JP2009022906A - Sewage purification system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sewage purification system which can easily eliminate the clogging of a filter, and has excellent filtration efficiency. <P>SOLUTION: The sewage purification system 100 comprises a filter tank 102 temporarily storing sewage 101, a polymeric microfilter 103 filtering the sewage, a drain pipe 105 draining the sewage 101 filtered by the polymeric microfilter 103, and an ultrasonic oscillator 108 oscillating the polymeric microfilter 103 by ultrasonic waves. While the sewage 101 is filtered, ultrasonic waves are generated from the ultrasonic oscillator 108 to oscillate the polymeric microfilter 103. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sewage purification system, and more particularly to a sewage purification system that filters sewage with a filter.

Organic sludge such as livestock sludge is generally filtered through a filter and subjected to purification treatment. This is because if a large amount of organic sludge is discarded as it is, rivers and the like become polluted and have a serious impact on the natural environment. For example, Patent Document 1 describes an organic sludge treatment method in which surplus sludge generated by an activated sludge method is treated in combination with high-temperature anaerobic digestion and solid-liquid separation using a filter (separation membrane).
JP 7-148500 A

  Since the conventional filter is clogged with fine substances contained in the sewage when it is used for a long time, it is necessary to clean or replace the filter every time it is clogged. Moreover, this clogging occurs quite frequently, depending on the type of sewage to be treated. For this reason, every time the filter is clogged, the filtration process is interrupted, and cleaning and replacement are performed, resulting in a problem that the filtration efficiency is lowered.

  Therefore, an object of the present invention is to provide a sewage purification system that can easily eliminate clogging of a filter and has good filtration efficiency.

  The object of the present invention is to provide a filtration tank for temporarily accumulating sewage, a polymer microfilter for filtering sewage, a drain pipe for draining sewage filtered by the polymer microfilter, and a polymer microfilter by ultrasonic waves. The polymer microfilter has a scram structure formed by an independent nuclear space that is the nucleus of the porous space and a continuous microspace that communicates between the multiple independent nuclear spaces. It is achieved by a sewage purification system comprising a porous layer having

  In the present invention, it is preferable that the ultrasonic transducer is disposed on the inside of the polymer microfilter inside the filtration tank. According to this, it is possible to suppress clogging of the polymer microfilter by generating ultrasonic waves while filtering sewage.

  In the present invention, it is preferable to further include a back washing mechanism for washing the polymer microfilter by flowing water from the drain pipe side of the polymer microfilter to the filtration tank side. According to this, clogging of the polymer microfilter can be solved more sufficiently.

  In the present invention, it is preferable that the ultrasonic transducer is disposed under the polymer microfilter, and the ultrasonic wave is generated simultaneously with the back washing of the polymer microfilter. According to this, when the polymer microfilter is washed by backwashing, it is possible to vibrate the polymer microfilter at the same time as the backwashing. Can be resolved well.

  In the present invention, the porous layer is preferably formed of fibers having a cross-sectional shape that is deformed by one or more convex portions and / or concave portions.

  In the present invention, it is preferable that the porous layer is integrally formed of a nonwoven fabric and a porous resin impregnated in the nonwoven fabric fiber layer.

  In the present invention, the polymer microfilter has a nonwoven fabric intermediate fiber layer having a higher porosity than the porous layer formed on the downstream side of the porous layer, and a support layer formed on the downstream side of the intermediate fiber layer. It is preferable to further have a nonwoven fabric base fiber layer having a higher porosity than the intermediate fiber layer formed on the downstream side of the support layer.

  ADVANTAGE OF THE INVENTION According to this invention, clogging of a filter can be eliminated easily and a sewage purification system with good filtration efficiency can be provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic cross-sectional view showing a configuration of a sewage purification system 100 according to a preferred first embodiment of the present invention.

  As shown in FIG. 1, a sewage purification system 100 includes a filtration tank 102 that temporarily accumulates sewage 101, a polymer microfilter housing part 104 that houses a polymer microfilter 103, a drain pipe 105, and a backwash. A water supply pipe 106, a switching valve 107 attached to a connection portion between the drain pipe 105 and the backwash water supply pipe 106, and an ultrasonic vibrator 108 are provided.

