JPH08309208A - Ion exchange device - Google Patents

Abstract

PURPOSE: To shorten regeneration time in an ion exchange device into which raw water is fed in an upflow and a regenerant is fed in a downflow by constituting a feeding means arranged on a bottom plate so that a regenerant can be fed to a strong electrolyte ion exchange resin bed of a main pipe and plural branch pipes and installing it at a prescribed height. CONSTITUTION: In an ion exchange device, raw water is fed in a downflow during pure water production, and a regenerant is fed in an upflow during regeneration. On a bottom plate 12 fitted to the lower end of a packed tower 11, a strong electrolyte ion exchange resin bed 13 is filled, and on a shield plate above it, a weak electrolyte ion exchange resin bed is filled, and a regenerant is fed to them by a feeding means 17. In this case, the feeding means 17 is constituted by connecting a main pipe 17B arranged above the bottom plate 12 to a nozzle 17A fitted to the packed tower 11 and connecting the other end or the main pipe 17B to plural branch pipes 17C arranged, trained over the bottom plate 12. The main pipe 17B is set at such a height that it is not exposed from the back surface of the ion exchange resin bed 13 pushed up by the feeding of the regenerant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ion exchange apparatus for supplying raw water in a downward flow and supplying a regenerant in an upward flow, and more particularly to a compact ion exchange apparatus excellent in regeneration efficiency. .

[0002]

2. Description of the Related Art Ion exchange apparatuses are widely used, for example, as pure water production apparatuses. As the ion exchange resin in this case, a combination of a hydrogen ion type strongly acidic cation exchange resin which is a strong electrolyte ion exchange resin and a hydroxide ion type strongly basic anion resin is used. There are mixed bed type and double bed type in this combination type. The mixed bed system is a system in which a mixed resin of a strongly acidic cation exchange resin and a strongly basic anion exchange resin is packed in the same column, and is used when producing high purity water. The multi-bed type is a system in which a tower of a strongly acidic cation exchange resin and a tower of a strongly basic anion exchange resin are combined, and although the purity is inferior to that of the mixed bed type,
It is widely used because of its economical efficiency such as the consumption of regenerant.

By the way, the ion exchange resin reaches the flow-through capacity by ion-exchanging the impurity ions in the raw water by using the ion exchange device, and therefore it is necessary to periodically regenerate the ion exchange resin by using a regenerant. Therefore, as the above-mentioned double bed type ion exchange device, a double bed type ion exchange device excellent in regeneration efficiency and economical efficiency is widely used. This multi-layer bed type ion exchange device includes a weak electrolyte ion exchange resin layer and a strong electrolyte ion exchange resin layer in one tower, and raw water is passed from the weak electrolyte ion exchange resin layer to the strong electrolyte ion exchange resin layer. It is configured to obtain treated water.

In the water flow system of the multi-layer floor type ion exchange device,
There are an upflow method in which raw water flows as an upward flow and a downward flow method in which raw water flows as a downward flow. In addition, the regeneration method includes a co-current regeneration type in which the regenerant is flowed in the same direction as the water flow direction and a countercurrent regeneration type in which the regenerant is flowed in the opposite direction to the water flow direction. The advantage is that the regeneration efficiency is better. Further, in order to improve the purity of the treated water in both cases of passing water and regeneration, it is necessary to prevent fluidization of the strong electrolyte ion-exchange resin layer and prevent the ion distribution in the layer from being disturbed as much as possible.

In the case of the downward flow regeneration type of upward flowing water, stable regeneration can be carried out, but since the ion exchange resin layer is pushed up to form a floating ion exchange resin layer during the passage of water, water collection is performed. If the step is interrupted, there is a problem that the resin layer is fluidized when the ion exchange resin layer descends and the purity of the treated water thereafter is lowered.

However, in the case of an ion exchanger of the downward flow water upward flow regeneration type, since the downward flow water is stable, the raw water treatment is stable, while the regenerant is flown in the upward flow direction. It is necessary to take measures to prevent the exchange resin layer from flowing. As an ion exchange device that prevents fluidization during regeneration, for example, the one shown in FIGS. 5 to 7 is known.

