WO2016038948A1 - Filtration unit - Google Patents

Filtration unit Download PDF

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Publication number
WO2016038948A1
WO2016038948A1 PCT/JP2015/066118 JP2015066118W WO2016038948A1 WO 2016038948 A1 WO2016038948 A1 WO 2016038948A1 JP 2015066118 W JP2015066118 W JP 2015066118W WO 2016038948 A1 WO2016038948 A1 WO 2016038948A1
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WIPO (PCT)
Prior art keywords
particles
filtration
cleaning
filtration unit
average particle
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PCT/JP2015/066118
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French (fr)
Japanese (ja)
Inventor
柏原　秀樹
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住友電気工業株式会社
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Priority to JP2015551926A priority Critical patent/JPWO2016038948A1/en
Publication of WO2016038948A1 publication Critical patent/WO2016038948A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D24/00—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D24/00—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof
    • B01D24/02—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof with the filter bed stationary during the filtration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D24/00—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof
    • B01D24/46—Regenerating the filtering material in the filter

Definitions

  • the present invention relates to a filtration unit.
  • a filtration unit containing filtration particles is used as a method for separating and removing oil and turbidity at a low cost.
  • oil and turbidity are filtered by a filtration layer formed by enclosed filtration particles.
  • the filtration unit of the above publication can improve the cleaning performance of the filtration particles, since the agitator is provided, the structure is complicated and the apparatus is inevitably increased in size.
  • This invention is made
  • a filtration unit which has been made to solve the above-described problem, is a filtration unit that is disposed in a downward flow filtration tower and is partitioned by a water-permeable partition plate at the bottom. Filtration particles and washing particles, and the washing particles have a larger average particle size and average specific gravity than the filtration particles.
  • the filtration particle washing method is a filtration unit that is disposed in a downward flow filtration tower and is partitioned by a water-permeable partition plate at the bottom.
  • the filtration unit according to one embodiment of the present invention has a simple structure and is excellent in the cleaning performance of the filtration particles. Moreover, the washing
  • FIG. 1 is a schematic cross-sectional view showing a downward flow filtration tower including a filtration unit according to an embodiment of the present invention.
  • a filtration unit is a filtration unit that is disposed in a downward flow-type filtration tower and that is partitioned by a water-permeable partition plate at the lower side. And the cleaning particles have a larger average particle size and average specific gravity than the filtering particles.
  • the filtration unit is filled with filtration particles and washing particles, so that large and heavy washing particles rise during backwashing and loosen a layer of filtration particles solidified by oil or turbidity, leaving gaps between the filtration particles. Free. Accordingly, the filtered particles can be efficiently exposed to the cleaning water, and the cleaning of the filtering particles is promoted by the rising of the filtering particles and colliding with other filtering particles or cleaning particles. Thus, the said filtration unit is excellent in the washing
  • the average particle size and average specific gravity of the cleaning particles are larger than that of the filtered particles, a layer of cleaning particles is formed on the lower side due to the difference in sedimentation speed, and a layer of filtered particles that does not contain much cleaning particles is formed on the upper side. Therefore, the removal of turbidity in the liquid to be treated is not hindered by the filtered particle layer.
  • the ratio of the average specific gravity of the cleaning particles to the average specific gravity of the filtered particles is preferably from 1.2 to 10.
  • the ratio of the average specific gravity of the cleaning particles to the average specific gravity of the filtered particles is within the above range, so that the cleaning efficiency at the time of backwashing can be further improved, and the layer of the filtered particles after the backwashing and the cleaning particles Thus, the filtration efficiency can be further improved.
  • the ratio of the average particle size of the cleaning particles to the average particle size of the filtration particles is preferably 1.2 or more and 10 or less.
  • the ratio of the average particle size of the cleaning particles to the average particle size of the filtered particles is within the above range, so that the cleaning efficiency at the time of backwashing can be further improved, and the filtering particles enter the gaps between the cleaning particles. It is difficult to form a layer of filtered particles more reliably.
  • the mixing volume ratio of the cleaning particles to the filtration particles is preferably 0.1 or more and 1.0 or less.
  • the volumetric efficiency of the said filtration unit can be raised.
  • the filtration particles have glass or polymer as a main component and the cleaning particles have glass, ceramics, metal or polymer as a main component.
  • the main component of the filtration particles is glass or polymer and the main component of the cleaning particles is glass, ceramics, metal, or polymer, both cleaning efficiency and filtration efficiency can be enhanced.
  • the filtration unit according to one embodiment of the present invention has a simple structure and is excellent in the cleaning performance of the filtration particles. For this reason, the said filtration unit can be used conveniently in order to purify the to-be-processed liquid containing an oil component and a turbidity.
  • the method for washing filtered particles is a method for washing filtered particles that are disposed in a downward flow filtration tower and filled in a filtration unit that is partitioned by a water-permeable partition plate below.
  • the filtration particle cleaning method is to fill the filtration unit with a particle having a larger average particle diameter and average specific gravity than the filtration particle, thereby forming a layer of the filtration particle on the layer formed by the precipitation of the washing particle first. Form and filter. And by letting the washing water flow upward through the partition plate to the filtration unit, the washing particles are remarkablyd to loosen the layer of filtration particles solidified by oil and turbidity, and to make a gap between the filtration particles. Cleaning of the filtered particles can be facilitated.
  • the “average particle diameter” is a sieve defined in JIS-Z8801-1 (2006), and sieved in order from a sieve having a large mesh size, and the mass ratio of particles passing through the mesh is measured. It means a value (d50) at which the integrated mass becomes 50% in the particle size distribution created with the nominal aperture as the particle size.
  • Average specific gravity is a value measured in accordance with JIS-Z8807 (2012).
  • the “turbidity” means a suspended substance excluding oil.
  • the “oil” and “turbidity” do not have to be separated, and an emulsion may be formed.
  • the “metal” includes a metal compound.
  • [Downward flow filtration tower] 1 is an apparatus for filtering the liquid to be treated.
  • the liquid to be treated to be filtered by the downflow type filtration tower typically includes petroleum-associated water containing oil and turbidity.
  • the turbidity includes, for example, particles such as sand, silica and calcium carbonate, iron powder, microorganisms, and wood chips.
  • the downflow type filtration tower is erected so that the central axis substantially coincides with the vertical direction, and the cylindrical main body 1 having a top plate portion and a bottom plate portion are spaced apart from each other inside the cylindrical main body 1.
  • Three filtration units (first filtration unit 2a, second filtration unit 2b, and third filtration unit 2c) according to an embodiment of the present invention that are arranged side by side are arranged at the upper end of the cylindrical main body 1.
  • the liquid to be processed is supplied to the cylindrical main body 1 and the liquid to be processed is supplied to the lower end of the cylindrical main body 1.
  • the processed liquid obtained by filtering the liquid to be processed is discharged from the cylindrical main body 1. And a treated liquid discharge flow path 4.
  • a space is also formed in the cylindrical main body 1 above the first filtration unit 2a on the most upstream side and below the third filtration unit 2c on the most downstream side. Further, the downward flow filtration tower includes a cleaning water supply device (not shown) for supplying cleaning water to the treated liquid discharge flow path 4.
  • the cylindrical main body 1 is formed of metal or resin so as to have a strength that can withstand the pressure of the liquid that is inserted into the cylindrical main body 1.
  • a material for forming the cylindrical body stainless steel or acrylonitrile-butadiene-styrene copolymer (ABS resin) is particularly preferable from the viewpoint of strength, heat resistance, chemical resistance, and the like.
  • ABS resin acrylonitrile-butadiene-styrene copolymer
  • the cylindrical main body 1 may be provided with a reinforcing member or a leg member for self-standing on the outside.
  • the planar shape of the cylindrical main body 1 is not particularly limited, and may be any shape such as a circle, an ellipse, a rectangle, etc., but it is easy to form a uniform liquid flow. From the viewpoint of preventing clogging and staying of cleaning particles and oil and turbidity, a shape without corners is preferable, and a circular shape is typically used. Moreover, making the planar shape of the cylindrical main body 1 without a corner has an advantage that the strength of the cylindrical main body 1 is easily obtained and the design is easy.
  • the top plate portion in which the liquid supply flow path 3 to be processed and the bottom plate portion in which the processed liquid discharge flow path 4 are disposed may be flat plates, but pressure resistance is obtained. It is preferable to use a mirror-plate shape.
  • the size of the cylindrical main body 1 is not particularly limited, and is selected according to the flow rate of water to be treated to be treated.
  • the average cross-sectional area of the cylindrical main body 1 can be, for example, 0.1 m 2 or more 10 m 2 or less.
  • the height of the cylindrical main body 1 it can be set to 0.5 m or more and 10 m or less, for example.
  • the first filtration unit 2a is partitioned by a first lower partition plate 5a that allows water to pass through the lower side, and is partitioned by a first upper partition plate 6a that allows water to pass through the first filtration unit 2a.
  • the first cleaning particles 8a having a larger average particle diameter and average specific gravity than the first filtration particles 7a are packed.
  • the 1st filtration unit 2a has the 1st space 9a above the 1st filtration particle
  • the second filtration unit 2b is partitioned by a second lower partition plate 5b that allows water to flow through the lower side, and partitioned by a second upper partition plate 6b that allows water to flow through the upper side. 7b and second cleaning particles 8b having a larger average particle diameter and average specific gravity than the second filtration particles 7b are packed. Moreover, the 2nd filtration unit 2b has the 2nd space 9b above the 2nd filtration particle 7b and the 2nd washing
  • the third filtration unit 2c is partitioned by a third lower partition plate 5c that allows water to flow through the lower side, and is partitioned by a third upper partition plate 6c that allows water to flow through the upper side.
  • third cleaning particles 8c having a larger average particle diameter and average specific gravity than the third filtration particles 7c.
  • the 3rd filtration unit 2c has the 3rd space 9c above the 3rd filtration particle 7c and the 3rd washing
  • the “filtration unit” refers to a unit structure having a structure for performing filtration, and does not necessarily mean a separable structure.
  • the side walls of the filtration units 2 a, 2 b, and 2 c are integrated with the side wall of the cylindrical main body 1.
  • the lower partition plates 5a, 5b, 5c and the upper partition plates 6a, 6b, 6c are formed of plate-like members that allow water to pass therethrough and not allow the filtered particles 7a, 7b, 7c and the cleaning particles 8a, 8b, 8c to pass therethrough. Is done. These lower partition plates 5a, 5b, 5c and upper partition plates 6a, 6b, 6c seal the filtration particles 9a, 9b, 9c and the cleaning particles 8a, 8b, 8c inside the filtration units 2a, 2b, 2c. Fulfills the function of
  • the lower partition plates 5a, 5b, and 5c and the upper partition plates 6a, 6b, and 6c include, for example, a porous plate having a large porosity, a plate in which many small holes are formed, a wire mesh, and the like. Can be mentioned.
  • the lower partition plates 5a, 5b, 5c and the upper partition plates 6a, 6b, 6c are a support member having a large mesh and a net-like, woven or non-woven fabric arranged so as to cover the eyes of the support member. It may consist of a combination with these members.
  • the material of the lower partition plates 5a, 5b, 5c and the upper partition plates 6a, 6b, 6c is not particularly limited, and metal, synthetic resin, or the like can be used.
  • metal it is preferable to use corrosion-resistant stainless steel (for example, SUS316L) from the viewpoint of corrosion prevention.
  • a support member such as a reinforcing wire in combination so that the opening is not changed by the water pressure or the weight of the particles.
  • a wire mesh it is preferable to use a mesh made of a wire material having excellent strength and heat resistance, such as stainless steel wire, Kevlar fiber, carbon fiber and the like.
  • the nominal mesh openings of the wire mesh are the corresponding filtration particles 7a, 7b, 7c and cleaning particles 8a, 8b, It is preferably designed to be less than the minimum diameter of 8c. Moreover, when the minimum diameter of the filtration particles 7a, 7b, 7c or the cleaning particles 8a, 8b, 8c is very small, if the opening of the wire mesh is made smaller than that, the differential pressure may become too large.
  • the nominal mesh opening of the wire mesh is not more than a value obtained by subtracting the standard deviation of the particle diameters of the corresponding filtration particles 7a, 7b, 7c from the average particle diameter of the corresponding filtration particles 7a, 7b, 7c. .
  • the filtration particles 7a, 7b, and 7c are filter media that form a layer for filtering the water to be treated.
  • known filtration particles can be used.
  • natural sand, inorganic particles, glass, ceramics, polymers (polymer compounds), natural organic materials and the like are the main components. Particles can be used.
  • the filtration particles 7a, 7b, and 7c have glass or a polymer as a main component.
  • the cost of the filtration units 2a, 2b, and 2c can be reduced.
  • the cost and weight of the said filtration units 2a, 2b, 2c can be reduced by making the filtration particle
  • grains 7a, 7b, 7c can be made small by using a polymer, the washing
  • glass beads are used as the filtration particles 7a, 7b, and 7c, oil and turbidity are easily peeled off from the surfaces of the filtration particles 7a, 7b, and 7c. Can be improved.
  • Examples of the glass that is the main component of the filtration particles 7a, 7b, and 7c include soda lime glass, titanium barium glass, lead glass, and borosilicate glass. Of these, soda-lime glass, which is widely available on a relatively inexpensive basis, is preferably used.
  • Examples of the polymer that is the main component of the filtration particles 7a, 7b, and 7c include fluororesin, vinyl resin, polyolefin, polyurethane, epoxy resin, polyester, polyamide, polyimide, melamine resin, and polycarbonate.
  • fluororesin, vinyl resin, a polyurethane, an epoxy resin, and an acrylic resin excellent in water resistance and oil resistance are preferable, and a fluororesin excellent in corrosion resistance and a polyolefin excellent in adsorptivity are more preferable.
  • polypropylene that is particularly excellent in oil adsorption capacity is preferable.
  • the fluororesin is excellent in strength, heat resistance, and chemical resistance, and has a relatively large specific gravity, so that it has a merit that it can settle quickly after washing and can be quickly filtered.
  • grains 7a, 7b, 7c may differ for every filtration unit, and may contain multiple types of particle
  • examples of the natural sand include anthracite, garnet, manganese sand, and the like, and these can be used alone or in combination of two or more.
  • the ceramic for example, ceramic particles mainly composed of silica, alumina, glass or the like can be used.
  • the natural organic material a natural organic material having a particle size adjusted by sieving can be used, and examples thereof include natural fibers such as walnut shell, sawdust and hemp.
  • the shape of the filtration particles 7a, 7b, and 7c is not particularly limited, and may be any shape such as a spherical shape or a column shape.
  • the filtration particles 7a, 7b, and 7c can be densely deposited, and the filtration efficiency is improved and the filtration particles 7a in a steady state. , 7b, 7c can be prevented.
  • the lower limit of the average specific gravity of the filtered particles 7a, 7b, 7c is preferably 0.8, more preferably 1.1, and even more preferably 1.4.
  • the upper limit of the average specific gravity of the filtration particles 7a, 7b, 7c is preferably 5, more preferably 3, and even more preferably 2.
  • the average specific gravity of the filtration particles 7a, 7b, 7c exceeds the above upper limit, the layer of the filtration particles 7a, 7b, 7c cannot be fluidized during backwashing, and the cleaning effect may not be improved.
  • grains 7a, 7b, 7c may differ for every filtration unit.
  • the lower limit of the uniformity coefficient of the filtration particles 7a, 7b, 7c is preferably 1.1, and more preferably 1.3.
  • the upper limit of the uniformity coefficient of the filtration particles 7a, 7b, and 7c is preferably 1.8, and more preferably 1.6.
  • the uniformity coefficient of the filtration particles 7a, 7b, and 7c is less than the lower limit, the variation in the particle diameter of the filtration particles 7a, 7b, and 7c may be too small to be densely deposited.
  • the “equality coefficient” is a sieve defined in JIS-Z8801-1 (2006), which is sieved in order from the sieve with the largest mesh, and the mass ratio of particles passing through the mesh is measured. This is a value obtained by dividing the value (d60) at which the accumulated mass is 60% in the particle size distribution created with the opening as the particle size by the value (d10) at which the accumulated mass is 10%.
  • the average particle diameter of the filtration particles 7a, 7b, 7c is larger as the filtration units 2a, 2b, 2c on the upstream side. That is, the average particle diameter of the second filtered particles 7b is smaller than the average particle diameter of the first filtered particles 7a, and the average particle diameter of the third filtered particles 7c is smaller than the average particle diameter of the second filtered particles 7b.
  • the lower limit of the average particle diameter of the first filtration particles 7a on the most upstream side is preferably 700 ⁇ m, more preferably 800 ⁇ m, and even more preferably 1000 ⁇ m.
  • the upper limit of the average particle diameter of the first filtration particles 7a is preferably 3000 ⁇ m, more preferably 2000 ⁇ m, and further preferably 1500 ⁇ m.
  • the average particle diameter of the first filtration particles 7a is less than the lower limit, the density of the layer formed by the first filtration particles 7a in the first filtration unit 2a is large and the gap is small. There is a concern that the pressure loss of 2a may increase and the frequency of clogging of the first filtration unit 2a may increase.
  • the average particle diameter of the 1st filtration particle 7a exceeds the said upper limit, the clearance gap between the 1st filtration particles 7a becomes large, and there exists a possibility that an oil component and turbidity cannot fully be removed.
  • the lower limit of the average particle size of the second filtration particles 7b is preferably 300 ⁇ m, more preferably 350 ⁇ m, and even more preferably 400 ⁇ m.
  • the upper limit of the average particle diameter of the second filtration particles 7b is preferably 1000 ⁇ m, more preferably 800 ⁇ m, and even more preferably 700 ⁇ m.
  • the average particle diameter of the second filtration particle 7b is less than the lower limit, the pressure loss of the second filtration unit 2b may increase, or the frequency of clogging of the second filtration unit 2b may increase.
  • the average particle diameter of the second filtration particles 7b exceeds the upper limit, the frequency of clogging of the third filtration unit 2c on the downstream side may increase.
  • the lower limit of the average particle diameter of the third filtration particles 7c on the most downstream side is preferably 5 ⁇ m, more preferably 10 ⁇ m, and further preferably 20 ⁇ m.
  • the upper limit of the average particle size of the third filtered particles 7c is preferably 400 ⁇ m, more preferably 350 ⁇ m, and even more preferably 300 ⁇ m. If the average particle size of the third filtration particles 7c is less than the lower limit, the pressure loss of the third filtration unit 2c may increase, and the cost and weight may increase. On the contrary, when the average particle diameter of the 3rd filtration particle 7c exceeds the said upper limit, there exists a possibility that a downward flow type filtration tower cannot remove a fine oil droplet and turbidity.
  • the average thickness of the layer formed by the first filtration particles 7a on the most upstream side in the steady state is not particularly limited, but may be, for example, 3 cm or more and 1 m or less. Although it does not specifically limit as average thickness of the layer which the 2nd filtration particle 7b forms in a steady state, For example, it can be 2 cm or more and 80 cm or less. In addition, the average thickness of the layer formed by the most downstream third filtration particle 7c in the steady state is not particularly limited, but may be, for example, 1 cm or more and 50 cm or less.
  • the cleaning particles 8a, 8b, and 8c rise at the time of backwashing and loosen the layer of the filtration particles 7a, 7b, and 7c solidified by oil and turbidity to form a gap, thereby cleaning the filtering particles 7a, 7b, and 7c. Promote.
  • the cleaning particles 8a, 8b, and 8c particles mainly composed of natural sand, glass, inorganic particles, ceramics, metals (including metal compounds), polymers, natural organic materials, and the like can be used. Particles mainly composed of ceramics, metals or polymers are preferred. Since the main component of the cleaning particles 8a, 8b, and 8c is glass, ceramics, metal, or polymer, the ratio of specific gravity with respect to the filtering particles 7a, 7b, and 7c can be easily optimized, and the cleaning of the filtering particles 7a, 7b, and 7c can be easily performed. Easy to get effect.
  • the use of glass beads as the cleaning particles 8a, 8b, and 8c makes it easy to remove oil and turbidity from the surfaces of the cleaning particles 8a, 8b, and 8c. Can be improved.
  • the material of the cleaning particles 8a, 8b, and 8c may be different for each filtration unit, and may include a plurality of types of particles.
  • Examples of the glass that is the main component of the cleaning particles 8a, 8b, and 8c include soda lime glass, titanium barium glass, lead glass, and borosilicate glass. Among them, the ratio of specific gravity with respect to the filtration particles 7a, 7b, 7c can be optimized when soda-lime glass whose particulate products are widely marketed relatively inexpensively or when glass beads are used as the filtration particles 7a, 7b, 7c. Titanium barium-based glass is preferably used.
  • Ceramics that are the main components of the cleaning particles 8a, 8b, and 8c include those containing glass, silica, alumina, and the like as main components.
  • Examples of the metal that is the main component of the cleaning particles 8a, 8b, and 8c include iron oxide having excellent rust resistance.
  • Examples of the polymer that is the main component of the cleaning particles 8a, 8b, and 8c include fluororesin, vinyl resin, polyolefin, polyurethane, epoxy resin, polyester, polyamide, polyimide, melamine resin, and polycarbonate.
  • fluororesin, vinyl resin, a polyurethane, an epoxy resin, and an acrylic resin that are excellent in water resistance and oil resistance are preferable, and a fluororesin that is excellent in corrosion resistance is more preferable.
  • examples of natural sand that is the main component of the cleaning particles 8a, 8b, and 8c include anthracite, garnet, and manganese sand.
  • a natural organic material having a particle size adjusted by sieving can be used as the natural organic material which is the main component of the cleaning particles 8a, 8b and 8c.
  • the shape of the cleaning particles 8a, 8b, and 8c is not particularly limited, and may be any shape such as a spherical shape or a column shape.
  • irregularly pulverized particles as the cleaning particles 8a, 8b, and 8c, it is possible to further promote the cleaning effect of the filtered particles during backwashing.
  • the lower limit of the average specific gravity of the cleaning particles 8a, 8b, 8c is preferably 1.3 and more preferably 1.6.
  • the upper limit of the average specific gravity of the cleaning particles 8a, 8b, 8c is preferably 15, and more preferably 10.
  • the cleaning particles 8a, 8b, and 8c may not settle before the filtering particles 7a, 7b, and 7c, and the layers of the filtering particles 7a, 7b, and 7c may not be formed.
  • the average specific gravity of the cleaning particles 8a, 8b, 8c exceeds the upper limit, the layer of the cleaning particles 8a, 8b, 8c cannot be fluidized at the time of backwashing, and the filtration particles 7a, 7b, 7c are washed. The effect may not be promoted.
  • the average specific gravity of the cleaning particles 8a, 8b, 8c may be different for each filtration unit.
  • the first cleaning particles 8a have an average specific gravity larger than that of the first filtered particles 7a
  • the second cleaning particles 8b have an average specific gravity larger than that of the second filtered particles 7b
  • the third cleaning particles 8c have an average higher than that of the third filtered particles 7c.
  • High specific gravity The ratio of the average specific gravity of the first cleaning particles 8a to the average specific gravity of the first filtered particles 7a, the ratio of the average specific gravity of the second cleaning particles 8b to the average specific gravity of the second filtered particles 7b, and the average specific gravity of the third cleaning particles 8c.
  • 1.2 is preferred
  • 1.5 is more preferred
  • 2.0 is still more preferred.
  • the upper limit of the ratio of the average specific gravity is preferably 10, and more preferably 8.
  • the ratio of the average specific gravity is less than the lower limit, the cleaning particles 8a, 8b, and 8c do not settle before the filtered particles 7a, 7b, and 7c, and the layer of the filtered particles 7a, 7b, and 7c may not be formed.
  • the ratio of the average specific gravity exceeds the upper limit, the layer of the filtration particles 7a, 7b, and 7c and the layer of the washing particles 8a, 8b, and 8c cannot be fluidized at the time of backwashing. There is a possibility that the cleaning effect of the particles 7a, 7b, 7c cannot be promoted.
  • the first cleaning particles 8a have a larger average particle size than the first filtration particles 7a
  • the second cleaning particles 8b have a larger average particle size than the second filtration particles 7b
  • the third cleaning particles 8c have a larger particle size than the third filtration particles 7c.
  • the lower limit of the ratio of the average particle diameter to the average particle diameter of the third filtered particles 7c is preferably 1.2, more preferably 1.4, and even more preferably 1.5.
  • the upper limit of the ratio of the average particle diameter is preferably 10, and more preferably 8.
  • the ratio of the average particle diameter is less than the lower limit, the collision energy of the cleaning particles 8a, 8b, and 8c against the filtration particles 7a, 7b, and 7c is small, and the layers of the filtration particles 7a, 7b, and 7c may not be broken.
  • the cleaning particles 8a, 8b, and 8c may not settle before the filtered particles 7a, 7b, and 7c, and the layer of the filtered particles 7a, 7b, and 7c may not be formed.
  • the ratio of the average particle diameters exceeds the upper limit, the filtration particles 7a, 7b, 7c may enter the gaps between the cleaning particles 8a, 8b, 8c and may not form a sufficiently thick filtration layer. .
  • the lower limit of the average particle diameter of the first cleaning particles 8a on the most upstream side is preferably 800 ⁇ m, more preferably 1000 ⁇ m, and further preferably 1200 ⁇ m.
  • the upper limit of the average particle diameter of the first cleaning particles 8a is preferably 5000 ⁇ m, more preferably 3000 ⁇ m, and further preferably 2000 ⁇ m.
  • the average particle diameter of the first cleaning particles 8a is less than the lower limit, the density of the layer formed by the first cleaning particles 8a is large, and the pressure loss may increase.
  • the average particle size of the first cleaning particles 8a exceeds the above upper limit, the first filtration particles 7a may enter the gaps between the first cleaning particles 8a, and the layer of the first filtration particles 7a may not be efficiently formed. is there.
  • the lower limit of the average particle size of the second cleaning particles 8b is preferably 500 ⁇ m, more preferably 600 ⁇ m, and even more preferably 800 ⁇ m.
  • the upper limit of the average particle size of the second cleaning particles 8b is preferably 4000 ⁇ m, more preferably 3000 ⁇ m, and further preferably 1800 ⁇ m. If the average particle size of the second cleaning particles 8b is less than the lower limit, the density of the layer formed by the second cleaning particles 8b may be large and the pressure loss may increase. Conversely, when the average particle size of the second cleaning particles 8b exceeds the above upper limit, the second filtration particles 7b may enter the gaps between the second cleaning particles 8b, and the layer of the second filtration particles 7b may not be formed efficiently. is there.
  • the lower limit of the average particle size of the third cleaning particles 8c on the most downstream side is preferably 10 ⁇ m, more preferably 30 ⁇ m, and even more preferably 100 ⁇ m.
  • the upper limit of the average particle size of the third cleaning particles 8c is preferably 3000 ⁇ m, more preferably 2000 ⁇ m, and further preferably 1500 ⁇ m.
  • the average particle size of the third cleaning particles 8c is less than the lower limit, the density of the layer formed by the third cleaning particles 8c is large, and the pressure loss may be increased.
  • the third filtration particles 7c may enter the gaps between the third cleaning particles 8c, and the third filtration particle 7c layer may not be formed efficiently. is there.
  • the mixing volume ratio of the first cleaning particles 8a to the first filtration particles 7a in the first filtration unit 2a, the mixing volume ratio of the second cleaning particles 8b to the second filtration particles 7b in the second filtration unit 2b, and the third filtration unit 2c As the lower limit of the mixing volume ratio of the third cleaning particles 8c to the third filtration particles 7c in FIG. 1, 0.1 is preferable, and 0.2 is more preferable. On the other hand, the upper limit of the volume ratio is preferably 1, and more preferably 0.5. When the said mixing
  • the average height inside the filtration units 2a, 2b, 2c (lower partition plates 5a, 5b, 5c and upper partition plates 6a, 6b, 6c and 30%) is preferable, and 50% is more preferable.
  • the upper limit of the average height of the spaces 9a, 9b, 9c is preferably 80% of the average height inside the filtration units 2a, 2b, 2c, more preferably 70%.
  • the filtration particles 7a, 7b, and 7c and the washing particles 8a, 8b, and 8c cannot move sufficiently during backwashing, and the filtration particles 7a, 7b, and 7c. There is a possibility that the cleaning effect of the material cannot be sufficiently promoted.
  • the average height of the spaces 9a, 9b, 9c exceeds the above upper limit, the space becomes too large and the frequency with which the filtered particles 7a, 7b, 7c and the cleaning particles 8a, 8b, 8c come into contact during backwashing is small. As a result, the cleaning effect of the filtration particles 7a, 7b, 7c may not be sufficiently promoted.
  • the water treatment method using the downward flow filtration tower in FIG. 1 includes a filtration step of filtering the liquid to be treated in the filtration units 2a, 2b, and 2c, and filtration particles 7a and 7b of the filtration units 2a, 2b, and 2c. , 7c and a filtration layer forming step of forming layers of filtration particles 7a, 7b, 7c in the filtration units 2a, 2b, 2c are repeated.
  • the liquid to be processed is supplied from the liquid supply path 3 to be processed, and the processed liquid obtained by filtering the liquid to be processed is discharged from the liquid discharge path 4 for the processed liquid.
  • layers of cleaning particles 8a, 8b, 8c are formed on the lower partition plates 5a, 5b, 5c in the filtration units 2a, 2b, 2c, and the cleaning particles 8a, 8b, 8c are formed.
  • a filtration layer is formed by the filtration particles 7a, 7b, and 7c on the layer, and spaces 9a, 9b, and 9c are formed between the filtration layer and the upper partition plates 6a, 6b, and 6c.
  • the supply method of the liquid to be treated is not particularly limited, and for example, a method such as pumping by a pump or natural flow by a water head can be used.
  • the lower limit of the supply amount of the liquid to be treated per unit cross-sectional area of the downward flow filtration tower in the water treatment method using the downward flow filtration tower is preferably 100 m 3 / m 2 ⁇ day, and 300 m 3 / m. 2 ⁇ day is more preferable.
  • the upper limit of the feed rate of the liquid to be treated is not particularly limited, but is preferably 3000m 3 / m 2 ⁇ day, more preferably 1000m 3 / m 2 ⁇ day.
  • the supply amount of the liquid to be processed is less than the lower limit, there is a risk that the processing capacity may be insufficient in an environment where a large amount of liquid to be processed is generated, or a large number of downflow filtration towers may be required.
  • the supply amount of the liquid to be treated exceeds the upper limit, the frequency of the backwashing process is increased, which may be inefficient.
  • the upper limit of the turbidity concentration of the treated liquid recovered by the water treatment method using the downward flow filtration tower in FIG. 1 is preferably 10 ppm, more preferably 5 ppm, further preferably 3 ppm, and particularly preferably 1 ppm.
  • the turbidity concentration means the concentration of suspended matter (SS) and is a value measured according to “14.1 Suspended matter” of JIS-K0102 (2008).
  • the upper limit of the oil concentration of the treated liquid recovered by the water treatment method using the downward flow filtration tower in FIG. 1 is preferably 100 ppm, more preferably 10 ppm, and even more preferably 1 ppm. If the oil concentration of the treated liquid exceeds the above upper limit, the load of the oil / water separation treatment downstream of the downflow filtration tower may be excessive, or the treated liquid can be discarded without causing any environmental load. There is a risk of disappearing.
  • wash water is supplied from the treated liquid discharge flow path 4, passes through the filtration units 2a, 2b, and 2c, and is separated from the filtered particles 7a, 7b, and 7c.
  • Washing wastewater containing oil and turbidity remaining in the space 9a of the unit 2a and the space inside the cylindrical main body 1 is discharged from the liquid supply passage 3 to be treated.
  • this washing wastewater may be supplied to the liquid to be processed supply channel 3 as a part of the liquid to be processed in the next filtration step.
  • the washing water flowing from the bottom to the top first causes the washing particles to rise, breaks up the layers of the filtration particles 7a, 7b, and 7c solidified with oil and turbidity, and the filtration particles 7a, 7b, and 7c are washed with the water 9a. , 9b, 9c.
  • the filtered particles 7a, 7b, and 7c that have been swollen into the spaces 9a, 9b, and 9c are agitated in the wash water, and the attached oil and turbidity are peeled off. Further, the raised filter particles 7a, 7b, 7c collide with the other filter particles 7a, 7b, 7c and the cleaning particles 8a, 8b, 8c, thereby promoting the separation of the attached oil and turbidity. .
  • the backwashing process may be performed at regular intervals, and when the pressure difference between the liquid supply flow path 3 to be processed and the liquid discharge flow path 4 has reached a constant pressure in the filtration process, It may be performed when the flow rate of the processing liquid supply channel 3 or the processed liquid discharge channel 4 is reduced to a constant flow rate, or may be performed by operating an operator.
  • the amount of wash water supplied per unit cross-sectional area of the downward flow filtration tower can be, for example, 200 L / m 2 ⁇ hr or more and 2000 L / m 2 ⁇ hr or less.
  • the backwash time can be, for example, 30 seconds to 10 minutes.
  • an interval of backwashing when backwashing is performed every predetermined time it can be set to 1 hour or more and 12 hours or less, for example.
  • the washing water is preferably supplied as a bubbling jet water stream in which bubbles are mixed.
  • the bubbling jet water stream can be produced using, for example, a bubbling jet device, an eductor, or the like.
  • a bubbling jet water stream it is possible to promote separation of oil and turbidity from the filtered particles 7a, 7b, and 7c by bubbles.
  • the washing water may be supplied as a jet water stream that does not contain bubbles.
  • the amount of air in the bubbling jet water flow is preferably, for example, from 1 NL / L to 5 NL / L. Moreover, as an average diameter of the bubble in a bubbling jet water flow, 1 mm or more and 4 mm or less are preferable. Furthermore, the water supply pressure of the washing water is preferably 0.2 MPa or more, and the bubbling jet water flow flux is preferably 20 m / s or more at the discharge port of the bubbling jet nozzle, for example.
  • ⁇ Filter layer forming step> the filtration units 2a, 2b, and 2c are filled with water, and the filtration particles 7a, 7b, and 7c and the cleaning particles 8a, 8b, and 8c are naturally settled.
  • the cleaning particles 8a, 8b, and 8c having a large average specific gravity and a large average particle size have a high sedimentation speed, and settle first to form a layer on the lower partition plates 5a, 5b, and 5c.
  • Filter particles 7a, 7b, and 7c having a smaller average specific gravity and average particle diameter and lower settling velocity than cleaning particles 8a, 8b, and 8c are deposited on the previously formed layer of cleaning particles 8a, 8b, and 8c.
  • a filtration layer is formed.
  • water that does not contain air is supplied from the treated liquid discharge flow path 4 at a flow rate that is equal to or higher than the flow rate of the washing water in the backwashing process.
  • 2c is filled with water and the filtering particles 7a, 7b, 7c and the cleaning particles 8a, 8b, 8c are pressed against the upper partition plates 6a, 6b, 6c, the cleaning particles 8a, 8b, 8c and the filtering particles Separation from 7a, 7b, 7c can be promoted.
  • the filtration units 2a, 2b, and 2c are filled with the filtration particles 7a, 7b, and 7c and the washing particles 8a, 8b, and 8c, so that the washing particles 8a, 8b, and 8c rise during the backwashing, and the filtration particles 7a. , 7b, 7c are broken up to promote the cleaning effect of the filtration particles 7a, 7b, 7c.
  • the said filtration unit 2a, 2b, 2c is excellent in the washing
  • the cleaning particles 8a, 8b, and 8c are larger than those of the filtering particles 7a, 7b, and 7c, a layer of the cleaning particles 8a, 8b, and 8c is formed on the lower side due to the difference in sedimentation speed.
  • a layer of filtered particles 7a, 7b, and 7c that does not contain much cleaning particles 8a, 8b, and 8c is formed on the upper side, the cleaning particles 8a, 8b, and 8c are treated liquids by the layer of filtered particles 7a, 7b, and 7c. Does not impede removal of turbidity inside.
  • the filtration units 2a, 2b, and 2c can exhibit a large processing capacity with a short downtime for backwashing even when purifying a liquid to be treated containing oil and turbidity.
  • the number of the filtration units arranged in the downflow filtration tower is not particularly limited, and can be any number of 1 or more.
  • the filtration unit may be used in combination with a unit having an adsorbent for oil such as porous ceramics, woven fabric, non-woven fabric, fiber, activated carbon or the like.
  • the oil adsorbent unit is preferably arranged on the downstream side of the filtration unit.
  • the filtration unit may be one in which no space is formed on the filtration particles and the washing particles.
  • a plurality of water supply channels for supplying washing water to the lower side of each filtration unit are provided on the main body side of the downward flow filtration tower. You may provide, and you may provide several drainage channels which discharge
  • the water supply path for supplying the cleaning water to the lower side of the filtration unit may have a nozzle for discharging the cleaning water toward the lower surface of the lower partition plate. By providing such a nozzle, a flow having a high flow velocity can be formed at least partially in the filtration unit, and the effect of breaking the layer of filtration particles with the washing particles can be promoted. Further, the nozzle may be disposed so as to be buried in the layer of the filtration particles or the cleaning particles, and the water pressure of the cleaning water may be directly applied to break the filtration particles and the cleaning particles.
  • the filtration unit may be supplied with the cleaning water from the side to the position of the space formed in the steady state.
  • the scrubbing effect of the filtered particles can be promoted by the washing water supplied to the spatial position of the filtration unit and having a flow in a direction different from the washing water from below.
  • the flow path for supplying cleaning water into the filtration unit may include a nozzle that protrudes into the filtration unit and opens downward. By providing such a nozzle, it is possible to promote the cleaning effect of the filtered particles by forming a downward flow, and to make the filtered particle layer break up by colliding with the cleaning particle having a large flow velocity against the filtered particle layer. it can.
  • the filtration tower No. 1-No. No. 3 was prototyped and filtered and backwashed to confirm the effect of the present invention.
  • Filter tower No. 1-No. 3 a cylindrical tubular body having an inner diameter of 40 mm was used, and the first filtration unit, the second filtration unit, and the third filtration unit were filled with the filtration particles and the cleaning particles shown in Table 1 below.
  • the differential pressure before and after the filtration tower increases at a flow rate of 0.5 m 3 / day. Until filtered. As a result, the filtration tower No. 1-No. No. 3 could be continuously filtered for 2 to 4 hours.
  • the filtration tower with the increased differential pressure was back-washed, and an experiment was conducted to remove filtered particles and oil adhering to the washed particles. The flow rate of cleaning water during backwashing was 1 to 3 times the flow rate of water to be treated. As a result, the filtration tower No. 1-No. In all cases 3, the differential pressure during filtration could be reduced to a substantially initial value by backwashing for 3 to 5 minutes. That is, the filtration tower No. 1-No. It was confirmed that all Nos. 3 had sufficient filtration ability and detergency.
  • the said filtration unit can be utilized suitably for the downward flow type filtration tower which removes an oil component and turbidity from the to-be-processed liquid which generate

