numbered membrane The treatment liquid W ′ is alternately supplied to the membrane elements 20 (No. 2, No. 4, No. 6) of the element group En.

  Then, the first valve V1 is opened and the second valve V2 is closed, so that the processing liquid W ′ is supplied to each membrane element 20 of the odd-numbered membrane element group On, and the inside of the membrane element 20 The treatment liquid W ′ pushes the filtration membranes 201, 201 from the side, and the suspended substances (cake layer) attached to the outer surfaces of the filtration membranes 201, 201 are pushed away. At this time, as shown in FIG. 5 (a), the filtration membranes 201, 201 of the membrane elements 20 ... are bulged outwardly by the pressure of the treatment liquid W ', but the even membrane element groups facing each other. Since the processing liquid W ′ is not supplied to each of the membrane elements 20 of En, these filtration membranes 201 are maintained in a steady state without bulging outward. Each of the membrane elements 20 in the even-numbered membrane element group En may be in a bulged state as compared with the steady state due to the treatment liquid W ′ remaining inside. In this case, it is preferable to suck the processing liquid W ′ in each film element 20 of the even film element group En before supplying the processing liquid W ′ to each film element 20 of the odd film element group On. Thus, as described above, even if the filtration membranes 201, 201 of the membrane elements 20 ... of the odd-numbered membrane element group On bulge, the membrane elements 20 ... (cake) to which the cake layer K to which the filtration membranes 201, 201 are attached face each other. It will not fall between the layers K) and will fall on the tray 81.

  Returning to FIG. 2, when the first valve V1 is closed and the second valve V2 is opened from the above state, the processing liquid W ′ is supplied to each of the membrane elements 20. The treatment liquid W ′ pushes the filtration membranes 201 and 201 from the inner side of the elements 20... And the cake layer K attached to the outer surfaces of the filtration membranes 201 and 201 is pushed away. At this time, the filtration membranes 201 and 201 of the membrane elements 20 of the even membrane element group En are in a state of bulging outward due to the pressure of the processing liquid W ′ as shown in FIG. 5B. Since the processing liquid W ′ is not supplied to each of the membrane elements 20 of the odd-numbered membrane element group On facing, the filtration membranes 201 and 201 of the membrane elements 20 are in a steady state without bulging outward. Will be maintained at. Each of the membrane elements 20 in the odd-numbered membrane element group On may be in a swelled state as compared with the steady state due to the treatment liquid W 'remaining inside. In this case, it is preferable to suck the processing liquid W ′ in each membrane element 20 of the odd-numbered membrane element group On before supplying the processing liquid W ′ to each membrane element 20 of the even-numbered membrane element group En. Thus, as described above, even when the filtration membranes 201, 201 of the membrane elements 20 ... of the even membrane element group En swell, the membrane elements 20 ... (filtering) on which the cake layer K to which the filtration membranes 201, 201 are attached are opposed. The film 201, 201 or the cake layer K) is not sandwiched and falls on the tray 81. Since the bottom of the tray 81 according to the present embodiment is configured in a mesh shape, when the cake layer K falls on the tray 81, the moisture contained in the cake layer K falls, and the cake layer K is drained. .

  In this way, by alternately and repeatedly switching the opening and closing of the first valve V1 and the second valve V2, the cake layers from the filtration membranes 201 and 201 of the membrane elements 20 of the odd membrane element group On and the even membrane element group En, respectively. K can be reliably removed, and the filtration performance can be recovered.

  Since the membrane separation apparatus 1 according to this embodiment is provided with three unit units U1, U2, and U3 as shown in FIG. 2, the odd-number membrane element group as described above is provided for each unit unit U1, U2, and U3. The alternate treatment liquid W ′ is supplied to On and the even-numbered film element group En. That is, in any one unit unit U1, while the first valve V1 and the second valve V2 are alternately opened and closed to clean the filtration membranes 201, 201 of each membrane element 20 ..., the other unit unit U1. , U2 and U3, the first valve V1 and the second valve V2 are closed, and when the cleaning of the filtration membranes 201 and 201 of the unit units U1, U2 and U3 to be cleaned is completed, the unit unit The first valve V1 and the second valve V2 corresponding to U1, U2, U3 are closed, and the first valve V1 and the second valve V2 corresponding to any one of the remaining unit units U1, U2, U3 are alternated. The filter membranes 201 and 201 of the membrane elements 20 are cleaned.

