JP2007203219A - Membrane separation type water purifier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a membrane separation type water purifier hardly causing clogging of a hollow fiber membrane of a membrane unit and capable of enhancing productivity to purify raw water by reducing a need to clean the membrane unit. <P>SOLUTION: The membrane unit 6 comprises: a first fixed part 1; a second fixed part 2 placed so as to surround the first fixed part 1; and the hollow fiber membrane 3 radially placed between the first fixed part 1 and the second fixed part 2 to fix one end on the first fixed part 1 and the other end on the second fixed part 2, wherein the first fixed part 1 is formed as a rotary shaft 4 and wherein a water passing part 5 communicating with the inside of the hollow fiber membrane 3 is provided inside the rotary shaft 4. The membrane unit 6 is mounted inside a septic tank 7 for purifying the raw water with activated sludge by supporting the rotary shaft 4 placed in a horizontal posture so as to be freely rotated. A suction and discharge means 8 sucking inside the water passing part 5, filtrating purified water inside the septic tank 7 by the hollow fiber membrane 3 and separating it from the activated sludge to discharge is connected to the water passing part 5. An air diffuser pipe 9 is provided inside the septic tank 7 on the downstream side of the membrane unit 6. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a membrane separation type water purification apparatus in which raw water is purified with activated sludge and the purified water is separated from activated sludge through a membrane unit and discharged.

  FIG. 9 shows a conventional example of a membrane separation type water purification device (see, for example, Non-Patent Document 1). In FIG. 9, 7 is a septic tank, 15 is a raw water pipe for supplying raw water to the septic tank 7, and the raw water pipe 15 is provided with a raw water on-off valve 16. A membrane unit 6 is provided in the septic tank 7, and a suction pipe 17 is connected to the membrane unit 6. The suction pipe 17 is provided with a suction opening / closing valve 18 and a suction pump 19, and a chemical tank 20 is connected to the suction pipe 17 through a chemical supply pipe 21. The medicine supply pipe 21 is provided with a medication opening / closing valve 22. An air diffuser 9 connected to the blower 23 is disposed at the bottom of the septic tank 7.

  9, raw water is supplied into the septic tank 7 from the raw water pipe 15 by opening the raw water on-off valve 16, and this raw water is purified by activated sludge in the septic tank 7. Then, by suctioning the inside of the membrane unit 6 with the suction pump 19, the purified water that has been purified passes through the membrane unit 6, is separated from the activated sludge, and is discharged through the suction pipe 17. In the membrane separation type water purification apparatus that filters the water purified by the action of activated sludge in this way and separates it from the activated sludge and discharges it, the surface of the membrane unit 3 that is stationary in the septic tank 7 The activated sludge accumulates on the surface and the dirt adheres, and the membrane unit 6 is easily clogged. When the membrane unit 6 is clogged in this way, the filtration efficiency of the purified water by the membrane unit 6 is lowered.

For this reason, in the membrane separation type water purification apparatus as shown in FIG. 9, it is necessary to frequently wash the membrane unit 6. When the membrane unit 6 is washed, first, the raw water on-off valve 16 is closed to stop the supply of raw water from the raw water pipe 15 to the septic tank 7, the suction pump 19 is stopped and the suction on-off valve 18 is closed to close the septic tank. Stop the purification operation of raw water by No.7. Then, the medicine opening / closing valve 22 is opened, the medicine is supplied from the medicine tank 20 through the medicine supply pipe 21 and the suction pipe 17 into the membrane unit 6, and the membrane unit 6 is filled with the medicine for a predetermined time. The clogging of the membrane unit 6 is cleaned by decomposing it with chemicals. After the clogging of the membrane unit 6 is washed with chemicals in this way, the suction pump 19 is operated and the suction on-off valve 18 is opened to discharge the chemicals in the membrane unit 6. Thereafter, the raw water on-off valve 16 is turned on. By opening and supplying raw water from the raw water pipe 15 to the septic tank 7, the purification operation as described above can be resumed.
Ministry of the Environment Minister's Secretariat Waste and Recycling Countermeasures Department Waste Management Division, Septic Tank Countermeasures Office, “Nitrogen Removal / Membrane Separation Small Merger Treatment Septic Tank Maintenance Guidelines and Explanation”, Japan Environmental Education Center, 2001 February, p. 174, p. 215-216

  Although the membrane unit 6 can be washed as described above, the purification operation for purifying the raw water cannot be performed while the membrane unit 6 is being washed. If the surface is contaminated and clogging is likely to occur as in the membrane unit 6 of the membrane separation type water purification device of FIG. 9, the raw water purification operation is stopped and the membrane unit is frequently washed. Since it was necessary, the problem that the productivity which purifies raw | natural water falls will arise.

  The present invention has been made in view of the above points, and the hollow fiber membrane of the membrane unit is less likely to be clogged, the need for cleaning the membrane unit can be reduced, and the productivity for purifying raw water is improved. An object of the present invention is to provide a membrane separation type water purification device that can be enhanced.