The ion exchange apparatus shown in FIG.
A bottom plate 2 attached near the lower end of the packed tower 1, and a strong electrolyte ion exchange resin layer 3 packed on the bottom plate 2.
And a shielding plate 5 attached to the strong electrolyte ion-exchange resin layer 3 via the gap 4, and a weak electrolyte ion-exchange resin layer 6 filled on the shielding plate 5. Originally, in the upflow regeneration, it is better to fill the ion exchange resin between the bottom plate 2 and the shield plate 5 without a gap, but the ion exchange resin does not flow during regeneration, but when the strong electrolyte ion exchange resin is regenerated, Since the volume swells slightly, it is necessary to preliminarily provide the above-mentioned gap in consideration of the increase in volume due to this swelling. Further, a nozzle plate 1A that forms the lower end of the packed tower 1 is provided with a nozzle 1B that supplies the regenerant while flowing out the treated water by the resin layers 6 and 3, and also the plate plate 1A.
A space 7 is formed between A and the bottom plate 2. Also,
The protrusions dispersed on the entire surface of the bottom plate 2 and the shield plate 5 are filtering members 8 formed in a cap shape, and the filtering member 8 has a plurality of slits that allow only water to pass through.

In the case of regenerating the ion exchange resin layers 3 and 6 of the above ion exchange apparatus, the inside of the strong electrolyte ion exchange resin layer 3 is passed from the nozzle 1B of the packed tower 1 through the space 7 between the end plate 1A and the bottom plate 2. The regenerant is flown into the resin, and the water pressure causes the strong electrolyte ion-exchange resin layer 3 to rise in a layered state, and the gap 4 at the upper portion is filled with the resin layer 6 while pressing the resin layer 6 against the shielding plate 5 so as to float. An ion exchange resin layer is formed.
Furthermore, the regenerant flows from the shield plate 5 into the weak electrolyte ion exchange resin layer 6.

Another ion exchange device shown in FIG. 6 is known. As shown in the figure, this ion exchange apparatus is provided with a bottom plate 2 for supporting a strong electrolyte ion exchange resin layer 3 at the lower end of a packed column 1, and a distributor for supplying a regenerant while flowing out treated water to the inner surface of the bottom plate 2. 9 is provided. As shown in the figure, the distributor 9 includes a nozzle 9A near the lower end of the packed tower 1, a main pipe 9B connected to the nozzle 9A and crossing the center of the packed tower 1, and a plurality of branch pipes orthogonal to the main pipe 9B. 9C, and the plurality of branch pipes 9C and the main pipe 9B are connected to each other via a connecting pipe 9D. A plurality of holes 9E are formed at equal intervals in the branch pipe 9C so as to face downward or obliquely downward so that the treated water flows out from each hole 9E and the regenerant is supplied toward the resin layer 3. .

[0010]

However, in the case of the conventional ion exchange apparatus shown in FIG. 5, the strong electrolyte ion exchange resin layer 3 hardly fluidizes during regeneration, but when the regeneration agent is replaced after regeneration. Has the following drawbacks. That is, immediately after the passage of the regenerant, the space 7 formed by the bottom plate 2 and the end plate 1A is filled with the regenerant, but if replacement water is supplied from the nozzle 1B to replace this, Tends to rise right above the nozzle 1B, and it becomes difficult to replace the regenerant on the outer peripheral side of the end plate 1A, and a large amount of replacement water is consumed, and the regenerant is diluted more than necessary during the replacement, Efficiency is also reduced.

In the case of the conventional ion exchange apparatus shown in FIG. 6 as compared with the apparatus shown in FIG. 5, the apparatus can be made compact because there is no space below the bottom plate 2, and there is no problem with replacement of the regenerant. However, if the structure of the distributor 9 is improper, there is a problem that the regeneration efficiency deteriorates and the purity of the treated water after regeneration decreases.

[0012] The present invention has been made to solve the above-mentioned problems. The apparatus can be made compact, the amount of replacement water used can be saved, the regeneration efficiency can be improved, the regeneration time can be shortened, and the treated water after regeneration can be shortened. It is an object of the present invention to provide an ion exchange device that does not reduce the purity of the ion exchange device.

