JP6043465B2 - Membrane separation apparatus and membrane element cleaning method - Google Patents

Description

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

  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 filtration tank that stores a liquid to be treated containing suspended solids, and a membrane element that includes a filtration membrane that filters the liquid to be treated containing suspended solids. The membrane element is connected to a pump via a pipe, and the treatment liquid is circulated in one direction with respect to the filtration membrane by operating the pump while being immersed in the treatment liquid in the filtration tank. It is configured to filter.

In the membrane separation apparatus having the above configuration, when the filtration treatment is performed every day, suspended substances accumulate as a cake layer on the surface of the filtration membrane and reduce the filtration ability. Therefore, the membrane element is immersed in the liquid to be treated. In the state, the filtration performance is recovered by performing a washing process on the filtration membrane by cross flow washing by aeration, back pressure washing, chemical washing, or the like (for example, see Patent Document 1).
Japanese Unexamined Patent Publication No. 2004-321998

  However, since the membrane separation apparatus having the above configuration cleans the filtration membrane in a state in which the membrane element is immersed in the liquid to be treated, the suspended substance separated from the filtration membrane by the washing is mixed with the liquid to be treated. Will increase the solid content concentration. As a result, even if the filtration capability of the filtration membrane is restored, there is a problem that suspended substances accumulate as a cake layer on the filtration membrane in a short period of time, and the frequency of washing increases to damage the filtration membrane.

  In addition, when the suspended matter (cake layer) peeled off from the filtration membrane by washing is recovered from the filtration tank, the recovered suspended matter has a high water content, and the suspended matter is discarded. There is a problem that transportation costs and processing costs for doing so increase.

  Therefore, in view of such circumstances, the present invention can remove suspended solids adhering to the filtration membrane without increasing the solid content concentration that causes damage to the filtration membrane. It is an object of the present invention to provide a membrane separation device that can be recovered by the method and a method for cleaning a membrane element.

The membrane separation apparatus according to the present invention has at least one membrane element provided with a filtration membrane for filtering a liquid to be treated containing suspended substances, and the membrane element is immersed in the liquid to be treated. In a membrane separation apparatus configured to filter a treatment liquid, pulling means for pulling up the membrane element from the liquid to be treated to the outside, and a filtration membrane for the membrane element pulled up from the liquid to be treated by the pulling means Removing means for removing suspended substances adhering to the filter, and collecting means for collecting suspended substances removed by the removing means, wherein the filtration membrane of the membrane element pulled out from the liquid to be treated by the lifting means and receiving the suspended matter falling from a recovery means for recovering該懸turbid substance, the collecting means, that are movable under the lifted membrane element from filtration tank And butterflies.

According to the membrane separation apparatus having the above-described configuration, the membrane element is pulled up from the liquid to be treated by the lifting means and then removed from the filtration membrane by the removing means in order to remove suspended substances attached to the filtration membrane. Suspended substances do not return to the liquid to be treated. Thus, filtering tank for the solid concentration of the suspended material (liquid to be treated) in is inadvertently dropped liquid to be treated can be prevented from being high because of removal processing of suspended solids relative to the filtration membrane The frequency can be suppressed, and as a result, damage to the filtration membrane can be suppressed. Also, by pulling up the membrane element to the outside, the water contained in the suspended substance attached to the filtration membrane will drip down, so that it is suspended at a lower moisture content than the suspended substance recovered from the liquid as in the past. Turbid substances can be recovered.

As one aspect of the present invention, the removing means is configured so that the suspended solid adhering to the filtration membrane of the membrane element is less than when it is pulled up from the liquid to be treated, and the filtration membrane from the filtrate side It is preferable that the fluid is circulated toward the liquid to be treated. If it does in this way, a suspended substance can be made to peel from a filtration membrane reliably with the fluid pressure which passes a filtration membrane.

The method for cleaning a membrane element according to the present invention includes a step of pulling out a membrane element immersed in a liquid to be treated to filter the liquid to be treated containing a suspended substance from the liquid to be treated, and from the liquid to be treated. A step of removing suspended substances adhering to the filtration membrane of the membrane element pulled up to the outside, and a step of recovering suspended substances removed in the step of removing suspended substances, and from the liquid to be treated to the outside characterized in that it comprises a step of recovering the suspended solids suspended matter accepted stopped by the falling from the filtration membrane of the membrane element in the recovery means is moved under the lifted film elements.

  According to the method for cleaning a membrane element having the above-described configuration, the suspended matter removed from the filtration membrane is removed in order to remove the suspended matter adhering to the filtration membrane after the membrane element is pulled up from the liquid to be treated. There is no return to the processing solution. This makes it difficult to increase the solid content concentration of the liquid to be treated, so that the frequency of the removal of the suspended substances from the filtration membrane can be suppressed, and as a result, damage to the filtration membrane can be suppressed. Also, by pulling up the membrane element to the outside, the water contained in the suspended substance attached to the filtration membrane will drip down, so that it is suspended at a lower moisture content than the suspended substance recovered from the liquid as in the past. Turbid substances can be recovered.

  As one embodiment of the present invention, the step of removing suspended substances is preferably performed by flowing a fluid from the filtrate side toward the liquid to be treated. If it does in this way, a suspended substance can be made to peel from a filtration membrane reliably with the fluid pressure which passes a filtration membrane.

  As described above, according to the membrane separation apparatus according to the present invention, the suspended matter adhered to the filtration membrane can be removed without increasing the solid content concentration that causes damage to the filtration membrane. Can be recovered with a low water content.

  Further, according to the method for cleaning a membrane element according to the present invention, it is possible to remove suspended substances adhering to the filtration membrane without increasing the solid content concentration that causes damage to the filtration membrane. An excellent effect that it can be recovered at a low water content can be obtained.