  The membrane separation type water purification apparatus according to claim 1 of the present invention includes a first fixed portion 1, a second fixed portion 2 disposed so as to surround the first fixed portion 1, and a first fixed portion. A hollow fiber membrane 3 that is radially arranged between 1 and the second fixing part 2 and has one end fixed to the first fixing part 1 and the other end fixed to the second fixing part 2; In the septic tank 7 which forms the membrane unit 6 by forming the fixed portion 1 as the rotating shaft 4 and providing the water passing portion 5 communicating with the inside of the hollow fiber membrane 3 in the rotating shaft 4 to purify the raw water with activated sludge. In addition, a membrane unit 6 is attached by supporting the rotary shaft 4 arranged in a horizontal posture so as to be freely rotatable, and the inside of the water passage 5 is sucked and the purified water in the septic tank 7 is filtered by the hollow fiber membrane 3. The suction discharge means 8 for separating and discharging from the activated sludge is connected to the water supply section 5, and an air diffuser 9 is provided in the septic tank 7 below the membrane unit 6. Be comprised Te is characterized in.

  According to this invention, the hollow fiber membrane 3 provided radially around the rotation shaft 4 is rotated in the vertical direction in water by rotationally driving the membrane unit 6 with the rotation shaft 4 arranged in a horizontal posture. The water pressure acting on the hollow fiber membrane 3 always changes, and the action of air diffused from the air diffuser 9 always changes. For this reason, the hollow fiber membrane 3 is less likely to be contaminated by activated sludge accumulation and the like, so that clogging can be reduced, and certain portions of the hollow fiber membrane 3 are not easily clogged. Thus, the necessity of cleaning the membrane unit 6 can be reduced.

  The membrane-separated water purification device according to claim 2 of the present invention includes a first fixed portion 1, a second fixed portion 2 disposed to face the first fixed portion 1, and a first fixed portion. A hollow fiber membrane 3 which is arranged in parallel between 1 and the second fixing part 2 and has one end fixed to the first fixing part 1 and the other end fixed to the second fixing part 2; At least one of the first fixing portion 1 and the second fixing portion 2 is provided with a water passage portion 5 communicating with the inside of the hollow fiber membrane 3 in at least one of the fixing portion 1 and the second fixing portion 2. A membrane unit 6 is formed by providing a rotary shaft 4 parallel to the hollow fiber membrane 3 in a septic tank 7 for purifying raw water with activated sludge. A membrane unit 6 is attached, the inside of the water passage 5 is sucked, and the purified water in the septic tank 7 is filtered through the hollow fiber membrane 3 to be separated from the activated sludge and discharged. The suction and discharge means 8 connected to the water passage 5 for and is characterized by comprising providing a pipe 9 diffusing into the septic tank in 7 at the lower side of the membrane unit 6.

  According to this invention, the hollow fiber membrane 3 provided between the first fixed portion 1 and the second fixed portion 2 is horizontally driven by rotationally driving the membrane unit 6 with the rotary shaft 4 arranged in a horizontal posture. In this state, the water can be pivoted up and down in the vertical direction, the water pressure acting on the hollow fiber membrane 3 always changes, and the action of the air diffused from the air diffusion tube 9 always changes. For this reason, the hollow fiber membrane 3 is less likely to be contaminated by activated sludge accumulation and the like, so that clogging can be reduced, and certain portions of the hollow fiber membrane 3 are not easily clogged. Thus, the necessity of cleaning the membrane unit 6 can be reduced.

  The invention of claim 3 is characterized in that in claim 1 or 2, it comprises a forced washing means 10 for washing the hollow fiber membrane 3 of the membrane unit 6 by a physical action.

  According to the present invention, when the hollow fiber membrane 3 is clogged, it can be efficiently washed by the forced washing means 10.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, at least one of the first fixed portion 1 and the second fixed portion 2 of the membrane unit 6 has a convex surface on the side of the hollow fiber membrane 3. It is formed on a curved surface.

  According to the present invention, it is possible to prevent the water flow generated in the septic tank 7 from being diffused by the air diffusing tube 9 from staying on the surfaces of the first fixed portion 1 and the second fixed portion 2, and A high clogging prevention effect can be obtained.

  The invention of claim 5 is characterized in that in any one of claims 1 to 4, an ultrasonic oscillator 11 is attached to the membrane unit 6.

  According to this invention, it is possible to reduce the occurrence of clogging in the hollow fiber membrane 3 by applying ultrasonic vibration to the hollow fiber membrane 3 of the membrane unit 6.

  According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the ultrasonic oscillator 11 includes at least one of a moving means that enables movement in the septic tank 7 and a frequency control means that makes the oscillation frequency variable. It is characterized by comprising one side.

  According to this invention, each part of the hollow fiber membrane 3 can be ultrasonically vibrated, and the clogging prevention effect of the hollow fiber membrane 3 can be obtained high.

  According to the present invention, the hollow fiber membrane 3 can be rotated up and down in the water of the septic tank 7 by rotating the membrane unit 6 around the rotary shaft 4, and the hollow fiber membrane 3 is clogged. Therefore, it is possible to reduce the necessity for cleaning the membrane unit 6 by stopping the purification operation of the raw water in the septic tank 7, and the productivity for purifying the raw water can be increased.

  Hereinafter, the best mode for carrying out the present invention will be described.

