JP2015080750A - Ion exchange resin column - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ion exchange resin column in which upflow regeneration is performed and the lower part of a resin layer is prevented from being fluidized without creating a space due to shrinkage of an ion exchange resin even in the initial stage of the regeneration so that a perfect fixed bed can be formed and turbid matter can be removed easily by a backwash operation.SOLUTION: A movable unit 10 comprising a butt strap 11, a plate 13 and a connecting body 12 is arranged on the upper side of a packed layer of an ion exchange resin 6 in an upflow regeneration type ion exchange resin column 1 in a column body 2 of which the packed layer of the ion exchange resin 6 is formed and the downflow circulating water is deionized. An opening 14 is arranged between the butt strap 11 and the plate 13 and an opening 15 is arranged in the upper part of the column body 2.

Description

  The present invention relates to an ion exchange resin tower, and more particularly to an ion exchange resin tower in which a water-permeable movable body is provided on the upper side of a packed bed of ion exchange resin.

When raw water such as industrial water and tap water is passed through the H-type cation exchange resin tower and then the OH-type anion exchange resin tower in this order, the cation in the raw water is hydrogen ion (H ⁺ ) and the anion is hydroxylated. It replaces the product ions (OH ⁻ ), resulting in pure water. If the raw water continues to flow, the ion exchange resin loses its ion removal ability and is regenerated with chemicals. Usually, cation exchange resins are often regenerated with hydrochloric acid and anion exchange resins with caustic soda.

  As an ion exchange resin tower, a cylindrical tower filled with an ion exchange resin (hereinafter sometimes simply referred to as resin) is often used. When this ion exchange resin tower is of the downward circulation water and upward flow regeneration system, it is important not to flow the resin layer during the regeneration process of the ion exchange resin. For this reason, it is widely performed to provide a water collecting plate with almost no gap above and below the ion exchange resin packed layer, and is generally called a packed bed.

The conventional packed bed type ion exchange resin tower has the following two disadvantages (A) and (B).
(A) If suspended matter accumulates in the resin layer for some reason, it is difficult to remove it. In normal regeneration operation, backwashing is not performed every time. However, assuming that the suspended matter gradually accumulates, it is important to make the device capable of backwashing in order to facilitate recovery from trouble. In general, a part or all of the ion exchange resin is extracted outside the ion exchange resin tower to fluidize the resin and remove turbidity. For example, the suspended matter that needs to be backwashed is generated as follows.
(1) Since pretreatment is insufficient, suspended substances contained in raw water accumulate in the ion exchange resin layer.
(2) The ion exchange resin is partially crushed in the resin layer, and the crushed material becomes a suspended substance and accumulates in the resin layer.
(3) A hardly soluble substance such as a silica compound is deposited and accumulated by a chemical reaction or the like in the ion exchange resin layer.
(B) At the start of regeneration, the ion exchange resin is in a contracted state, and a gap is formed between the resin layer upper part and the water collecting plate. There is a risk of deteriorating water quality.

  Next, the shrinkage and swelling of the ion exchange resin will be described. In general, the resin layer height of the strongly acidic cation exchange resin and the strongly basic anion exchange resin is reduced by passing water. That is, at the start of water flow after completion of regeneration, the ion exchange resin particles are swollen and the resin layer height is large, but at the end of water flow (before the start of regeneration), the ion exchange resin particles are contracted and the resin layer height is high. Becomes smaller. For example, according to an ion exchange resin manufacturer's document (Diaion Manual), in the case of the strongly acidic cation exchange resin SK1B, the H-type resin has a resin layer height that is about 9% larger than the Na-type resin. In the case of the strongly basic anion exchange resin SA10A, the resin layer height of the OH type resin is about 24% larger than that of the Cl type resin.

  When a strongly acidic ion exchange resin that is Na-type is sandwiched between water collecting plates and the water collecting plate is fixed, when the resin is regenerated to be H-type, the spherical shape of the resin is destroyed due to swelling pressure. there is a possibility. Therefore, the resin filling amount is often determined based on the state of the H-type resin.