[0013]

Means for Solving the Problems The present inventors have earnestly studied the problems of the ion exchange apparatus shown in FIG. 6 and, as a result of various studies, have obtained the following findings.

That is, in the case of the ion exchange device shown in FIG. 6, since the distributor 9 is installed right above the bottom plate 2, a plurality of holes 9 of each branch pipe 9C are provided at the time of regeneration.
When the regenerant is ejected from E as shown by the arrow in FIG. 7 and the strong electrolyte ion exchange resin layer 3 is gradually pushed up by the supply pressure, the strong electrolyte ion exchange resin 3A moves around the main pipe 9B to some extent. A rotating phenomenon occurs. The reason for this is as described below.

That is, in the case of the conventional ion exchange device, since the installation position of the main pipe 9B is relatively close to the bottom plate 2,
When the strong electrolyte ion exchange resin layer 3 is pushed up, FIG.
As shown in FIG. 5, the main pipe 9B floats out from the lower surface of the strong electrolyte ion-exchange resin layer 3 formed, and finally the main pipe 9B is formed.
May be completely exposed from the bottom surface. Even if a part of the main pipe 9B protrudes from the lower surface of the resin layer 3 described above, the regenerant flows from the periphery of the main pipe 9B as shown by the arrow A as shown in FIG. 7, and the regenerant does not flow evenly. This promotes fluidization of the strong electrolyte ion exchange resin 3A in that portion. In the case of an ion exchange device of downward flow water upflow regeneration method, if the portion where the regenerant comes into contact first is not sufficiently regenerated, sodium leak occurs in the case of a cation tower and silica occurs in the case of an anion tower. It causes a leak and reduces the purity of the treated water. Therefore, in the case of the ion exchange device of the downward flow water upward flow regeneration system, it is important to perform regeneration so that the portion where the regenerant first comes into contact does not fluidize. In FIG. 7, the fluidized strong electrolyte ion-exchange resin 3A is schematically shown in the form of particles, and the portion which is hardly fluidized and retains the layered state is schematically shown with diagonal lines.

The present invention was made based on the above findings, and the invention according to claim 1 supplies raw water in a downward flow,
Further, in an ion exchange device that supplies the regenerant in an upward flow, a bottom plate attached to the lower end of the packed column, a strong electrolyte ion exchange resin layer packed on the bottom plate, and a strong electrolyte ion exchange resin layer Supply means arranged on the bottom plate so as to supply a regenerant, the supply means comprising a main pipe arranged above the bottom plate and a plurality of branches arranged along the bottom plate. An ion exchange device, characterized in that the main pipe is set to a height that is not exposed from the lower surface of the strong electrolyte ion exchange resin layer that is pushed up by the supply of the regenerant and floats to form. By doing so, the above object is achieved.

The invention according to claim 2 of the present invention is
In an ion exchange device that supplies raw water in a downward flow and regenerant in an upward flow, a bottom plate attached to the lower end of the packed column and a strong electrolyte ion exchange resin packed as a lower layer on the bottom plate. Layer, a weak electrolyte ion exchange resin layer filled as an upper layer on the shielding plate attached above the strong electrolyte ion exchange resin layer, and an arrangement on the bottom plate so as to supply a regenerant to these upper and lower layers. And a plurality of branch pipes arranged along the bottom plate, wherein the main pipe is the regenerant. The present invention provides an ion exchange device characterized in that the height is set so as not to be exposed from the lower surface of the strong electrolyte ion exchange resin layer that is lifted up and formed by the supply of.

The invention according to claim 3 of the present invention is
The invention according to claim 1 or claim 2 provides an ion exchange device characterized in that the distance between the main pipe and the bottom plate is set to at least 400 mm.

The invention according to claim 4 of the present invention is
In the invention according to claim 2, the gap between the main pipe and the bottom plate is set to be larger than at least the gap between the upper surface of the strong electrolyte ion-exchange resin layer and the shielding plate that have been subjected to the sink filling. Ion exchange device.

The invention according to claim 5 of the present invention is
The invention according to any one of claims 1 to 4, wherein the strong electrolyte ion exchange resin layer comprises a strongly acidic cation resin layer or a strongly basic anion resin layer. To do.