  FIG. 1 shows an example of an embodiment of the present invention, in which a membrane unit 6 and a diffuser tube 9 are arranged in a septic tank 7. The septic tank 7 is made of any material such as stainless steel or cement. A raw water pipe 15 is connected to the upper part of the septic tank 7, and the raw water to be purified is supplied to the septic tank 7 by opening a raw water on-off valve 16 provided in the raw water pipe 15. Although the kind of raw | natural water on-off valve 16 is not specifically limited, It is desirable to form with an electric valve so that automatic operation can be performed.

  FIG. 2 shows an example of the membrane unit 6, and the second fixing portion 2 is arranged so as to surround the outer periphery of the first fixing portion 1 from the outside. The first fixed portion 1 serves as the rotating shaft 4 and is formed in a cylindrical pipe shape. The second fixing portion 2 is formed in a cylindrical shape, and a plurality of spoke-like connecting rods 25 are connected between the outer periphery of the first fixing portion 1 and the inner periphery of the second fixing portion 2. Thus, as shown in FIG. 2B, the second fixing portion 2 is attached to the first fixing portion 1 in a concentric arrangement. The second fixing portion 2 is attached to a plurality of locations at equal intervals along the longitudinal direction of the first fixing portion 1. A plurality of hollow fiber membranes 3 are arranged radially between the first fixing portion 1 and each second fixing portion 2, and one end of the hollow fiber membrane 3 is connected to the first fixing portion 1 with the hollow fiber. The other end of the membrane 3 is fixed to the second fixing portion 2. The inside of the 1st fixing | fixed part 1 formed in a cylindrical pipe becomes the water flow part 5, and the 1st fixation so that the opening part of the end of the hollow fiber membrane 3 may open in this water flow part 5 It is fixed to the part 1, and the opening at the other end of the hollow fiber membrane 3 is closed by the second fixing part 2. The hollow fiber membrane 3 can be made of any material such as polyethylene, polyvinylidene fluoride, polytetrafluoroethylene, polyacrylonitrile, porsulfone, and the pore diameter is not particularly limited.

  The membrane unit 6 formed as described above is provided in the septic tank 7 and is arranged in a horizontal posture so that the first fixed portion 1 serving as the rotation shaft 4 is parallel to the water surface. It is attached in the septic tank 7 in a state where it is supported by 4. In the embodiment of FIG. 1, both end portions of the rotating shaft 4 are rotatably supported by penetrating the side walls of the septic tank 7, but it is needless to say that the present invention is not limited to such an embodiment. The inside of the rotating shaft 4 formed by the cylindrical pipe is formed as the water passing portion 5 as described above, but one end of the water passing portion 5 is closed, and the end of the closed rotating shaft 4 is closed. A drive unit 26 such as a motor is connected to the motor. The other end portion of the water flow portion 5 is opened, and the suction / discharge means 8 is connected to the open end portion of the water flow portion 5.

  The suction / discharge means 8 is formed with a suction pipe 17, and the suction pipe 17 is connected to the opening of the water passage 5 at the end of the rotating shaft 4. The suction pipe 17 and the water passage portion 5 can be connected using a rotary joiner having a water sealing function. The suction pipe 17 is provided with a suction pump 19, and the suction pump 19 is operated to suck the inside of the water passage 5, thereby allowing water to pass through the hollow fiber membrane 3 of the membrane unit 6. The passed water is discharged from the water portion 5 through the suction pipe 17. In addition to forcibly sucking the inside of the water flow portion 5 using the suction pump 19 as described above, it is possible to form a structure that naturally sucks using the height difference without using the suction pump 19.

  The air diffuser 9 is disposed at the bottom of the septic tank 7 below the membrane unit 6 and is connected to a blower 23 disposed outside the tank. The blower 23 may be anything as long as it blows a gas containing oxygen such as air, such as a machine that blows air, such as a blower or a compressor, or a pressure cylinder containing air. The amount of blast should just be what can ensure the amount of dissolved oxygen which the activated sludge in the septic tank 7 requires. The air diffuser 9 is used to make the gas sent from the blower 23 into fine bubbles so that oxygen can be distributed in the septic tank 7. For example, the air diffuser 9 is formed as a pipe having a plurality of holes having a diameter of about 2 mm. Can do.

  The structure of the diffuser part of the diffuser tube 9 can also be formed as shown in FIG. In this structure, valve seats 36 whose inner peripheral openings are mortar-shaped diffuser holes 35 are provided at a plurality of locations along the longitudinal direction of the diffuser tubes 9 arranged horizontally. A stopper box 37 is attached so as to cover the valve seat 36, and a vent hole 38 is opened on the upper surface of the stopper box 37. In the stopper box 37, a valve lid 39 is attached to the valve seat 36 so as to be movable up and down, and the air diffusion hole 35 can be opened and closed by the valve lid 39. The valve lid 39 is formed in an inverted frustoconical shape, and the diameter of the upper surface of the valve lid 39 is larger than the diameter of the vent hole 38.

  In this case, when a gas such as air is sent from the blower 23 to the diffuser tube 9, the valve lid 39 is pushed up by the blowing pressure to open the diffuser hole 35, and the blown gas is discharged from the diffuser hole 35. The air is diffused into the septic tank 7 through the vent hole 38. Further, when the operation of the blower 23 is stopped and the gas is not sent, the valve lid 39 is pushed down by water pressure and the air diffusion hole 35 is closed, and the activated sludge in the septic tank 7 flows back into the air diffusion pipe 9. It is possible to prevent the inside of the air diffuser 9 from being clogged with activated sludge.