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  • Chemical Kinetics & Catalysis (AREA)
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Abstract

The present invention addresses the problem of providing a filtration unit which has a simple structure including filtration particles and which has the excellent ability to clean the filtration particles. The filtration unit according to an embodiment is a filtration unit disposed in a downflow filtration tower and separated by a water-permeable partition disposed on the downside, the filtration unit including packed filtration particles and packed cleaning particles, the cleaning particles having a larger average particle diameter and a higher average specific gravity than the filtration particles. It is preferable that the filtration unit in a stationary state have a space over the filtration particles and cleaning particles. The ratio of the average specific gravity of the cleaning particles to the average specific gravity of the filtration particles is preferably 1.2-10. The ratio of the average particle diameter of the cleaning particles to the average particle diameter of the filtration particles is preferably 1.2-10. The ratio of the volume of the cleaning particles to the volume of the filtration particles is preferably 0.1-1. It is preferable that the filtration particles comprise a polymer as the main component and the cleaning particles comprise a glass, ceramic, metal, or polymer as the main component.

Description

濾過ユニットFiltration unit
　本発明は、濾過ユニットに関する。 The present invention relates to a filtration unit.
　油田や工場等で発生する油分や濁質を含んだ油水混合液は、環境保全の観点から油分や濁質の混合量を一定値以下まで低減してから廃棄する必要がある。油分や濁質を混合液から分離除去する方法としては、重力分離、蒸留分離、薬品分離等があるが、低コストで油分や濁質を分離除去する方法として濾過粒子を封入した濾過ユニットを用いる方法がある。このような濾過ユニットでは、封入した濾過粒子によって形成される濾過層により油分や濁質を濾過する。 Oil / water mixtures containing oil and turbidity generated in oil fields and factories need to be discarded after the amount of oil and turbidity is reduced to a certain value or less from the viewpoint of environmental conservation. There are gravity separation, distillation separation, chemical separation, etc. as a method for separating and removing oil and turbidity from the liquid mixture. As a method for separating and removing oil and turbidity at a low cost, a filtration unit containing filtration particles is used. There is a way. In such a filtration unit, oil and turbidity are filtered by a filtration layer formed by enclosed filtration particles.
　上記濾過ユニットは、濾過粒子に油分や濁質が付着することにより、濁質の分離が不十分となったり、通水量が減少したりする。このため、濾過ユニットに通常の通水方向とは逆向きに洗浄水を通水し、濾過粒子に付着した油分や濁質を除去する洗浄工程、いわゆる逆洗が行われる。 In the above filtration unit, oil or turbidity adheres to the filtered particles, resulting in insufficient separation of turbidity or reduced water flow rate. For this reason, a washing process, that is, so-called back washing is performed in which washing water is passed through the filtration unit in a direction opposite to a normal water passage direction to remove oil and turbidity adhering to the filtration particles.
　しかしながら、油分やゼリー状の濁質が濾過粒子に付着している場合、濾過層に逆向きに通水するだけでは、濾過粒子から油分や濁質を容易に除去することができない。そこで、逆洗時に濾過層を形成する濾過粒子を撹拌する攪拌機を設けることが提案されている（特開平５－１５４３０９号公報参照）。 However, when oil or jelly-like turbidity adheres to the filtration particles, the oil or turbidity cannot be easily removed from the filtration particles simply by passing water in the reverse direction through the filtration layer. Therefore, it has been proposed to provide a stirrer that stirs the filter particles that form the filter layer during backwashing (see JP-A-5-154309).
特開平５－１５４３０９号公報JP-A-5-154309
　上記公報の濾過ユニットは、濾過粒子の洗浄性を高められるが、攪拌機を設けるため、構造が複雑であり、装置の大型化が避けられない。 Although the filtration unit of the above publication can improve the cleaning performance of the filtration particles, since the agitator is provided, the structure is complicated and the apparatus is inevitably increased in size.
　本発明は、上述のような事情に基づいてなされたものであり、簡素な構造で、濾過粒子の洗浄性能に優れる濾過ユニット及び洗浄効率のよい濾過粒子の洗浄方法を提供することを課題とする。 This invention is made | formed based on the above situations, and makes it a subject to provide the washing | cleaning method of the filtration particle | grain with the simple structure and the washing | cleaning performance of filtration particle | grains which are excellent in the washing | cleaning efficiency of filtration particle | grains. .
　上記課題を解決するためになされた本発明の一態様に係る濾過ユニットは、下向流式濾過塔内に配設され、下方が通水性の仕切板で区画される濾過ユニットであって、充填される濾過粒子と洗浄粒子とを備え、上記洗浄粒子の平均粒径及び平均比重が濾過粒子よりも大きい。 A filtration unit according to an aspect of the present invention, which has been made to solve the above-described problem, is a filtration unit that is disposed in a downward flow filtration tower and is partitioned by a water-permeable partition plate at the bottom. Filtration particles and washing particles, and the washing particles have a larger average particle size and average specific gravity than the filtration particles.
　上記課題を解決するためになされた本発明の別の態様に係る濾過粒子の洗浄方法は、下向流式濾過塔内に配設され、下方が通水性の仕切板で区画される濾過ユニットに充填される濾過粒子の洗浄方法であって、上記濾過粒子よりも平均粒径及び平均比重が大きい洗浄粒子が充填されている上記濾過ユニットに上記仕切板を通して上向きに洗浄水を通水することにより上記洗浄粒子を舞い上がらせる工程を備える。 The filtration particle washing method according to another aspect of the present invention, which has been made to solve the above-described problems, is a filtration unit that is disposed in a downward flow filtration tower and is partitioned by a water-permeable partition plate at the bottom. A method of cleaning the filtration particles to be filled by passing the cleaning water upward through the partition plate to the filtration unit filled with cleaning particles having an average particle size and an average specific gravity larger than the filtration particles. A step of raising the cleaning particles.
　本発明の一態様に係る濾過ユニットは、簡素な構造で、濾過粒子の洗浄性能に優れる。また、本発明の別の態様に係る濾過粒子の洗浄方法は、洗浄効率がよい。 The filtration unit according to one embodiment of the present invention has a simple structure and is excellent in the cleaning performance of the filtration particles. Moreover, the washing | cleaning efficiency of the washing | cleaning method of the filtration particle which concerns on another aspect of this invention is good.
図１は、本発明の一実施形態の濾過ユニットを備える下向流式濾過塔を示す模式的断面図である。FIG. 1 is a schematic cross-sectional view showing a downward flow filtration tower including a filtration unit according to an embodiment of the present invention.
［本発明の実施形態の説明］
　本発明の一態様に係る濾過ユニットは、下向流式濾過塔内に配設され、下方が通水性の仕切板で区画される濾過ユニットであって、充填される濾過粒子と洗浄粒子とを備え、上記洗浄粒子の平均粒径及び平均比重が濾過粒子よりも大きい。 [Description of Embodiment of the Present Invention]
A filtration unit according to an aspect of the present invention is a filtration unit that is disposed in a downward flow-type filtration tower and that is partitioned by a water-permeable partition plate at the lower side. And the cleaning particles have a larger average particle size and average specific gravity than the filtering particles.
　当該濾過ユニットは、濾過粒子と洗浄粒子とが充填されていることによって、逆洗時に大きくて重たい洗浄粒子が舞い上がって油分や濁質で固まった濾過粒子の層をほぐし、濾過粒子間に隙間を空ける。これにより、濾過粒子を効率よく洗浄水に暴露できると共に、濾過粒子が舞い上がって他の濾過粒子や洗浄粒子と衝突することにより濾過粒子の洗浄が促進される。このように、当該濾過ユニットは、簡素な構造でありながら、濾過粒子の洗浄性能に優れる。また、洗浄粒子の平均粒径及び平均比重が濾過粒子よりも大きいことによって、沈降速度の差により下側に洗浄粒子の層が形成され、上側に洗浄粒子をあまり含まない濾過粒子の層が形成されるので、この濾過粒子の層により被処理液中の濁質の除去が阻害されない。 The filtration unit is filled with filtration particles and washing particles, so that large and heavy washing particles rise during backwashing and loosen a layer of filtration particles solidified by oil or turbidity, leaving gaps between the filtration particles. Free. Accordingly, the filtered particles can be efficiently exposed to the cleaning water, and the cleaning of the filtering particles is promoted by the rising of the filtering particles and colliding with other filtering particles or cleaning particles. Thus, the said filtration unit is excellent in the washing | cleaning performance of filtration particle | grains, although it is a simple structure. In addition, because the average particle size and average specific gravity of the cleaning particles are larger than that of the filtered particles, a layer of cleaning particles is formed on the lower side due to the difference in sedimentation speed, and a layer of filtered particles that does not contain much cleaning particles is formed on the upper side. Therefore, the removal of turbidity in the liquid to be treated is not hindered by the filtered particle layer.
　定常状態で上記濾過粒子及び洗浄粒子の上方に空間を有するとよい。このように、定常状態で濾過粒子及び洗浄粒子の上方に空間を有することによって、逆洗時に濾過粒子及び洗浄粒子が舞い上がって勢いよくぶつかり合うので、洗浄効果を一層促進できる。また、逆洗時に濾過粒子及び洗浄粒子がこの上方の空間内に舞い上がるため、濾過粒子間に捕捉された油分や濁質等を効果的に排出することができる。これにより、当該濾過ユニットは、逆洗時間及び逆洗水量を低減することができ、ひいては高い水処理効率を発揮することができる。 It is good to have a space above the filtration particles and cleaning particles in a steady state. Thus, by having a space above the filtered particles and the cleaning particles in a steady state, the filtered particles and the cleaning particles rise and collide with each other at the time of backwashing, so that the cleaning effect can be further promoted. In addition, since the filtered particles and the washed particles rise into the space above during backwashing, oil or turbidity trapped between the filtered particles can be effectively discharged. Thereby, the said filtration unit can reduce the backwashing time and the amount of backwashing water, and can exhibit high water treatment efficiency by extension.
　上記濾過粒子の平均比重に対する洗浄粒子の平均比重の比としては、１．２以上１０以下が好ましい。このように、濾過粒子の平均比重に対する洗浄粒子の平均比重の比が上記範囲内であることによって、逆洗時の洗浄効率をさらに向上できると共に、逆洗終了後の濾過粒子の層と洗浄粒子の層とを確実に分離して濾過効率をさらに向上できる。 The ratio of the average specific gravity of the cleaning particles to the average specific gravity of the filtered particles is preferably from 1.2 to 10. Thus, the ratio of the average specific gravity of the cleaning particles to the average specific gravity of the filtered particles is within the above range, so that the cleaning efficiency at the time of backwashing can be further improved, and the layer of the filtered particles after the backwashing and the cleaning particles Thus, the filtration efficiency can be further improved.
　上記濾過粒子の平均粒径に対する洗浄粒子の平均粒径の比としては、１．２以上１０以下が好ましい。このように、濾過粒子の平均粒径に対する洗浄粒子の平均粒径の比が上記範囲内であることによって、逆洗時の洗浄効率をさらに向上できると共に、洗浄粒子同士の隙間に濾過粒子が入り込みにくく、濾過粒子の層の形成がより確実になる。 The ratio of the average particle size of the cleaning particles to the average particle size of the filtration particles is preferably 1.2 or more and 10 or less. Thus, the ratio of the average particle size of the cleaning particles to the average particle size of the filtered particles is within the above range, so that the cleaning efficiency at the time of backwashing can be further improved, and the filtering particles enter the gaps between the cleaning particles. It is difficult to form a layer of filtered particles more reliably.
　上記濾過粒子に対する洗浄粒子の配合体積比としては、０．１以上１．０以下が好ましい。このように、濾過粒子に対する洗浄粒子の配合体積比が上記範囲内であることによって、逆洗時の洗浄効率をより向上できると共に、当該濾過ユニットの体積効率を高められる。 The mixing volume ratio of the cleaning particles to the filtration particles is preferably 0.1 or more and 1.0 or less. Thus, when the mixing | blending volume ratio of the washing | cleaning particle with respect to filtration particle | grains exists in the said range, while improving the washing | cleaning efficiency at the time of backwashing, the volumetric efficiency of the said filtration unit can be raised.
　上記濾過粒子がガラス又はポリマーを主成分とし、上記洗浄粒子がガラス、セラミックス、金属又はポリマーを主成分とするとよい。このように、濾過粒子の主成分がガラス又はポリマーであり、洗浄粒子の主成分がガラス、セラミックス、金属又はポリマーであることによって、洗浄効率と濾過効率とを両立して高められる。 It is preferable that the filtration particles have glass or polymer as a main component and the cleaning particles have glass, ceramics, metal or polymer as a main component. As described above, when the main component of the filtration particles is glass or polymer and the main component of the cleaning particles is glass, ceramics, metal, or polymer, both cleaning efficiency and filtration efficiency can be enhanced.
　本発明の一態様に係る濾過ユニットは、簡素な構造で、濾過粒子の洗浄性能に優れる。このため、当該濾過ユニットは、油分及び濁質を含有する被処理液を浄化するために好適に使用できる。 The filtration unit according to one embodiment of the present invention has a simple structure and is excellent in the cleaning performance of the filtration particles. For this reason, the said filtration unit can be used conveniently in order to purify the to-be-processed liquid containing an oil component and a turbidity.
　本発明の別の態様に係る濾過粒子の洗浄方法は、下向流式濾過塔内に配設され、下方が通水性の仕切板で区画される濾過ユニットに充填される濾過粒子の洗浄方法であって、上記濾過粒子よりも平均粒径及び平均比重が大きい洗浄粒子が充填されている上記濾過ユニットに上記仕切板を通して上向きに洗浄水を通水することにより上記洗浄粒子を舞い上がらせる工程を備える。 The method for washing filtered particles according to another aspect of the present invention is a method for washing filtered particles that are disposed in a downward flow filtration tower and filled in a filtration unit that is partitioned by a water-permeable partition plate below. A step of causing the washing particles to rise by passing washing water upward through the partition plate into the filtration unit filled with washing particles having an average particle diameter and an average specific gravity larger than the filtration particles. .
　当該濾過粒子の洗浄方法は、濾過ユニットに濾過粒子よりも平均粒径及び平均比重が大きい洗浄粒子を充填することによって、洗浄粒子が先に沈降して形成した層の上に濾過粒子の層を形成して濾過を行う。そして、濾過ユニットに上記仕切板を通して上向きに洗浄水を通水することにより洗浄粒子を舞い上がらせることにより、油分や濁質で固まった濾過粒子の層をほぐし、濾過粒子間に隙間を空けることで濾過粒子の洗浄を促進することができる。 The filtration particle cleaning method is to fill the filtration unit with a particle having a larger average particle diameter and average specific gravity than the filtration particle, thereby forming a layer of the filtration particle on the layer formed by the precipitation of the washing particle first. Form and filter. And by letting the washing water flow upward through the partition plate to the filtration unit, the washing particles are soared to loosen the layer of filtration particles solidified by oil and turbidity, and to make a gap between the filtration particles. Cleaning of the filtered particles can be facilitated.
　ここで、「平均粒径」とは、ＪＩＳ－Ｚ８８０１－１（２００６）に規定される篩を用い、目開きの大きい篩から順に篩分けて目開きを通過する粒子の質量割合を測定し、公称目開きを粒径として作成される粒径分布において積算質量が５０％となる値（ｄ５０）を意味する。「平均比重」とは、ＪＩＳ－Ｚ８８０７（２０１２）に準拠して測定される値である。また、「濁質」とは、油分を除く懸濁物質を意味する。なお、「油分」と「濁質」とが分離されている必要はなく、エマルジョンを形成していてもよい。また、「金属」とは、金属化合物を含む。 Here, the “average particle diameter” is a sieve defined in JIS-Z8801-1 (2006), and sieved in order from a sieve having a large mesh size, and the mass ratio of particles passing through the mesh is measured. It means a value (d50) at which the integrated mass becomes 50% in the particle size distribution created with the nominal aperture as the particle size. “Average specific gravity” is a value measured in accordance with JIS-Z8807 (2012). The “turbidity” means a suspended substance excluding oil. The “oil” and “turbidity” do not have to be separated, and an emulsion may be formed. The “metal” includes a metal compound.
［本発明の実施形態の詳細］
　以下、本発明の一実施形態の濾過ユニットを備える下向流式濾過塔について図面を参照しつつ詳説する。 [Details of the embodiment of the present invention]
Hereinafter, it explains in full detail, referring to drawings for a downward flow type filtration tower provided with a filtration unit of one embodiment of the present invention.
［下向流式濾過塔］
