JP2007245020A - Ion-exchange tower - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ion-exchange tower which can carry out efficiently a desirable back washing and a resin refilling after the back washing, and hold treat water in passing water with a high purity. <P>SOLUTION: The tower is a counter flow type ion-exchange tower, and is provided with a fixed filling chamber filled with an ion-exchange resin so as to form a fixed bed in the tower, a back washing chamber extracting the ion-exchange resin from the fixed filling chamber upward to back-wash the ion-exchange resin inside the fixed filling chamber, and a communicating tube carrying out a mutual transfer of the fixed filling chamber and the back washing chamber of the ion-exchange resin through a valve. The ion-exchange tower is characterized in that the back washing chamber has a resin-fluidizing means which enables a fluidization of the ion-exchange resin forming a water flow in the back washing chamber by pouring water locally in the back washing chamber. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ion exchange tower, and more particularly to an ion exchange tower that can efficiently wash a packed ion exchange resin.

  Conventionally, as a pure water production apparatus, a cation exchange tower filled with a cation exchange resin, a decarbonation tower for removing carbon dioxide from the treated water, and an anion exchange tower filled with an anion exchange resin are used. A three-column system is common.

  In the above ion exchange tower, if the ion exchange resin flows during water flow or regeneration, the purity of the treated water and the utilization efficiency of the ion exchange resin deteriorate, so the type of ion that can be used with the resin fixed as much as possible An exchange device is adopted.

  As raw water for the ion exchange device, river water and industrial water are pre-treated with a coagulation filtration device, etc., but a minute amount of suspended matter remains in this raw water, and once every 1 to 24 months. To a certain extent, it becomes necessary to clean the ion exchange resin in the ion exchange tower. For this reason, a pure water production apparatus (illustrated in FIG. 1, for example, Patent Document 1) of a type in which a part of resin is transferred to a resin washing tower installed outside the tower and washed, or resin is transferred to a part of the tower. A deionized water production apparatus (illustrated in FIG. 2) of the type that provides a chamber, transfers a part of the fixed resin to the resin transfer chamber, and secures an upper space in the resin filling chamber is devised. Yes.

In the apparatus illustrated in FIG. 1, in the normal water flow step (A), raw water is passed through the ion exchange tower 2 filled with the ion exchange resin 1 to obtain treated water. Part of the ion exchange resin 1 initially filled in (B) is transferred to the resin washing tower 3 by transfer water, and the resin transferred to the resin washing tower 3 in the backwashing step (C), and ion exchange The resin left in the tower 2 is backwashed using backwash water. In the apparatus illustrated in FIG. 2, the inside of the ion exchange column 11 is partitioned into two upper and lower chambers by the eyeplate 12, and a communication pipe 13 that can communicate between the upper and lower two chambers is provided. Then, in a state where the upper space 14 (sometimes referred to as a free board) is formed in the upper chamber, the raw water is passed to be treated water. In the resin transfer and backwashing step (B), the communication pipe 13 is opened, and the resin transfer and backwashing are performed under the conditions that take into account the volume expansion of the resin.
JP 2005-329275 A

  However, if the resin is to be transferred to the outside of the tower as shown in FIG. 1, it is necessary to install automatic valves and piping for washing the resin in the resin washing tower. There is a problem that the area is increased.

  Further, as shown in FIG. 2, when an upper space is secured in the tower and the resin is transferred through the upper and lower communication pipes, the resin fixed on the lower chamber side is extracted to the upper chamber side. After backwashing, even if you try to return the resin to the lower chamber side in order to fix the resin again, the optimal amount of resin for fixing may not be filled, and the purity of the treated water during water flow deteriorates There is a problem.

  The optimal amount of resin for immobilization is an amount that is not too small, and is an amount that the resin does not flow during regeneration or water flow, and is an amount that is not too much, due to excessive clogging of the resin in the resin packed layer. It is the amount that does not increase the water flow differential pressure or damage the resin.

The volume of the ion exchange resin varies by several to 20% between the regenerated type and the salt type. For example, when a strongly acidic cation exchange resin is packed in a cation exchange tower of a two-bed, three-column type pure water production apparatus, the regeneration type of the strong acid cation exchange resin is H type, and the salt type is Na or Ca type. Yes, when the salt type has a volume of several percent smaller than the regenerated type, and the anion exchange column is filled with a strongly basic anion exchange resin, the regenerated type of the strongly basic anion exchange resin is OH type, and the salt type is Cl or It is HCO ₃ type, and the salt type has a volume that is nearly 20% smaller than the regenerated type.