  Moreover, the structure of the diffuser part of the diffuser tube 9 can also be formed as shown in FIGS. In this structure, valve seats 36 whose inner peripheral openings are diffused holes 35 are provided at a plurality of locations of the air diffuser tube 9, and the upper and lower ends are surrounded by the valve seat 36 so as to rise above the valve seat 36. A guide cylinder 41 having an opening is attached. A horizontal bar 42 penetrating the inside and outside of the guide cylinder 41 is attached to the guide cylinder 41, and both end portions of the horizontal bar 42 protrude outward of the guide cylinder 41. Two horizontal bars 42 are provided so as to cross each other in a cross. Below the horizontal bar 42, a valve ball 43 is attached to the valve seat 36 so as to be movable up and down so that the air diffuser hole 35 can be opened and closed by the valve ball 43. The upper portion of the guide tube 41 is covered with a trap container 44 whose bottom surface is open. A frustoconical valve lid 45 is provided on the upper bottom surface of the guide cylinder 41 so that the upper end opening of the guide cylinder 41 can be opened and closed by the valve lid 45. Further, a vertically long slide hole 46 is formed in the peripheral wall of the trap container 44, and the end of the horizontal bar 42 is inserted into the slide hole 46. Accordingly, the trap container 44 is moved up and down within a range in which the slide hole 46 can move up and down with respect to the horizontal bar 42. Further, a diffuser slit 47 is formed in the circumferential wall of the trap container 44 at a plurality of locations in the circumferential direction, and each diffuser slit 47 is opened at the lower end edge of the peripheral wall of the trap container 44.

  In this case, when a gas such as air is sent from the blower 23 to the diffuser tube 9, the valve ball 43 is pushed up by the blown pressure to open the diffuser hole 35, and the valve lid 45 together with the trap container 44. The gas is pushed up and flows into the trap container 44 through the guide tube 41 from the diffuser hole 35 and is diffused into the septic tank 7 through the diffuser slit 47. Since the diffuser slit 47 is open at the lower end edge of the peripheral wall of the trap container 44, the diffuser slit 47 is less likely to be clogged with activated sludge. Further, when the operation of the blower 23 is stopped and the gas cannot be sent, the valve ball 43 falls by its own weight and the air diffusion hole 35 is closed, and the trap container 44 is pushed down by the water pressure to open the upper end of the guide cylinder 41. Can be blocked by the valve lid 45, and the activated sludge in the septic tank 7 can be prevented from flowing back into the diffuser tube 9, and the activated sludge can be prevented from entering and clogging the diffuser tube 9. It is something that can be done. Here, the backflow of the activated sludge is prevented in triplicate by the trap effect between the trap container 44 and the guide tube 41, the blockage of the guide tube 41 by the valve lid 45, and the blockage of the air diffusion hole 35 by the valve ball 43. Therefore, it is possible to reliably prevent the inside of the air diffuser 9 from being clogged with activated sludge.

  Further, a water level detecting means 27 is provided in the septic tank 7 so that the water level in the septic tank 7 is detected. As the water level detection means 27, a float switch or a pressure sensor can be used. The pressure sensor detects the water level by detecting the water pressure.

  In the membrane separation type water purification apparatus, the raw water on-off valve 16, the suction pump 19, the blower 23, the drive unit 26, the water level detection means 27, etc. are electrically connected to a control device (not shown), respectively. It is supposed to be controlled automatically.

Therefore, when performing the purification operation for purifying the raw water with the membrane separation type water purification apparatus formed as described above, first, the raw water on-off valve 16 is opened, and the raw water is supplied to the septic tank 7 through the raw water piping 15, and the membrane unit. When the entire 6 reaches to a predetermined water level L _1, which is immersed, to stop the supply of raw water by closing the raw water on-off valve 16. On the other hand, the air blower 23 is operated to supply a gas such as air from the air diffuser 9 into the septic tank 7 to diffuse the air, and the suction pump 19 is operated to supply the water flow section in the rotating shaft 4 of the membrane unit 6. 5 is aspirated. Furthermore, the drive part 26 is driven, the rotating shaft 4 is rotationally driven, and the whole film | membrane unit 6 is rotated centering on the rotating shaft 4. FIG. The rotation drive of the membrane unit 6 may be continuous, intermittent, or either.

The raw water thus supplied to the septic tank 7 is purified in the septic tank 7 by the action of activated sludge. At this time, the purification action by the activated sludge is further activated by supplying oxygen to the activated sludge by the aeration action from the aeration tube 9. And since the inside of the water flow part 5 in the rotating shaft 4 of the membrane unit 6 is depressurized by suction by the suction pump 19, the raw water purified in the septic tank 7 passes through the hollow fiber membrane 3 and passes through the water flow part 5. It is separated from activated sludge as purified water. Thus, the purified water that has passed through the membrane unit 6 is discharged from the septic tank 7 through the water passage 5 and the suction pipe 17. Further, by discharging the purified water from the septic tank 7, the water level of the septic tank 7 is lowered. When the water level is lowered to a predetermined water level L ₂ , the raw water on / off valve 16 is opened to supply the raw water to the septic tank 7. _{1 is} supplied. The water levels L ₁ and L ₂ are detected by the water level detection means 27, and the raw water on-off valve 16 is automatically controlled to open and close in response to the detection of the water levels L ₁ and L ₂ .