  Then, since the resin contracts at the end of water flow, a gap (water) is generated between the resin layer and the upper water collecting plate. For example, when an H-type strongly acidic cation exchange resin having a layer height of 1000 mm is sandwiched between water collecting plates, a gap of 50 mm or more is generated at the end of water flow (that is, at the start of regeneration).

  Such a gap may adversely affect the flow of regenerative chemicals when regenerating with an upward flow. That is, when regeneration is started in an upward flow, some of the particles below the resin layer flow, and resin that is not sufficiently regenerated exists at the bottom of the resin layer. As a result, the quality of the treated water is reduced when water flow is resumed.

  Even in the conventional packed bed ion exchange resin tower (downstream water / upstream regeneration), the above problem has not been solved.

  The linear velocity at the time of reproduction is usually about ¼ to ３ of the linear velocity at the time of water flow. By increasing the flow rate during regeneration, the ion exchange resin layer can be considered as a fixed bed. However, if the linear velocity during regeneration is increased too much, the utilization efficiency of chemicals decreases.

  Some ion-exchange resin towers in packed beds are for up-flow water and down-flow regeneration.

  When the regeneration is performed in the downward flow, the regeneration is possible without the resin flowing during the regeneration. On the other hand, if the operation is interrupted when water is passed, the problem is that the adsorption zone in the resin layer is disturbed due to fluidization of the resin and the quality of the treated water is deteriorated (for example, JP 2000-202440 (Patent No. 3922824)). Paragraph).

The following prior art exists as what suppresses the fluidization of the resin at the time of regeneration and forms a fixed bed.
a) JP-A-11-319404
It is described that a variable-length cylindrical body such as a corrugated tube is connected to the upper part of the column so that the vertical position of the distributor can be adjusted according to the expansion and contraction of the granular carrier.
b) JP-A-2005-327571
In the ion exchange resin column, the ion exchange resin layer is pushed with a liquid-permeable plate. Examples of the means include an elastic body and a string spring. It also describes that only a stainless plate is placed on the top of the resin layer.
c) JP-A-63-12323
In an apparatus for removing carbon dioxide gas using an ion exchange resin, it is described that the ion exchange resin layer is pressurized with a spring device through a movable perforated plate to prevent the air to be treated from flowing out.
d) Japanese Patent Laid-Open No. 7-232091 (Japanese Patent No. 3150249)
It is described that a complete fixed bed is formed by filling a filter mat and a granular filler floating in water under an ion exchange resin layer.
e) JP 2002-136968 A
In a horizontal cartridge type ion exchanger, it is described that a pressing means such as a compression spring is provided to absorb a volume change due to swelling / shrinkage of the ion exchange resin so that a short-circuit flow does not occur.
f) JP2004230215
It is described that an ion exchange filter is provided with a pressing mechanism by an elastic body (spring) for the purpose of absorbing a volume change due to freezing of water when it is below freezing.
g) JP 2004-283647 A
An ion exchange resin column structure is described in which a filter is disposed so as to sandwich an ion exchange resin, and at least one of the filters is slidable.

JP 2000-202440 A JP-A-11-319404 JP 2005-327571 A JP-A-63-12323 Japanese Patent Laid-Open No. 7-232091 (Japanese Patent No. 3150249) JP 2002-136968 A JP2004230215 JP 2004-283647 A

  Patent Document 2 has the following problems. For example, when 600 mm of Cl-type anion exchange resin is filled, the volume increases by about 20% to 720 mm. If the fixed-length cylindrical portion is set to 600 mm, a free board is generated even if the variable-length cylindrical portion is in the most contracted state.

  Even if the fixed long cylindrical portion is set to 500 mm, the variable length portion needs to be 100 mm in the most contracted state and 220 mm in the most extended state. (Expansion and contraction rate 220%). When such a high expansion / contraction ratio is required, it is conceivable to use a bellows made of a thin resin, but it is practical to use it as a part of a container that requires pressure resistance such as an ion exchange resin tower. It is difficult.

  When almost no fixed long cylindrical part is used and most of the part is a variable length part, the side wall part of the resin layer of the ion-exchange resin tower is made up of thin bellows, and the structure of the tower itself is It becomes unstable.