  Thus, by cleaning the filtration membranes 201, 201 of the membrane elements 20 for each unit unit U1, U2, U3, there is no need to set the discharge pressure of the liquid W to be processed in the pressure pump 300 high. The pump 300 can be made small, and the pressure pump 300 is used to supply the processing liquid W ′ to the odd-numbered membrane element group On and the even-numbered membrane element group En of each unit unit U1, U2, U3. There is no need for complicated control.

  That is, when the processing liquid W ′ is supplied to the membrane elements 20 to clean the filtration membranes 201 and 201, all of the membrane elements 20 of the membrane module M (all unit units U1, U2, U3). When the processing liquid W ′ for cleaning is supplied, a pressure drop of the processing liquid W ′ occurs. Therefore, it is necessary to control the pressure pump 300 with an inverter or the like to correct the pressure drop.

  However, compared with the circulation amount of the treatment liquid W ′ circulated in the supply pipe 301 and the main pipe 302, the treatment liquid W ′ used for cleaning the filtration membranes 201, 201 of the membrane elements 20 of one unit unit U1. Since the flow rate is very small, as described above, there is no extreme pressure drop even if the first valve V1 and the second valve V2 of one unit unit U1 are alternately opened and closed while circulating the processing liquid W ′ at a constant pressure. There is no need to control the discharge amount (discharge pressure) of the pressure feed pump 300 with an inverter or the like.

  Then, when the cleaning of the membrane elements 20 of the unit units U1, U2 and U3... Filtration membranes 201 and 201 is completed, the tray 81 of the collecting means 80 moves to a position off the membrane module M. The bottom of 81 is opened, and the cake layer K (suspended material) is recovered in the container 82 (flexible bag F).

  When the filtration membranes 201, 201 of the membrane elements 20 are completely cleaned and the treatment liquid W is filtered again, the opening and closing of the valves are switched as described above, and the filtration of the treatment liquid W is performed. Is resumed. Note that the membrane separation device 1 according to the present embodiment is provided with the fourth valve V4. This is because the liquid level sensor LG provided in the liquid tank T detects a predetermined liquid level, that is, an allowable value. When the amount of stored liquid is exceeded, the third valve V3 is closed and the fourth valve V4 is opened to return the processing liquid W ′ to the filtration tank 10. The filtration tank 10 is also provided with a liquid level sensor LG, and when the allowable liquid storage amount is exceeded, the flow path is switched by the three-way valve V connected to the submerged pump 100 to force the external To be discharged.

  As described above, according to the membrane separation device 1 and the filtration membrane cleaning method of the membrane separation device 1 according to the present embodiment, the odd-numbered odd-numbered membrane element group On in the parallel order of the plurality of membrane elements 20. Since the fluid is alternately supplied to the even-numbered membrane element group En, even if the intervals between the plurality of membrane elements 20 are reduced and the size is reduced, the filtration membranes 201 and 201 of the membrane elements 20. It is possible to achieve an excellent effect that the suspended matter adhering to the surface can be removed reliably and efficiently.

  Further, suspended substances can be removed well while simplifying the piping system for the membrane elements 20.

  In addition, this invention is not limited to the said embodiment, Of course, a various change can be added in the range which does not deviate from the summary of this invention.

  In the above-described embodiment, the plurality of membrane elements 20 arranged in parallel are divided into two groups (groups), and the treatment liquid W ′ is alternately supplied to these to clean the filtration membranes 201, 201. However, the present invention is not limited to this, and the supply of the fluid for removing the suspended solids may be configured to have different timings in the adjacent membrane elements 20. Specifically, the plurality of membrane elements 20 arranged in parallel with the filtration membranes 201 and 201 facing each other are divided into three or more groups in order from the end, and the treatment liquid W ′ is sequentially applied to each group. May be supplied to clean the filtration membranes 201 and 201 of the membrane elements 20 for each group.