  Further, the sewage purification system 100 includes a sewage supply pipe 109 that supplies the sewage 101 to be filtered to the filtration tank 102, a pump 110 that supplies cleaning water to the backwash water supply pipe 106, and an ultrasonic transducer 108 at the tip. And a support 111 for supporting the same.

  The polymer microfilter 103 is arranged at the bottom of the filtration tank 102 by the polymer microfilter housing portion 104. And the sewage 101 from the filtration tank 102 is received and this is filtered.

  The switching valve 107 switches the state where the polymer microfilter housing 104 and the drain pipe 105 are connected and the state where the polymer microfilter housing 104 and the backwash water supply pipe 106 are connected as necessary.

  In the sewage purification system 100, when the filtration process is performed, the polymer microfilter housing part 104 and the drain pipe 105 are connected by switching the switching valve 107 to the drain pipe 105 side. Thereby, as shown by the broken line arrow in FIG. 1, the sewage 101 stored in the filtration tank 102 is filtered by the polymer microfilter 103, and the filtered water is discharged to the drain pipe 105.

  The ultrasonic vibrator 108 is disposed on the upper side (upstream side) of the polymer microfilter 103 in the sewage 101 in the filtration tank 102 by the support 111, and the sewage 101 is transferred to the polymer microfilter 103 as a medium. As vibration can be given. Ultrasound is generated periodically or continuously. Thereby, simultaneously with filtration of the sewage 101 by the polymer microfilter 103, clogging of the polymer microfilter 103 can be prevented by vibration caused by ultrasonic waves.

  In addition, the sewage purification system 100 is configured to backwash the polymer microfilter 103 by flowing water from the polymer microfilter housing part 104 side (drainage pipe 105 side) of the polymer microfilter 103 to the filtration tank 102 side. It has a mechanism.

  FIG. 2 is a schematic cross-sectional view for explaining the backwash process in the preferred sewage purification system 100 of the present invention.

  When backwashing is performed, first, the supply of sewage from the sewage supply pipe 109 to the filtration tank 102 is stopped. Further, the generation of ultrasonic waves from the ultrasonic transducer 108 is also stopped.

  Then, as shown in FIG. 2, the polymer microfilter housing portion 104 is connected to the backwash water supply pipe 106 by switching the switching valve 107 to the backwash water supply pipe 106 side. As a result, as indicated by a broken line arrow in FIG. 2, the backwash water supplied from the pump 110 is supplied to the polymer microfilter 103 via the backwash water supply pipe 106, and the backwash water is further supplied to the polymer microfilter. It is sent to the filtration tank 102 through 103.

  Thus, the polymer microfilter 103 is washed by flowing backwash water from the downstream side (polymer microfilter housing part 104 side) to the upstream side (filter tank 102 side) of the polymer microfilter 103. Can do.

  Thus, according to this embodiment, clogging of the polymer microfilter 103 can be suppressed while filtering sewage. Further, since it is not necessary to physically scrape the clog of the polymer microfilter 103 with a brush or a scraper, the polymer microfilter is not damaged, and therefore the polymer microfilter 103 is used for a long period of time. Is possible.

  Next, a sewage purification system according to a preferred second embodiment of the present invention will be described.

  FIG. 3 is a schematic cross-sectional view showing a configuration of a sewage purification system 200 according to a preferred second embodiment of the present invention.

  The present embodiment is different from the first embodiment in the position of the ultrasonic transducer and the support that supports the ultrasonic transducer, and the other configurations are the same as those in the first embodiment. Therefore, the description is omitted.

  As shown in FIG. 3, in the sewage purification system 200 according to the present embodiment, the ultrasonic transducer 208 is disposed below the polymer microfilter 103 (downstream side) in the polymer microfilter housing portion 104 by the support 211. ing. Then, when the polymer microfilter 103 is back-washed, ultrasonic waves are generated from the ultrasonic transducer 208, and the polymer microfilter 103 is vibrated from the lower surface side.