  During the purification operation as described above, the membrane unit 6 is driven to rotate about the rotating shaft 4. By rotating the membrane unit 6 in this manner, the membrane unit 6 is radially centered about the rotating shaft 4. The hollow fiber membrane 3 provided on the water moves while rotating in the vertical direction of the water depth. When the hollow fiber membrane 3 moves while rotating in the vertical direction of the water depth in this way, the depth immersed in water changes, so the water pressure acting on the hollow fiber membrane 3 always changes. Further, a circulating flow is generated in the septic tank 7 due to the diffused air from the diffuser tube 9, and this circulating flow acts uniformly on the entire hollow fiber membrane 3 by the pivotal movement of the hollow fiber membrane 3. To do. For this reason, the activated sludge does not accumulate on a part of the hollow fiber membrane 3 and the dirt adheres to it, so that the entire hollow fiber membrane 3 is hardly clogged. Further, since the hollow fiber membrane 3 vibrates when rotating in water, and the hollow fiber membrane 3 vibrates also by the action of air diffused from the air diffuser tube 9, activated sludge is also generated in the hollow fiber membrane 3 by this vibration action. It is possible to reduce clogging by reducing the accumulation of dirt and adhesion. Since the membrane unit 6 is rotationally driven in this manner, the hollow fiber membrane 3 is less likely to be clogged, so that the necessity for washing the membrane unit 6 is reduced. Therefore, the membrane unit 6 is washed. Therefore, the time for stopping the purification operation for purifying the raw water is reduced, and the productivity for purifying the raw water is improved.

  FIG. 4 shows another embodiment of the present invention. FIG. 4B shows an example of the membrane unit 6 used in the present embodiment, and the configuration other than the membrane unit 6 is the same as that of FIG. The first fixing portion 1 and the second fixing portion 2 are each formed in a disk shape and are arranged to face each other in parallel. The 1st fixing | fixed part 1 and the 2nd fixing | fixed part 2 are couple | bonded by connecting the connecting rod 25 between the center parts which oppose. A plurality of hollow fiber membranes 3 aligned in parallel are arranged between the first fixed part 1 and the second fixed parts 2 in a direction perpendicular to the fixed parts 1 and 2. One end is fixed to the first fixing portion 1 and the other end of the hollow fiber membrane 3 is fixed to the second fixing portion 2. The first fixing part 1 and the second fixing part 2 are formed in a hollow shape and serve as a water passing part 5, so that openings at both ends of the hollow fiber membrane 3 are opened in the water passing part 5. The first fixed part 1 and the second fixed part 2 are fixed. A rotating shaft 4 projects from the central portion of the outer surface of the first fixed portion 1 and the central portion of the outer surface of the second fixed portion 2. Each rotary shaft 4 protrudes in parallel with the hollow fiber membrane 3 on the extension line of the connecting rod 25. Of the pair of rotating shafts 4 a and 4 b, one rotating shaft 4 a provided in the first fixing portion 1 is formed hollow, and the inner peripheral communication hole 29 is formed as the water passing portion 5 of the first fixing portion 1. It communicates with the inside. The connecting rod 25 is also formed hollow and has a communication hole 30 on the inner periphery. The communication hole 30 is communicated with each water flow portion 5 of the first fixing portion 1 and the second fixing portion 2. is there. Accordingly, the water passage portion 5 of the second fixing portion 2 communicates with the communication hole 29 via the communication hole 30 of the connecting rod 25 and the water passage portion 5 of the first fixing portion 1.

  As shown in FIG. 4A, the membrane unit 6 formed as described above is disposed in the septic tank 7 with the rotary shaft 4 placed in a horizontal posture parallel to the water surface and supported by the rotary shaft 4. It is In the embodiment of FIG. 4, the rotary shafts 4 a and 4 b are rotatably supported by passing through the side walls of the septic tank 7, but it goes without saying that the invention is not limited to such a mode. The suction pipe 17 of the suction / discharge means 8 is connected to the communication hole 29 of one rotating shaft 4a in the same manner as in the embodiment of FIG. 1, and the driving unit 26 such as a motor is connected to the other rotating shaft 4b. is there.

  Accordingly, in the membrane separation type water purification apparatus formed as shown in FIG. 4A, the drive unit 26 is driven to move the entire membrane unit 6 around the rotary shaft 4 continuously or intermittently. The purification operation for purifying the raw water can be performed in the same manner as described above while rotating. Here, the water flow portions 5 of the first and second fixing portions 1 and 2 of the membrane unit 6 are depressurized by suction by the suction pump 19 through the communication holes 29 and the communication holes 30. The raw water thus passed passes through the hollow fiber membrane 3 and flows into the water flow portions 5 of the first and second fixing portions 1 and 2 and is separated from the activated sludge as purified water. Thus, the purified water that has passed through the membrane unit 6 is discharged from the septic tank 7 from each of the water passing portions 5 through the communication hole 30, the communication hole 29, and the suction pipe 17.