  Moreover, it is also conceivable that the ion exchange resin is sandwiched between corrugated tubes and bellows corrugated portions, thereby hindering their vertical movement. In the case of a structure in which the upper lid moves in the vertical direction (FIG. 2 of Patent Document 2), there is no waveform seen in the corrugated tube, but the amount of movement in the vertical direction is limited, and the resin layer is backwashed and developed. It is difficult to secure just a free board.

  In Patent Documents 3, 4, 6, and 7, a spring is used, but application is difficult when the column is large.

  When trying to use a spring in a general ion exchange resin tower (tower diameter of 700 mm or more) used in water treatment etc., if you try to secure a sufficient free board during backwashing, the length of the spring is long enough. is necessary. For example, if it is intended to secure a 300 mm free board, a compression spring having a free length of at least about 600 mm is required, and the height of the tower becomes large. In addition, when the resin is fluidized during backwashing, it is not necessary to press with a spring at all, and it is necessary to devise such as removing the spring once or fixing it in a state where it is temporarily compressed by some means. It is.

  Patent Document 3 (Japanese Patent Laid-Open No. 2005-327571), paragraphs 0023 to 0024 and FIG. 1A show that a thick and heavy stainless steel pan is placed on the upper side of the ion exchange resin layer. Yes. However, such an eye plate may be tilted by the upward flow. The flat eye plate is only slightly tilted, and a gap is formed between the outer edge of the eye plate and the inner wall of the resin column, and the resin leaks from there.

  In Patent Document 5 (Japanese Patent Application Laid-Open No. 7-232091), even if water is passed from the lower part of the resin layer at the time of backwashing, the resin layer is fixed by lifting the filter mat and the resin is completely fluidized. Therefore, it is considered that turbidity cannot be excluded. It is not easy to remove the filter mat, and the resin itself must be taken out of the tower and backwashed.

  In patent document 8, the structure which excludes turbidity is not provided. Patent Document 8 is applicable only to an ultra-compact ion exchange resin column having a diameter of about 6 mm as shown in the examples. When an ion exchange resin tower having a structure of φ500 mm or more having a structure as shown in FIG. 2 of Patent Document 8 is configured, it is considered that the resin is fluidized at the time of rising circulating water and no fixed bed is formed.

  The present invention eliminates the above-described conventional problems, and in an ion exchange resin tower that allows water to flow in a downward flow and regenerates by an upward flow, a gap due to contraction of the ion exchange resin may occur even at the initial stage of regeneration. It is another object of the present invention to provide an ion exchange resin tower that can prevent fluidization in the lower part of the resin layer, form a complete fixed bed, and easily remove turbidity by backwashing.

  The ion exchange resin tower of the present invention is a down-flowing water in which a packed bed of an ion exchange resin made of a cation exchange resin or an anion exchange resin is formed in the tower body, A movable body that is provided above the exchange resin packing layer and is capable of moving up and down to press the ion exchange resin packing layer from above, and is disposed above the movable body; With respect to the movable body, the plate integrated by a connecting body extending in the vertical direction, and between the downward flow and the plate in any flow state of the downward flow water and the upward flow regeneration. A first circulation part for liquid circulation provided on the side surface of the tower body, and a second circulation part for liquid circulation provided on the upper part of the tower body higher than the plate in the state of backwashing the upward flow Provided in the circulation section and the bottom of the tower Characterized in that a third distribution unit for distribution.

The total mass of the movable body, the plate, and the connected body is 60 to 150 kg / m ² per horizontal cross-sectional area of the ion exchange resin tower, and the mass ratio of the plate is 60 to 90% of the total mass. Is preferably set to occupy.

  The LV of the upward flow when the ion exchange resin of this ion exchange resin tower is regenerated is preferably 10 to 15 m / h, and the LV of the upward flow when backwashing is preferably 20 to 50 m / h. .

  The plate preferably has a disk shape having a diameter such that a gap with the inner peripheral surface of the tower body is 0.1 to 1.0%, particularly 0.2 to 0.5% of the inner diameter of the tower. . In this case, the plate may be provided with a check valve that allows only the flow of water from above to below, and a raw water inflow portion may be provided at the top of the tower body.