  The filtration process in the sewage purification system 200 is substantially the same as that of the sewage purification system 100 according to the first embodiment. That is, the switching valve 107 is switched to the drain pipe 105 side, the sewage 101 stored in the filtration tank is filtered by the polymer microfilter 103, and the filtered water is drained to the drain pipe 105. At this time, unlike the sewage purification system 100, the sewage purification system 200 does not apply ultrasonic vibration to the polymer microfilter 103 during the filtration process.

  That is, the sewage purification system 200 does not perform the clogging prevention process of the polymer microfilter 103 during the filtration process, and removes the clogging of the polymer microfilter 103 when performing the backwashing.

  In the sewage purification system 200, in order to perform backwashing, the supply of sewage from the sewage supply pipe 109 to the filtration tank 102 is first stopped as in the first embodiment. Further, the generation of ultrasonic waves from the ultrasonic transducer 108 is also stopped.

  Then, as shown in FIG. 3, the polymer microfilter housing 104 is connected to the backwash water supply pipe 106 by switching the switching valve 107 to the backwash water supply pipe 106 side. Thereby, the backwash water supplied from the pump 110 is supplied to the polymer microfilter 103 via the backwash water supply pipe 106, and the backwash water is further sent to the filtration tank through the polymer microfilter 103. .

  As a result, the polymer microfilter 103 is cleaned. In this embodiment, at the same time, an ultrasonic wave is generated from the ultrasonic vibrator 208, and vibration is applied to the polymer microfilter 103 using backwash water as a medium. By performing backwashing while applying vibration to the polymer microfilter 103 in this manner, it is possible to wash the polymer microfilter 103 more efficiently than simply performing backwashing.

  As described above, according to the second embodiment, the ultrasonic transducer 208 is provided on the downstream side (lower part) of the polymer microfilter 103, and the ultrasonic wave is generated simultaneously with the backwashing. Since the backwashing is performed while applying ultrasonic vibration to the fine substance, the polymer microfilter 103 can be efficiently washed in a short time.

  Next, the polymer microfilter 103 used in the first and second embodiments will be described in detail.

  FIG. 4 is a schematic cross-sectional view showing the structure of the polymer microfilter 103.

  As shown in FIG. 4, the polymer microfilter 103 is formed of a porous layer 2 having a scram structure formed by deforming the cross-sectional shape of the fibers of the nonwoven fabric, and a nonwoven fabric on the downstream side of the porous layer 2. A support layer 4 formed on the downstream side of the intermediate fiber layer 3 with a reinforcing material such as an intermediate fiber layer 3 having a higher porosity than the formed porous layer 2, a woven fabric, a net, and other porous membranes. A lower fiber layer 5 having a higher porosity than the intermediate fiber layer 3 formed of a nonwoven fabric is provided on the downstream side.

  As the material of the nonwoven fabric forming the porous layer 2, the intermediate fiber layer 3, and the lower fiber layer 5, synthetic fibers such as polyamide, polyester, polyolefin, polyacrylonitrile, polyvinyl chloride, polyvinylidene chloride, and polyvinyl alcohol (vinylon) are used. Can be used. The average fiber diameter of each layer can be appropriately selected according to the porosity and the like. The average fiber diameter of the synthetic fibers forming the porous layer 2 is preferably 3 μm to 25 μm. As the average fiber diameter becomes thinner than 3 μm, handling becomes difficult, and the mass productivity and durability of the nonwoven fabric tend to be lacking. As the fiber becomes thicker than 25 μm, the pores increase and the porosity increases, and the filtration performance decreases. This is because it tends to be easier. In view of water resistance, chemical resistance and weather resistance, polyester and polypropylene are preferable.

It is preferred basis weight of the polymer micro-filter 103 is a ^{500g / m 2 ~1000g / m 2} . Basis weight As is less than 500 g / m ^2, a long period becomes difficult to withstand repeated exerted pressure through the use, there is a tendency that durability is liable to lower, as the greater than 1000 g / m ^2, mass productivity is lowered This is because it tends to be easy.