[0021]

According to the first aspect of the present invention, when the strong electrolyte ion exchange resin layer of the ion exchange apparatus is regenerated, the main pipe of the supply means disposed on the bottom plate at the lower end of the packed column is regenerated. When the regenerant is supplied for a predetermined time, the regenerant is supplied from the main pipe through the plurality of branch pipes into the strong electrolyte ion exchange resin layer. Then, the strong electrolyte ion exchange resin layer is gradually pushed up by the supply pressure of the regenerant, the strong electrolyte ion exchange resin layer floats up from the branch pipe, and the regenerant flows upward in this floating layer, so that the strong electrolyte ion The exchange resin layer is regenerated. Further, according to the present invention, even if the strong electrolyte ion exchange resin layer is pushed up to the highest position, the main pipe of the supply means does not stick out from the lower surface of the strong electrolyte ion exchange resin layer, so that the strong electrolyte ions around the main pipe are Fluidization of the exchange resin hardly occurs, the ion distribution of the strong electrolyte ion exchange resin layer is not disturbed, and the regenerant can be uniformly supplied. Therefore, the purity of the treated water does not decrease when the raw water is treated after the regeneration. Further, since the main pipe is inside the strong electrolyte ion exchange resin layer, the lower surface of the strong electrolyte ion exchange resin layer is easily stabilized during regeneration, and the replacement operation performed after passing the regenerant can be effectively performed.

Further, according to the second aspect of the present invention, when the strong electrolyte ion exchange resin layer and the weak electrolyte ion exchange resin layer of the ion exchange apparatus are regenerated, the bottom plate at the lower end of the packed column is regenerated. When the regenerant is supplied to the main pipe of the arranged supply means for a predetermined time, the regenerant is supplied from the main pipe into the strong electrolyte ion exchange resin layer through the plurality of branch pipes. Then, the strong electrolyte ion exchange resin layer is gradually pushed up by the supply pressure of the regenerant, the strong electrolyte ion exchange resin layer floats up from the branch pipe, and the regenerant flows upward in this floating layer, so that the strong electrolyte ion The exchange resin layer is regenerated. The regenerant flowing out from the strong electrolyte ion exchange resin is further supplied into the weak electrolyte ion exchange resin layer through the shielding plate, and the weak electrolyte ion exchange resin is also regenerated. Further, according to the present invention, even if the strong electrolyte ion exchange resin layer is pushed up to the highest position, the main pipe of the supply means does not stick out from the lower surface of the strong electrolyte ion exchange resin layer, so that the strong electrolyte ions around the main pipe are Fluidization of the exchange resin hardly occurs, and the ion distribution of the strong electrolyte ion exchange resin layer is not disturbed. Therefore, the purity of the treated water does not decrease when the raw water is treated after the regeneration. Further, since the main pipe is inside the strong electrolyte ion exchange resin layer, the lower surface of the strong electrolyte ion exchange resin layer is easily stabilized during regeneration, and the replacement operation performed after passing the regenerant can be effectively performed.

According to the invention of claim 3 of the present invention, in the invention of claim 1 or 2,
Since the distance between the lower end of the main pipe and the surface of the bottom plate is set to at least 400 mm, even if the strong electrolyte ion exchange resin layer is pushed up to the highest position by the regenerant, the main pipe is There is no danger of protruding from the bottom surface.

According to a fourth aspect of the present invention, in the invention according to the second aspect, the interval between the main pipe and the bottom plate is at least the above-mentioned strong electrolyte ion exchange resin that has been settlingly packed. Since the gap between the upper surface of the layer and the shielding plate is set larger, even if the strong electrolyte ion exchange resin layer is pushed up to the shielding plate by the regenerant, the height of the main pipe is pushed up by the strong electrolyte ion exchange resin layer. Since the height is higher than the height, there is no fear that the main pipe protrudes from the lower surface of the strong electrolyte ion exchange resin layer.