  That is, as shown in FIG. 6, the plurality of membrane elements 20 are grouped into a plurality of groups in order (parallel order) from the end (for example, I group, II group, III group ..., I group, II in order from the end). Group, group III, etc.), and the membrane elements 20 of the corresponding groups may be connected to each other by piping, and the processing liquid W ′ may be supplied so that the timing is different from these. . Also in this case, by providing a two-way valve in the pipe corresponding to each group and switching the opening and closing of the two-way valve, the fluid (treatment liquid W ′) is supplied to the adjacent membrane elements 20 at different timings. Since the filter membranes 201 and 201 facing each other do not bulge and approach each other at the same time, the distance between the membrane elements 20 can be made as small as possible to reduce the size of the entire apparatus. The suspended substances adhering to 201 and 201 can be removed reliably and smoothly.

  In the above embodiment, the membranes M (the plurality of membrane elements 20...) Are lifted from the filtration tank 10 and then the filtration membranes 201 and 201 are cleaned. However, the present invention is not limited to this. In the state where the membrane module M is immersed in the liquid W to be treated in the filtration tank 10, the treatment liquid W ′ is supplied to the membrane elements 20 to remove suspended substances attached to the filtration membranes 201 and 201. Good. However, in this case, since suspended substances accumulate in the filtration tank 10, it is necessary to remove the suspended substances from the filtration tank 10, so that the membrane module is removed from the filtration tank 10 as in the above embodiment. It is preferable that the filtration membrane 201 is cleaned after the M is pulled up and the suspended substance is removed by the collecting means 80.

  Further, the collecting means 80 is not limited to the above-described embodiment. For example, instead of the tray 81 of the collecting means 80, the pulling means 70 is configured to be able to travel, and the membrane module M lifted from the filtration tank 10 is used. The filter membrane 201 may be cleaned after being moved to a position outside the arrangement of the filtration tank 10 to receive the suspended matter removed by the container 82 provided immediately below.

  In the embodiment described above, the odd group piping 51 of the odd piping systems 50a, 50b, 50c of the unit units U1, U2, U3 and the even group piping 56 of the even piping systems 55a, 55b, 55c are respectively connected to the main piping 302. In addition, the first valve V1 and the second valve V2 are provided to the first valve V1 and the second valve V2, and the first valve V1 and the second valve V2 are alternately opened and closed. The group pipe 51 and the even group pipe 56 are connected to the two ports of the three-way valve to merge them, and the remaining ports are connected to the main pipe 302. By switching the three-way valve flow path, the odd-number membrane element group Alternately, the treatment liquid W ′ may be supplied to On and the even-numbered film element group En.

  In the above embodiment, the membrane module M is configured by providing a plurality of unit units U1, U2, U3. However, the present invention is not limited to this, and the unit units U1, U2, U3 constituting the membrane module M are at least Of course, it may be one. That is, in the above embodiment, the plurality of membrane elements 20 are arranged side by side in the vertical and horizontal directions, but the present invention is not limited to this. For example, the plurality of membrane elements 20 are arranged in a row in the horizontal direction. The membrane module M may be configured.

  In the above embodiment, the odd group pipe 51 or the even group pipe 56 is connected to the cylindrical connecting portion 202 provided on one end face of the membrane element 20... However, the present invention is not limited to this. For example, the membrane element 20 is provided with two connection portions 202 and filtered. A pipe for sucking the processing liquid W ′ and a pipe for supplying the processing liquid W ′ at the time of cleaning the filtration membrane 201 may be provided independently, and these may be connected to each connection portion 202. In this case, the pipes for supplying the processing liquid W ′ for cleaning the filtration membrane 201 are assembled and connected to the main pipe 302. In this case, the odd group pipe 51 and the even group are also connected. The pipe 56 is provided with a two-way valve, or these are joined via a three-way valve and connected to the main pipe 302, and the odd-numbered membrane element group On and the even-numbered membrane element group En by opening and closing or switching the flow path. May be alternately cleaned.