  During the purification operation, the membrane unit 6 is driven to rotate about the rotating shaft 4 as described above. By rotating the membrane unit 6 in this manner, the membrane unit 6 is provided in parallel with the rotating shaft 4. The hollow fiber membrane 3 is moved while rotating in the vertical direction. When the hollow fiber membrane 3 moves while rotating in the vertical direction of the water depth in this way, the depth immersed in water changes, so the water pressure acting on the hollow fiber membrane 3 always changes. Further, a circulating flow is generated in the septic tank 7 due to the diffused air from the diffuser tube 9, and this circulating flow acts uniformly on the entire hollow fiber membrane 3 by the pivotal movement of the hollow fiber membrane 3. To do. For this reason, the activated sludge does not accumulate on a part of the hollow fiber membrane 3 and the dirt adheres to it, so that the entire hollow fiber membrane 3 is hardly clogged. Further, since the hollow fiber membrane 3 vibrates when rotating in water, and the hollow fiber membrane 3 vibrates also by the action of air diffused from the air diffuser tube 9, activated sludge is also generated in the hollow fiber membrane 3 by this vibration action. It is possible to reduce clogging by reducing deposition and contamination. In particular, air bubbles rising from the air diffuser 9 strike the hollow fiber membrane 3 perpendicularly to the longitudinal direction thereof, so that the hollow fiber membrane 3 can be vibrated efficiently and clogging prevention is highly effective. is there. Since the membrane unit 6 is rotationally driven in this manner, the hollow fiber membrane 3 is less likely to be clogged, so that the necessity for washing the membrane unit 6 is reduced. Therefore, the membrane unit 6 is washed. Therefore, the time for stopping the purification operation for purifying the raw water is reduced, and the productivity for purifying the raw water is improved.

  5 (a) and 5 (b) show an embodiment in which a forced washing means 10 for washing the hollow fiber membrane 3 of the membrane unit 6 by a physical action is provided, and FIG. FIG. 5 (b) shows a configuration in which the forced cleaning means 10 is provided in FIG. 4 (a). In the embodiment of FIG. 5, a shower pipe 32 is used as the forced cleaning means 1, and the shower pipe 32 is horizontally attached at a position above the water surface of the septic tank 7. It is desirable that the shower tube 32 is disposed in parallel with the rotation shaft 4 immediately above the membrane unit 6.

  If the purification operation for purifying the raw water is continued for a long time as described above, the hollow fiber membrane 3 of the membrane unit 6 is clogged. Therefore, the forced washing means 10 cleans the hollow fiber membrane 3. Is.

In performing the washing operation for washing the hollow fiber membrane 3, even if the water level in the septic tank 7 is lowered to L ₂ (see FIG. 1 or 4), the raw water on-off valve 16 is kept closed and the raw water is kept The water level in the septic tank 7 is lowered to the rotating shaft 4 of the membrane unit 6 (water level L ₃ ) by keeping the suction pump 19 from sucking, and the upper half of the membrane unit 6 is exposed. Then, after stopping the operation of the suction pump 19 at this time, the cleaning water is supplied to the shower pipe 32 while being continuously driven to rotate the membrane unit 6, and sprayed from the nozzle hole provided in the shower pipe 32. the wash water is showering the hollow fiber membrane 3 which is rotated upward from L _3. Here, in the embodiment of FIG. 5A, the nozzle holes are formed so that the washing water is jetted between the adjacent second fixing portions 2 of the membrane unit 6, and the hollows are arranged radially. Washing water is efficiently sprayed onto the thread membrane 3 so that it can be showered. Thus, the clogging can be efficiently removed by removing the dirt attached to the surface of the hollow fiber membrane 3 by the physical washing action when the washing water is showered on the hollow fiber membrane 3. After this cleaning is performed for a predetermined time, the supply of the cleaning water to the shower pipe 32 is stopped, the raw water on-off valve 16 is opened, and the raw water is supplied from the raw water pipe 15 to the septic tank 7, and the water level is L ₁ (FIG. 1 or FIG. 4), the washing operation of the raw water can be resumed.

  In the above embodiment, the forced cleaning means 10 is formed by showering with the shower tube 32. However, the forced cleaning means 10 is not limited to this, and dirt on the surface of the hollow fiber membrane 3 is removed. It may be scraped off.

  6 (a) and 6 (b), at least one hollow fiber membrane 3 side surface of the first fixed portion 1 and the second fixed portion 2 of the membrane unit 6 is protruded toward the hollow fiber membrane 3 side. An embodiment formed on the convex curved surface 49 is shown. FIG. 6A shows the membrane unit 6 of FIG. 4 or FIG. 5B in which the opposing surfaces of the first fixing portion 1 and the second fixing portion 2 are formed on the convex curved surface 49. FIG. 6B shows the membrane unit 6 shown in FIGS. 1 and 5A in which the inner peripheral surface of the second fixing portion 2 is formed as a convex curved surface 49. In the embodiment of FIG. 6, the cross-section obtained by cutting the surface of the first fixing portion 1 or the second fixing portion 2 on the side of the hollow fiber membrane 3 with a plane parallel to the hollow fiber membrane 3 is the hollow fiber membrane 3. A convex curved surface 49 is formed so as to be a streamline with a convex side.