According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the strong electrolyte ion exchange resin layer is a strong acid cation exchange resin. Since it is composed of a layer or a strongly basic anion resin layer, for example, when removing calcium ions, magnesium ions or sodium ions, a strong acid cation exchange resin is used, and for example when removing sulfate ions, chloride ions or silica. Strongly basic anion exchange resins can be used.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in FIGS. In each of the drawings, FIG. 1 is a schematic view showing an embodiment of the ion exchange device of the present invention, FIG. 2 is a perspective view showing a partially cutaway lower structure of the ion exchange device shown in FIG. 1, and FIG. 2 is an explanatory view showing the behavior of the ion exchange resin at the time of regeneration by the distributor shown in FIG. 2, and FIG. 4 is a main pipe of the distributor for stabilizing the strong electrolyte ion exchange resin layer at the time of regeneration by the experimental tower of the ion exchange apparatus shown in FIG. 5 is a graph showing test results showing the influence of the height of the.

The ion exchange apparatus of this embodiment is constructed so that raw water is supplied in a downward flow when producing pure water, and a regenerant is supplied in an upward flow when the ion exchange resin layer is regenerated. That is, as shown in FIG. 1, this ion exchange apparatus includes a bottom plate 12 attached to the lower end of a packed column 11, a strong electrolyte ion exchange resin layer 13 filled as a lower layer on the bottom plate 12, and the strong electrolyte. Weak electrolyte ion exchange resin layer 16 filled as an upper layer on a shielding plate 15 attached above the ion exchange resin layer 13 via a gap 14.
And a supply means 17 disposed on the bottom plate 12 so as to supply the regenerant to the upper and lower layers 13, 16. The supply means 17 has a function as an outflow means for supplying the regenerant and flowing out the treated water when treating the raw water. In this embodiment, attention is focused on the function of the regenerant supply means, and therefore the supply means 17 will be referred to as the first distributor 17 in the following description.
Further, the shielding plate 15 is formed so that water and a regenerant are allowed to pass therethrough and an ion exchange resin is not allowed to pass therethrough. A strong acid cation exchange resin is used for the strong electrolyte ion exchange resin layer 13 when removing, for example, calcium ions, magnesium ions and sodium ions, and a weak acid cation exchange resin is used for the weak electrolyte ion exchange resin layer 16. Is used.

A space 18 is formed above the weak electrolyte ion exchange resin layer 16. A second distributor 19 is disposed in this space 18, and a branch pipe 20A for supplying raw water to the second distributor 19 and a branch pipe 20B for discharging regenerated waste liquid are provided through a pipe 20.
Is connected. Valves 21A and 21B such as air-operated valves are attached to the respective branch pipes 20A and 20B, and these valves 21A and 21B are driven by a command signal from a controller (not shown). A valve 2 when raw water is supplied into the packed tower 11.
1A is opened, the valve 21B is closed, and when discharging the regeneration waste liquid at the time of regeneration, the valve 21B is opened and the valve 21A is closed.

On the other hand, a branch pipe 22A for flowing out treated water and a branch pipe 22B for supplying a regenerant are connected to the first distributor 17 through a pipe 22. Valves 23A and 23B such as air operated valves are attached to the respective branch pipes 22A and 22B, and these valves 21A and 21B are driven by a command signal from a controller (not shown). When the treated water is taken out, the valve 23A is opened, the valve 23B is closed, and when the regenerant is supplied at the time of regeneration, the valve 23A is used.
B is opened and the valve 23A is closed.

The first distributor 17 will be described in more detail. As shown in an enlarged view in FIG. 2, the first distributor 17 is provided with a nozzle 17A attached to the lower part of the peripheral surface of the packed tower 11, and a nozzle 17A connected to the nozzle 17A in the tower and arranged above the bottom plate 12. Main pipe 17B and a plurality of pipes (6 pipes in this embodiment) arranged along the bottom plate 12
17C, and the main pipe 17B is set to a height not exposed from the lower surface of the strong electrolyte ion exchange resin layer 13 pushed up by the supply of the regenerant. The main pipe 17B and the branch pipe 17C are connected via a vertical connecting pipe 17D. The main pipe 17B is formed slightly shorter than the diameter of the bottom plate 12, and is arranged parallel to the bottom plate 12. Each branch 1
7C are arranged at equal intervals, and are in a positional relationship orthogonal to the main pipe 17B. In addition, each branch pipe 17
Each C is provided with a plurality of downward or obliquely downward holes 17E. The holes 17E in each of the branch pipes 17C are formed at equal intervals. Therefore, the regenerant is uniformly supplied to the entire cross-sectional area of the packed tower 1 from the holes 17E of the all branch pipes 17C, and the treated water is evenly collected from the holes 17E.