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 explanatory drawing of a part (drainage means) of the collection | recovery means of the membrane separator which concerns on the same embodiment is shown. It is a schematic sectional drawing of the operation state of the membrane element of the membrane separation apparatus which concerns on the same embodiment, Comprising: (a) shows the state which is filtering the to-be-processed liquid, (b) is suspended substance from a filtration membrane. The state which is removing is shown. The partial schematic plan view of the drainage system (primary side piping) of the membrane separator which concerns on other embodiment of this invention is shown. The schematic of the membrane separator which concerns on another embodiment of this invention is shown.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Membrane separation apparatus, 10 ... Filtration tank, 20 ... Membrane element, 30 ... Drainage system, 40 ... Lifting means (winch), 41 ... Rope, 42 ... Connecting means (hook), 45 ... Running part, 50 ... Removal means, 60 ... recovery means, 200 ... membrane module, 201 ... element body, 202 ... filtration membrane, 203 ... connection part, 204 ... flow passage, 204a ... first hole part, 204b ... second hole part, 205 ... mesh 210 ... element rack 211 ... upper frame 211a, 211b ... horizontal beam 212 ... lower frame 213 ... support column 214 ... bracket 300a 300b 300c primary side pipe 301a 301b 301c branch pipe 302a , 302b, 302c ... compound meter, 310a, 310b, 310c ... suction pump, 320 ... secondary piping, 320a, 320b, 320c Branch pipe, 321a, 321b, 321c ... Flow meter, 322 ... Turbidimeter, 323 ... Three-way valve, 324 ... Reverse pipe, 325 ... Drain pipe, 326 ... Water tank, 327a, 327b, 327c ... Valve, 50 ... Removal 500, fluid supply piping, 500a, 500b, 500c ... branch pipe, 501 ... pressure feed pump, 502 ... piping, 503a, 503b, 503c ... valve, 600 ... container, 601 ... draining means, 601a, 601b ... receiving member 602 ... Mesh member, 603 ... Water receiving member, 604 ... Frame, 605 ... Water guiding member, 606a, 606b ... Cylinder, A, B, C ... Unit unit, L ... Rail, W ... Liquid to be treated, W '... Treatment liquid

  Hereinafter, a 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 has a filtration tank 10 for storing a liquid W to be processed containing suspended substances, and the liquid to be processed by passing the liquid W to be processed in one direction. Membrane element 20 having a filtration membrane for filtering treatment liquid W, and wastewater that is fluidly connected to the membrane element 20 and that discharges treatment liquid (filtrate) W ′ filtered as it passes through the filtration membrane to the outside Suspended material adhering to the membrane of the system 30, the pulling means 40, 40 for pulling up the membrane element 20 from the liquid W to be treated, and the membrane element 20 lifted to the outside by the pulling means 40, 40 The removal means 50 which removes, and the collection | recovery means 60 which collect | recover the suspended solids removed from the filtration membrane are provided.

  The said filtration tank 10 is a container which can store the to-be-processed liquid W supplied from a water source. The filtration tank 10 is open at the top, and has a pipe from a water source (a liquid tank for temporarily storing the untreated liquid W to be treated) and a liquid to be treated when a predetermined liquid level is exceeded. A pipe for returning W to the water source is connected.

  In the present embodiment, a plurality of the membrane elements 20 are provided and are modularized by being supported by the element rack 210 (hereinafter, the plurality of modular membrane elements 20... Are referred to as membrane modules 200).

  As shown in FIG. 3, the membrane element 20... Includes an element main body 201 as a base and a filtration membrane 202 laminated on the outer surface of the element main body 201. The element main body 201 is provided with a cylindrical connecting portion 203 for connecting pipes (primary side pipes 300a, 300b, 300c, which will be described later) through which the liquid W to be processed that has passed through the filtration membrane 202 is circulated. A flow passage 204 that penetrates the surface on which the filtration membrane 202 is laminated and the connecting portion 203 is formed.

  The element body 201 according to the present embodiment is formed in a plate shape. In the present embodiment, the element body 201 is formed in a quadrangular shape (rectangular shape), and the connecting portion 203 is provided on one end surface in the longitudinal direction. Accordingly, the flow passage 204 is formed so as to penetrate between one end surface of the element body 201 and the surface on which the filtration membrane 202 is laminated.

  In the membrane element 20 according to this embodiment, filtration membranes 202 are laminated on both surfaces of the element body 201, and the flow path 204 is a first hole extending from one end surface of the element body 201 toward the inside. 204a and a second hole portion 204b penetrating both surfaces of the element body 201 so as to intersect the first hole portion 204a.

  The filtration membrane 202 is formed in a shape corresponding to the element body 201, and is formed in a quadrangular shape (rectangular shape) in the present embodiment. The filtration membrane 202 can be a hollow fiber membrane, a tubular membrane, a polymer membrane without a support, a ceramic membrane, or the like. In this embodiment, a nonwoven fabric made of a synthetic resin is used. As the support, one having a resin coating and a large number of micropores (for example, micropores having an average pore diameter of 0.4 μm) is employed. As such a filtration membrane 202, for example, a Yumicron membrane manufactured by GS Yuasa Corporation can be used. The filtration membrane 202 having such an average pore diameter is called a microfiltration membrane from the definition of JIS K 3802.