  In the above-described embodiment, the membrane element 20 in which the cylindrical connection portion 202 is provided on one end surface of the plate-shaped element body 200 in which the filtration membranes 201 and 201 are laminated on both surfaces is employed. The membrane element 20 is not, for example, a laminated region of the filtration membranes 201, 201 of the plate-like element body 200 having a rectangular shape in plan view in which the filtration membranes 201, 201 are laminated on both sides as shown in FIG. A pair of flow passage formation holes 230a and 230b penetrating both surfaces are formed at diagonal positions on the outside, communicated with one flow formation hole 230a, and on both surfaces in the laminated region of the filtration membranes 201 and 201 A penetrating through hole 231 is formed, and one or both surfaces of the element body 200 project cylindrical bodies 232 and 232 communicating with the pair of flow path forming holes 230a and 230b. It may be the one that is. In this way, when the plurality of membrane elements 20 are arranged side by side, the adjacent membrane elements 20 are rotated by 180 ° along the surface of the element body 200 so that one of the membrane elements 20. The channel forming hole 230a and the other channel forming hole 230b of the other membrane element 20 are communicated with each other through the cylindrical body 232, and the other channel forming hole 230b of the one membrane element 20 and the other membrane element are communicated. 20 are arranged so as to communicate with one of the flow passage forming holes 230a through the cylindrical body 232, so that two flow passages are formed across the plurality of membrane elements 20 arranged in parallel (stacked). The

  And since one flow path formation hole 230a of each membrane element 20 ... communicates with the through hole 231 penetrating both surfaces in the laminated flow area of the filtration membranes 201, 201, one flow path has a plurality of membranes. This is a path for supplying fluid to the odd-numbered odd-numbered membrane element group On in the parallel order of the elements 20..., And the other flow path supplies fluid to the even-numbered even-numbered membrane element group En in the parallel order of the plurality of membrane elements 20. This is the supply route. Therefore, one odd group pipe 51 is connected to one of the two flow paths, and one even group pipe 56 is connected to the other, so that each of the odd film element group On and the even film element group En. The fluid can be supplied independently. In this case, a two-way valve is provided for each of the odd group pipe 51 and the even group pipe 56, or the odd group pipe 51 and the even group pipe 56 are joined via the three way valve and connected to the main pipe 302. Thus, the fluid can be alternately supplied to the odd-numbered membrane element group On and the even-numbered membrane element group En by opening / closing the valve and switching the flow path. As described above, when the membrane elements 20... In which the pair of channel formation holes 230a, 230b are formed in the diagonal position of the element body 200 are arranged in parallel, the channel formation of the membrane element 20 located at the end in the parallel direction is performed. Since the holes 230a and 230b are opened, it goes without saying that the flow path forming holes 230a and 230b that do not connect the odd group pipe 51 and the even group pipe 56 are closed with caps or the like.

  When the cylindrical body 232 is provided only on one surface of the element main body 200, the concave portion into which the tip of the cylindrical body 232 is fitted is formed on the other surface, thereby positioning the adjacent membrane elements 20. Can be sure. In addition, when the cylindrical body 232 is provided on both surfaces of the element body 200, the positioning of the adjacent membrane elements 20 is ensured by configuring the cylindrical body 232 so that the tips of the cylindrical bodies 232 can be fitted to each other. Can do. Further, by providing the projecting portion 233 having an extension amount corresponding to the cylindrical body 232 at the remaining diagonal position other than the diagonal position at which the cylindrical body 232 is projected, the membrane element 20 adjacent to the projecting portion 233 is provided. The distance between the membrane elements 20 can be ensured by the contact with. Even in this case, when the convex portion 233 is formed on one surface of the element main body 200, a concave portion into which the tip end portion of the convex portion 233 is fitted is formed on the other surface, When the convex part 233 is formed on the surface, reliable positioning is achieved by configuring the convex part 233 so that the tips of the convex part 233 can be engaged with each other.