　図１の下向流式濾過塔は、被処理液を濾過する装置である。この下向流式濾過塔によって濾過する被処理液としては、典型的には油分と濁質とを含有する石油随伴水が挙げられる。この濁質とは、例えば砂、シリカや炭酸カルシウムなどの粒子、鉄粉、微生物、木片等を含む。 [Downward flow filtration tower]
1 is an apparatus for filtering the liquid to be treated. The liquid to be treated to be filtered by the downflow type filtration tower typically includes petroleum-associated water containing oil and turbidity. The turbidity includes, for example, particles such as sand, silica and calcium carbonate, iron powder, microorganisms, and wood chips.
　この下向流式濾過塔は、中心軸が鉛直方向と略一致するよう立設され、天板部及び底板部を有する筒状本体１と、この筒状本体１の内部に互いに間隔を空けて上下に並んで配設される本発明の実施形態に係る３つの濾過ユニット（第１濾過ユニット２ａ、第２濾過ユニット２ｂ及び第３濾過ユニット２ｃ）と、筒状本体１の上端に配設され、筒状本体１内に被処理液を供給する被処理液供給流路３と、筒状本体１の下端に配設され、筒状本体１内から被処理液を濾過した処理済液を排出する処理済液排出流路４とを備えている。筒状本体１内には、最上流側の第１濾過ユニット２ａの上方及び最下流側の第３濾過ユニット２ｃの下方にも空間が形成されている。また、下向流式濾過塔は、処理済液排出流路４に洗浄水を供給する洗浄水供給装置（不図示）を備える。 The downflow type filtration tower is erected so that the central axis substantially coincides with the vertical direction, and the cylindrical main body 1 having a top plate portion and a bottom plate portion are spaced apart from each other inside the cylindrical main body 1. Three filtration units (first filtration unit 2a, second filtration unit 2b, and third filtration unit 2c) according to an embodiment of the present invention that are arranged side by side are arranged at the upper end of the cylindrical main body 1. The liquid to be processed is supplied to the cylindrical main body 1 and the liquid to be processed is supplied to the lower end of the cylindrical main body 1. The processed liquid obtained by filtering the liquid to be processed is discharged from the cylindrical main body 1. And a treated liquid discharge flow path 4. A space is also formed in the cylindrical main body 1 above the first filtration unit 2a on the most upstream side and below the third filtration unit 2c on the most downstream side. Further, the downward flow filtration tower includes a cleaning water supply device (not shown) for supplying cleaning water to the treated liquid discharge flow path 4.
＜筒状本体＞
　筒状本体１は、金属や樹脂によって、内部に挿通する液体の圧力に耐える強度を有するよう形成される。筒状本体１を形成する材料としては、特に、強度、耐熱性、耐薬品性等の観点からステンレス又はアクリロニトリル－ブタジエン－スチレン共重合体（ＡＢＳ樹脂）が好ましい。また、筒状本体１は、外側に補強部材や自立するための脚部材等が設けられてもよい。 <Cylindrical body>
The cylindrical main body 1 is formed of metal or resin so as to have a strength that can withstand the pressure of the liquid that is inserted into the cylindrical main body 1. As a material for forming the cylindrical body 1, stainless steel or acrylonitrile-butadiene-styrene copolymer (ABS resin) is particularly preferable from the viewpoint of strength, heat resistance, chemical resistance, and the like. Moreover, the cylindrical main body 1 may be provided with a reinforcing member or a leg member for self-standing on the outside.
　筒状本体１の平面形状としては、特に限定されず、例えば円形、楕円形、矩形等の任意の形状とすることができるが、一様な液体の流れを形成しやすく、後述する濾過粒子及び洗浄粒子並びに油分及び濁質の詰まりや滞留を防止できることから、角のない形状が好ましく、典型的には円形とされる。また、筒状本体１の平面形状を角のない形状とすることは、筒状本体１の強度を得やすく設計が容易となるメリットもある。筒状本体１の被処理液供給流路３が配設される天板部及び処理済液排出流路４が配設される底板部は、平板であってもよいが、耐圧性が得られる鏡板状とすることが好ましい。 The planar shape of the cylindrical main body 1 is not particularly limited, and may be any shape such as a circle, an ellipse, a rectangle, etc., but it is easy to form a uniform liquid flow. From the viewpoint of preventing clogging and staying of cleaning particles and oil and turbidity, a shape without corners is preferable, and a circular shape is typically used. Moreover, making the planar shape of the cylindrical main body 1 without a corner has an advantage that the strength of the cylindrical main body 1 is easily obtained and the design is easy. The top plate portion in which the liquid supply flow path 3 to be processed and the bottom plate portion in which the processed liquid discharge flow path 4 are disposed may be flat plates, but pressure resistance is obtained. It is preferable to use a mirror-plate shape.
　筒状本体１の大きさとしては、処理すべき被処理水の流量等に応じて選択され、特に限定されない。筒状本体１の平均断面積としては、例えば０．１ｍ２以上１０ｍ２以下とすることができる。また、筒状本体１の高さとしては、例えば０．５ｍ以上１０ｍ以下とすることができる。 The size of the cylindrical main body 1 is not particularly limited, and is selected according to the flow rate of water to be treated to be treated. The average cross-sectional area of the cylindrical main body 1 can be, for example, 0.1 m 2 or more 10 m 2 or less. Moreover, as the height of the cylindrical main body 1, it can be set to 0.5 m or more and 10 m or less, for example.
＜濾過ユニット＞
　第１濾過ユニット２ａは、下方が通水可能な第１下側仕切板５ａで区画され、上方が通水可能な第１上側仕切板６ａで区画され、その内部に第１濾過粒子７ａとこの第１濾過粒子７ａよりも平均粒径及び平均比重が大きい第１洗浄粒子８ａとが充填されている。また、第１濾過ユニット２ａは、定常状態（連続的に濾過を行っている状態）で第１濾過粒子７ａ及び第１洗浄粒子８ａの上方に第１空間９ａを有する。 <Filtration unit>
The first filtration unit 2a is partitioned by a first lower partition plate 5a that allows water to pass through the lower side, and is partitioned by a first upper partition plate 6a that allows water to pass through the first filtration unit 2a. The first cleaning particles 8a having a larger average particle diameter and average specific gravity than the first filtration particles 7a are packed. Moreover, the 1st filtration unit 2a has the 1st space 9a above the 1st filtration particle | grains 7a and the 1st washing | cleaning particle | grains 8a in the steady state (state which filters continuously).
　同様に、第２濾過ユニット２ｂは、下方が通水可能な第２下側仕切板５ｂで区画され、上方が通水可能な第２上側仕切板６ｂで区画され、その内部に第２濾過粒子７ｂとこの第２濾過粒子７ｂよりも平均粒径及び平均比重が大きい第２洗浄粒子８ｂとが充填されている。また、第２濾過ユニット２ｂは、定常状態で第２濾過粒子７ｂ及び第２洗浄粒子８ｂの上方に第２空間９ｂを有する。 Similarly, the second filtration unit 2b is partitioned by a second lower partition plate 5b that allows water to flow through the lower side, and partitioned by a second upper partition plate 6b that allows water to flow through the upper side. 7b and second cleaning particles 8b having a larger average particle diameter and average specific gravity than the second filtration particles 7b are packed. Moreover, the 2nd filtration unit 2b has the 2nd space 9b above the 2nd filtration particle 7b and the 2nd washing | cleaning particle 8b in a steady state.
　さらに、第３濾過ユニット２ｃは、下方が通水可能な第３下側仕切板５ｃで区画され、上方が通水可能な第３上側仕切板６ｃで区画され、その内部に第３濾過粒子７ｃとこの第３濾過粒子７ｃよりも平均粒径及び平均比重が大きい第３洗浄粒子８ｃとが充填されている。また、第３濾過ユニット２ｃは、定常状態で第３濾過粒子７ｃ及び第３洗浄粒子８ｃの上方に第３空間９ｃを有する。 Further, the third filtration unit 2c is partitioned by a third lower partition plate 5c that allows water to flow through the lower side, and is partitioned by a third upper partition plate 6c that allows water to flow through the upper side. And third cleaning particles 8c having a larger average particle diameter and average specific gravity than the third filtration particles 7c. Moreover, the 3rd filtration unit 2c has the 3rd space 9c above the 3rd filtration particle 7c and the 3rd washing | cleaning particle 8c in a steady state.
　なお、「濾過ユニット」とは、濾過を行う構成の単位構造を指し、必ずしも分離可能な構造を意味しない。図１の下向流式濾過塔において、濾過ユニット２ａ，２ｂ，２ｃは、側壁が筒状本体１の側壁と一体である。 It should be noted that the “filtration unit” refers to a unit structure having a structure for performing filtration, and does not necessarily mean a separable structure. 1, the side walls of the filtration units 2 a, 2 b, and 2 c are integrated with the side wall of the cylindrical main body 1.
（仕切板）
　下側仕切板５ａ，５ｂ，５ｃ及び上側仕切板６ａ，６ｂ，６ｃは、水を通過させ、かつ濾過粒子７ａ，７ｂ，７ｃ及び洗浄粒子８ａ，８ｂ，８ｃを通過させない板状の部材で形成される。これらの下側仕切板５ａ，５ｂ，５ｃ及び上側仕切板６ａ，６ｂ，６ｃは、濾過粒子９ａ，９ｂ，９ｃ及び洗浄粒子８ａ，８ｂ，８ｃを濾過ユニット２ａ，２ｂ，２ｃの内部に封止する機能を果たす。 (Partition plate)
The lower partition plates 5a, 5b, 5c and the upper partition plates 6a, 6b, 6c are formed of plate-like members that allow water to pass therethrough and not allow the filtered particles 7a, 7b, 7c and the cleaning particles 8a, 8b, 8c to pass therethrough. Is done. These lower partition plates 5a, 5b, 5c and upper partition plates 6a, 6b, 6c seal the filtration particles 9a, 9b, 9c and the cleaning particles 8a, 8b, 8c inside the filtration units 2a, 2b, 2c. Fulfills the function of
　この下側仕切板５ａ，５ｂ，５ｃ及び上側仕切板６ａ，６ｂ，６ｃの具体的な材料としては、例えば気孔率の大きい多孔質板、多数の小孔が形成された板、ワイヤーメッシュ等が挙げられる。また、下側仕切板５ａ，５ｂ，５ｃ及び上側仕切板６ａ，６ｂ，６ｃは、目開きの大きい支持部材と、この支持部材の目を覆うよう配設された網状、織布状又は不織布状の部材との組み合わせからなってもよい。 Specific materials for the lower partition plates 5a, 5b, and 5c and the upper partition plates 6a, 6b, and 6c include, for example, a porous plate having a large porosity, a plate in which many small holes are formed, a wire mesh, and the like. Can be mentioned. Further, the lower partition plates 5a, 5b, 5c and the upper partition plates 6a, 6b, 6c are a support member having a large mesh and a net-like, woven or non-woven fabric arranged so as to cover the eyes of the support member. It may consist of a combination with these members.
　下側仕切板５ａ，５ｂ，５ｃ及び上側仕切板６ａ，６ｂ，６ｃの材質としては、特に限定されず、金属や合成樹脂等を用いることができる。金属を用いる場合、防食の観点から耐食性ステンレス鋼（例えばＳＵＳ３１６Ｌ等）を用いることが好ましい。板状の合成樹脂を用いる場合、水圧や粒子の重量によって目開きが変化しないよう補強ワイヤー等の支持部材を併用することが好ましい。ワイヤーメッシュを用いる場合、例えばステンレス鋼線、ケブラー繊維、カーボン繊維等の強度及び耐熱性に優れる線材からなるメッシュを使用することが好ましい。 The material of the lower partition plates 5a, 5b, 5c and the upper partition plates 6a, 6b, 6c is not particularly limited, and metal, synthetic resin, or the like can be used. When using a metal, it is preferable to use corrosion-resistant stainless steel (for example, SUS316L) from the viewpoint of corrosion prevention. When using a plate-shaped synthetic resin, it is preferable to use a support member such as a reinforcing wire in combination so that the opening is not changed by the water pressure or the weight of the particles. When using a wire mesh, it is preferable to use a mesh made of a wire material having excellent strength and heat resistance, such as stainless steel wire, Kevlar fiber, carbon fiber and the like.
　下側仕切板５ａ，５ｂ，５ｃ及び上側仕切板６ａ，６ｂ，６ｃをワイヤーメッシュで形成する場合、ワイヤーメッシュの公称目開きは、対応する濾過粒子７ａ，７ｂ，７ｃ及び洗浄粒子８ａ，８ｂ，８ｃの最小径以下となるよう設計されることが好ましい。また、濾過粒子７ａ，７ｂ，７ｃ又は洗浄粒子８ａ，８ｂ，８ｃの最小径が微小である場合、ワイヤーメッシュの目開きをそれよりも小さくすると差圧が大きくなり過ぎるおそれがある。このため、ワイヤーメッシュの公称目開きは、対応する濾過粒子７ａ，７ｂ，７ｃの平均粒径から対応する濾過粒子７ａ，７ｂ，７ｃの粒径の標準偏差を引いた値以下とすることが好ましい。 When the lower partition plates 5a, 5b, 5c and the upper partition plates 6a, 6b, 6c are formed of wire mesh, the nominal mesh openings of the wire mesh are the corresponding filtration particles 7a, 7b, 7c and cleaning particles 8a, 8b, It is preferably designed to be less than the minimum diameter of 8c. Moreover, when the minimum diameter of the filtration particles 7a, 7b, 7c or the cleaning particles 8a, 8b, 8c is very small, if the opening of the wire mesh is made smaller than that, the differential pressure may become too large. For this reason, it is preferable that the nominal mesh opening of the wire mesh is not more than a value obtained by subtracting the standard deviation of the particle diameters of the corresponding filtration particles 7a, 7b, 7c from the average particle diameter of the corresponding filtration particles 7a, 7b, 7c. .
（濾過粒子）
　濾過粒子７ａ，７ｂ，７ｃは、被処理水を濾過する層を形成する濾材である。この濾過粒子７ａ，７ｂ，７ｃとしては、公知の濾過処理用の粒子を用いることができ、例えば天然砂、無機物粒子、ガラス、セラミックス、ポリマー（高分子化合物）、天然有機素材等を主成分とする粒子を用いることができる。 (Filtered particles)
The filtration particles 7a, 7b, and 7c are filter media that form a layer for filtering the water to be treated. As the filtration particles 7a, 7b, 7c, known filtration particles can be used. For example, natural sand, inorganic particles, glass, ceramics, polymers (polymer compounds), natural organic materials and the like are the main components. Particles can be used.
　ただし、濾過粒子７ａ，７ｂ，７ｃは、ガラス又はポリマーを主成分とすることが好ましい。濾過粒子７ａ，７ｂ，７ｃをガラスを主成分とするものとすることによって、当該濾過ユニット２ａ，２ｂ，２ｃのコストを低減することができる。また、濾過粒子７ａ，７ｂ，７ｃをポリマーを主成分とするものとすることによって、当該濾過ユニット２ａ，２ｂ，２ｃのコスト及び重量を低減することができる。また、ポリマーを用いることにより、濾過粒子７ａ，７ｂ，７ｃの比重を小さくできるため、逆洗時の撹拌作用による濾過粒子７ａ，７ｂ，７ｃの洗浄促進効果をさらに高めることができる。特に、濾過粒子７ａ，７ｂ，７ｃとしてガラスビーズを使用すれば、濾過粒子７ａ，７ｂ，７ｃの表面から油分や濁質が剥離し易くなるため、逆洗時の洗浄促進効果を比較的容易に向上することができる。 However, it is preferable that the filtration particles 7a, 7b, and 7c have glass or a polymer as a main component. By making the filtration particles 7a, 7b, and 7c mainly contain glass, the cost of the filtration units 2a, 2b, and 2c can be reduced. Moreover, the cost and weight of the said filtration units 2a, 2b, 2c can be reduced by making the filtration particle | grains 7a, 7b, 7c into a polymer as a main component. Moreover, since the specific gravity of filtration particle | grains 7a, 7b, 7c can be made small by using a polymer, the washing | cleaning promotion effect of filtration particle | grains 7a, 7b, 7c by the stirring action at the time of backwashing can further be heightened. In particular, if glass beads are used as the filtration particles 7a, 7b, and 7c, oil and turbidity are easily peeled off from the surfaces of the filtration particles 7a, 7b, and 7c. Can be improved.
　濾過粒子７ａ，７ｂ，７ｃの主成分とされるガラスとしては、例えばソーダ石灰ガラス、チタンバリウム系ガラス、鉛ガラス、硼珪酸ガラス等を挙げることができる。中でも、粒子状の製品が比較的安価に広く市販されているソーダ石灰ガラスが好適に用いられる。 Examples of the glass that is the main component of the filtration particles 7a, 7b, and 7c include soda lime glass, titanium barium glass, lead glass, and borosilicate glass. Of these, soda-lime glass, which is widely available on a relatively inexpensive basis, is preferably used.
　濾過粒子７ａ，７ｂ，７ｃの主成分とされるポリマーとしては、例えばフッ素樹脂、ビニル樹脂、ポリオレフィン、ポリウレタン、エポキシ樹脂、ポリエステル、ポリアミド、ポリイミド、メラミン樹脂、ポリカーボネート等を挙げることができる。これらの中でも耐水性、耐油性等に優れるフッ素樹脂、ビニル樹脂、ポリウレタン、エポキシ樹脂、アクリル樹脂が好ましく、耐食性に優れるフッ素樹脂及び吸着性に優れるポリオレフィンがより好ましい。さらに、ポリオレフィンの中では、特に油分吸着能力に優れるポリプロピレンが好ましい。また、フッ素樹脂は、強度、耐熱性及び耐薬品性に優れ、かつ比較的比重が大きいので洗浄後に沈降が早く、早く濾過を再開できるというメリットがある。なお、濾過粒子７ａ，７ｂ，７ｃの材質は、濾過ユニット毎に異なっていてもよく、それぞれ複数種類の粒子を含んでもよい。 Examples of the polymer that is the main component of the filtration particles 7a, 7b, and 7c include fluororesin, vinyl resin, polyolefin, polyurethane, epoxy resin, polyester, polyamide, polyimide, melamine resin, and polycarbonate. Among these, a fluororesin, a vinyl resin, a polyurethane, an epoxy resin, and an acrylic resin excellent in water resistance and oil resistance are preferable, and a fluororesin excellent in corrosion resistance and a polyolefin excellent in adsorptivity are more preferable. Further, among polyolefins, polypropylene that is particularly excellent in oil adsorption capacity is preferable. In addition, the fluororesin is excellent in strength, heat resistance, and chemical resistance, and has a relatively large specific gravity, so that it has a merit that it can settle quickly after washing and can be quickly filtered. In addition, the material of filtration particle | grains 7a, 7b, 7c may differ for every filtration unit, and may contain multiple types of particle | grains, respectively.
　また、上記天然砂としては、例えばアンスラサイト、ガーネット、マンガン砂等を挙げることができ、これらを１種で又は２種以上混合して用いることができる。上記セラミックスとしては、例えばシリカ、アルミナ、ガラス等を主成分とするセラミックス粒子を用いることができる。上記天然有機素材としては、天然の有機物を篩い分けして粒子サイズを整えたものを使用することができ、例えばクルミの殻、おがくず、麻などの天然繊維等を挙げることができる。 Moreover, examples of the natural sand include anthracite, garnet, manganese sand, and the like, and these can be used alone or in combination of two or more. As the ceramic, for example, ceramic particles mainly composed of silica, alumina, glass or the like can be used. As the natural organic material, a natural organic material having a particle size adjusted by sieving can be used, and examples thereof include natural fibers such as walnut shell, sawdust and hemp.