  The filtration membrane 202 has an outer peripheral end attached to the element main body 201, and an opening of the second hole portion 204b is positioned in a region surrounded by the attached portion. The attachment of the filtration membrane 202 to the element main body 201 may be heat welding using a hot plate or welding using ultrasonic waves. However, in consideration of a decrease in strength of the filtration membrane 202 at the attachment portion, filtration is performed. It is preferable to stick the film 202 to the element body 201 without melting it. That is, when the filtration membrane 202 is heated and welded to the element main body 201, if the filtration membrane 202 is melted, the portion becomes thin and the strength is reduced. Therefore, when the filtration membrane 202 is adhered to the element main body 201, the filtration membrane 202 is filtered. It is preferable not to melt the film 202.

  And it is preferable to stick the filtration membrane 202 so that it can be replaced, for example, you may stick to the element main body 201 by the method of Unexamined-Japanese-Patent No. 2006-231139. That is, it is preferable to form the outer peripheral end of the element body 201 made of thermoplastic resin on a smooth surface, and to join the filtration membrane 202 to the smooth surface, and to control the temperature of the filtration membrane 202 so as to form a recess on the smooth surface. More preferably, the filtration membrane 202 is joined to the element main body 201 by applying pressure with the heated plate. In this way, when the filtration membrane 202 and the element main body 201 are heat-welded, the temperature of the hot plate may be controlled below the melting point of the filtration membrane 202 (nonwoven fabric as a support) and above the Vicat softening temperature of the element main body 201. . 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 the present embodiment, a mesh 205 is interposed between the element main body 201 and the filtration membrane 202, and a fluid is formed by forming a gap between the element main body 201 and the filtration membrane 202. The liquid W ′) can be distributed smoothly. As the mesh 205 is interposed as described above, the element body 201 according to the present embodiment has a region (region where the mesh 205 is interposed) surrounded by the outer peripheral end to which the filtration membrane 202 is attached. It is recessed from the end. Thereby, even if the mesh 205 is interposed, the region facing the mesh 205 of the filtration membrane 202 does not bulge and becomes flat.

  Returning to FIG. 1, the element rack 210 is configured to hold the membrane elements 20 at a predetermined position. The element rack 210 according to the present embodiment includes an upper frame 211 that is framed in a square shape in plan view, a lower frame 212 that is formed in a square shape in plan view, a corner portion of the upper frame 211, and a corner portion of the lower frame 212. Are connected to each other, and holding means (not shown) for holding the membrane elements 20 in a predetermined posture is provided on the lower frame 212. The element rack 210 (holding means) is configured so that a plurality of unit units A, B, and C in which a plurality of membrane elements 20.

  The plurality of membrane elements 20 constituting each unit A, B, C are arranged such that the membrane elements 20 adjacent in the lateral direction face each other with the filtration membranes 202 facing each other at a predetermined interval. The membrane elements 20 of each unit unit A, B, C in the direction are arranged in a line in the vertical direction. That is, the plurality of unit units A, B, and C arranged in the vertical direction are arranged such that the filtration membranes 202 of the membrane elements 20 adjacent in the vertical direction are substantially flush with each other.

  Since the membrane separation apparatus 1 according to this embodiment is configured to pull up the membrane elements 20 from the liquid W to be treated by the lifting means 40, 40 as described above, the membrane separation apparatus 1 is attached to the upper frame 211 of the element rack 210. Are provided with brackets 214, 214 for hooking hooks 42, which will be described later, of the lifting means 40, 40. Since the element rack 210 according to the present embodiment is framed so that the upper frame 211 has a quadrangular shape in plan view, the brackets 214 and 214 constitute a pair of transverse beams 211a and 211b that constitute the upper frame 211 and face each other. Is provided. In addition, since the element rack 210 (upper frame 211) according to the present embodiment is formed in a rectangular shape in plan view, brackets 214 and 214 are provided on a pair of transverse beams 211a and 211b at both ends in the longitudinal direction. .

  As shown in FIG. 2, the drainage system 30 includes primary side pipes 300a, 300b, and 300c that are fluidly connected to the membrane elements 20, and a suction pump 310a that is connected to the primary side pipes 300a, 300b, and 300c. 310b, 310c and a secondary side pipe 320 connected to the discharge side of the suction pumps 310a, 310b, 310c.

  In the primary side pipes 300a, 300b, 300c, the primary side connected to the membrane module 200 (membrane element 20 ...) is branched into a plurality of branches, and the branched branches 301a ..., 301b ..., 301c ... are each membrane element. 20 ... fluidly connected. The primary side pipes 300a, 300b, 300c are provided with branch pipes 301a ... 301b ... 301c ... corresponding to the number of membrane elements 20 ... built in the membrane module 200, so that the membrane module 200 as a whole is provided. In this embodiment, the primary side pipes 300a, 300b, and 300c are unit units A, B, and C of the membrane module 200 (the membrane elements 20 divided in the vertical direction). It is provided for each group.

  The primary side pipes 300a, 300b, 300c employ flexible hoses (not numbered) between the connecting portions to the suction pumps 310a, 310b, 310c and the plurality of branch pipes 301a, 301b, 301c,. When the membrane element 20 (membrane module 200) is pulled up from the filtration tank 10 (liquid to be treated W), or when the membrane element 20 ... (membrane module 200) is immersed in the filtration tank 10 (liquid to be treated W), The movement of the membrane elements 20 (membrane module 200) can be allowed.

  Various types of suction pumps 310a, 310b, and 310c can be employed. In this embodiment, a vane pump is employed, and the suction pressure of the liquid W to be processed is set to 90 KPa. In this embodiment, in order to monitor the driving pressures of the suction pumps 310a, 310b, and 310c, the total meters 302a and 302b are connected to the suction side (primary pipes 300a, 300b, and 300c) of the suction pumps 310a, 310b, and 310c. , 302c are installed. As described above, since the primary side pipes 300a, 300b, and 300c are provided for the unit units A, B, and C, the suction pumps 310a, 310b, and 310c are also provided for the primary side pipes 300a, 300b, and 300c (units). Units A, B, and C).