  Considering this change in volume, the resin layer in the fixed state is the most ideal fixed state in which the filling state is almost full after regeneration, and a gap corresponding to the volume reduction is opened after passing water. If refilling is not possible, there is a problem that the purity during water flow deteriorates or the water pressure differential increases.

  Further, in order to obtain an ideal filling state even in such an apparatus, an invalid resin 15 (shown in FIG. 2A) that hardly engages in ion exchange treatment is placed in a chamber having an upper space 300 to 500 mm. There is also a problem that the cost increases due to this ineffective resin.

  When the amount of the ineffective resin is small, when resin is transferred by resin transfer water from the upper chamber (backwash chamber) after backwashing to the lower chamber (chamber in which the fixed packed bed is formed), for example, FIG. ) In the state of the resin filling process, if the resin transfer water is supplied from the upper part and the resin is transferred to the lower resin layer side through the communication pipe, the transfer water passes through the eye plate and enters the communication pipe. As a result, the resin hardly flows, and eventually, there is a possibility that the resin cannot be transferred to the lower layer or the water is not formed. If the resin is to be reliably transferred, a large amount of invalid resin is filled as shown in FIG. 3B, and the resin is placed in the lower part so that the transfer water flows through the communication pipe rather than the eyeplate due to the water flow differential pressure of the resin. Need to be transferred to the layer. When a large amount of invalid resin is filled, as described above, a problem of cost increase is caused. This is the same even when water flow and regeneration are performed in a reverse flow.

  Therefore, the object of the present invention is to pay attention to the above-mentioned problems, and can efficiently perform desired backwashing and resin refilling after backwashing even when there is almost no invalid resin, and at the time of water flow. Another object of the present invention is to provide an ion exchange tower capable of keeping the treated water of high purity.

  In order to solve the above-mentioned problems, the ion exchange tower according to the present invention obtains a treatment liquid by passing a stock solution and passes a regenerating solution opposite to the stock solution to regenerate the ion exchange resin. An exchange tower, which is filled with an ion exchange resin so as to form a fixed bed in the tower, and the ion exchange resin in the fixed filling chamber is backwashed by extracting the ion exchange resin upward from the fixed filling chamber. In the ion exchange tower having a communication pipe for transferring the ion exchange resin between the backwashing chamber and the fixed filling chamber and the backwashing chamber through a valve, the ion exchange in the backwashing chamber is performed in the backwashing chamber. A resin fluidizing means capable of fluidizing the ion exchange resin by forming a water flow in the backwash chamber by locally injecting water into the backwash chamber is provided. .

  More specifically, for example, a fixed filling chamber for securing a packed bed of ion exchange resin in the ion exchange resin tower and a capacity corresponding to an upper space necessary for backwashing the resin in the upper part thereof. In order to fluidize the resin in the backwashing chamber as a resin fluidizing means having a backwashing chamber and communicating with the backwashing chamber and the fixed filling chamber through the valve to communicate the resin downward It is an ion exchange tower characterized by having piping for supplying the flowing water in the backwashing chamber.

  In such an ion exchange tower, at least a part of the water injected by the resin fluidizing means can be used as water for transferring the resin from the backwashing chamber to the fixed filling chamber.

  Further, the resin fluidizing means is preferably constituted by means for forming a swirling flow in the backwash chamber. The swirl flow may be formed into a flow swirling in a horizontal direction or an oblique direction, or a swirl flow divided as described later.

  In addition, the positional relationship between the backwashing chamber and the fixed filling chamber can be configured such that the fixed filling chamber is disposed below the backwashing chamber via the eyeplate, but a reverse vertical positional relationship is also possible. It is. Moreover, the structure by which another resin chamber is interposed between both chambers is also possible.

  In particular, in the present invention, a form in which the stock solution is passed in a downward flow and the regenerated solution is passed in an upward flow can be cited as a representative form.

  According to the ion exchange tower of the present invention, by forming a water flow in the backwash chamber and fluidizing the internal resin, in particular, by forming a swirl flow in the backwash chamber, the internal resin becomes a slurry, Even if there is almost no ineffective resin, refilling of the ion-exchange resin after backwashing into the fixed filling chamber can be performed efficiently without forming a waterway. By repeating this swirl flow formation and backwashing, the same effect can be obtained even in a large tower.

  Moreover, since there is no invalid resin or the amount of resin can be suppressed to a very small amount, it is not necessary to adjust the amount of resin extracted from the fixed filling chamber and the amount of resin to be refilled, and a series of operations can be easily automated. .