The distance between the main pipe 17B and the bottom plate 12, that is, the height h of the main pipe 17B from the bottom plate 12 is at least the clearance 14 between the upper surface of the strong electrolyte ion-exchange resin layer 13 and the shielding plate 15 which are filled with the sinking. It is preferable that it is set larger than If the main pipe 17B is set to such a height, even if the strong electrolyte ion exchange resin layer 13 is pushed up by the regenerant at the time of regeneration, the main pipe 17B does not run off from the lower surface of the strong electrolyte ion exchange resin layer 13. . More specifically, the main pipe 17B extends from the bottom plate 12 to at least 4
It is preferably arranged at a height of 00 mm. That is, the width of the gap 14 is usually set to about 5% of the height of the strong electrolyte ion-exchange resin layer 13, and for example, the maximum height of the strong electrolyte ion-exchange resin layer 13 is 2%.
Even if it is 500 mm, the height corresponding to 5% is 12
Therefore, if the height of the main pipe 17B is set to at least 400 mm, the main pipe 17B will be regenerated at the time of reproduction.
This is because there is no possibility that B will stick out from the lower surface of the strong electrolyte ion exchange resin layer 13.

Next, the operation will be described. When treating the raw water, the valves 21A and 22A are opened based on the command signal from the controller, and the valves 21B and
23B is closed, and raw water is supplied to the second distributor 19 at a predetermined flow rate. By this operation, the raw water becomes weak electrolyte ion exchange resin layer 16 and strong electrolyte ion exchange resin layer 1
3 is passed in a downward flow to remove predetermined ions,
The treated water flows out via the first distributor 17, the pipe 22 and the branch pipe 22A.

On the other hand, when the ion exchange resin layers 13 and 16 are regenerated, the valves 21B and 22B are opened based on the command signal from the controller, and the valve 21 is regenerated.
A and 23A are closed, and the regenerant is supplied to the first distributor 17 below the packed column 11 at a predetermined flow rate. The regenerant flowing into the first distributor 17 is the nozzle 17A,
As shown by the arrow in FIG. 3, the strong electrolyte ion-exchange resin layer 13 flows through the main pipe 17B, the connecting pipe 17D, and the plurality of branch pipes 17C into the entire surface of the lower layer of the strong electrolyte ion-exchange resin layer 13 through the holes 17E, and The exchange resin layer 13 is floated and the regeneration is started. Before flowing the regenerant, a flow rate of the regenerant that was equal to, or slightly higher than, the flow rate of the regenerant was flowed from the first distributor 17 to sufficiently float the strong electrolyte ion exchange resin layer 13. After that, the regenerant may be introduced.

Here, the action of the regenerant for the strong electrolyte ion exchange resin layer 13 will be described in detail. When the regenerant is ejected from each of the plurality of holes 17E of each branch pipe 17C and gradually pushes up the strong electrolyte ion exchange resin layer 13 by the supply pressure, the main pipe 17B relatively moves the strong electrolyte ion exchange. The space portion that descends from the resin layer 13 and is formed after the movement of the main pipe 17B is gently replenished with the surrounding strong electrolyte ion exchange resin 13A.

A liquid layer portion 24 filled with a regenerant in which an upward flow is generated is formed immediately above the branch pipe 17C, and a strong electrolyte ion exchange resin layer 13 that is floated above the liquid layer portion 24 is formed. It Moreover, in this embodiment, the main pipe 17B
Is set to a position higher than the conventional one, and the strong electrolyte ion-exchange resin layer 13 is pressed against the upper shield plate 15, the main pipe 17B may protrude from the lower surface of the resin layer 13 as shown in FIG. However, since it is buried in the resin layer 13, the regenerant is evenly supplied to the floated strong electrolyte ion-exchange resin layer 13 and the arrow A is drawn from around the main pipe 17B as in the conventional apparatus shown in FIG. As indicated by, there is no possibility of preferentially flowing into the resin layer, and there is no flow of the ion exchange resin.