  It is preferable that the movable body is composed of a mesh plate in which a mesh is sandwiched between upper and lower sides by a perforated plate.

  In the ion exchange resin tower of the present invention, since the movable body moves up and down in accordance with the swelling / shrinkage of the ion exchange resin, a fixed bed can always be formed. Since the resin layer is regenerated in a completely fixed state from the beginning of the regeneration, the H-type (or OH-type) conversion rate of the resin below the resin layer is improved, and the quality of treated water is improved. In the present invention, a plate is provided integrally with the movable body above the movable body, and the movable body always maintains a substantially horizontal state by this plate.

It is a longitudinal cross-sectional view of the ion exchange resin tower which concerns on embodiment. It is a perspective view of a movable unit. It is a see-through | perspective perspective view of another movable unit.

  The first embodiment will be described with reference to FIGS.

  As shown in FIG. 1, an ion exchange resin tower 1 includes a tower body 2, a water collecting plate 3 provided at a lower portion in the tower body 2, and a plurality of strainers 4 provided on the water collecting plate 3. The movable unit 10 disposed in the upper part of the tower body 2 so as to be movable up and down, the layer of the inert resin particles 5 filled along the lower surface of the movable unit 10, and the layer of the inert resin particles 5 A layer of ion exchange resin 6 filled between the water collecting plate 3 and the like is provided.

  A lower opening (third flow section) 8 and an upper opening 9 are provided in the center of the lower end plate and the upper end plate of the tower body 2, respectively. The tower body 2 has a cylindrical shape between the upper and lower end plates. The water collecting plate 3 is provided horizontally at the lowermost part of the cylindrical portion. The plurality of strainers 4 are equally arranged on the water collecting plate 3.

  A first opening (first circulation part) 14 is provided in the middle of the tower body 2 in the vertical direction, and a second opening (second circulation part) 15 is provided at the upper part. A valve 14 a is connected to the first opening 14, and a valve 15 a is connected to the second opening 15. Note that the first opening 14 may be provided with a mesh, a strainer, or the like for preventing the outflow of ion exchange resin particles or inert resin particles.

  As clearly shown in FIG. 2, the movable unit 10 is arranged on the upper side of the eye plate 11 as a movable body and the eye plate 11, and is connected and integrated with the eye plate 11 via a connecting body 12. Plate 13.

The face plate 11 is obtained by sandwiching a mesh having an opening smaller than the particle size of the ion exchange resin 6 from above and below with a porous plate. The mesh opening is preferably about 0.1 to 0.3 mm, and the perforated plate preferably has a pore diameter of 2 to 10 mm and a porosity of about 5 to 30%.
In addition, if it is a perforated plate which has a micropore of 0.4 mm or less, it can also be applied independently instead of a mesh or a face plate in consideration of strength and cost.

  The face plate 11 has a disc shape, and the diameter thereof is set so that the gap between the outer peripheral surface of the eye plate 11 and the inner peripheral surface of the tower body 2 is 0 to 1.0 mm. Since there is a layer of inactive resin particles 5 under the eye plate 11, it is sufficient that this gap is smaller than the diameter of the inactive resin particles 5. However, when no inert resin is used, the gap is made smaller than the particle size of the ion exchange resin particles.

  The connecting body 12 has a rod shape, and a lower end is fixed to the eye plate 11 and an upper end is fixed to the plate 13.

  The plate 13 has a circular plate shape, and the diameter of the plate 13 is determined in consideration of both the horizontal holding of the plate and the flow of water during backwashing on the outer peripheral surface of the plate 13 and the inner peripheral surface of the tower body 2. It is preferable that a gap of 0.1 to 1.0%, particularly 0.2 to 0.5% of the inner diameter of the steel is formed.