  The secondary side pipe 320 is connected to the discharge side of the suction pumps 310a, 310b, 310c, and flow meters 321a, 321b, 321c and a turbidimeter 322 are provided in the middle. The secondary pipe 320 is provided with a three-way valve 323 that switches the flow path based on the detection result of the turbidimeter 322 on the downstream side of the turbidimeter 322, and the three-way valve 323 is sufficiently filtered. A reverse pipe 324 for returning the non-treatment liquid W ′ to the filtration tank 10 and a drain pipe 325 for draining the treated liquid W ′ filtered as specified (supplied to the water storage tank 326) are connected.

  In this embodiment, since the suction pumps 310a, 310b, 310c are provided for each of the unit units A, B, C, the secondary side pipe 320 is located upstream of the three-way valve 323 (in this embodiment, Branches at the upstream side of the turbidimeter 322) and is connected to the suction pumps 310a, 310b, 310c, and the flow meters 321a, 321b, 321c are provided for the branch pipes 320a, 320b,. ing.

  As shown in FIGS. 1 and 2, the pulling means 40, 40 are configured to raise and lower the membrane module 200. In this embodiment, a winch is adopted. The winches 40, 40 are provided with a drum (not shown) for winding the wire 41 such as a wire rope or a chain, and a motor (not numbered) for rotating the drum, and the tip of the wire 41 Is provided with connecting means 42 for connecting to the membrane module 200 (element rack 210). In the present embodiment, a hook is employed for the connecting means 42, and is hooked and connected to brackets 214, 214 provided on the upper frame 211 of the element rack 210. Accordingly, when the drum 41 is driven to rotate and the strip 41 is wound up, the membrane module 200 (membrane element 20...) Is lifted from the filtration tank 10 (liquid W to be treated), and the winding of the strip 41 with respect to the drum is released. The membrane module 200 (membrane element 20...) Is immersed in the filtration tank 10 (liquid W to be treated).

  In the present embodiment, as described above, the element rack 210 of the membrane module 200 is formed in a rectangular shape in plan view, and the distance between the pair of horizontal beams 211a and 211b provided with the brackets 214 and 214 is wide. Two sets of upper means 40, 40 are provided corresponding to the arrangement of the horizontal beams 211a, 211b. In this embodiment, in order to move the membrane module 200 pulled up from the liquid W to be processed to a position outside the arrangement of the filtration tank 10, the lifting means 40, 40 (winches 40, 40) It is also movable in a direction perpendicular to the pulling direction. That is, each pulling means 40, 40 moves along the rails L, L provided above the filtration tank 10, and the position where the pulled up membrane module 200 is removed from the arrangement of the filtration tank 10. Can be placed in. Along with this, the lifting means 40, 40 has a traveling portion 45 provided with rollers (not shown) that roll on the rails L, L. The traveling unit 45 according to the present embodiment includes a motor (not numbered) that drives the roller, and is self-propelled.

  As shown in FIG. 2, the removing means 50 is configured to supply a fluid between the element body 201 of the membrane elements 20... And the filtration membrane 202, and the supplied fluid passes through the filtration membrane 202. Thus, the suspended substances attached to the filtration membrane 202 are peeled off. That is, when removing the liquid W to be processed, the removing means 50 is in a direction opposite to the one direction through which the liquid W to be processed passes through the filtration membrane 202 (the liquid for processing (filtrate) with respect to the filtration film 202). By circulating the fluid (from the W ′ side toward the liquid W to be treated), the suspended substances attached to the filtration membrane 202 are peeled and removed.

  More specifically, the removing means 50 according to the present embodiment includes a fluid supply pipe 500 fluidly connected to the membrane elements 20 and a fluid supply pressure feed pump connected to the fluid supply pipe 500. 501. The removing means 50 is configured to supply water as a fluid to the membrane elements 20... And the suction side of the pressure pump 501 is connected to a water tank via a pipe 502. In the present embodiment, the treatment liquid W ′ filtered by the membrane module 200 (membrane element 20...) Is used.

  The pressure pump 501 employs a spiral pump and is connected to a water storage tank 326 that receives the treatment liquid W ′ from the drain pipe 325 of the drainage system 30. The pressure pump 501 supplies fluid while applying an internal pressure of about 50 KPa to each membrane element 20.

  The removing means 50 according to the present embodiment includes one pressure feed pump 501, and the fluid supply pipe 500 branches into a plurality on the downstream side in the discharge direction of the pressure feed pump 501, and the branch pipes 500 a. ..., 500c ... are connected to each unit A, B, C (membrane element 20 ...). In the present embodiment, each branch pipe 500a, 500b, 500c of the fluid supply pipe 500 is provided so as to merge with each primary side pipe 300a, 300b, 300c of the drainage system 30, and the primary side pipe 300a, 300b and 300c are utilized as a part of the fluid supply pipe 500.

  Therefore, the branch pipes 500a, 500b, and 500c of the fluid supply pipe 500 are provided with valves 503a, 503b, and 503c for opening and closing the flow paths, and when the fluid is not supplied to the membrane elements 20,. When the treatment liquid W is filtered by the elements 20 and the treatment liquid W ′ flows into the primary side pipes 300a, 300b, 300c, the flow path of the fluid supply pipe 500 (branch pipes 500a, 500b, 500c) is closed. It is like that. Further, when the fluid is supplied from the fluid supply pipe 500, valves 327a, 327b, and 327c are also provided in the drainage system 30 so that the fluid flows to the membrane elements 20. In addition, the valves 327a, 327b, and 327c of the drainage system 30 according to the present embodiment are provided on the upstream side of the flow meters 321a, 321b, and 321c of the secondary side pipe 320.