  Furthermore, since it is not necessary to adjust the amount of resin, as long as the initial filling amount is adjusted to an optimum amount, the purity of the treated water is not deteriorated during water flow due to the flow of the resin.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 4 shows an ion exchange tower 21 according to the first embodiment of the present invention, and this ion exchange tower 21 passes a stock solution (treatment liquid [treatment water]) to obtain a treatment liquid. The counter flow type ion exchange tower which reproduces | regenerates the ion exchange resin 22 by letting a regeneration liquid flow through facing a stock solution. In this ion exchange column 21, a fixed packing chamber 24 that is filled with an ion exchange resin 22 so as to form a fixed packed bed 23 as a fixed bed in the column, and the ion exchange resin 22 is extracted upward from the fixed packing chamber 24. The backwashing chamber 25 for backwashing the ion exchange resin 22 in the fixed filling chamber 24 is partitioned by the eyeplate 26, and the mutual ion exchange resin between the fixed filling chamber 24 and the backwashing chamber 25 is A communication pipe 28 is provided for performing the transfer through the valve 27. In the backwash chamber 25, the ion exchange resin in the backwash chamber 25 is locally injected into the backwash chamber 25 to form a water flow in the backwash chamber 25 to fluidize the ion exchange resin. Resin fluidizing means is provided. In this embodiment, a fluidized water supply pipe 30 for locally injecting water to form a swirl flow 29 in the backwash chamber 25 is provided as a resin fluidizing means.

  In the present embodiment, in the water flow step (FIG. 4A), the water to be treated is introduced from the upper side in a downward flow to be treated water while the amount of ineffective resin on the eye plate 26 is extremely small. In the backwashing step and the resin filling step after backwashing (FIG. 4B), the swirling flow 29 is formed in the backwashing chamber 25 by the flowing water supplied from the flowing water supply pipe 30, and the resin is fluidized. In this state, the resin is backwashed, and the washed resin is transferred into the fixed filling chamber 24 via the communication pipe 28 by the resin transfer water supplied from above. The transfer water may be discharged downward from the fixed filling chamber 24.

  The ion exchange column according to the present invention can take the following various forms in addition to the configuration of the first embodiment. For example, as shown in FIG. 5 showing an ion exchange tower 31 according to the second embodiment of the present invention, water to be treated is introduced from an upper space of a fixed filling chamber 33 that forms a fixed packed bed 32 of ion exchange resin, Above this, a backwashing chamber 34 may be provided in the form of a separate chamber, and a communication pipe 36 for transferring the ion exchange resin between the fixed filling chamber 33 and the backwashing chamber 34 via a valve 35 may be provided. As in the first embodiment, a water flow is formed in the backwashing chamber 34 by locally injecting the ion exchange resin in the backwashing chamber 34 into the backwashing chamber 34. A fluid water supply pipe 37 is attached as a resin fluidizing means capable of fluidizing the ion exchange resin. In this configuration, the treated water is discharged from the lower portion of the fixed filling chamber 33, and the backwash drainage is discharged through the backwash drain outlet pipe 38 connected to the upper portion of the backwash chamber 34.

  Further, the ion exchange tower according to the present invention has a configuration in which another resin chamber is interposed between the fixed filling chamber and the backwashing chamber, and a mode in which the other resin chamber is provided above the backwashing chamber. It can be taken. For example, as shown in FIG. 6 which shows an ion exchange tower 41 according to the third embodiment of the present invention, between the fixed filling chamber 43 and the backwash chamber 44 forming the fixed packed bed 42 of ion exchange resin, A second resin chamber 48 as a resin chamber may be provided, and a communication pipe 46 for transferring the ion exchange resin between the fixed filling chamber 43 and the backwash chamber 44 via the valve 45 may be provided. As in the first embodiment, a water flow is formed in the backwashing chamber 44 by locally injecting the ion exchange resin in the backwashing chamber 44 into the backwashing chamber 44. A fluid water supply pipe 47 is attached as a resin fluidizing means capable of fluidizing the ion exchange resin.

  Further, as shown in FIG. 7 showing an ion exchange tower 51 according to a fourth embodiment of the present invention, a fixed filling chamber 53 and a backwash chamber 54 for forming a fixed packed bed 52 of ion exchange resin are provided in the same manner as in the first embodiment. A second resin chamber 58 as another resin chamber is provided above the backwashing chamber 54, and the ion exchange resin is transferred between the fixed filling chamber 53 and the backwashing chamber 54 via the valve 55. A communication pipe 56 may be provided. As in the first embodiment, a water flow is formed in the backwashing chamber 54 by locally injecting the ion exchange resin in the backwashing chamber 54 into the backwashing chamber 54. Thus, a fluidized water supply pipe 57 is attached as a resin fluidizing means capable of fluidizing the ion exchange resin.