  In the above description, the membrane element 20 is formed by rotating the layer 180 ° along the surface and forming two flow paths, but for example, if the membrane element 20 including the element body 200 shown in FIG. The two flow paths can also be formed by rotating the membrane element 20 (element body 200) by rotating 180 degrees in the direction in which the front and back surfaces are interchanged. In the membrane element 20 (element main body 200) shown in this figure, two flow paths can be formed by exchanging the front and back surfaces particularly along the horizontal plane. It can be provided in the upper half. Therefore, compared with the case where the two flow paths and the surrounding portions are provided in the lower half of the element main body 200, the suspended matter falling from the filtration membrane 201 is suppressed. In order to form a gap between the plurality of membrane elements 20, for example, a spacer may be interposed between the membrane elements 20 without providing the cylindrical body 232 in the element body 200. In this case, on the assumption that the spacer is interposed so as to correspond to the arrangement of the flow path forming holes 230a and 230b, a through hole for communicating the flow path forming holes 230a and 230b of the adjacent membrane elements 20 with each other. Is provided. Thereby, two flow paths can be formed while forming a gap between the membrane elements 20.

  In the above embodiment, the filtered treatment liquid W ′ is used as a fluid for cleaning the filtration membranes 201, 201 of each membrane element 20..., But is not limited to this. A gas as a fluid for cleaning the gas may be supplied to the membrane elements 20. Even in this case, the cake layer K adhering to the filtration membranes 201 and 201 can be peeled and removed by the gas supply pressure. However, if the moisture exists on the surfaces of the filtration membranes 201 and 201, the cake layer K can be peeled off (removed) more smoothly. For example, moisture remains in the filtration membranes 201 and 201 or the membrane elements 20. It is preferable that gas is supplied in a state or a liquid is supplied as in the above embodiment. Moreover, in the said embodiment, although the piping system 60 for fluid supply and the piping system 40 for drainage were integrated, the merged piping system 60 was comprised, However, It is not limited to this, For example, the piping system 30 for fluid supply The drainage piping system 40 may be an independent piping system.

  In the embodiment described above, the filtration membranes 201 and 201 are heat-welded to the element body 200 using a hot plate. However, the present invention is not limited to this. For example, the filtration membranes 201 and 201 are attached to the element body 200. May be welded by ultrasonic waves, or may be stuck using an adhesive. In addition, when the filtration membranes 201 and 201 are welded to the element main body 200 by ultrasonic waves, a large number of minute protrusions are provided in the region where the filtration membranes 201 and 201 of the element main body 200 are adhered, and the protrusions are melted. It is preferable to stick the filtration membranes 201 and 201.

  In the above embodiment, the peripheral portions of the element main body 200 and the filtration membranes 201 and 201 are attached to each other. For example, when the membrane elements 20 (the filtration region of the filtration membranes 201 and 201) are large in size. In order to increase the bonding strength between the element main body 200 and the filtration membranes 201 and 201, the region (enclosed region) surrounded by the region where the outer peripheral ends are adhered is divided into two or more. As described above, the element body 200 and the filtration membranes 201 and 201 may be attached. In this case, it is preferable that the sticking portion that divides the surrounding region of the element main body 200 is a smooth surface, like the outer peripheral end portion.

  In the above-described embodiment, the membrane element 20 is configured by interposing the mesh 204 between the element body 200 and the filtration membranes 201, 201. However, the present invention is not limited to this. As described above, a groove connected to the second hole 203b is formed on the surface of the element body 200 facing the filtration membranes 201 and 201, or a plurality of convex portions are formed on the surface of the element body 200 facing the filtration membranes 201 and 201. Alternatively, the membrane elements 20 may be formed. Even if it does in this way, a clearance gap will be formed between the element main body 200 and the filtration membranes 201 and 201, and the smooth distribution | circulation of the fluid will be achieved similarly to having interposed the said mesh 204. FIG.