  The distance between the eye plate 11 and the plate 13 is not less than 25% of the tower diameter, particularly 40 to 100% in consideration of the vertical sliding caused by the swelling / shrinkage of the ion exchange resin 6 while keeping the movable unit 10 horizontal. And 20% or more, particularly 20 to 60%, of the layer height of the ion exchange resin 6 (layer height after regeneration) is preferable. As described above, the circular plate 13 having a diameter slightly smaller than the inner diameter of the tower body is arranged above the eye plate 11 and connected and integrated by the connecting body 12, so that the eye plate 11 is substantially the same as the movable unit 10. Thus, the inside of the tower body 2 can be smoothly moved up and down while maintaining the horizontal state.

  The particle diameter of the inert resin particles 5 is larger than the mesh opening of the mesh plate 11 and the gap between the mesh plate 11 and the inner peripheral surface of the tower body 2. The particle size of the inert resin particles 5 is preferably about 2 to 6 times the particle size of the ion exchange resin 6. For example, when the particle size of the ion exchange resin 6 is about 0.5 to 0.7 mm, the inert resin particles The particle size of 5 is preferably about 1.5 to 3 mm. The specific gravity of the inert resin particles 5 is smaller than the specific gravity of the ion exchange resin 6 and less than 1. The packed bed height of the inert resin particles 5 is preferably about 20 to 100 mm, particularly about 50 to 100 mm.

The installation height of the first opening 14 is between the eye plate 11 and the plate 13 when the raw water is flowing down as shown in FIG. The opening 14 is set to be positioned. Further, the length of the connecting body 12 is set so that the liquid level in the tower body 2 is lower than the plate 13 in both the descending circulating water state of the raw water and the rising circulating water state of the regenerated liquid. .
Here, the height of the opening 14 is set as described above when the inflow point is above the plate (the type without the check valve) when the water flows downward. Since a large amount of raw water passes through a small gap, there is a concern that the pressure loss will increase, and when the plate is submerged during upflow regeneration, buoyancy is applied to the plate, and the ion exchange resin 6 This is because an extra “weight” is required to suppress the flow of the slag.

  The second opening 15 is provided so as to be above the plate 13 even in a state where the backwash water is flowed up and the layer height of the ion exchange resin 6 is increased as shown in FIG. .

  In the ion exchange resin tower 1 configured as described above, raw water is introduced into the tower body 2 through the first opening 14 as shown in FIG. 1A, and passes through the layers of the eye plate 11 and the inert resin particles 5. Then, after being deionized by contact with the ion exchange resin 6, it passes through the strainer 4 and is taken out from the lower opening 8.

  As the ion exchange reaction of the ion exchange resin 6 proceeds, the particle size of the ion exchange resin 6 decreases, and the packed bed height of the ion exchange resin 6 decreases. In this case, the movable unit 10 follows and moves downward. In this case, since the movable unit 10 includes the plate 13, the eyeplate 11 moves downward while maintaining a substantially horizontal state. In addition, since the length of the coupling body 12 is set to be sufficiently long, the plate 13 is positioned higher than the first opening 14 even when the layer height of the ion exchange resin 6 is minimized.

  When the ion exchange resin 6 is regenerated, the regenerated liquid is introduced into the tower body 2 through the lower opening 8, the ascending circulation water is supplied at about LV 10 to 15 m / h, and the regenerated waste liquid is discharged from the first opening 14. Even if the regeneration solution is passed in an upward flow, the weight of the movable unit 10 is added to the ion exchange resin 6, so that fluidization does not occur in the packed bed of the ion exchange resin 6. Since the plate 13 is positioned above the water surface, the plate 13 is not buoyant and the weight of the plate 13 is added to the layer of the ion exchange resin 6 as it is.

  The ion exchange resin 6 may be either a cation exchange resin or an anion exchange resin. When regenerating strong acidic cation exchange resin, after passing HCl aqueous solution (concentration 1-5%) in an upward flow at LV = 10-15 m / h, reclaimed water (usually ion-exchange tower treated water) Is preferably extruded.

  When regenerating a strongly basic anion exchange resin, a NaOH aqueous solution (concentration: 1 to 5%) is passed in an upward flow at LV = 10 to 15 m / h, and then regenerated water (in general, ion exchange tower treated water). ) Is preferably extruded. Although the supply time of a chemical | medical solution is about 5-30 minutes normally, it is not limited to this.