　濾過粒子７ａ，７ｂ，７ｃの形状としては、特に限定されず、例えば球形、柱形等任意の形状とすることができる。特に、濾過粒子７ａ，７ｂ，７ｃとして、不定形の粉砕粒子を用いることで、濾過粒子７ａ，７ｂ，７ｃを緻密に堆積させることができ、濾過効率を向上させると共に、定常状態における濾過粒子７ａ，７ｂ，７ｃの浮き上がりを防止することができる。 The shape of the filtration particles 7a, 7b, and 7c is not particularly limited, and may be any shape such as a spherical shape or a column shape. In particular, by using irregularly pulverized particles as the filtration particles 7a, 7b, and 7c, the filtration particles 7a, 7b, and 7c can be densely deposited, and the filtration efficiency is improved and the filtration particles 7a in a steady state. , 7b, 7c can be prevented.
　濾過粒子７ａ，７ｂ，７ｃの平均比重の下限としては、０．８が好ましく、１．１がより好ましく、１．４がさらに好ましい。一方、濾過粒子７ａ，７ｂ，７ｃの平均比重の上限としては、５が好ましく、３がより好ましく、２がさらに好ましい。濾過粒子７ａ，７ｂ，７ｃの平均比重が上記下限に満たない場合、被処理水の流速よりも濾過粒子７ａ，７ｂ，７ｃの浮上速度が大きくなることにより濾過粒子７ａ，７ｂ，７ｃが沈降せず、当該濾過ユニット２ａ，２ｂ，２ｃの中で被処理液を濾過する層を形成できないおそれがある。逆に、濾過粒子７ａ，７ｂ，７ｃの平均比重が上記上限を超える場合、逆洗時に濾過粒子７ａ，７ｂ，７ｃの層が流動化できず、洗浄効果を向上できないおそれがある。なお、濾過粒子７ａ，７ｂ，７ｃの平均比重は、濾過ユニット毎に異なっていてもよい。 The lower limit of the average specific gravity of the filtered particles 7a, 7b, 7c is preferably 0.8, more preferably 1.1, and even more preferably 1.4. On the other hand, the upper limit of the average specific gravity of the filtration particles 7a, 7b, 7c is preferably 5, more preferably 3, and even more preferably 2. When the average specific gravity of the filtered particles 7a, 7b, and 7c is less than the lower limit, the rising speed of the filtered particles 7a, 7b, and 7c is larger than the flow rate of the water to be treated, so that the filtered particles 7a, 7b, and 7c are settled. Therefore, there is a possibility that a layer for filtering the liquid to be treated cannot be formed in the filtration units 2a, 2b, 2c. Conversely, when the average specific gravity of the filtration particles 7a, 7b, 7c exceeds the above upper limit, the layer of the filtration particles 7a, 7b, 7c cannot be fluidized during backwashing, and the cleaning effect may not be improved. In addition, the average specific gravity of filtration particle | grains 7a, 7b, 7c may differ for every filtration unit.
　濾過粒子７ａ，７ｂ，７ｃの均等係数の下限としては、１．１が好ましく、１．３がより好ましい。一方、濾過粒子７ａ，７ｂ，７ｃの均等係数の上限としては、１．８が好ましく、１．６がより好ましい。濾過粒子７ａ，７ｂ，７ｃの均等係数が上記下限に満たない場合、各濾過粒子７ａ，７ｂ，７ｃの粒径のバラツキが小さ過ぎて緻密に堆積させることができないおそれがある。逆に、濾過粒子７ａ，７ｂ，７ｃの均等係数が上記上限を超える場合、当該濾過ユニット２ａ，２ｂ，２ｃの内部で油滴や濁質の分離能力が不均一となるおそれがある。なお、「均等係数」とは、ＪＩＳ－Ｚ８８０１－１（２００６）に規定される篩を用い、目開きの大きい篩から順に篩分けて目開きを通過する粒子の質量割合を測定し、公称目開きを粒径として作成される粒径分布において積算質量が６０％となる値（ｄ６０）を積算質量が１０％となる値（ｄ１０）で除した値である。 The lower limit of the uniformity coefficient of the filtration particles 7a, 7b, 7c is preferably 1.1, and more preferably 1.3. On the other hand, the upper limit of the uniformity coefficient of the filtration particles 7a, 7b, and 7c is preferably 1.8, and more preferably 1.6. When the uniformity coefficient of the filtration particles 7a, 7b, and 7c is less than the lower limit, the variation in the particle diameter of the filtration particles 7a, 7b, and 7c may be too small to be densely deposited. On the contrary, when the uniformity coefficient of the filtration particles 7a, 7b, and 7c exceeds the above upper limit, there is a possibility that the separation ability of oil droplets and turbidity is not uniform in the filtration units 2a, 2b, and 2c. The “equality coefficient” is a sieve defined in JIS-Z8801-1 (2006), which is sieved in order from the sieve with the largest mesh, and the mass ratio of particles passing through the mesh is measured. This is a value obtained by dividing the value (d60) at which the accumulated mass is 60% in the particle size distribution created with the opening as the particle size by the value (d10) at which the accumulated mass is 10%.
　濾過粒子７ａ，７ｂ，７ｃの平均粒径は、上流側の当該濾過ユニット２ａ，２ｂ，２ｃほど大きい。つまり、第１濾過粒子７ａの平均粒径よりも第２濾過粒子７ｂの平均粒径が小さく、第２濾過粒子７ｂの平均粒径よりも第３濾過粒子７ｃの平均粒径が小さい。 The average particle diameter of the filtration particles 7a, 7b, 7c is larger as the filtration units 2a, 2b, 2c on the upstream side. That is, the average particle diameter of the second filtered particles 7b is smaller than the average particle diameter of the first filtered particles 7a, and the average particle diameter of the third filtered particles 7c is smaller than the average particle diameter of the second filtered particles 7b.
　最上流側の第１濾過粒子７ａの平均粒径の下限としては、７００μｍが好ましく、８００μｍがより好ましく、１０００μｍがさらに好ましい。一方、第１濾過粒子７ａの平均粒径の上限としては、３０００μｍが好ましく、２０００μｍがより好ましく、１５００μｍがさらに好ましい。第１濾過粒子７ａの平均粒径が上記下限に満たない場合、当該第１濾過ユニット２ａに第１濾過粒子７ａによって形成される層の密度が大きく、隙間が小さくなるので、当該第１濾過ユニット２ａの圧損が大きくなるおそれや、当該第１濾過ユニット２ａの目詰まりの頻度が大きくなるおそれがある。逆に、第１濾過粒子７ａの平均粒径が上記上限を超える場合、第１濾過粒子７ａ間の隙間が大きくなり、十分に油分や濁質を除去できないおそれがある。 The lower limit of the average particle diameter of the first filtration particles 7a on the most upstream side is preferably 700 μm, more preferably 800 μm, and even more preferably 1000 μm. On the other hand, the upper limit of the average particle diameter of the first filtration particles 7a is preferably 3000 μm, more preferably 2000 μm, and further preferably 1500 μm. When the average particle diameter of the first filtration particles 7a is less than the lower limit, the density of the layer formed by the first filtration particles 7a in the first filtration unit 2a is large and the gap is small. There is a concern that the pressure loss of 2a may increase and the frequency of clogging of the first filtration unit 2a may increase. On the contrary, when the average particle diameter of the 1st filtration particle 7a exceeds the said upper limit, the clearance gap between the 1st filtration particles 7a becomes large, and there exists a possibility that an oil component and turbidity cannot fully be removed.
　第２濾過粒子７ｂの平均粒径の下限としては、３００μｍが好ましく、３５０μｍがより好ましく、４００μｍがさらに好ましい。一方、第２濾過粒子７ｂの平均粒径の上限としては、１０００μｍが好ましく、８００μｍがより好ましく、７００μｍがさらに好ましい。第２濾過粒子７ｂの平均粒径が上記下限に満たない場合、当該第２濾過ユニット２ｂの圧損が大きくなるおそれや、当該第２濾過ユニット２ｂの目詰まりの頻度が大きくなるおそれがある。逆に、第２濾過粒子７ｂの平均粒径が上記上限を超える場合、下流側の第３濾過ユニット２ｃの目詰まりの頻度が大きくなるおそれがある。 The lower limit of the average particle size of the second filtration particles 7b is preferably 300 μm, more preferably 350 μm, and even more preferably 400 μm. On the other hand, the upper limit of the average particle diameter of the second filtration particles 7b is preferably 1000 μm, more preferably 800 μm, and even more preferably 700 μm. When the average particle diameter of the second filtration particle 7b is less than the lower limit, the pressure loss of the second filtration unit 2b may increase, or the frequency of clogging of the second filtration unit 2b may increase. Conversely, when the average particle diameter of the second filtration particles 7b exceeds the upper limit, the frequency of clogging of the third filtration unit 2c on the downstream side may increase.
　最下流側の第３濾過粒子７ｃの平均粒径の下限としては、５μｍが好ましく、１０μｍがより好ましく、２０μｍがさらに好ましい。一方、第３濾過粒子７ｃの平均粒径の上限としては、４００μｍが好ましく、３５０μｍがより好ましく、３００μｍがさらに好ましい。第３濾過粒子７ｃの平均粒径が上記下限に満たない場合、当該第３濾過ユニット２ｃの圧損が大きくなるおそれや、コスト及び重量が増加するおそれがある。逆に、第３濾過粒子７ｃの平均粒径が上記上限を超える場合、下向流式濾過塔が微細な油滴や濁質を除去できないおそれがある。 The lower limit of the average particle diameter of the third filtration particles 7c on the most downstream side is preferably 5 μm, more preferably 10 μm, and further preferably 20 μm. On the other hand, the upper limit of the average particle size of the third filtered particles 7c is preferably 400 μm, more preferably 350 μm, and even more preferably 300 μm. If the average particle size of the third filtration particles 7c is less than the lower limit, the pressure loss of the third filtration unit 2c may increase, and the cost and weight may increase. On the contrary, when the average particle diameter of the 3rd filtration particle 7c exceeds the said upper limit, there exists a possibility that a downward flow type filtration tower cannot remove a fine oil droplet and turbidity.
　定常状態において最上流側の第１濾過粒子７ａが形成する層の平均厚さとしては、特に限定されないが、例えば３ｃｍ以上１ｍ以下とすることができる。定常状態において第２濾過粒子７ｂが形成する層の平均厚さとしては、特に限定されないが、例えば２ｃｍ以上８０ｃｍ以下とすることができる。また、定常状態において最下流側の第３濾過粒子７ｃが形成する層の平均厚さとしては、特に限定されないが、例えば１ｃｍ以上５０ｃｍ以下とすることができる。 The average thickness of the layer formed by the first filtration particles 7a on the most upstream side in the steady state is not particularly limited, but may be, for example, 3 cm or more and 1 m or less. Although it does not specifically limit as average thickness of the layer which the 2nd filtration particle 7b forms in a steady state, For example, it can be 2 cm or more and 80 cm or less. In addition, the average thickness of the layer formed by the most downstream third filtration particle 7c in the steady state is not particularly limited, but may be, for example, 1 cm or more and 50 cm or less.
（洗浄粒子）
　洗浄粒子８ａ，８ｂ，８ｃは、逆洗時に舞い上がり、油分や濁質で固まった濾過粒子７ａ，７ｂ，７ｃの層をほぐして隙間を形成することにより、濾過粒子７ａ，７ｂ，７ｃの洗浄効果を促進する。 (Washing particles)
The cleaning particles 8a, 8b, and 8c rise at the time of backwashing and loosen the layer of the filtration particles 7a, 7b, and 7c solidified by oil and turbidity to form a gap, thereby cleaning the filtering particles 7a, 7b, and 7c. Promote.
　この洗浄粒子８ａ，８ｂ，８ｃとしては、天然砂、ガラス、無機物粒子、セラミックス、金属（金属化合物を含む）、ポリマー、天然有機素材等を主成分とする粒子を用いることができ、中でも、ガラス、セラミックス、金属又はポリマーを主成分とする粒子が好ましい。洗浄粒子８ａ，８ｂ，８ｃの主成分がガラス、セラミックス、金属又はポリマーであることによって、濾過粒子７ａ，７ｂ，７ｃに対する比重の比率を容易に適正化でき、濾過粒子７ａ，７ｂ，７ｃの洗浄効果を得やすい。特に、洗浄粒子８ａ，８ｂ，８ｃとしてガラスビーズを使用することにより、洗浄粒子８ａ，８ｂ，８ｃの表面から油分や濁質が剥離し易くなるため、逆洗時の洗浄促進効果を比較的容易に向上することができる。なお、洗浄粒子８ａ，８ｂ，８ｃの材質は、濾過ユニット毎に異なっていてもよく、それぞれ複数種類の粒子を含んでもよい。 As the cleaning particles 8a, 8b, and 8c, particles mainly composed of natural sand, glass, inorganic particles, ceramics, metals (including metal compounds), polymers, natural organic materials, and the like can be used. Particles mainly composed of ceramics, metals or polymers are preferred. Since the main component of the cleaning particles 8a, 8b, and 8c is glass, ceramics, metal, or polymer, the ratio of specific gravity with respect to the filtering particles 7a, 7b, and 7c can be easily optimized, and the cleaning of the filtering particles 7a, 7b, and 7c can be easily performed. Easy to get effect. In particular, the use of glass beads as the cleaning particles 8a, 8b, and 8c makes it easy to remove oil and turbidity from the surfaces of the cleaning particles 8a, 8b, and 8c. Can be improved. In addition, the material of the cleaning particles 8a, 8b, and 8c may be different for each filtration unit, and may include a plurality of types of particles.
　洗浄粒子８ａ，８ｂ，８ｃの主成分とされるガラスとしては、例えばソーダ石灰ガラス、チタンバリウム系ガラス、鉛ガラス、硼珪酸ガラス等を挙げることができる。中でも、粒子状の製品が比較的安価に広く市販されているソーダ石灰ガラスや、濾過粒子７ａ，７ｂ，７ｃとしてガラスビーズを用いる場合に濾過粒子７ａ，７ｂ，７ｃに対する比重の比率を適正化できるチタンバリウム系ガラスが好適に用いられる。 Examples of the glass that is the main component of the cleaning particles 8a, 8b, and 8c include soda lime glass, titanium barium glass, lead glass, and borosilicate glass. Among them, the ratio of specific gravity with respect to the filtration particles 7a, 7b, 7c can be optimized when soda-lime glass whose particulate products are widely marketed relatively inexpensively or when glass beads are used as the filtration particles 7a, 7b, 7c. Titanium barium-based glass is preferably used.
　洗浄粒子８ａ，８ｂ，８ｃの主成分とされるセラミックスとしては、例えばガラス、シリカ、アルミナ等を主成分とするものが挙げられる。 Examples of ceramics that are the main components of the cleaning particles 8a, 8b, and 8c include those containing glass, silica, alumina, and the like as main components.
　洗浄粒子８ａ，８ｂ，８ｃの主成分とされる金属としては、例えば耐錆性に優れる酸化鉄等が挙げられる。 Examples of the metal that is the main component of the cleaning particles 8a, 8b, and 8c include iron oxide having excellent rust resistance.
　洗浄粒子８ａ，８ｂ，８ｃの主成分とされるポリマーとしては、例えばフッ素樹脂、ビニル樹脂、ポリオレフィン、ポリウレタン、エポキシ樹脂、ポリエステル、ポリアミド、ポリイミド、メラミン樹脂、ポリカーボネート等を挙げることができる。これらの中でも耐水性、耐油性等に優れるフッ素樹脂、ビニル樹脂、ポリウレタン、エポキシ樹脂、アクリル樹脂が好ましく、耐食性に優れるフッ素樹脂がより好ましい。 Examples of the polymer that is the main component of the cleaning particles 8a, 8b, and 8c include fluororesin, vinyl resin, polyolefin, polyurethane, epoxy resin, polyester, polyamide, polyimide, melamine resin, and polycarbonate. Among these, a fluororesin, a vinyl resin, a polyurethane, an epoxy resin, and an acrylic resin that are excellent in water resistance and oil resistance are preferable, and a fluororesin that is excellent in corrosion resistance is more preferable.
　また、洗浄粒子８ａ，８ｂ，８ｃの主成分とされる天然砂としては、例えばアンスラサイト、ガーネット、マンガン砂等を挙げることができる。洗浄粒子８ａ，８ｂ，８ｃの主成分とされる天然有機素材としては、天然の有機物を篩い分けして粒子サイズを整えたものを使用することができる。 Further, examples of natural sand that is the main component of the cleaning particles 8a, 8b, and 8c include anthracite, garnet, and manganese sand. As the natural organic material which is the main component of the cleaning particles 8a, 8b and 8c, a natural organic material having a particle size adjusted by sieving can be used.
　洗浄粒子８ａ，８ｂ，８ｃの形状としては、特に限定されず、例えば球形、柱形等任意の形状とすることができる。特に、洗浄粒子８ａ，８ｂ，８ｃとして、不定形の粉砕粒子を用いることで、逆洗時の濾過粒子の洗浄効果をより促進することができる。 The shape of the cleaning particles 8a, 8b, and 8c is not particularly limited, and may be any shape such as a spherical shape or a column shape. In particular, by using irregularly pulverized particles as the cleaning particles 8a, 8b, and 8c, it is possible to further promote the cleaning effect of the filtered particles during backwashing.
　洗浄粒子８ａ，８ｂ，８ｃの平均比重の下限としては、１．３が好ましく、１．６がより好ましい。一方、洗浄粒子８ａ，８ｂ，８ｃの平均比重の上限としては、１５が好ましく、１０がより好ましい。洗浄粒子８ａ，８ｂ，８ｃの平均比重が上記下限に満たない場合、洗浄粒子８ａ，８ｂ，８ｃの濾過粒子７ａ，７ｂ，７ｃに対する衝突エネルギーが小さく、濾過粒子７ａ，７ｂ，７ｃの層を割りほぐすことができないおそれや、洗浄粒子８ａ，８ｂ，８ｃが濾過粒子７ａ，７ｂ，７ｃより先に沈降せず、濾過粒子７ａ，７ｂ，７ｃの層を形成できないおそれがある。逆に、洗浄粒子８ａ，８ｂ，８ｃの平均比重が上記上限を超える場合、逆洗時に洗浄粒子８ａ，８ｂ，８ｃの層が流動化することができず、濾過粒子７ａ，７ｂ，７ｃの洗浄効果を促進できないおそれがある。なお、洗浄粒子８ａ，８ｂ，８ｃの平均比重は、濾過ユニット毎に異なっていてもよい。 The lower limit of the average specific gravity of the cleaning particles 8a, 8b, 8c is preferably 1.3 and more preferably 1.6. On the other hand, the upper limit of the average specific gravity of the cleaning particles 8a, 8b, 8c is preferably 15, and more preferably 10. When the average specific gravity of the cleaning particles 8a, 8b, and 8c is less than the lower limit, the collision energy of the cleaning particles 8a, 8b, and 8c against the filtered particles 7a, 7b, and 7c is small, and the layers of the filtered particles 7a, 7b, and 7c are broken up. The cleaning particles 8a, 8b, and 8c may not settle before the filtering particles 7a, 7b, and 7c, and the layers of the filtering particles 7a, 7b, and 7c may not be formed. On the other hand, when the average specific gravity of the cleaning particles 8a, 8b, 8c exceeds the upper limit, the layer of the cleaning particles 8a, 8b, 8c cannot be fluidized at the time of backwashing, and the filtration particles 7a, 7b, 7c are washed. The effect may not be promoted. The average specific gravity of the cleaning particles 8a, 8b, 8c may be different for each filtration unit.