  The recovery means 60 includes a container 600 that receives the suspended substance removed from the filtration membrane 202. In the present embodiment, there are provided a draining means 601 for cutting off the moisture dripping from the membrane module 200 and the moisture adhering to the suspended substance, and a frame 604 for supporting the draining means 601 above the container 600, the draining means. The suspended solids drained by 601 are received by the container 600.

  More specifically, as shown in FIG. 4, the draining means 601 is opposed to the mesh member 602 for draining the suspended matter separated from the filtration membrane 202, and the mesh member 602. Receiving members 601a and 601b configured with plate-shaped water receiving members 603 that receive water dripping through the mesh member 602 are provided. The receiving members 601a and 601b are arranged such that the water receiving member 603 is inclined forward and downward, and guides the water received by the water receiving member 603 to the forward downward side. The draining means 601 according to the present embodiment is provided with two receiving members 601a and 601b, and is provided in a state in which the end portions are overlapped with each other. That is, the water receiving member 603 of one receiving member 601a receives the water by the water receiving member 603 of the other receiving member 601b and guides water in the same direction.

  And the collection | recovery means 60 which concerns on this embodiment is provided adjacent to the filtration tank 10, receives the water induced | guided | derived by the receiving members 601a and 601b (water receiving member 603), and the upper part of the filtration tank 10. A water guiding member 605 for guiding is provided. The water guiding member 605 is formed in a plate shape, and has a frame 604 so that one end is positioned below the tip of the other receiving member 601b and the other end is lowered and positioned on the filtration tank 10. It is fixed to.

  In the collection means 60 according to the present embodiment, the base end side of one receiving member 601a is pivotally connected to the frame 604, and the distal end side of the other receiving member 601b is pivotally connected to the frame 604. 601a and 601b tilt downward and are opened above the container 600. The receiving members 601a and 601b are pivotally connected to the rod ends of cylinders 606a and 606b that are pivotally connected to the frame 604, and rotate (tilt) upward and downward by the expansion and contraction of the rods. It is like that.

  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.

  When the treatment liquid W supplied to the filtration tank 10 is filtered, as shown in FIG. 2, the suction pumps 310a, 310b, 310c of the drainage system 30 are operated to make the inside of the membrane element 20 ... negative pressure. Then, the liquid W to be processed in the filtration tank 10 flows toward the drainage system 30 through the filtration membrane 202. At this time, the suspended substances contained in the liquid W to be treated are caught by the filtration membrane 202 and deposited on the surface thereof to become the cake layer K (see FIG. 5A). When the turbidity (transparency) of the treatment liquid (filtrate) W ′ flowing through the drainage system 30 is measured by the turbidimeter 322 and determined to be a predetermined turbidity that satisfies the treatment standard, the turbidimeter The treated water W ′ that has passed through 322 is drained through the drain pipe 325 and stored in the water tank 326. Then, when the water level in the water storage tank 326 exceeds a predetermined level, the processing liquid W ′ is discharged to the outside. On the other hand, if it is determined from the detection result by the turbidimeter 322 of the drainage system 30 that the processing liquid W ′ does not have a predetermined turbidity (transparency), the flow path by the three-way valve 323 is switched, and the turbidity. The treated water W ′ that has passed through the total 322 is returned to the filtration tank 10.

  In this way, the filtration treatment of the liquid W to be treated is continuously performed, and when suspended substances are deposited on the filtration membrane 202 (the thickness of the cake layer K is increased), the filtration function cannot be sufficiently exhibited. The module 200 is pulled up from the liquid W to be processed to the outside by the pulling means 40. The superiority or inferiority of the filtration function is determined by pressure monitoring by the coupled meters 302a, 302b, 302c. That is, when the difference (pressure difference) between the pressure on the processing liquid W side (upstream side) and the pressure on the processing liquid W ′ side (downstream side) with respect to the filtration membrane 202 exceeds a predetermined value, the thickness of the cake layer K increases. Therefore, it is determined that the filtering function is in an abnormal state that is out of the proper state.

  This determination method can be substituted by a method in which only the pressure on the processing liquid W ′ side is compared with a predetermined value. In the case of this method, the pressure on the treatment liquid W ′ side is preferably −50 kPa (gauge pressure) or less. This is because by filtering at such a high level of negative pressure, not only the filtration speed increases, but also the liquid W to be treated having a higher concentration can be filtered. For example, in this embodiment, the upper limit of the concentration (solid content concentration) of the liquid W to be processed is 20% by weight, and if it is within this range, the effect that the suspended solids can be recovered with a low water content is remarkably recognized. . In the membrane separation apparatus of this embodiment, the lower limit of the concentration (solid content concentration) of the liquid W to be processed is 1 ppm (0.0001 wt%). The lower limit of this concentration range is a value determined based on physical properties such as the pore size of the microfiltration membrane. As described above, according to the membrane separation apparatus according to the present embodiment, it is possible to filter the liquid W to be processed in a wide range of concentrations using only this apparatus, while adopting a microfiltration membrane as the filtration membrane 202.

  The above-described superiority or inferiority of the filtration function can also be determined by monitoring the filtration flow rate using the flow meters 321a, 321b, and 321c. That is, when the amount of the liquid W to be processed that passes through the filtration membrane 202 is equal to or less than a predetermined value, it is determined that the thickness of the cake layer K becomes too thick and the filtration function is out of the proper state. This determination method is effective when filtering is continued until the amount of the cake layer K becomes relatively large. This is because the decrease in the filtration flow rate accompanying the increase in the amount of the cake layer K can be clearly grasped even when the amount of the cake layer K increases. By the way, in the case of the determination method using the pressure difference, when a cake layer K of a certain level or more is formed, the gauge pressure of the pressure gauge becomes near the capacity limit of the pump, and as a result, the gauge accompanying the increase in the cake layer K Pressure changes can be difficult to grasp.