  As the regeneration of the ion exchange resin 6 proceeds, the particle size of the ion exchange resin 6 increases, the height of the packed bed of the ion exchange resin 6 increases, and an expansion pressure is applied to the movable unit 10 upward. In this case, the movable unit 10 moves upward. Also in this case, the movable unit 10 moves upward while the eye plate 11 remains substantially horizontal. In addition, since the layer of the inactive resin particles 5 having a larger particle size and a smaller specific gravity than the ion exchange resin 6 is provided on the upper side of the packed bed of the ion exchange resin 6, the ion exchange resin 6 is connected to the eye plate 11 and the tower body 2. It does not flow out between the inner peripheral surface of the.

  When turbidity flows into or accumulates in the layer of ion exchange resin 6, the layer of ion exchange resin 6 is back-washed as shown in FIG. In this case, backwash water is supplied into the tower body 2 from the lower opening 8, and the backwash drainage is caused to flow out from the second opening 15. As a result, the packed bed of the ion exchange resin 6 expands, the water surface in the tower rises, the plate 13 is submerged, a dynamic pressure is applied to the plate 13, and buoyancy is also applied. Thereby, the movable unit 10 rises, and the ion exchange resin 6 layers can be fluidized while being relatively low LV. Even if the movable unit 10 rises to the highest position, the plate 13 is positioned lower than the second opening 15. At this time, only the lower part of the ion exchange resin 6 layer flows, and the upper part may form a fixed bed. However, when the backwash water supply is stopped, the ion exchange resin 6 layer is lowered by gravity. As it moves, the layer collapses and flows, and the turbidity moves to the top.

  If the valve 15a of the second opening 15 (backwash drain outlet) is closed after the backwash water supply is stopped, the movable unit 10 hardly settles (or settles very slowly), and ion exchange is performed. It is possible to secure time for the resin 6 to settle after fluidization. If the ion exchange resin 6 is calmed down, the wastewater containing turbidity can be discharged from the first opening 14 by opening the valve 14a.

  In addition, LV at the time of backwashing has preferable about 20-50 m / h. Moreover, it is preferable that the backwashing expansion rate of the ion exchange resin (= resin high after flow / resin high before flow) is about 1.3 to 1.6.

  In the movable unit 10 of the above embodiment, the plate 13 has a non-porous plate shape. However, like the movable unit 10 ′ in FIG. 3, only the flow from the top to the bottom is allowed to the plate 13, A check valve 16 may be provided to prevent the flow from the bottom to the top. In this case, the raw water can be introduced into the tower body 2 not from the first opening 14 but from above the plate 13 such as the tower top.

  The material of the constituent members such as the tower body 2 and the movable units 10 and 10 'may be a material having chemical resistance (for example, vinyl chloride). As the mesh of the face plate 11, a saran net or the like can be used. In order to reduce friction with the inner peripheral surface of the tower body 2, the contact portion of the outer periphery of the eyeplate 11 with the inner peripheral surface may be covered with a fluororesin.

  In the above embodiment, the inert resin particles are used, but a nonwoven fabric, a sponge-like porous body, or the like may be used instead of the inert resin particles.

The dimensions of an ion exchange resin tower suitable for applying the present invention are shown below.
(1) Tower diameter: 500-3500 mm
(2) Ion exchange resin filling height: 500 to 2000 mm
(3) Ion exchange resin type: cation exchange resin or anion exchange resin (4) Ion exchange resin particle size: 0.5 to 0.7 mm (small particle size cut product or uniform particle size resin
desirable. )
(5) Lower water collecting structure: existing general one (for example, water collecting plate with strainer)
A glass bead layer (height 50-200mm) is provided on the top of the water collecting plate
May be.
(6) Mass of plate:
P = (total mass of movable unit) / (horizontal cross section of tower)
In this case, it is necessary to increase P as the LV during upward flow regeneration is higher. However, when LV = 10 to 15 m / h, P is preferably about 60 to 150 kg / m ² . Moreover, 60 to 90% is good for the ratio which the mass of a plate occupies among the whole mass of a movable unit.
Desirably, the mass of the plate is adjustable. For example, the plate may have a container structure such as a plastic tank, and water may be put therein. A method in which a weight (for example, a glass bead, a plate, a ring, a container structure for containing water) is placed on the plate 13, and the amount of glass beads, the number of the plate, the ring, the amount of water is adjusted. But you can.
(7) A mechanism may be provided in which the movable units 10 and 10 ′ are fixed at the position after the movable units 10 and 10 ′ are raised to a predetermined height by the flow rate of the upward flow at the time of backwashing.