  Here, a circulating flow is generated in the septic tank 7 by the diffusion from the diffuser tube 9 provided at the bottom thereof, and the surface of the hollow fiber membrane 3 is washed and the hollow fiber membrane 3 is vibrated by this circulating flow. Therefore, it is possible to reduce clogging due to contamination of the hollow fiber membrane 3. At this time, as described above, the surface of the first fixed portion 1 or the second fixed portion 2 on the hollow fiber membrane 3 side is formed on the convex curved surface 49, so that the circulation flows along the convex curved surface 49. Therefore, it is possible to obtain a high effect of reducing dirt from adhering to the hollow fiber membrane 3 by using the circulating flow. is there.

  6 (a) and 6 (b), the ultrasonic oscillator 11 is arranged and provided in the vicinity of the membrane unit 6 facing the hollow fiber membrane 3 in the water in the septic tank 7. . FIG. 6A is a plan view in which convex curved surfaces 49 are provided on the first and second fixing portions 1 and 2 of the membrane unit 6 in FIG. 4 and a support rod 51 is suspended above the septic tank 7 directly above the membrane unit 6. The ultrasonic oscillator 11 is provided downward on the lower surface of the support bar 51. In FIG. 6B, a convex curved surface 49 is provided on the second fixed portion 2 of the membrane unit 6 in FIG. 1, and a support rod 51 is suspended above the septic tank 7 and directly above the membrane unit 6. The drooping rod 52 is suspended along the side wall of the septic tank 7 at both ends, and the ultrasonic oscillator 11 is provided on the surface of the dripping rod 52 on the membrane unit 6 side. When the raw water purification operation is performed in the purification tank 7, the ultrasonic wave is oscillated from the ultrasonic oscillator 11 to vibrate the hollow fiber membrane 3 of the membrane unit 6, and dirt adheres to the hollow fiber membrane 3. This can be reduced. Further, when the hollow fiber membrane 3 is washed, the ultrasonic wave is oscillated from the ultrasonic oscillator 11 to vibrate the hollow fiber membrane 3, whereby the dirt can be peeled off from the hollow fiber membrane 3 to obtain a high washing effect. It is. In addition, you may make it provide the support rod 51 and the ultrasonic oscillator 11 in the septic tank 7 of said FIG. 5 (a) similarly to FIG. 6 (a), and also in the septic tank 7 of said FIG. 5 (b). Similarly to FIG. 6B, the support bar 51, the hanging bar 52, and the ultrasonic oscillator 11 may be provided.

  7 and 8 show an embodiment in which a moving means for enabling the ultrasonic oscillator 11 to move within the septic tank 7 is provided. The moving means can be formed from, for example, a pulley 54 and a belt 55 spanned between the pulleys 54.

  FIG. 7 shows an embodiment applied when the membrane unit 6 of FIG. 4 or FIG. 6A is used. A pulley 54 is provided on each opposing side wall of the septic tank 7, and a belt is provided between the pulleys 54. 55 is bridged, and the ultrasonic oscillator 11 is attached to the belt 55 downward. The belt 55 is disposed in parallel with the rotary shaft 4 at a position directly above the membrane unit 6, and the ultrasonic oscillator 11 is moved along the entire length of the hollow fiber membrane 3 by driving the pulley 54 to rotate. It can be moved. The embodiment of FIG. 7 corresponds to a configuration in which a pulley 54 and a belt 55 are provided in place of the support bar 51 in FIG.

  FIG. 8 shows an embodiment applied when the membrane unit 6 shown in FIG. 1 or FIG. 6B is used, and the septic tank 7 is disposed above the membrane unit 6 as shown in FIG. A pair of parallel support rods 56 are suspended on the upper portions on both sides of the two, and a plurality of pulleys 54 are attached to the lower surface of each support rod 56. Each pulley 54 is provided at a position corresponding to the second fixing portion 2 provided in the membrane unit 6 as shown in FIG. 8B, and is attached to a pair of support rods 56 as shown in FIG. They are provided alternately. An auxiliary support bar 58 is provided in parallel with the support bar 56, and a pair of auxiliary pulleys 59 are attached to the lower surface of the auxiliary support bar 58. A pair of support rods 56 alternately hangs a belt 55 on the pulley 54 and further hangs the belt 55 on an auxiliary pulley 59. By laying the belt 55 in this way, the portion of the belt 55 that is orthogonal to the support rod 56 is located between the adjacent second fixing portions 2 of the membrane unit 6 or at the second end. It arrange | positions along the outer side of the fixing | fixed part 2 of this. An upper end portion of a pantograph-shaped lifting tool 57 as shown in FIG. 8C is coupled to the belt 55, and the lifting tool 57 is suspended. The ultrasonic oscillator 11 is attached to the lower end of the lifting tool 57, and the ultrasonic oscillator 11 is arranged on the side of the radial hollow fiber membrane 3 of the membrane unit 6. Then, the pulley 54 is driven to rotate to run the belt 55, so that the ultrasonic oscillator 11 moves along the belt 55 and moves between the adjacent hollow fiber membranes 3 as shown in FIG. 8B. Or move along the hollow fiber membrane 3 located at the end. In addition, the ultrasonic oscillator 11 is driven up and down by driving the elevating tool 57 to expand and contract, and the ultrasonic oscillator 11 can be moved along the entire length of the hollow fiber membrane 3. In the embodiment of FIG. 8, a pulley 54, a belt 55, a support bar 56, a lifting tool 57, an auxiliary support bar 58, and an auxiliary pulley 59 are provided in place of the support bar 51 and the hanging bar 52 in FIG. This is equivalent to

  As described above, by moving the ultrasonic oscillator 11 by the moving means, ultrasonic waves can be oscillated from the ultrasonic oscillator 11 to each part of the entire length of the hollow fiber membrane 3. Each part of the full length can be vibrated uniformly, and the effect of reducing the clogging of the hollow fiber membrane 3 and the cleaning effect of peeling dirt from the hollow fiber membrane 3 can be highly obtained.