  The support layer 4 is preferably formed by disposing a reinforcing material such as a woven fabric, a net, or other porous membrane between the intermediate fiber layer 3 and the lower fiber layer 5. As the reinforcing material, a monofilament or multifilament woven fabric is preferably used, but a spun woven fabric may also be used. In addition, as the material of the reinforcing material, the same material as that of the above-mentioned nonwoven fabric is preferably used. In the case of a net, a composite of a stainless steel wire and polyester may be arranged vertically and horizontally in a mesh shape.

It is preferred apparent density of the polymer micro-filter 103 is ^{0.35g / cm 2 ~0.55g / cm 2} . As the apparent density becomes smaller than 0.35 g / cm ^2, the filtration area in contact with the sewage becomes insufficient, and the filtration efficiency tends to decrease. As the apparent density becomes larger than 0.55 g / cm ² , the water flow rate becomes larger. This is because it tends to be insufficient and it becomes difficult to filter a large amount of sewage.

The polymer microfilter 103 is formed such that the air passage amount when a pressure difference of 98 kPa is applied is 1 (cm ³ / s) / cm ² to 10 (cm ³ / s) / cm ² . Is preferred. As the air flow rate becomes smaller than 1 (cm ³ / s) / cm ² , the water flow rate becomes insufficient, and it becomes difficult to filter a large amount of sewage, and 10 (cm ³ / s) / cm greater as made of ^2, amount of fibers in contact with the sewage becomes insufficient, filtration efficiency tend to easily decrease.

  FIG. 5 is a cross-sectional view of the main part showing the structure of the porous layer 2 of the polymer microfilter 103.

  As shown in FIG. 5, the porous layer 2 has a scram structure, a porous resin 15 impregnated into a nonwoven fabric fiber layer forming the porous layer 2 and integrated with the nonwoven fabric, and a porous layer An independent nucleus space 15a serving as a nucleus of the two porous spaces and a continuous fine space 15b communicating between the plurality of independent nucleus spaces 15a.

  The average pore diameter of the continuous fine space (open cell) 15b of the porous layer 2 is preferably 0.5 μm to 8 μm, and more preferably 1 μm to 4 μm. As the average pore diameter becomes smaller than 1 μm, clogging is likely to occur, and it tends to be difficult to filter a large amount of sewage. As the mean diameter becomes larger than 4 μm, the amount of water passing increases and the filtration performance decreases. It is because the tendency which becomes easy to see is seen. In addition, as the average pore diameter becomes smaller than 0.5 μm, the water permeability tends to greatly decrease and the filtration efficiency tends to decrease, and as the average pore diameter becomes larger than 8 μm, a fine suspended substance can be captured. This is because it becomes difficult and the suspended substance is caught in the internal pores and becomes in a closed state and cannot be removed by backwashing or washing.

  The thickness of the porous layer 2 is preferably 10 μm to 1000 μm. As the thickness of the porous layer 2 becomes thinner than 10 μm, the continuous fine space 15b cannot be sufficiently secured, the filtration capability becomes insufficient, and the porous layer 2 can be quickly cleaned by physical washing with a brush or the like. 2 is easy to break, the effect of the scrum structure is insufficient and the life tends to decrease, and as it becomes thicker than 1000 μm, the water permeability tends to be insufficient and the filtration efficiency tends to decrease. It is. By making the thickness of the porous layer 2 in the range of 10 μm to 1000 μm, even if the surface layer side of the porous layer 2 is broken, the inner side becomes a new surface layer, and the continuous fine space 15b is continuously filtered. Excellent filtration performance reliability and long life.

  FIGS. 6A to 6C are schematic perspective views showing the structure of the fibers forming the porous layer 2.

  FIG. 6A shows an example in which a plurality of convex portions 11 are formed on the circumference of the fiber 10 forming the porous layer 2, and FIG. 6B shows the fiber 10 a forming the porous layer 2. 6 (c) is an example in which a plurality of substantially spherical convex portions 11 b are formed on the outer peripheral surface of the fiber 10 b forming the porous layer 2. This is an example. These convex portions 11, 11a, and 11b can be formed by passing the fibers 10, 10a, and 10b between rolling rollers that have irregularities corresponding to the convex portions 11, 11a, and 11b formed on the surface.