　第１洗浄粒子８ａは平均比重が第１濾過粒子７ａよりも大きく、第２洗浄粒子８ｂは第２濾過粒子７ｂよりも平均比重が大きく、第３洗浄粒子８ｃは第３濾過粒子７ｃよりも平均比重が大きい。第１洗浄粒子８ａの平均比重の第１濾過粒子７ａの平均比重に対する比、第２洗浄粒子８ｂの平均比重の第２濾過粒子７ｂの平均比重に対する比及び第３洗浄粒子８ｃの平均比重の第３濾過粒子７ｃの平均比重に対する比の下限としては、１．２が好ましく、１．５がより好ましく、２．０がさらに好ましい。一方、上記平均比重の比の上限としては、１０が好ましく、８がより好ましい。上記平均比重の比が上記下限に満たない場合、洗浄粒子８ａ，８ｂ，８ｃが濾過粒子７ａ，７ｂ，７ｃより先に沈降せず、濾過粒子７ａ，７ｂ，７ｃの層を形成できないおそれがある。逆に、上記平均比重の比が上記上限を超える場合、逆洗時に、濾過粒子７ａ，７ｂ，７ｃの層と洗浄粒子８ａ，８ｂ，８ｃの層とを同時に流動化することができず、濾過粒子７ａ，７ｂ，７ｃの洗浄効果を促進できないおそれがある。 The first cleaning particles 8a have an average specific gravity larger than that of the first filtered particles 7a, the second cleaning particles 8b have an average specific gravity larger than that of the second filtered particles 7b, and the third cleaning particles 8c have an average higher than that of the third filtered particles 7c. High specific gravity. The ratio of the average specific gravity of the first cleaning particles 8a to the average specific gravity of the first filtered particles 7a, the ratio of the average specific gravity of the second cleaning particles 8b to the average specific gravity of the second filtered particles 7b, and the average specific gravity of the third cleaning particles 8c. As a minimum of ratio to average specific gravity of 3 filtration particles 7c, 1.2 is preferred, 1.5 is more preferred, and 2.0 is still more preferred. On the other hand, the upper limit of the ratio of the average specific gravity is preferably 10, and more preferably 8. When the ratio of the average specific gravity is less than the lower limit, the cleaning particles 8a, 8b, and 8c do not settle before the filtered particles 7a, 7b, and 7c, and the layer of the filtered particles 7a, 7b, and 7c may not be formed. . On the other hand, when the ratio of the average specific gravity exceeds the upper limit, the layer of the filtration particles 7a, 7b, and 7c and the layer of the washing particles 8a, 8b, and 8c cannot be fluidized at the time of backwashing. There is a possibility that the cleaning effect of the particles 7a, 7b, 7c cannot be promoted.
　第１洗浄粒子８ａは第１濾過粒子７ａよりも平均粒径が大きく、第２洗浄粒子８ｂは第２濾過粒子７ｂよりも平均粒径が大きく、第３洗浄粒子８ｃは第３濾過粒子７ｃよりも平均粒径が大きい。第１洗浄粒子８ａの平均粒径の第１濾過粒子７ａの平均粒径に対する比、第２洗浄粒子８ｂの平均粒径の第２濾過粒子７ｂの平均粒径に対する比及び第３洗浄粒子８ｃの平均粒径の第３濾過粒子７ｃの平均粒径に対する比の下限としては、１．２が好ましく、１．４がより好ましく、１．５がさらに好ましい。一方、上記平均粒径の比の上限としては、１０が好ましく、８がより好ましい。上記平均粒径の比が上記下限に満たない場合、洗浄粒子８ａ，８ｂ，８ｃの濾過粒子７ａ，７ｂ，７ｃに対する衝突エネルギーが小さく、濾過粒子７ａ，７ｂ，７ｃの層を割りほぐすことができないおそれや、洗浄粒子８ａ，８ｂ，８ｃが濾過粒子７ａ，７ｂ，７ｃより先に沈降せず、濾過粒子７ａ，７ｂ，７ｃの層を形成できないおそれがある。逆に、上記平均粒径の比が上記上限を超える場合、濾過粒子７ａ，７ｂ，７ｃが洗浄粒子８ａ，８ｂ，８ｃ間の隙間に入り込んで十分な厚さの濾過層を形成できないおそれがある。 The first cleaning particles 8a have a larger average particle size than the first filtration particles 7a, the second cleaning particles 8b have a larger average particle size than the second filtration particles 7b, and the third cleaning particles 8c have a larger particle size than the third filtration particles 7c. Has a large average particle size. The ratio of the average particle size of the first cleaning particles 8a to the average particle size of the first filtration particles 7a, the ratio of the average particle size of the second cleaning particles 8b to the average particle size of the second filtration particles 7b, and the third cleaning particles 8c The lower limit of the ratio of the average particle diameter to the average particle diameter of the third filtered particles 7c is preferably 1.2, more preferably 1.4, and even more preferably 1.5. On the other hand, the upper limit of the ratio of the average particle diameter is preferably 10, and more preferably 8. When the ratio of the average particle diameter is less than the lower limit, the collision energy of the cleaning particles 8a, 8b, and 8c against the filtration particles 7a, 7b, and 7c is small, and the layers of the filtration particles 7a, 7b, and 7c may not be broken. Alternatively, the cleaning particles 8a, 8b, and 8c may not settle before the filtered particles 7a, 7b, and 7c, and the layer of the filtered particles 7a, 7b, and 7c may not be formed. On the other hand, when the ratio of the average particle diameters exceeds the upper limit, the filtration particles 7a, 7b, 7c may enter the gaps between the cleaning particles 8a, 8b, 8c and may not form a sufficiently thick filtration layer. .
　最上流側の第１洗浄粒子８ａの平均粒径の下限としては、８００μｍが好ましく、１０００μｍがより好ましく、１２００μｍがさらに好ましい。一方、第１洗浄粒子８ａの平均粒径の上限としては、５０００μｍが好ましく、３０００μｍがより好ましく、２０００μｍがさらに好ましい。第１洗浄粒子８ａの平均粒径が上記下限に満たない場合、第１洗浄粒子８ａによって形成される層の密度が大きく、圧損が大きくなるおそれがある。逆に、第１洗浄粒子８ａの平均粒径が上記上限を超える場合、第１洗浄粒子８ａ間の隙間に第１濾過粒子７ａが入り込み、第１濾過粒子７ａの層を効率よく形成できないおそれがある。 The lower limit of the average particle diameter of the first cleaning particles 8a on the most upstream side is preferably 800 μm, more preferably 1000 μm, and further preferably 1200 μm. On the other hand, the upper limit of the average particle diameter of the first cleaning particles 8a is preferably 5000 μm, more preferably 3000 μm, and further preferably 2000 μm. When the average particle diameter of the first cleaning particles 8a is less than the lower limit, the density of the layer formed by the first cleaning particles 8a is large, and the pressure loss may increase. Conversely, if the average particle size of the first cleaning particles 8a exceeds the above upper limit, the first filtration particles 7a may enter the gaps between the first cleaning particles 8a, and the layer of the first filtration particles 7a may not be efficiently formed. is there.
　第２洗浄粒子８ｂの平均粒径の下限としては、５００μｍが好ましく、６００μｍがより好ましく、８００μｍがさらに好ましい。一方、第２洗浄粒子８ｂの平均粒径の上限としては、４０００μｍが好ましく、３０００μｍがより好ましく、１８００μｍがさらに好ましい。第２洗浄粒子８ｂの平均粒径が上記下限に満たない場合、第２洗浄粒子８ｂによって形成される層の密度が大きく、圧損が大きくなるおそれがある。逆に、第２洗浄粒子８ｂの平均粒径が上記上限を超える場合、第２洗浄粒子８ｂ間の隙間に第２濾過粒子７ｂが入り込み、第２濾過粒子７ｂの層を効率よく形成できないおそれがある。 The lower limit of the average particle size of the second cleaning particles 8b is preferably 500 μm, more preferably 600 μm, and even more preferably 800 μm. On the other hand, the upper limit of the average particle size of the second cleaning particles 8b is preferably 4000 μm, more preferably 3000 μm, and further preferably 1800 μm. If the average particle size of the second cleaning particles 8b is less than the lower limit, the density of the layer formed by the second cleaning particles 8b may be large and the pressure loss may increase. Conversely, when the average particle size of the second cleaning particles 8b exceeds the above upper limit, the second filtration particles 7b may enter the gaps between the second cleaning particles 8b, and the layer of the second filtration particles 7b may not be formed efficiently. is there.
　最下流側の第３洗浄粒子８ｃの平均粒径の下限としては、１０μｍが好ましく、３０μｍがより好ましく、１００μｍがさらに好ましい。一方、第３洗浄粒子８ｃの平均粒径の上限としては、３０００μｍが好ましく、２０００μｍがより好ましく、１５００μｍがさらに好ましい。第３洗浄粒子８ｃの平均粒径が上記下限に満たない場合、第３洗浄粒子８ｃによって形成される層の密度が大きく、圧損が大きくなるおそれがある。逆に、第３洗浄粒子８ｃの平均粒径が上記上限を超える場合、第３洗浄粒子８ｃ間の隙間に第３濾過粒子７ｃが入り込み、第３濾過粒子７ｃの層を効率よく形成できないおそれがある。 The lower limit of the average particle size of the third cleaning particles 8c on the most downstream side is preferably 10 μm, more preferably 30 μm, and even more preferably 100 μm. On the other hand, the upper limit of the average particle size of the third cleaning particles 8c is preferably 3000 μm, more preferably 2000 μm, and further preferably 1500 μm. When the average particle size of the third cleaning particles 8c is less than the lower limit, the density of the layer formed by the third cleaning particles 8c is large, and the pressure loss may be increased. Conversely, if the average particle size of the third cleaning particles 8c exceeds the upper limit, the third filtration particles 7c may enter the gaps between the third cleaning particles 8c, and the third filtration particle 7c layer may not be formed efficiently. is there.
　第１濾過ユニット２ａにおける第１濾過粒子７ａに対する第１洗浄粒子８ａの配合体積比、第２濾過ユニット２ｂにおける第２濾過粒子７ｂに対する第２洗浄粒子８ｂの配合体積比、及び第３濾過ユニット２ｃにおける第３濾過粒子７ｃに対する第３洗浄粒子８ｃの配合体積比の下限としては、０．１が好ましく、０．２がより好ましい。一方、上記配合体積比の上限としては、１が好ましく、０．５がより好ましい。上記配合体積比が上記下限に満たない場合、洗浄効果を十分に向上できないおそれがある。一方、上記配合体積比が上記上限を超える場合、濾過粒子７ａ，７ｂ，７ｃによる層の形成が不確実となるおそれや、当該濾過ユニット２ａ，２ｂ，２ｃが不必要に大きくなるおそれがある。 The mixing volume ratio of the first cleaning particles 8a to the first filtration particles 7a in the first filtration unit 2a, the mixing volume ratio of the second cleaning particles 8b to the second filtration particles 7b in the second filtration unit 2b, and the third filtration unit 2c. As the lower limit of the mixing volume ratio of the third cleaning particles 8c to the third filtration particles 7c in FIG. 1, 0.1 is preferable, and 0.2 is more preferable. On the other hand, the upper limit of the volume ratio is preferably 1, and more preferably 0.5. When the said mixing | blending volume ratio is less than the said minimum, there exists a possibility that a cleaning effect cannot fully be improved. On the other hand, when the said mixing | blending volume ratio exceeds the said upper limit, there exists a possibility that formation of the layer by filtration particle | grains 7a, 7b, 7c may become uncertain, and there exists a possibility that the said filtration unit 2a, 2b, 2c may become unnecessarily large.
（空間）
　定常状態の当該濾過ユニット２ａ，２ｂ，２ｃにおいて、濾過粒子７ａ，７ｂ，７ｃ及び洗浄粒子８ａ，８ｂ，８ｃの上方にそれぞれ形成される空間９ａ，９ｂ，９ｃは、逆洗時において濾過粒子７ａ，７ｂ，７ｃ及び洗浄粒子８ａ，８ｂ，８ｃが洗浄水の流れにより舞い上がって互いにぶつかり合うよう運動するためのスペースを提供する。 (space)
In the filtration units 2a, 2b, and 2c in the steady state, the spaces 9a, 9b, and 9c formed above the filtration particles 7a, 7b, and 7c and the washing particles 8a, 8b, and 8c, respectively, are filtered particles 7a during backwashing. , 7b, 7c and the cleaning particles 8a, 8b, 8c move up by the flow of the cleaning water and move to collide with each other.
　この空間９ａ，９ｂ，９ｃの平均高さの下限としては、当該濾過ユニット２ａ，２ｂ，２ｃの内部の平均高さ（下側仕切板５ａ，５ｂ，５ｃと上側仕切板６ａ，６ｂ，６ｃとの間隔）の３０％が好ましく、５０％がより好ましい。一方、空間９ａ，９ｂ，９ｃの平均高さの上限としては、当該濾過ユニット２ａ，２ｂ，２ｃの内部の平均高さの８０％が好ましく、７０％がより好ましい。空間９ａ，９ｂ，９ｃの平均高さが上記下限に満たない場合、逆洗時に濾過粒子７ａ，７ｂ，７ｃ及び洗浄粒子８ａ，８ｂ，８ｃが十分に運動できず、濾過粒子７ａ，７ｂ，７ｃの洗浄効果を十分に促進できないおそれがある。逆に、空間９ａ，９ｂ，９ｃの平均高さが上記上限を超える場合、スペースが大きくなり過ぎて逆洗時に濾過粒子７ａ，７ｂ，７ｃ及び洗浄粒子８ａ，８ｂ，８ｃが当接する頻度が小さくなることにより濾過粒子７ａ，７ｂ，７ｃの洗浄効果を十分に促進できないおそれがある。 As the lower limit of the average height of the spaces 9a, 9b, 9c, the average height inside the filtration units 2a, 2b, 2c ( lower partition plates 5a, 5b, 5c and upper partition plates 6a, 6b, 6c and 30%) is preferable, and 50% is more preferable. On the other hand, the upper limit of the average height of the spaces 9a, 9b, 9c is preferably 80% of the average height inside the filtration units 2a, 2b, 2c, more preferably 70%. When the average height of the spaces 9a, 9b, and 9c is less than the above lower limit, the filtration particles 7a, 7b, and 7c and the washing particles 8a, 8b, and 8c cannot move sufficiently during backwashing, and the filtration particles 7a, 7b, and 7c. There is a possibility that the cleaning effect of the material cannot be sufficiently promoted. On the other hand, when the average height of the spaces 9a, 9b, 9c exceeds the above upper limit, the space becomes too large and the frequency with which the filtered particles 7a, 7b, 7c and the cleaning particles 8a, 8b, 8c come into contact during backwashing is small. As a result, the cleaning effect of the filtration particles 7a, 7b, 7c may not be sufficiently promoted.
［水処理方法］
　続いて、図１の下向流式濾過塔を用いた水処理方法について説明する。 [Water treatment method]
Then, the water treatment method using the downward flow type filtration tower of FIG. 1 is demonstrated.
　図１の下向流式濾過塔を用いた水処理方法は、当該濾過ユニット２ａ，２ｂ，２ｃにおいて被処理液を濾過する濾過工程と、当該濾過ユニット２ａ，２ｂ，２ｃの濾過粒子７ａ，７ｂ，７ｃを洗浄する逆洗工程と、当該濾過ユニット２ａ，２ｂ，２ｃ内に濾過粒子７ａ，７ｂ，７ｃの層を形成する濾過層形成工程とを繰り返す。 The water treatment method using the downward flow filtration tower in FIG. 1 includes a filtration step of filtering the liquid to be treated in the filtration units 2a, 2b, and 2c, and filtration particles 7a and 7b of the filtration units 2a, 2b, and 2c. , 7c and a filtration layer forming step of forming layers of filtration particles 7a, 7b, 7c in the filtration units 2a, 2b, 2c are repeated.
＜濾過工程＞
　上記濾過工程は、被処理液供給流路３から被処理液を供給し、被処理液を濾過した処理済液を処理済液排出流路４から排出する。この濾過工程において、当該濾過ユニット２ａ，２ｂ，２ｃ内には、下側仕切板５ａ，５ｂ，５ｃの上に洗浄粒子８ａ，８ｂ，８ｃの層が形成され、洗浄粒子８ａ，８ｂ，８ｃの層の上に濾過粒子７ａ，７ｂ，７ｃにより濾過層が形成され、濾過層と上側仕切板６ａ，６ｂ，６ｃとの間には空間９ａ，９ｂ，９ｃが形成された状態とされる。 <Filtering process>
In the filtration step, the liquid to be processed is supplied from the liquid supply path 3 to be processed, and the processed liquid obtained by filtering the liquid to be processed is discharged from the liquid discharge path 4 for the processed liquid. In this filtration step, layers of cleaning particles 8a, 8b, 8c are formed on the lower partition plates 5a, 5b, 5c in the filtration units 2a, 2b, 2c, and the cleaning particles 8a, 8b, 8c are formed. A filtration layer is formed by the filtration particles 7a, 7b, and 7c on the layer, and spaces 9a, 9b, and 9c are formed between the filtration layer and the upper partition plates 6a, 6b, and 6c.
　被処理液の供給方法は特に限定されず、例えばポンプによる圧送、水頭による自然流下等の方法を用いることができる。 The supply method of the liquid to be treated is not particularly limited, and for example, a method such as pumping by a pump or natural flow by a water head can be used.
　下向流式濾過塔を用いた水処理方法における下向流式濾過塔の単位断面積当たりの被処理液の供給量の下限としては、１００ｍ３／ｍ２・ｄａｙが好ましく、３００ｍ３／ｍ２・ｄａｙがより好ましい。一方、上記被処理液の供給量の上限としては、特に限定されないが、３０００ｍ３／ｍ２・ｄａｙが好ましく、１０００ｍ３／ｍ２・ｄａｙがより好ましい。上記被処理液の供給量が上記下限に満たない場合、大量に被処理液が発生する環境下で処理能力が不足するおそれや、多数の下向流式濾過塔が必要となるおそれがある。逆に、上記被処理液の供給量が上記上限を超える場合、逆洗工程の頻度が大きくなり、非効率となるおそれがある。 The lower limit of the supply amount of the liquid to be treated per unit cross-sectional area of the downward flow filtration tower in the water treatment method using the downward flow filtration tower is preferably 100 m 3 / m 2 · day, and 300 m 3 / m. 2 · day is more preferable. In contrast, the upper limit of the feed rate of the liquid to be treated is not particularly limited, but is preferably 3000m 3 / m 2 · day, more preferably 1000m 3 / m 2 · day. When the supply amount of the liquid to be processed is less than the lower limit, there is a risk that the processing capacity may be insufficient in an environment where a large amount of liquid to be processed is generated, or a large number of downflow filtration towers may be required. On the contrary, when the supply amount of the liquid to be treated exceeds the upper limit, the frequency of the backwashing process is increased, which may be inefficient.
　濾過工程において、第１濾過粒子７ａの層により分離された油分や濁質は、多くが複数の第１濾過粒子７ａの間に保持されるが、一部が空間９ａ及びその上の空間に滞留（浮上分離）する。 In the filtration step, most of the oil and turbidity separated by the layer of the first filtration particles 7a are retained between the plurality of first filtration particles 7a, but a part of them stays in the space 9a and the space above it. (Floating and separating).
　図１の下向流式濾過塔を用いた水処理方法で回収した処理済液の濁質濃度の上限としては、１０ｐｐｍが好ましく、５ｐｐｍがより好ましく、３ｐｐｍがさらに好ましく、１ｐｐｍが特に好ましい。処理済液の濁質濃度が上記上限を超える場合、処理済液を環境に負荷を与えず廃棄することや産業用水として利用することができないおそれがある。なお、濁質濃度とは、浮遊物質（ＳＳ）の濃度を意味し、ＪＩＳ－Ｋ０１０２（２００８）の「１４．１　懸濁物質」に準拠して測定される値である。 The upper limit of the turbidity concentration of the treated liquid recovered by the water treatment method using the downward flow filtration tower in FIG. 1 is preferably 10 ppm, more preferably 5 ppm, further preferably 3 ppm, and particularly preferably 1 ppm. When the turbidity concentration of the treated liquid exceeds the above upper limit, the treated liquid may not be disposed of without causing a load on the environment or may not be used as industrial water. The turbidity concentration means the concentration of suspended matter (SS) and is a value measured according to “14.1 Suspended matter” of JIS-K0102 (2008).