  The ultrasonic oscillator 11 may be provided with frequency control means for making the oscillation frequency variable. Any frequency control means such as a frequency modulator can be used. By making the frequency of the ultrasonic wave oscillated from the ultrasonic oscillator 11 variable in this way, for example, when the raw water is being purified, it is super at a frequency that does not adversely affect the microorganisms in the activated sludge. When the hollow fiber membrane 3 is washed, the ultrasonic wave can be oscillated at a frequency at which the hollow fiber membrane 3 can be vibrated efficiently. In addition, since the portion that easily vibrates such as the central portion and the end portion of the hollow fiber membrane 3 is changed by changing the oscillation frequency, each portion of the entire length of the hollow fiber membrane 3 is uniformly distributed by changing the oscillation frequency. It can be vibrated. It should be noted that the clogging prevention and cleaning can be performed more efficiently by forming the oscillating ultrasonic oscillator 11 of FIG. 7 and FIG.

It is a schematic front sectional view showing an embodiment of the present invention. The embodiment of a membrane unit same as the above is shown, (a) is a front sectional view, and (b) is a side sectional view. (A) is a partial longitudinal sectional view showing an example of an embodiment of a diffuser tube, (b) and (c) show another example, and (b) is a cross section taken along line BB in (c). FIG. 4C is a cross-sectional view taken along line AA in FIG. BRIEF DESCRIPTION OF THE DRAWINGS Embodiment of this invention is shown, (a) is a whole schematic front sectional drawing, (b) is front sectional drawing of a membrane unit. The other embodiment of this invention is shown, (a) (b) is a schematic front sectional drawing, respectively. The other embodiment of this invention is shown, (a) (b) is a schematic front sectional drawing, respectively. It is a schematic front sectional drawing which shows other embodiment of this invention. The other embodiment of this invention is shown, (a) is a schematic plan view, (b) is a schematic front sectional drawing, (c) is a front view of a lifting tool. It is a schematic front view of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st fixing | fixed part 2 2nd fixing | fixed part 3 Hollow fiber membrane 4 Rotating shaft 5 Water flow part 6 Membrane unit 7 Septic tank 8 Suction / discharge means 9 Air diffuser tube 10 Forced washing means 11 Ultrasonic oscillator

Claims (6)

  A plurality of first fixing portions, a second fixing portion arranged so as to surround the first fixing portion, and a plurality of radial ends are arranged between the first fixing portion and the second fixing portion. A water passage portion that includes a hollow fiber membrane having the other end fixed to the second fixing portion on the first fixing portion, and that forms the first fixing portion as a rotating shaft and communicates with the inside of the hollow fiber membrane in the rotating shaft. A membrane unit is formed by installing a membrane unit in a septic tank that purifies raw water with activated sludge, and a rotating shaft arranged in a horizontal position is rotatably supported, and the inside of the water passage is sucked into the septic tank. A suction discharge means for filtering the purified water in the inside through a hollow fiber membrane to separate it from the activated sludge and discharging it is connected to the water section, and a diffusion pipe is provided in the purification tank below the membrane unit. A membrane separation type water purification device.   The first fixed portion, the second fixed portion disposed opposite to the first fixed portion, and a plurality of the first fixed portion and the second fixed portion are arranged in parallel between the first fixed portion and the second fixed portion. A hollow fiber membrane having the other end fixed to the second fixing portion on the first fixing portion, and at least one of the first fixing portion and the second fixing portion communicating with the inside of the hollow fiber membrane. In the septic tank that forms a membrane unit by providing a rotating shaft parallel to the hollow fiber membrane in at least one of the first fixed portion and the second fixed portion, and purifies the raw water with activated sludge. A membrane unit is attached by supporting the rotating shaft arranged in a horizontal posture so that it can be driven for rotation, and the inside of the water passage is sucked, and the purified water in the septic tank is filtered through a hollow fiber membrane and separated from the activated sludge and discharged. The suction / discharge means to be connected is connected to the water section, and a diffusion tube is provided in the septic tank below the membrane unit. Membrane separation type water purifier according to claim.   The membrane-separated water purification device according to claim 1 or 2, further comprising forced washing means for washing the hollow fiber membrane of the membrane unit by a physical action.   The membrane separation according to claim 1 or 2, wherein a surface of at least one hollow fiber membrane side of the first fixing portion and the second fixing portion of the membrane unit is formed into a convex curved surface. Water purification device.   The membrane separation type water purification device according to any one of claims 1 to 4, wherein an ultrasonic oscillator is attached to the membrane unit. 6. The membrane-separated water according to claim 5, wherein the ultrasonic oscillator comprises at least one of a moving means that enables movement in the septic tank and a frequency control means that makes the oscillation frequency variable. Purification equipment.

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