  The size of the protrusions 11, 11a, 11b depends on the fiber diameter of the fibers 10, 10a, 10b, but when the fiber diameter is 10 μm to 25 μm, the diameter of the protrusions 11, 11a, 11b is 2 μm to 5 μm. It is preferable. As the diameter of the convex parts 11, 11a, 11b becomes smaller than 2 μm, the effect of deforming becomes insufficient, the water permeability tends to decrease and the filtration efficiency tends to decrease, and the convex parts 11, 11a, 11b This is because as the diameter becomes larger than 5 μm, it becomes difficult to maintain the cross-sectional shape and the productivity tends to decrease, and the porosity tends to increase and the filtration performance tends to decrease.

  In the process of forming the porous layer 2 of the polymer microfilter 103, the fibers 10, 10a, 10b having a cross-sectional shape deformed by one or more convex portions 11, 11a, 11b are used as a method such as a needle punch or a water jet needle. By forming the porous layer 2 by entanglement in three dimensions, a substantially uniform continuous microspace 15b communicating with the independent nucleus space 15a can be formed, and the continuous microspace (microspace) of the porous layer 2 can be formed. The average pore diameter of the (hole) 15b can be formed to the aforementioned 0.5 μm to 8 μm, preferably 1 μm to 4 μm.

  FIGS. 7A to 7F are schematic cross-sectional views showing modifications of the structure of the fibers forming the porous layer 2.

  FIG. 7A is an example in which five protrusions 11c are formed on the outer periphery of the fiber 10c, and FIG. 7B is an example in which four protrusions 11d are formed on the outer periphery of the fiber 10d. FIG. 7C is an example in which three convex portions 11e are formed on the outer periphery of the fiber 10e, and FIG. 7D is an example in which four concave portions 11f are formed on the outer periphery of the fiber 10f. 7 (e) is an example in which three concave portions 11g are formed on the outer periphery of the fiber 10g, and FIG. 7 (f) is an example in which two concave portions 11h are formed on the outer periphery of the fiber 10h.

  By stretching the fiber from a mold having a cross-sectional shape similar to that of the fibers 10c to 10h shown in FIG. 7, the cross-sectional shape of the fiber can be made irregular, and the convex shape is continuous in the longitudinal direction of the fiber. A shape or a concave shape can be formed. Further, by twisting the fiber during stretching, a convex shape or a concave shape can be formed in a spiral shape as shown in FIG. By stretching the fiber in the liquid, the deformed cross-sectional shape can be reliably maintained, and the productivity is excellent.

  In FIG. 7, the cross-sectional shape is modified by two to five convex portions 11c to 11e and concave portions 11f to 11h, but the number of convex portions 11c to 11e and concave portions 11f to 11h is two to two. Eight can be formed. As the number of the convex portions 11c to 11e and the concave portions 11f to 11h is less than two, the effect of deforming becomes insufficient, the water permeability tends to decrease, and the filtration efficiency tends to decrease. As the number of 11e and recesses 11f to 11h increases from eight, it becomes difficult to maintain the cross-sectional shape and the productivity tends to decrease, and the porosity tends to increase and the filtration performance tends to decrease. Because. In addition, each fiber 10a thru | or 10h shown in FIG.6 and FIG.7 may each be used independently, and may be used in combination of multiple types.

  The polymer microfilter 103 configured as described above has the following effects. First, by narrowing the eyes of the upstream porous layer 2 having a scram structure, particles in the sewage can be reliably captured at the surface portion to prevent entry into the interior, and the filtration performance is excellent. In addition, by adjusting the porosity of each layer so that the porosity increases from the porous layer 2 side that is the upstream side to the lower fiber layer 5 side that is the downstream side during filtration, In addition, it can be surely captured and filtered on the surface of the porous layer 2, and the filtered water of the filtered sewage can be quickly discharged from the lower fiber layer 5 side, and the filtration efficiency is excellent.

  In addition, the suspended material adhered to the surface of the porous layer 2 by backwashing or physical peeling by narrowing the eyes of the upstream porous layer 2 and making the downstream lower fiber layer 5 rough. Can be easily removed, clogging hardly occurs, it can be used continuously for a long period of time, and it is excellent in maintainability and practicality.