  When the membrane module 200 is pulled up to the outside, the liquid W to be processed attached to the membrane module 200 drips down. At this time, the water content of the suspended matter adhering to the filtration membrane 202 also hangs down to the filtration tank 10, so that the moisture content of the suspended matter is lowered. However, since there is a limit in reducing the water content of the suspended solids only by natural fall, in this embodiment, when the membrane module 200 is pulled up from the liquid W to be treated to the outside, and after being pulled up. Also, the suction pumps 310a, 310b, 310c of the drainage system 30 are operated. That is, with the suspended matter (cake layer K) adhering to the filtration membrane 202 coming out, the suction pumps 310a, 310b, 310c are operated for a predetermined time to remove the moisture from the cake layer K. Yes. This makes the water content of the suspended material very low.

  And the pulling-up means 40 and 40 are made to run along the rails L and L, and the membrane module 200 is located at a position deviated from the arrangement of the filtration tank 10, that is, above the draining means 601 (container 600). Therefore, the suction pumps 310a, 310b, 310c of the drainage system 30 are stopped, the valves 327a, 327b, 327c of the drainage system 30 are closed, while the valves 503a, 503b, 503c of the removing means 50 are opened, and a pressure feed pump for fluid supply 501 is activated. Then, the treatment liquid W ′ stored in the water storage tank 326 flows in the direction opposite to the flow of the treatment liquid W ′ at the time of filtration and is supplied to the membrane elements 20... Then, as shown in FIG. 5B, the fluid flows from the filtrate W ′ side toward the liquid W to be treated, and adheres to the outer surface of the filtration membrane 202 by the supply pressure. The suspended substance thus pushed is peeled off from the filtration membrane 202. The supply pressure of the fluid is preferably 10 kPa (gauge pressure) or more in order to cause the action of pushing the cake layer K away from the filtration membrane 202, and in order to reliably and sufficiently bring the action of pushing the cake layer K away. 50 kPa or more is more preferable. The reason why the fluid supply pressure is preferably 50 kPa or more is that a uniform pressure can be applied to the filtration membrane 202. Note that the upper limit of the fluid supply pressure is preferably 200 kPa because the water content of the suspended substance to be recovered can be reduced.

  In particular, in the present embodiment, water (treatment liquid W ′) is supplied as a fluid, and therefore slips between the filtration membrane 202 and the suspended substance due to the presence of the treatment liquid W ′ that has passed through the filtration membrane 202. Is likely to occur, and the suspended substance is efficiently peeled off. Moreover, in this embodiment, since the outer peripheral edge part of the filtration membrane 202 is stuck on the outer peripheral edge part of the element main body 201, when the above internal pressure acts, the filtration membrane 202 will be pushed outside. The swelled state is obtained, and the suspended substance is efficiently peeled by the curvature of the filtration membrane 202 due to the swell. Thereby, the clogging of the filtration membrane 202 is eliminated, and the filtration function is restored.

  As shown in FIG. 2, the suspended substance (cake layer) K peeled off from the filtration membrane 202 falls downward and is received by the draining means 601. At this time, the treated water W ′ supplied to peel the cake layer K from the filtration membrane 202 adheres to the suspended matter or falls directly from the filtration membrane 202, but the water is passed through the mesh member 602. It is received by the receiving member 603 and guided to the filtration tank 10.

  After the suspended matter K is sufficiently drained, the receiving members 601a and 601b are tilted, and the suspended matter K on the mesh member 602 is dropped into the container 600 below and collected. become.

  Then, after the membrane module 200 is immersed again in the filtration tank 10 (liquid W to be treated), the flow path is changed by switching the valves 327a, 327b, 327c, 503a, 503b, 503c, and the pump 310a that operates Switching of 310b, 310c, 501 is performed and the filtration process is resumed.

  As described above, the membrane separation apparatus 1 according to the present embodiment has the membrane module 200 (membrane element 20...) Pulled up from the liquid W to be treated by the lifting means 40, 40 and then filtered by the removing means 50. Since the suspended matter adhering to the membrane 202 is removed, the suspended matter removed from the filtration membrane 202 does not return into the liquid W to be treated. Thereby, it can prevent that the solid content density | concentration of the to-be-processed liquid W increases, and the damage of the filtration membrane 202 can be suppressed. Also, by pulling up the membrane elements 20 to the outside, the moisture contained in the suspended substance attached to the filtration membrane 202 drips down, so that the moisture content is lower than that of the suspended substance recovered from the liquid as in the prior art. The suspended matter can be recovered in the state.

  In particular, since the suction by the suction pumps 310a, 310b, and 310c is continued even when the membrane module 200 (membrane element 20...) Comes out from the liquid W to be processed, the suspended substance K adhering to the filtration membrane 202 is removed. Can be close to dry.

  Furthermore, since the removing means 50 is configured to circulate the fluid in the other direction with respect to the filtration membrane 202, the suspended substance is reliably removed from the filtration membrane 202 by the pressure of the fluid passing through the filtration membrane 202. Can be removed.