Next, the regeneration of the weak electrolyte ion exchange resin layer 16 will be described. In FIG. 1, the regenerant that has passed through the strong electrolyte ion exchange resin layer 13 passes through the shield plate 15 and passes upward to the weak electrolyte ion exchange resin layer 16. Since the weak electrolyte ion exchange resin layer 16 has a very high regeneration efficiency, even if the regenerant that has passed through the strong electrolyte ion exchange resin layer 13 retains the acid or alkali as the regenerant, the weak electrolyte ion exchange resin layer 16 Can be fully reproduced. Then, the regenerated waste liquid after regenerating the weak electrolyte ion exchange resin layer 16 is collected by the second distributor 19 and discharged from the branch pipe 20B via the pipe 20.

Since the weak electrolyte ion exchange resin 16 has a very high regeneration efficiency as described above, it can be sufficiently regenerated even when the weak electrolyte ion exchange resin layer 16 is in a fluid state, and thus the shield plate 15 is provided. By filling the amount of the weak electrolyte ion-exchange resin to a resin layer height that allows it to flow during regeneration, the weak electrolyte ion-exchange resin can be backwashed during regeneration and weakly washed in water. The suspended substance trapped in the electrolyte ion-exchange resin layer 16 can be discharged to the outside of the packed column during regeneration.

As described above, according to this embodiment,
Since the main pipe 17B is set to a height (specifically, a height of at least 400 mm from the bottom plate 12) that does not protrude from the lower surface of the strong electrolyte ion exchange resin layer 13 during regeneration, the main pipe 17B
There is no risk that the regenerant will preferentially flow in from around B to fluidize the resin layer, and by extension, the strong electrolyte ion exchange resin layer 13
The ion distribution of is not disturbed and stable treated water can be obtained even after regeneration.

Further, since the strong electrolyte ion exchange resin 13A does not move around the main tube 17B, the strong electrolyte ion exchange resin layer 13 including the area around the main tube 17B can be effectively regenerated.

Further, according to this embodiment, since there is no space for the regenerant to accumulate under the bottom plate 12, it is possible to solve the problem of replacing the regenerant as in the conventional apparatus shown in FIG. You can That is, in the case of the apparatus shown in FIG. 5, when replacing the regenerant after passing the regenerant, not only a large amount of replacement water is required, but also the regenerant is diluted with the replacement water more than necessary, and the regeneration efficiency is increased. However, in this embodiment, the liquid layer portion 24
Since the width of is small, the amount of replacement water is small, and
Substitution water is supplied to the filling resin layer 13 from almost the entire surface,
Since the regenerant is replaced as a plug flow (piston flow), the regenerant is not diluted more than necessary and the regeneration efficiency is not reduced. Therefore, the replacement water can be saved and the regeneration time can be shortened.

When the ion exchange apparatus of this embodiment is used in a pure water producing apparatus, the cation tower uses a strong acid cation resin, which is a strong electrolyte ion exchange resin, in the lower layer and a weak electrolyte ion exchange resin. Certain weakly acidic cation exchange resins can be used in the upper layer. As the anion tower, a strong basic anion exchange resin that is a strong electrolyte ion exchange resin can be used in the lower layer, and a weak basic anion exchange resin that is a weak electrolyte ion exchange resin can be used in the upper layer.

Test Example 1 In this test example, when the resin layer was pushed up by the regenerant during regeneration, the relationship between the time required for the fluidized portion of the resin layer to stabilize and the height of the main pipe of the first distributor was examined. Is a test of. Therefore, in this test example, three branch pipes of the first distributor are arranged at a pitch of 120 mm in an experimental tower having an inner diameter of 450 mm, and the main pipe does not protrude when it protrudes from the lower surface of the resin layer (height: 200 mm). In the case (height: 500 mm), an upward flowing water test was conducted. In this test, the water flow rate (LV) was changed variously to pass water, and the time until the respective resin layers were stabilized was measured, and the test results are shown in FIG. The time until the resin layer is stabilized means the time until the fluidized resin layer in the vicinity of the lower surface of the resin layer is in the same state as the fixed resin layer above the resin layer. According to the test result shown in FIG.
It can be seen that the height of the main pipe is stabilized at 500 mm in a shorter time than at 200 mm. From this, it can be seen that when the resin layer is pushed up during the regeneration, the case where the main pipe exists inside the resin layer can be regenerated in a shorter time and the regeneration efficiency is better than the case where it is not.