　図１の下向流式濾過塔を用いた水処理方法で回収した処理済液の油濃度の上限としては、１００ｐｐｍが好ましく、１０ｐｐｍがより好ましく、１ｐｐｍがさらに好ましい。処理済液の油濃度が上記上限を超える場合、下向流式濾過塔の下流で行う油水分離処理の負荷が過大となるおそれや、処理済液を環境に負荷を与えず廃棄することができなくなるおそれがある。 The upper limit of the oil concentration of the treated liquid recovered by the water treatment method using the downward flow filtration tower in FIG. 1 is preferably 100 ppm, more preferably 10 ppm, and even more preferably 1 ppm. If the oil concentration of the treated liquid exceeds the above upper limit, the load of the oil / water separation treatment downstream of the downflow filtration tower may be excessive, or the treated liquid can be discarded without causing any environmental load. There is a risk of disappearing.
＜逆洗工程＞
　上記逆洗工程では、処理済液排出流路４から洗浄水を供給し、当該濾過ユニット２ａ，２ｂ，２ｃを通過し、濾過粒子７ａ，７ｂ，７ｃから分離した油分や濁質並びに第１濾過ユニット２ａの空間９ａ及びその上の筒状本体１内の空間に滞留していた油分や濁質を含む洗浄廃水を被処理液供給流路３から排出する。なお、この洗浄廃水は、次の濾過工程において、被処理液の一部として被処理液供給流路３に供給してもよい。 <Backwash process>
In the backwashing step, wash water is supplied from the treated liquid discharge flow path 4, passes through the filtration units 2a, 2b, and 2c, and is separated from the filtered particles 7a, 7b, and 7c. Washing wastewater containing oil and turbidity remaining in the space 9a of the unit 2a and the space inside the cylindrical main body 1 is discharged from the liquid supply passage 3 to be treated. In addition, this washing wastewater may be supplied to the liquid to be processed supply channel 3 as a part of the liquid to be processed in the next filtration step.
　下から上に向かって流れる洗浄水は、先ず洗浄粒子を舞い上がらせ、油分や濁質で固まった濾過粒子７ａ，７ｂ，７ｃの層を割りほぐして濾過粒子７ａ，７ｂ，７ｃが洗浄水によって空間９ａ，９ｂ，９ｃに舞い上げられるようにする。空間９ａ，９ｂ，９ｃに舞い上げられた濾過粒子７ａ，７ｂ，７ｃは、洗浄水中で撹拌されることによって付着した油分や濁質が剥離される。また、舞い上げられた濾過粒子７ａ，７ｂ，７ｃは、他の濾過粒子７ａ，７ｂ，７ｃ及び洗浄粒子８ａ，８ｂ，８ｃとぶつかり合うことにより、付着した油分や濁質の剥離が促進される。 The washing water flowing from the bottom to the top first causes the washing particles to rise, breaks up the layers of the filtration particles 7a, 7b, and 7c solidified with oil and turbidity, and the filtration particles 7a, 7b, and 7c are washed with the water 9a. , 9b, 9c. The filtered particles 7a, 7b, and 7c that have been swollen into the spaces 9a, 9b, and 9c are agitated in the wash water, and the attached oil and turbidity are peeled off. Further, the raised filter particles 7a, 7b, 7c collide with the other filter particles 7a, 7b, 7c and the cleaning particles 8a, 8b, 8c, thereby promoting the separation of the attached oil and turbidity. .
　上記逆洗工程は、一定時間毎に行われてもよく、上記濾過工程において被処理液供給流路３と処理済液排出流路４との圧力差が一定の圧力に達したときや、被処理液供給流路３又は処理済液排出流路４の流量が一定の流量に低下したときに行ってもよく、オペレターの操作により行われてもよい。 The backwashing process may be performed at regular intervals, and when the pressure difference between the liquid supply flow path 3 to be processed and the liquid discharge flow path 4 has reached a constant pressure in the filtration process, It may be performed when the flow rate of the processing liquid supply channel 3 or the processed liquid discharge channel 4 is reduced to a constant flow rate, or may be performed by operating an operator.
　下向流式濾過塔の単位断面積当たりの洗浄水の給水量としては、例えば２００Ｌ／ｍ２・ｈｒ以上２０００Ｌ／ｍ２・ｈｒ以下とすることができる。 The amount of wash water supplied per unit cross-sectional area of the downward flow filtration tower can be, for example, 200 L / m 2 · hr or more and 2000 L / m 2 · hr or less.
　また、逆洗時間としては、例えば３０秒以上１０分以下とすることができる。また、一定時間毎に逆洗を行う場合の逆洗の間隔としては、例えば１時間以上１２時間以下とすることができる。 Also, the backwash time can be, for example, 30 seconds to 10 minutes. Moreover, as an interval of backwashing when backwashing is performed every predetermined time, it can be set to 1 hour or more and 12 hours or less, for example.
　供給する洗浄水としては、市水や濾過工程において処理済液排出流路４から排出された処理済み液を使用することができる。また、洗浄水は気泡を混入したバブリングジェット水流として供給されることが好ましい。バブリングジェット水流は、例えばバブリングジェット装置、エダクタ等を用いて製造することができる。バブリングジェット水流を使用することによって、気泡により濾過粒子７ａ，７ｂ，７ｃからの油分や濁質の剥離を促進できる。また、洗浄水は気泡を含まないジェット水流として供給してもよい。 As the wash water to be supplied, city water or the treated liquid discharged from the treated liquid discharge flow path 4 in the filtration step can be used. The washing water is preferably supplied as a bubbling jet water stream in which bubbles are mixed. The bubbling jet water stream can be produced using, for example, a bubbling jet device, an eductor, or the like. By using a bubbling jet water stream, it is possible to promote separation of oil and turbidity from the filtered particles 7a, 7b, and 7c by bubbles. Further, the washing water may be supplied as a jet water stream that does not contain bubbles.
　バブリングジェット水流中の空気量（常温大気圧における容積の水の体積に対する比）としては、例えば１ＮＬ／Ｌ以上５ＮＬ／Ｌ以下が好ましい。また、バブリングジェット水流中の気泡の平均径としては、１ｍｍ以上４ｍｍ以下が好ましい。さらに、洗浄水の送水圧としては、０．２ＭＰａ以上が好ましく、バブリングジェット水流の流束としては、例えばバブリングジェットノズルの吐出口において２０ｍ／ｓ以上が好ましい。 The amount of air in the bubbling jet water flow (ratio of the volume of water at room temperature and atmospheric pressure to the volume of water) is preferably, for example, from 1 NL / L to 5 NL / L. Moreover, as an average diameter of the bubble in a bubbling jet water flow, 1 mm or more and 4 mm or less are preferable. Furthermore, the water supply pressure of the washing water is preferably 0.2 MPa or more, and the bubbling jet water flow flux is preferably 20 m / s or more at the discharge port of the bubbling jet nozzle, for example.
＜濾過層形成工程＞
　濾過層形成工程では、当該濾過ユニット２ａ，２ｂ，２ｃ内を水で満たした状態とし、濾過粒子７ａ，７ｂ，７ｃ及び洗浄粒子８ａ，８ｂ，８ｃを自然沈降させる。この時、平均比重及び平均粒径が大きい洗浄粒子８ａ，８ｂ，８ｃは、沈降速度が大きく、先に沈降して下側仕切板５ａ，５ｂ，５ｃの上に層を形成する。洗浄粒子８ａ，８ｂ，８ｃよりも平均比重及び平均粒径が小さく、沈降速度が小さい濾過粒子７ａ，７ｂ，７ｃは、先に形成された洗浄粒子８ａ，８ｂ，８ｃの層の上に降り積もって濾過層を形成する。 <Filter layer forming step>
In the filtration layer forming step, the filtration units 2a, 2b, and 2c are filled with water, and the filtration particles 7a, 7b, and 7c and the cleaning particles 8a, 8b, and 8c are naturally settled. At this time, the cleaning particles 8a, 8b, and 8c having a large average specific gravity and a large average particle size have a high sedimentation speed, and settle first to form a layer on the lower partition plates 5a, 5b, and 5c. Filter particles 7a, 7b, and 7c having a smaller average specific gravity and average particle diameter and lower settling velocity than cleaning particles 8a, 8b, and 8c are deposited on the previously formed layer of cleaning particles 8a, 8b, and 8c. A filtration layer is formed.
　濾過層形成工程の最初（逆洗工程終了時）に、処理済液排出流路４から空気を含まない水を逆洗工程の洗浄水の流量以上の流量で供給し、当該濾過ユニット２ａ，２ｂ，２ｃ内を水で満たし、かつ濾過粒子７ａ，７ｂ，７ｃ及び洗浄粒子８ａ，８ｂ，８ｃを上側仕切板６ａ，６ｂ，６ｃに押し付けるようにすれば、洗浄粒子８ａ，８ｂ，８ｃと濾過粒子７ａ，７ｂ，７ｃとの分離を促進することができる。 At the beginning of the filtration layer forming process (at the end of the backwashing process), water that does not contain air is supplied from the treated liquid discharge flow path 4 at a flow rate that is equal to or higher than the flow rate of the washing water in the backwashing process. , 2c is filled with water and the filtering particles 7a, 7b, 7c and the cleaning particles 8a, 8b, 8c are pressed against the upper partition plates 6a, 6b, 6c, the cleaning particles 8a, 8b, 8c and the filtering particles Separation from 7a, 7b, 7c can be promoted.
［利点］
　当該濾過ユニット２ａ，２ｂ，２ｃは、濾過粒子７ａ，７ｂ，７ｃと洗浄粒子８ａ，８ｂ，８ｃとが充填されていることによって、逆洗時に洗浄粒子８ａ，８ｂ，８ｃが舞い上がって濾過粒子７ａ，７ｂ，７ｃの層を割りほぐして濾過粒子７ａ，７ｂ，７ｃの洗浄効果を促進する。これにより、当該濾過ユニット２ａ，２ｂ，２ｃは、簡素な構造でありながら濾過粒子の洗浄性能に優れる。 [advantage]
The filtration units 2a, 2b, and 2c are filled with the filtration particles 7a, 7b, and 7c and the washing particles 8a, 8b, and 8c, so that the washing particles 8a, 8b, and 8c rise during the backwashing, and the filtration particles 7a. , 7b, 7c are broken up to promote the cleaning effect of the filtration particles 7a, 7b, 7c. Thereby, the said filtration unit 2a, 2b, 2c is excellent in the washing | cleaning performance of filtration particle | grains, although it is a simple structure.
　また、洗浄粒子８ａ，８ｂ，８ｃの平均粒径及び平均比重が濾過粒子７ａ，７ｂ，７ｃよりも大きいことによって、沈降速度の差により下側に洗浄粒子８ａ，８ｂ，８ｃの層が形成され、上側に洗浄粒子８ａ，８ｂ，８ｃをあまり含まない濾過粒子７ａ，７ｂ，７ｃの層が形成されるので、洗浄粒子８ａ，８ｂ，８ｃが濾過粒子７ａ，７ｂ，７ｃの層による被処理液中の濁質の除去を阻害しない。 In addition, since the average particle diameter and average specific gravity of the cleaning particles 8a, 8b, and 8c are larger than those of the filtering particles 7a, 7b, and 7c, a layer of the cleaning particles 8a, 8b, and 8c is formed on the lower side due to the difference in sedimentation speed. In addition, since a layer of filtered particles 7a, 7b, and 7c that does not contain much cleaning particles 8a, 8b, and 8c is formed on the upper side, the cleaning particles 8a, 8b, and 8c are treated liquids by the layer of filtered particles 7a, 7b, and 7c. Does not impede removal of turbidity inside.
　従って、当該濾過ユニット２ａ，２ｂ，２ｃは、油分及び濁質を含油する被処理液を浄化する場合にも、逆洗のためのダウンタイムが短く、大きな処理能力を発揮できる。 Therefore, the filtration units 2a, 2b, and 2c can exhibit a large processing capacity with a short downtime for backwashing even when purifying a liquid to be treated containing oil and turbidity.
［その他の実施形態］
　今回開示された実施の形態はすべての点で例示であって制限的なものではないと考えられるべきである。本発明の範囲は、上記実施形態の構成に限定されるものではなく、特許請求の範囲によって示され、特許請求の範囲と均等の意味及び範囲内でのすべての変更が含まれることが意図される。 [Other Embodiments]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is not limited to the configuration of the above-described embodiment, but is defined by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims. The
　下向流式濾過塔に配設される当該濾過ユニットの数は、特に限定されず、１以上の任意の数とすることができる。 The number of the filtration units arranged in the downflow filtration tower is not particularly limited, and can be any number of 1 or more.
　また、当該濾過ユニットは、例えば多孔セラミックス、織布、不織布、繊維、活性炭等の油用吸着材を有するユニットと併用してもよい。油用吸着材ユニットは、当該濾過ユニットよりも下流側に配設されることが好ましい。 The filtration unit may be used in combination with a unit having an adsorbent for oil such as porous ceramics, woven fabric, non-woven fabric, fiber, activated carbon or the like. The oil adsorbent unit is preferably arranged on the downstream side of the filtration unit.
　また、当該濾過ユニットには、濾過粒子及び洗浄粒子の上に空間が形成されないものであってもよい。 Further, the filtration unit may be one in which no space is formed on the filtration particles and the washing particles.
　また、下向流式濾過塔に複数の当該濾過ユニットが配設される場合、下向流式濾過塔の本体側部に、各濾過ユニットの下方に洗浄水をそれぞれ供給する複数の給水路を設けてもよく、各濾過ユニットの上方から洗浄廃水をそれぞれ排出する複数の排水路を設けてもよい。上記濾過ユニットの下方に洗浄水を供給する給水路は、下側仕切板の下側面に向かって洗浄水を吐出するノズルを有してもよい。このようなノズルを設けることにより、濾過ユニット内に少なくとも部分的に流速の大きい流れを形成し、洗浄粒子によって濾過粒子の層を割りほぐす効果を促進することができる。また、ノズルは、濾過粒子又は洗浄粒子の層の中に埋没するよう配置し、洗浄水の水圧を直接作用させて濾過粒子や洗浄粒子を割りほぐすようにしてもよい。 Further, when a plurality of the filtration units are arranged in the downward flow filtration tower, a plurality of water supply channels for supplying washing water to the lower side of each filtration unit are provided on the main body side of the downward flow filtration tower. You may provide, and you may provide several drainage channels which discharge | emit washing waste water from the upper direction of each filtration unit, respectively. The water supply path for supplying the cleaning water to the lower side of the filtration unit may have a nozzle for discharging the cleaning water toward the lower surface of the lower partition plate. By providing such a nozzle, a flow having a high flow velocity can be formed at least partially in the filtration unit, and the effect of breaking the layer of filtration particles with the washing particles can be promoted. Further, the nozzle may be disposed so as to be buried in the layer of the filtration particles or the cleaning particles, and the water pressure of the cleaning water may be directly applied to break the filtration particles and the cleaning particles.
　また、当該濾過ユニットには、下側仕切板を通して洗浄水を供給するのに加えて、定常状態において形成される空間の位置に側方から洗浄水を供給するようにしてもよい。当該濾過ユニットの空間位置に供給され、下方からの洗浄水とは異なる向きの流れを有する洗浄水によって、濾過粒子のもみ洗い効果を促進することができる。この当該濾過ユニットの中に洗浄水を供給する流路は、当該濾過ユニットの内部に突出し、下向きに開口するノズルを備えてもよい。このようなノズルを設けることにより、下降流を形成して濾過粒子の洗浄効果を促進できると共に、濾過粒子の層に対して流速の大きい洗浄水を衝突させて、濾過粒子の層を割りほぐすことができる。 Further, in addition to supplying the cleaning water through the lower partition plate, the filtration unit may be supplied with the cleaning water from the side to the position of the space formed in the steady state. The scrubbing effect of the filtered particles can be promoted by the washing water supplied to the spatial position of the filtration unit and having a flow in a direction different from the washing water from below. The flow path for supplying cleaning water into the filtration unit may include a nozzle that protrudes into the filtration unit and opens downward. By providing such a nozzle, it is possible to promote the cleaning effect of the filtered particles by forming a downward flow, and to make the filtered particle layer break up by colliding with the cleaning particle having a large flow velocity against the filtered particle layer. it can.
　以下、実施例に基づき本発明を詳述するが、この実施例の記載に基づいて本発明が限定的に解釈されるものではない。 Hereinafter, the present invention will be described in detail based on examples, but the present invention is not construed as being limited based on the description of the examples.
　上述の実施形態に準じて濾過塔Ｎｏ．１～Ｎｏ．３を試作し、濾過及び逆洗を行って、本発明の効果を確認した。 According to the above embodiment, the filtration tower No. 1-No. No. 3 was prototyped and filtered and backwashed to confirm the effect of the present invention.
　濾過塔Ｎｏ．１～Ｎｏ．３として、それぞれ内径４０ｍｍの円筒状の筒状本体を用い、第１濾過ユニット、第２濾過ユニット及び第３濾過ユニットに次の表１に示す濾過粒子及び洗浄粒子を層分けして充填した。 Filter tower No. 1-No. 3, a cylindrical tubular body having an inner diameter of 40 mm was used, and the first filtration unit, the second filtration unit, and the third filtration unit were filled with the filtration particles and the cleaning particles shown in Table 1 below.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　上記被処理水としてＣ重油５００ｐｐｍをエマルジョン化して水中に分散させたもの（エマルジョンの粒径は約０．３μｍ）を、０．５ｍ３／ｄａｙの流量で濾過塔の前後の差圧が大きくなるまで続けて濾過した。この結果、濾過塔Ｎｏ．１～Ｎｏ．３は、いずれも２～４時間の濾過を連続して行うことができた。また、差圧が上昇した濾過塔について、逆洗を行って、濾過粒子及び洗浄粒子に付着した油分を除去する実験を行った。なお、逆洗時の洗浄水の流量は被処理水の流量の１～３倍とした。この結果、濾過塔Ｎｏ．１～Ｎｏ．３は、いずれも３～５分間の逆洗により、濾過時の差圧を略初期状態の値に低減することができた。つまり、濾過塔Ｎｏ．１～Ｎｏ．３は、いずれも十分な濾過能力及び洗浄性を有することが確認された。 As the water to be treated, 500 ppm C heavy oil emulsified and dispersed in water (emulsion particle size is about 0.3 μm), the differential pressure before and after the filtration tower increases at a flow rate of 0.5 m 3 / day. Until filtered. As a result, the filtration tower No. 1-No. No. 3 could be continuously filtered for 2 to 4 hours. In addition, the filtration tower with the increased differential pressure was back-washed, and an experiment was conducted to remove filtered particles and oil adhering to the washed particles. The flow rate of cleaning water during backwashing was 1 to 3 times the flow rate of water to be treated. As a result, the filtration tower No. 1-No. In all cases 3, the differential pressure during filtration could be reduced to a substantially initial value by backwashing for 3 to 5 minutes. That is, the filtration tower No. 1-No. It was confirmed that all Nos. 3 had sufficient filtration ability and detergency.
　以上のように、当該濾過ユニットは、油田や工場で発生する被処理液から油分や濁質を除去する下向流式濾過塔に好適に利用することができる。 As mentioned above, the said filtration unit can be utilized suitably for the downward flow type filtration tower which removes an oil component and turbidity from the to-be-processed liquid which generate | occur | produces in an oil field or a factory.
１　筒状本体
２ａ，２ｂ，２ｃ　濾過ユニット
３　被処理液供給流路
４　処理済液排出流路
５ａ，５ｂ，５ｃ　下側支持板
６ａ，６ｂ，６ｃ　上側支持板
７ａ，７ｂ，７ｃ　濾過粒子
８ａ，８ｂ，８ｃ　洗浄粒子
９ａ，９ｂ，９ｃ　空間 DESCRIPTION OF SYMBOLS 1 Cylindrical main body 2a, 2b, 2c Filtration unit 3 Processed liquid supply flow path 4 Processed liquid discharge flow path 5a, 5b, 5c Lower support plate 6a, 6b, 6c Upper support plate 7a, 7b, 7c Filter particle 8a , 8b, 8c Cleaning particles 9a, 9b, 9c Space