  In addition, a recovery means 60 for recovering the suspended substance K removed by the removal means 50 at a position deviating from the arrangement of the filtration tank 10 is provided, and the lifting means 40, 40 is a membrane pulled up from the filtration tank 10. Since the elements 20... Are movably provided so as to be arranged at positions corresponding to the recovery means 60, the suspended matter K is removed or removed after the pulled membrane elements 20 are arranged at positions away from the filtration tank 10. It can collect | recover and it can prevent that the suspended solid K falls inadvertently in the filtration tank 10, and raises the solid content density | concentration of the to-be-processed liquid W.

  The membrane separation apparatus of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

  In the above embodiment, the removing means 50 is configured to supply the fluid to the plurality of membrane elements 20 arranged in parallel to remove the suspended substance K from the filtration membrane 202. However, the present invention is not limited to this. For example, the fluid may be alternately supplied to the plurality of membrane elements 20.

  Specifically, as shown in FIG. 6, the order (No. 1 to No. 7 shown in the figure) from the ends of the plurality of membrane elements 20 arranged in parallel in the horizontal direction is an odd-numbered group (hereinafter, The odd number group) is divided into an even numbered group from the end (hereinafter even number group), and the pipe Ga connected to the odd group film elements 20 and the even group film elements 20. It is good also as the fluid supply piping 500 connected to the pressure pump 501 by collecting the connected piping Gb via the three-way valve 350.

  In this way, by switching the three-way valve 350, the fluid (treated water W ′) can be alternately supplied to the even-numbered group and the odd-numbered group, and the distance between the membrane elements 20. Can be planned. That is, in consideration of the fact that the filtration membrane 202 swells due to pressure when the fluid is supplied by the removing means 50, it is necessary to set the gap between the membrane elements 20 to be large so that the filtration membranes 202 of the adjacent membrane elements 20 do not interfere with each other. However, if every other fluid is supplied to the membrane elements 20..., The adjacent filtration membranes 202 can be prevented from bulging and interfering with each other. It is possible to reduce the size of the apparatus by narrowing the interval. However, in this case, the fluid in the filtered state in which the liquid W to be treated is circulated all over the membrane elements 20 and in the removed state of the cake layer K in which the treatment liquid W ′ is alternately circulated in the membrane elements 20. Therefore, the fluid supply pipe 500 (branch pipes 500a, 500b, 500c) and the drain side system primary pipes 300a, 300b, 300c (branch pipes 301a, 301b, 301c) are made independent of each other. Needless to say, they are connected to the membrane elements 20.

  In the above-described embodiment, a winch is employed as the lifting means 40, and the wire module 41 is wound and released, whereby the membrane module 200 is lifted from the filtration tank 10 (liquid W to be treated) and immersed. However, the present invention is not limited to this. For example, as shown in FIG. 7, the pulling means 40 ′ is composed of a rotatable arm 450 and a driving means (not shown) for rotating the arm 450. The membrane module 200 may be connected to the arm 450. In this way, the membrane module 200 can be pulled up from the liquid W to be treated as the arm 450 rotates. Further, if the rotation range of the arm 450 is increased, the membrane module 200 can be moved to a position outside the arrangement of the filtration tank 10. In this case, the rotation fulcrum of the arm 450 is preferably positioned above the membrane module 200 immersed in the filtration tank 10 (liquid W to be treated) (preferably outside the filtration tank 10). However, it is needless to say that the rotation fulcrum is set so that the rotation radius of the membrane module 200 becomes as small as possible in consideration of the miniaturization of the apparatus.

  In the above embodiment, the flat plate type membrane element in which the element main body 201 is formed in a plate shape is adopted. However, the present invention is not limited to this. For example, the element main body 201 is formed in a cylindrical shape whose both ends are sealed. The thing etc. which stuck the filtration membrane 202 to the outer peripheral surface of the main body 20 may be sufficient. That is, it is not limited to the shape of the membrane elements 20..., And may be any membrane element 20 (membrane module 200) having the filtration membrane 202 that filters the liquid W to be processed in one direction.

  In the above embodiment, the membrane module 200 is pulled up from the liquid W to be treated, and the membrane module 200 is moved to a position out of the arrangement of the filtration tank 10, and then the suspended substance (cake layer) K is peeled off. However, for example, the pulling means 40 is configured so as to simply move the membrane module 200 up and down, and the collecting means 60 (container 600) is moved below the pulled membrane module 200 so that the cake layer K to be peeled off is removed. You may make it receive. In this case, the entire recovery means 60, the container 600, or the draining means 601 are configured to be movable (running), and the recovery means 60 and the container 600 are placed between the filtration tank 10 and the position where the membrane module 200 is pulled up by the lifting means. Alternatively, a rail for guiding the draining means 601 may be provided. When the draining unit 601 is configured to be movable, the draining unit 601 below the membrane module 200 receives the suspended substance (cake layer) K and drains it, and then returns the draining unit 601 to the collecting unit 60 and the lower container 600. Suspended material K is recovered by the procedure of dropping suspended material in In this case, the entire draining means 601 may be movable, or only one of the pair of receiving members 601a and 601b may be movable. Of course, the mesh member 602 may be movable.

  In the above embodiment, the plurality of membrane elements 20 are configured as the membrane module 200, and the membrane module 200 is pulled up from the liquid to be processed W by the lifting means 40, so that the membrane elements 20 are externally connected from the liquid W to be processed. However, for example, only the membrane element 20 may be lifted from the liquid W to be treated. In this case, the membrane element 20 (unit units A, B, and C) is configured to be detachable with respect to the element rack 210 that supports the membrane element 20 in the liquid W to be treated, and the membrane element 20 (preferably, the element body 201). A connecting portion (for example, the bracket 214 in the above embodiment) to which the connecting means 42 of the lifting means 40 is connected may be provided.