The present invention is not limited to the above-described embodiments, and the design can be changed as necessary without departing from the spirit of the present invention.

[0044]

According to the first to third aspects of the present invention, the apparatus can be made compact, the amount of replacement water used can be saved, the regeneration efficiency is good, and the regeneration time can be shortened and the regeneration can be performed. It is possible to provide an ion exchange device that does not reduce the purity of the treated water afterwards.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the strong electrolyte ion exchange resin layer is a strong acidic cation resin layer. Alternatively, since it is composed of a strongly basic anion resin layer, it is possible to provide an ion exchange apparatus that can be suitably used in a pure water production apparatus.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of an ion exchange device of the present invention.

FIG. 2 is a perspective view showing a lower structure of the ion exchange device shown in FIG.

FIG. 3 is an explanatory diagram showing the behavior of the ion exchange resin during regeneration by the first distributor of the ion exchange device shown in FIG.

FIG. 4 is a graph showing test results showing the influence of the height of the main pipe of the first distributor on the stabilization of the strong electrolyte ion exchange resin layer during regeneration by the experimental tower of the ion exchange apparatus shown in FIG.

FIG. 5 is a diagram showing a lower structure of an example of a conventional ion exchange device.

FIG. 6 is a perspective view corresponding to FIG. 2 showing another example of the conventional ion exchange device.

7 is an explanatory diagram showing the behavior of the ion exchange resin during regeneration by the distributor of the ion exchange device shown in FIG.

[Explanation of symbols]

 11 Packing Tower 12 Bottom Plate 13 Strong Electrolyte Ion Exchange Resin Layer 13A Strong Electrolyte Ion Exchange Resin 14 Gap 15 Shielding Plate 16 Weak Electrolyte Ion Exchange Resin Layer 17 First Distributor (Supply Means) 17B Main Pipe 17C Branch Pipe h Main Pipe Height

Claims (5)

[Claims] 1. An ion exchange apparatus for supplying raw water in a downward flow and regenerant in an upward flow, and a bottom plate attached to a lower end of a packed column, and a strong electrolyte filled on the bottom plate. An ion exchange resin layer and a supply means arranged on the bottom plate so as to supply a regenerant to the strong electrolyte ion exchange resin layer, the supply means being a main pipe arranged above the bottom plate. And a plurality of branch pipes arranged along the bottom plate, the main pipe being pushed up by the supply of the regenerant and being floated to form a height not exposed from the lower surface of the strong electrolyte ion exchange resin layer. An ion exchange device characterized by being set to. 2. An ion exchange apparatus in which raw water is supplied in a downward flow and regenerant is supplied in an upward flow, and a bottom plate attached to a lower end of a packed column and a lower layer packed on the bottom plate. A strong electrolyte ion exchange resin layer, a weak electrolyte ion exchange resin layer filled as an upper layer on a shielding plate attached above this strong electrolyte ion exchange resin layer, and a regenerant for supplying these upper and lower layers. A supply means disposed on the bottom plate, wherein the supply means includes a main pipe disposed above the bottom plate and a plurality of branch pipes disposed along the bottom plate, An ion exchange apparatus, wherein the main pipe is set to a height that is not exposed from the lower surface of the strong electrolyte ion exchange resin layer that is pushed up by the supply of the regenerant and is floated. 3. The ion exchange apparatus according to claim 1 or 2, wherein a distance between the main pipe and the bottom plate is set to at least 400 mm. 4. The gap between the main pipe and the bottom plate is set to be larger than at least the gap between the upper surface of the strong electrolyte ion-exchange resin layer and the shielding plate, which have been settled and filled. 2. The ion exchange device according to 2. 5. The ion exchange device according to any one of claims 1 to 4, wherein the strong electrolyte ion exchange resin layer comprises a strongly acidic cation resin layer or a strongly basic anion resin layer. .