  Moreover, by having the support layer 4 formed between the intermediate | middle fiber layer 3 and the lower fiber layer 5, it can reinforce the whole and can prevent a vertical / horizontal deformation, and is excellent in durability. In addition, the entire thickness and strength of the polymer microfilter 103 can be adjusted by the lower fiber layer 5, and when it is washed with a scraper, a brush or the like, an impact can be absorbed by its cushioning property, and the porous It is difficult for the layer 2 to be broken, and the filtered water can be freely moved and discharged to improve water permeability.

  Furthermore, the fibers 10 to 10h forming the porous layer 2 have a cross-sectional shape deformed by one or more convex portions 11 to 11e and concave portions 11f to 11h, so that the porous layer 2 is substantially uniform. A continuous fine space can be formed, and the uniformity of filtration performance is excellent. In addition, since the porous layer 2 has a scram structure in which substantially uniform continuous fine spaces are formed in multiple layers, even if the fibers 10 to 10 h are torn on the surface of the porous layer 2, the inner fibers Filtration can be carried out continuously by a continuous fine space formed in 10 to 10 hours, and the reliability of filtration performance and long life are excellent.

  This polymer microfilter 103 can perform gravity filtration, is less likely to clog, and can release suspended substances with a small external stimulus. It can be cleaned by a method, a water jet cleaning method, a suction cleaning method, a scraper cleaning method, etc., can cope with sewage with a high concentration, and has excellent versatility. In addition, the suspended matter adhering to the surface of the porous layer 2 can be peeled off in a coherent state by sedimentation cleaning such as brush cleaning or scraper cleaning, and settled on the bottom of a filtration tank or the like. It is possible to prevent thickening and to obtain a stable filtration flow rate.

  Moreover, since the polymer microfilter 103 does not require a filtration pressure device, it is excellent in energy saving, the entire filtration device can be reduced in size and weight, and mass productivity and handleability can be improved. Moreover, without using a flocculant etc., it is possible to carry out purification treatment by removing only suspended substances while leaving the minerals contained in the sewage, and it can be discharged into rivers etc. as fresh water So it has excellent environmental protection. Moreover, even if suspended substances in the sewage adhere to the surface of the porous layer 2 of the polymer microfilter 103, the filtration efficiency does not decrease, and excellent filtration performance can be maintained. Excellent reliability.

  8A and 8B are cross-sectional views showing a modification of the porous layer 2 of the polymer microfilter 103, where FIG. 8A is a cross-sectional view of the main part, and FIG. It is an enlarged view of the part shown by.

As shown in FIGS. 8A and 8B, in the present embodiment, a structure in which a part of the nonwoven fabric fibers 10 constituting the porous layer 2 protrudes to the inside of each pore of the continuous microspace 15b. It has become. The average fiber diameter d ₁ of the nonwoven fabric fibers 10 constituting the porous layer 2 is made smaller than the average pore diameter d ₂ of the continuous fine space 15b.

When the porous layer 2 is configured as shown in FIG. 8, the average pore diameter d ₂ of the continuous fine space (open cell) 15 b of the porous layer 2 is preferably 0.5 μm to 8 μm. The average fiber diameter d ₁ of the nonwoven fabric fibers 10 constituting the porous layer 2 is preferably 8 μm or less, and more preferably 4 μm or less. Continuous average pore diameter d ₂ of the micro-space, becomes smaller than 0.5 [mu] m, water-permeable filtration efficiency less efficient by significantly reduced. Further, when the average fiber diameter d ₁ of the nonwoven fabric fibers 10 constituting the porous layer 2 is larger than 8 μm, the average pore diameter d ₂ of the continuous fine space is made larger than the average fiber diameter d ₁ of the nonwoven fabric fibers 10. Because it is necessary, it becomes difficult to capture a minute solid substance, and it becomes caught in a hole and becomes a closed state, and cannot be removed by backwashing or washing. Thus, the average pore diameter d ₂ of the continuous fine space not less than 4 [mu] m, an average fiber diameter d ₁ of the fiber 10 of the nonwoven fabric is particularly preferably a 4 [mu] m or less.