Claims (8)

  1. 　下向流式濾過塔内に配設され、下方が通水性の仕切板で区画される濾過ユニットであって、
    　充填される濾過粒子と洗浄粒子とを備え、
    　上記洗浄粒子の平均粒径及び平均比重が濾過粒子よりも大きい濾過ユニット。     A filtration unit that is disposed in a downward flow filtration tower and that is partitioned by a water-permeable partition at the bottom,
    Comprising filtration particles to be filled and cleaning particles;
    A filtration unit in which the average particle size and average specific gravity of the cleaning particles are larger than those of the filtration particles.
  2. 　定常状態で上記濾過粒子及び洗浄粒子の上方に空間を有する請求項１に記載の濾過ユニット。 The filtration unit according to claim 1, which has a space above the filtration particles and cleaning particles in a steady state.
  3. 　上記濾過粒子の平均比重に対する洗浄粒子の平均比重の比が１．２以上１０以下である請求項１又は請求項２に記載の濾過ユニット。 The filtration unit according to claim 1 or 2, wherein the ratio of the average specific gravity of the cleaning particles to the average specific gravity of the filtration particles is 1.2 or more and 10 or less.
  4. 　上記濾過粒子の平均粒径に対する洗浄粒子の平均粒径の比が１．２以上１０以下である請求項１、請求項２又は請求項３に記載の濾過ユニット。 4. The filtration unit according to claim 1, wherein the ratio of the average particle diameter of the cleaning particles to the average particle diameter of the filtration particles is 1.2 or more and 10 or less.
  5. 　上記濾過粒子に対する洗浄粒子の配合体積比が０．１以上１以下である請求項１から請求項４のいずれか１項に記載の濾過ユニット。 The filtration unit according to any one of claims 1 to 4, wherein a mixing volume ratio of the cleaning particles to the filtration particles is 0.1 or more and 1 or less.
  6. 　上記濾過粒子がガラス又はポリマーを主成分とし、
    　上記洗浄粒子がガラス、セラミックス、金属又はポリマーを主成分とする請求項１から請求項５のいずれか１項に記載の濾過ユニット。     The filtration particles are mainly glass or polymer,
    The filtration unit according to any one of claims 1 to 5, wherein the cleaning particles are mainly composed of glass, ceramics, metal, or polymer.
  7. 　油分及び濁質を含有する被処理液を浄化する請求項１から請求項６のいずれか１項に記載の濾過ユニット。 The filtration unit according to any one of claims 1 to 6, wherein a treatment liquid containing oil and turbidity is purified.
  8. 　下向流式濾過塔内に配設され、下方が通水性の仕切板で区画される濾過ユニットに充填される濾過粒子の洗浄方法であって、
    　上記濾過粒子よりも平均粒径及び平均比重が大きい洗浄粒子が充填されている上記濾過ユニットに上記仕切板を通して上向きに洗浄水を通水することにより上記洗浄粒子を舞い上がらせる工程を備える濾過粒子の洗浄方法。     A method for washing filtered particles that is disposed in a downward flow filtration tower and filled in a filtration unit that is partitioned by a water-permeable partition at the bottom,
    A filtration particle comprising a step of causing the washing particles to rise by passing washing water upward through the partition plate into the filtration unit filled with washing particles having a larger average particle diameter and average specific gravity than the filtration particles. Cleaning method.
PCT/JP2015/066118 2014-09-08 2015-06-03 Filtration unit WO2016038948A1 (en)