[Example 1]
A strongly acidic cation exchange resin (manufactured by Mitsubishi Chemical Corporation, SK1B) was packed in a transparent vinyl chloride (vinyl chloride) column having an inner diameter of φ68 mm at a packed bed height of 500 mm. Furthermore, the movable unit shown in FIG. 2 was arranged on the upper side of the resin layer, and the ion exchange resin tower shown in FIG. A plurality of PVC annular bodies (washers) were placed on the plate of the movable unit. When the number of washers to be mounted was variously changed and the weight at which the resin layer did not move and a complete fixed bed was formed with an upward flow of LV = 12 m / h (730 ml / min), the total weight was 330 g or more. It was confirmed that the resin layer was fixed. (At this time, the water surface is between the plate and the eye plate.)
The total weight of the washer and the movable unit is 330 g, and the flow rate from the lower part is LV: 18 m / h (1100
ml / min), the entire movable unit was submerged, and the movable unit gradually rose. When the movable unit was fixed in the raised state and the supply of backwash water was stopped, the entire resin layer settled while flowing.

  As a result, it is possible to form a fixed bed completely during normal regeneration, and even when turbidity flows into the resin layer or precipitates are generated by the reaction in the resin layer, the upward flow By simply increasing the LV to about 1.5 to 2 times, it became possible to fluidize the resin layer and eliminate turbidity.

DESCRIPTION OF SYMBOLS 1 Ion exchange resin tower 2 Tower body 3 Water collecting plate 4 Strainer 5 Inactive resin particle 6 Ion exchange resin 10,10 'movable unit 11 Eyeplate 12 Connection body 13 Plate 14 1st opening 15 2nd opening 16 Check valve

Claims (7)

Downflow water in which a packed bed of an ion exchange resin made of a cation exchange resin or an anion exchange resin is formed in the tower body, an ion exchange resin tower of an upflow regeneration system,
A movable body having water permeability that can be moved up and down and is provided on the upper side of the packed bed of ion exchange resin, for pressing the packed bed of ion exchange resin from above;
A plate disposed on the upper side of the movable body and connected to the movable body by a connecting body extending in the vertical direction;
A first circulation part for liquid circulation provided on the side surface of the tower body between the downward flow and the plate in any water flow state of the downward circulation water and the upward flow regeneration;
A second circulation part for liquid circulation provided in the upper part of the tower body, which is higher than the plate in the state where the upward flow is backwashed;
An ion exchange resin tower comprising a third circulation part for liquid circulation provided at the bottom of the tower body. In Claim 1, the total mass of the said movable body, a plate, and a coupling body is set to 60-150 kg / m < ² > per horizontal cross-sectional area of an ion exchange resin tower, and the mass ratio of a plate is included among the total mass. Is set so as to occupy 60 to 90%.   3. The ion exchange resin tower according to claim 1, wherein an LV of an upflow when the ion exchange resin is regenerated is set to 10 to 15 m / h.   The ion exchange resin tower according to any one of claims 1 to 3, wherein an LV of an upflow when the ion exchange resin is backwashed is set to 20 to 50 m / h.   5. The plate according to claim 1, wherein the plate has a disk shape having a diameter such that a gap with the inner peripheral surface of the tower body is 0.1 to 1.0% of an inner diameter of the tower. An ion exchange resin tower characterized by   6. The check valve according to claim 5, wherein the plate is provided with a check valve that allows only the flow of water from above and below, and a raw water inflow portion is provided above the tower above the plate. An ion exchange resin tower characterized by that.   7. The ion exchange resin tower according to claim 1, wherein the movable body includes a mesh plate sandwiching a mesh from both upper and lower sides with a perforated plate.

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