  In the above embodiment, the plurality of membrane elements 20 are arranged side by side in the vertical and horizontal directions. However, the present invention is not limited to this. For example, the plurality of membrane elements 20 are arranged side by side in the horizontal direction, A plurality of membrane elements 20 may be arranged in a line in the vertical direction. Moreover, in the said embodiment, although the several membrane element 20 ... was provided, it is not limited to this, For example, what provided the one membrane element 20 may be used. That is, the membrane elements 20 may be provided in a number corresponding to the required filtration capacity.

  In the above embodiment, the removing means 50 is configured to supply the filtered treatment liquid W ′ to the membrane elements 20..., But is not limited thereto. For example, the removing means 50 is applied to the membrane elements 20. You may comprise so that gas may be pumped toward. Even in this case, the cake layer K attached to the filtration membrane 202 can be peeled and removed by the gas supply pressure. However, if the moisture exists on the surface of the filtration membrane 202, the peeling of the cake layer K becomes smoother. Therefore, the removing means 50 is, for example, a gas with moisture remaining in the filtration membrane 202 or the membrane element 20. It is preferable that the liquid is supplied as in the above embodiment.

  Moreover, in the said embodiment, although the cake layer K was removed by supplying process liquid W 'to the membrane element 20 ..., it is not limited to this, For example, the removal means 50 is a film | membrane. The cake layer K adhering to the filtration membrane 202 of the element 20 may be scraped off with a scraper or the like, or the cake layer K may be peeled off by applying vibration to the entire membrane module 200 or the membrane element 20. Further, the removing means 50 is configured to supply fluid to the membrane elements 20 as in the above embodiment, and in addition to this, the cake layer K is peeled off by applying vibration to the entire membrane module 200 or the membrane element 20. You may make it fall off. However, in any case, it goes without saying that the removing means 50 is operated with the membrane module 200 pulled up from the liquid W to be treated.

  In the above embodiment, the filter membrane 202 is heated and welded to the element body 201 using a hot plate. However, the present invention is not limited to this. For example, the filter membrane 202 is ultrasonically applied to the element body 201. You may make it weld and may make it stick using an adhesive agent. When the filtration membrane 202 is welded to the element body 201 by ultrasonic waves, a large number of minute protrusions are provided in the region of the element body 201 to which the filtration membrane 202 is attached, and the protrusion is melted to provide a filtration membrane. It is preferable to stick 202.

  In the above embodiment, the peripheral portions of the element main body 201 and the filtration membrane 202 are adhered to each other. For example, the membrane element 20 (the filtration region of the filtration membrane 202) has a large size (for example, the vertical dimension is 0). (5m or more, lateral dimension is 1m or more), in order to increase the bonding strength between the element body 201 and the filtration membrane 202, the region surrounded by the region where the outer peripheral ends are adhered (enclosed region) The element main body 201 may be adhered to the filtration membrane 202 so as to be divided into two or more. In this case, it is preferable that the sticking portion that defines the surrounding region of the element main body 201 is a smooth surface as in the outer peripheral end portion.

  In the above embodiment, the membrane element 20 is configured by interposing the mesh 205 between the element main body 201 and the filtration membrane 202. However, the present invention is not limited to this, and for example, to promote the flow of fluid. A membrane element is formed by forming a groove connected to the second hole 204b on the surface of the element body 201 facing the filtration membrane 202 or forming a plurality of convex portions on the surface of the element body 201 facing the filtration membrane 202. 20 may be configured. Even if it does in this way, a clearance gap will be formed between the element main body 201 and the filtration membrane 202, and the smooth distribution | circulation of the fluid will be achieved similarly to having interposed the said mesh.

  In the above-described embodiment, the membrane elements 20 are configured by laminating the filtration membranes 202 on both surfaces of the element body 201. However, the present invention is not limited to this. For example, the filtration membrane 202 is provided only on one surface of the element body 201. The membrane element 20 may be configured by stacking layers. In this case, of course, the second hole portion 204b is formed in a non-penetrating state, and the flow passage 204 is allowed to penetrate between the end surface of the element body 201 and one surface.

Claims (4)

It has at least one membrane element equipped with a filtration membrane for filtering the liquid to be treated containing suspended substances, and is configured to filter the liquid to be treated in a state where the membrane element is immersed in the liquid to be treated. In the membrane separation apparatus, the lifting means for lifting the membrane element from the liquid to be processed to the outside, and the suspended substances attached to the filtration membrane of the membrane element pulled from the liquid to be processed to the outside by the lifting means are removed. A removing means and a collecting means for collecting suspended substances removed by the removing means, and receiving suspended substances falling from the filtration membrane of the membrane element pulled out from the liquid to be treated by the lifting means. and a recovery means for recovering該懸turbid substance, the collecting means, membrane separation apparatus characterized by being movable under the lifted membrane element from filtration bath. The removing means is directed from the filtrate side toward the liquid to be treated with respect to the filtration membrane in a state where the water content of the suspended matter adhering to the filtration membrane of the membrane element is less than when it is pulled up from the liquid to be treated. The membrane separation device according to claim 1 , wherein the membrane separation device is configured to circulate a fluid.   A step of pulling out the membrane element immersed in the liquid to be treated to filter the liquid to be treated containing the suspended substance from the liquid to be treated, and a filter membrane of the membrane element pulled up from the liquid to be treated to the outside A process for removing adhering suspended solids and a process for recovering suspended solids removed in the process of removing suspended solids, which are moved below the membrane element pulled out from the liquid to be treated. And a step of receiving the suspended substance falling from the filtration membrane of the membrane element by the collecting means and collecting the suspended substance. 4. The method for cleaning a membrane element according to claim 3 , wherein the step of removing suspended substances is performed by flowing a fluid from the filtrate side toward the liquid to be treated.

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