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Cited By (1)

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KR20220023631A (en) * 2020-08-21 2022-03-02 (주)동부그린 apparatus for treating wastewater produced from manufacture process of oxydianiline and treating mothed using the same

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JPS5322664A (en) * 1976-08-16 1978-03-02 Nippon Zeon Co Complex filter layer
JPH0192299U (en) * 1987-12-11 1989-06-16
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JPH0889726A (en) * 1994-09-27 1996-04-09 Matsushita Electric Ind Co Ltd Water purifying device
JPH1199398A (en) * 1997-07-28 1999-04-13 Toto Ltd Septic tank
JP2008283873A (en) * 2007-05-15 2008-11-27 Hitachi Plant Technologies Ltd Purification apparatus and method for operating the purification apparatus
JP2009268443A (en) * 2008-05-12 2009-11-19 Akechi Ceramics Co Ltd Sterile filtration device of nutritious liquid
JP2013248563A (en) * 2012-05-31 2013-12-12 Kamata Bio Eng Kk Filtering device, filtering method of the same, and backwashing method of filter medium

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Publication number Priority date Publication date Assignee Title
JPS5322664A (en) * 1976-08-16 1978-03-02 Nippon Zeon Co Complex filter layer
JPH0192299U (en) * 1987-12-11 1989-06-16
JPH05208104A (en) * 1992-01-31 1993-08-20 Nkk Corp Apparatus for removing suspensible solid
JPH0889726A (en) * 1994-09-27 1996-04-09 Matsushita Electric Ind Co Ltd Water purifying device
JPH1199398A (en) * 1997-07-28 1999-04-13 Toto Ltd Septic tank
JP2008283873A (en) * 2007-05-15 2008-11-27 Hitachi Plant Technologies Ltd Purification apparatus and method for operating the purification apparatus
JP2009268443A (en) * 2008-05-12 2009-11-19 Akechi Ceramics Co Ltd Sterile filtration device of nutritious liquid
JP2013248563A (en) * 2012-05-31 2013-12-12 Kamata Bio Eng Kk Filtering device, filtering method of the same, and backwashing method of filter medium

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20220023631A (en) * 2020-08-21 2022-03-02 (주)동부그린 apparatus for treating wastewater produced from manufacture process of oxydianiline and treating mothed using the same
KR102548062B1 (en) * 2020-08-21 2023-06-27 (주)동부그린 apparatus for treating wastewater produced from manufacture process of oxydianiline and treating mothed using the same

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