  According to such a configuration, even when the fine particles 16 enter the continuous fine space by filtration, the fine particles 16 are caught by the non-woven fibers 10 existing in the continuous fine space. Can be prevented from entering. Thereby, clogging of the polymer microfilter can be prevented. Further, even in the backwashing, since the fine particles 16 do not penetrate deep into the porous layer 2, the cleaning effect can be enhanced.

  As described above, according to the present invention, clogging of the polymer microfilter can be suppressed by ultrasonic vibration while filtering sewage. Moreover, since it is not necessary to physically scrape the clogging of the polymer microfilter with a brush or a scraper, the polymer microfilter can be prevented from being damaged. Therefore, the polymer microfilter can be used for a long time.

  In addition, an ultrasonic vibrator is installed on the downstream side (lower part) of the polymer microfilter, and ultrasonic waves are generated at the same time as backwashing, so that backwashing is performed while applying ultrasonic vibrations to fine substances that cause clogging. Therefore, the polymer microfilter can be efficiently cleaned in a short time.

  The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention, and these are also included in the scope of the present invention. Needless to say.

  For example, the use of the sewage purification system according to the present invention is not particularly limited, treatment of human waste / livestock sewage, treatment of cement / concrete products or aggregates, wastewater generated during the manufacture of masonry products, treatment of selected coal effluent. It can also be used for the treatment of industrial wastewater and other wastewater generated in various industries.

  It is also possible to adopt a configuration in which the first and second embodiments are combined. That is, the ultrasonic transducer 108 may be disposed on the polymer microfilter 103 and the ultrasonic transducer 208 may be disposed on the lower portion, so that two ultrasonic transducers may be used as appropriate.

FIG. 1 is a schematic cross-sectional view showing a configuration of a sewage purification system 100 according to a preferred first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view for explaining backwash processing in the sewage purification system 100 according to the preferred first embodiment of the present invention. FIG. 3 is a schematic cross-sectional view showing a configuration of a sewage purification system 200 according to a preferred second embodiment of the present invention. FIG. 4 is a schematic cross-sectional view showing the structure of the polymer microfilter 103. FIG. 5 is a cross-sectional view of the main part showing the structure of the porous layer 2 of the polymer microfilter 103. FIGS. 6A to 6C are schematic perspective views showing the structure of the fibers forming the porous layer 2. FIGS. 7A to 7F are schematic cross-sectional views showing modifications of the structure of the fibers forming the porous layer 2. 8A and 8B are cross-sectional views showing a modification of the porous layer 2 of the polymer microfilter 103. FIG.

Explanation of symbols

2 Porous layer 3 Intermediate fiber layer 4 Support layer 5 Lower fiber layer 10 Fiber 10a-10h Fiber 11 Convex part 11a-11e Convex part 11f-11h Concave part 15 Porous resin 15a Independent nuclear space 15b Continuous fine space 100, 200 Sewage Purification system 101 Sewage 102 Filtration tank 103 Polymer microfilter 104 Polymer microfilter housing part 105 Drain pipe 106 Backwash water supply pipe 107 Switching valve 108, 208 Ultrasonic vibrator 109 Sewage supply pipe 110 Pump 111, 211 Support

Claims (4)

A filtration tank for temporarily accumulating sewage,
A polymer microfilter for filtering the wastewater;
A drain pipe for draining the sewage filtered by the polymer microfilter;
An ultrasonic vibrator that vibrates the polymer microfilter with ultrasonic waves,
The polymer microfilter includes a porous layer having a scram structure formed of an independent nucleus space serving as a nucleus of a porous space and a continuous fine space communicating between the plurality of independent nucleus spaces. Sewage purification system.   2. The sewage purification system according to claim 1, wherein the ultrasonic transducer is disposed above the polymer microfilter inside the filtration tank.   The sewage according to claim 1 or 2, further comprising a backwashing mechanism for allowing water to flow from the drain pipe side of the polymer microfilter to the filtration tank side and cleaning the polymer microfilter. Purification system.   2. The sewage purification system according to claim 1, wherein the ultrasonic vibrator is disposed below the polymer microfilter and generates ultrasonic waves when the polymer microfilter is backwashed.

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