1 shows a partial schematic perspective view of a membrane separation apparatus according to an embodiment of the present invention. FIG. The whole conceptual diagram of the membrane separator concerning the embodiment is shown. The disassembled perspective view of the membrane element employ | adopted for the membrane separator which concerns on the same embodiment is shown. The schematic for demonstrating the arrangement | sequence (group structure) of the membrane element of the membrane separator which concerns on the same embodiment is shown. It is a schematic cross-sectional view of the operating state of the membrane element of the membrane separation apparatus according to the embodiment, (a) shows a state in which suspended substances are removed from the filtration membrane of the membrane element of the odd-numbered membrane element group, (B) shows a state in which suspended substances are removed from the filtration membranes of the membrane elements of the even membrane element group. The schematic for demonstrating the arrangement | sequence (group structure) of the membrane element of the membrane separator which concerns on other embodiment of this invention is shown. The disassembled perspective view of the membrane element of the membrane separator which concerns on another embodiment of this invention is shown. It is explanatory drawing of the element main body which comprises the membrane element of the membrane separator which concerns on another embodiment of this invention, Comprising: (a) shows the surface side of an element main body, (b) is the back surface of an element main body. Shows the side.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Membrane separator, 10 ... Filtration tank, 20 ... Membrane element, 30 ... Fluid supply piping system, 40 ... Drainage piping system, 50 ... Connection piping system, 50a, 50b, 50c ... Odd piping system, 51 ... Odd group piping, 52 ... Branch piping, 55a, 55b, 55c ... Even piping system, 56 ... Even group piping, 57 ... Branch piping, 60 ... Merged piping system, 70 ... Winch (lifting means), 71 ... Rope 72, hook (connecting means), 80 ... collection means, 81 ... tray, 82 ... container, 100 ... submerged pump, 101 ... stirring device, 200 ... element body, 201 ... filtration membrane, 202 ... connection part, 203 ... Flow passage, 203a ... First hole, 203b ... Second hole, 204 ... Mesh, 230a, 230b ... Flow path forming hole, 231 ... Through hole, 232 ... Cylinder, 233 ... Protrusion, 250 ... Element rack 251 ... top Frame, 252 ... Lower frame, 253 ... Column, 254 ... Bracket, 251a, 251a ... Cross beam, 300 ... Pressure feed pump, 301 ... Supply pipe, 302 ... Main pipe, 400 ... Vacuum pump, 401 ... Vacuum tank, 402 ... For suction Piping, 403 ... Return piping, 410 ... Branch piping, 411 ... Piping, 412 ... Piping, En ... Even membrane element group, F ... Flexible container (flexible bag), K ... Cake layer (suspended material), LG ... Liquid level Sensor, M ... Membrane module, On ... Odd membrane element group, P, P ', P "... Pipe, PG ... Pressure gauge, Ra ... First flow path, Rb ... Second flow path, T ... Liquid tank, U1, U2, U3 ... Unit unit, V ... Three-way valve, V1 ... First valve, V2 ... Second valve, V3 ... Third valve, V4 ... Fourth valve, V5 ... Fifth valve, V6 ... Sixth valve, V7 ... Seventh valve, VR ... Pressure release valve W ... the liquid to be treated, W '... processing solution

Claims (4)

  A plurality of membrane elements each provided with a filtration membrane for filtering the liquid to be treated containing suspended substances are provided on both sides, and the plurality of membrane elements are arranged in parallel at predetermined intervals so that the filtration membranes face each other. By flowing the liquid to be treated through the filtration membrane toward the inside of the membrane element, the liquid to be treated is filtered, while supplying the fluid to the membrane element and flowing the fluid from the inside to the outside of the membrane element. In the membrane separation apparatus configured to remove suspended substances attached to the filtration membrane, the timing of supplying fluid to the membrane element is configured to be different between adjacent membrane elements. Membrane separator.   The membrane separator according to claim 1, wherein the fluid is alternately supplied to an odd-numbered membrane element group and an even-numbered membrane element group in a parallel order of a plurality of membrane elements.   A plurality of membrane elements each provided with a filtration membrane for filtering the liquid to be treated containing suspended substances are provided on both sides, and the plurality of membrane elements are arranged in parallel at predetermined intervals so that the filtration membranes face each other. By flowing the liquid to be treated through the filtration membrane toward the inside of the membrane element, the liquid to be treated is filtered, while supplying the fluid to the membrane element and flowing the fluid from the inside to the outside of the membrane element. In the filtration membrane cleaning method of the membrane separation device configured to remove suspended substances attached to the filtration membrane, the timing of supplying fluid to the membrane element is different between adjacent membrane elements. A filtration membrane cleaning method for a membrane separator.   The method of cleaning a membrane of a membrane separation device according to claim 3, wherein the fluid is alternately supplied to an odd-numbered membrane element group and an even-numbered membrane element group in parallel order of a plurality of membrane elements.

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