  In each of the above embodiments, the fluid water supply pipe for supplying fluid water for fluidizing the resin in the backwash chamber into the backwash chamber is attached to, for example, a lateral portion of the backwash chamber. The flowing water supply pipe is preferably attached in the horizontal direction (perpendicular to the wall surface of the ion exchange tower). When the ion exchange resin in the backwash chamber is a cation exchange resin, the pipe attached to the side part has a flow rate of 1.5 to 5.0 m / sec (preferably 2.0 to 4.0 m / sec), In the case of an anion exchange resin, flowing water is allowed to flow into the backwashing chamber at a flow rate of 0.8 to 4.0 m / sec (preferably 1.5 to 3.0 m / sec) through a pipe attached to the lateral portion. Thus, the flow state of the ion exchange resin is improved, and the ion exchange resin can be transferred to the fixed filling chamber without remaining in the backwash chamber.

  Moreover, as a mounting position of the flowing water supply pipe, for example, it is preferable that the flowing water is arranged so as to generate a swirling flow including a horizontal swirling flow or an oblique component in the backwash chamber. When the swirl flow is generated, it is difficult to form a zone with a low flow velocity (dead zone) in the backwash chamber, the ion exchange resin can be uniformly flowed, and the remaining ion exchange resin can be further reduced. More preferably, it is desirable to arrange in the central portion or tangential direction of the lower backwashing chamber. For example, as shown in FIG. 8 (A), when the flowing water supply pipe 61 is attached to the central portion in the cross section of the backwash chamber 62, a substantially symmetrical swirl flow 63 is generated, which is shown in FIG. 8 (B). As described above, if the flowing water supply pipe 64 is attached in the tangential direction in the cross section of the backwashing chamber 65, one swirling flow 66 is substantially formed in the backwashing chamber 65. However, the method of generating the swirling flow is not limited to these examples.

  The ion exchange resin in the backwash chamber is more or less settled and remains on the partition plate (eye plate) with the fixed filling chamber, so that the height position of the flowing water supply pipe is above the partition plate, For example, it is preferably installed at a position up to 400 mm, more preferably 200 mm or less.

  Further, if the height of the backwash room is increased, it is preferable to install the flowing water supply pipes at a plurality of locations. For example, if the height exceeds 1000 mm, it is desirable to install two or more locations in the height direction. . For example, as shown in FIG. 9, in the ion exchange tower provided with the fixed filling chamber 71, the backwash chamber 72, the raw water inlet pipe 73, the treated water outlet pipe 74, and the communication pipe 75, fluid water is supplied to the backwash chamber 72. The structure which provided the piping 76 in two upper and lower places can be illustrated.

  In addition, if the tower diameter is increased, it is preferable to install a plurality of fluidized water supply pipes in the tower week direction. For example, if the circumference exceeds 5000 mm (1600 mmφ), two or more places are installed in the circumferential direction. desirable. For example, as shown in FIG. 10, when the circumferential length exceeds 5000 mm, it is preferable to provide the flowing water supply pipe 77 at two positions facing the circumferential direction. When the circumferential length exceeds 10,000 mm, 120 degrees in the circumferential direction. It is desirable to have three places on the pitch. The flow velocity of the swirling flow is weaker as it is farther from the injection point along the streamline in the backwash chamber, and is weaker toward the center of the swirling flow. Therefore, it is preferable to employ the above-described structure.

  In a regenerative two-bed / three-column ion exchange apparatus (cation exchange tower-decarboxylation tower-anion exchange tower), if the cation exchange tower where turbidity accumulates is backwashed, the resin layer is disturbed. If it is not used in an amount of about 3 times, high-purity treated water such as 0.1 to 0.5 μS / cm cannot be obtained, so backwashing is preferably performed as little as possible, but the turbidity in the raw water is Accumulate in the ion-exchange resin layer and backwash as appropriate so that the differential pressure in running water increases and the flow rate decreases, or the differential pressure during passing the medicine increases during regeneration and the flow rate of the regenerative chemical does not decrease. It is desirable. That is, during normal operation, high-purity water quality can be obtained by operating without backwashing (so that the resin flow in the fixed filling chamber is as small as possible). The present invention can be applied to either an upward circulation water upward flow regeneration system as shown in FIG. 11 or an ion exchange tower of an upward circulation water downward flow regeneration system as shown in FIG. FIG. 11 shows a water flow process in which the ion exchange tower shown in FIG. 4 is changed to the upward circulation water downward flow regeneration system.

  The present invention can be applied to any counter-current ion exchange tower, and is particularly suitable for an ion exchange tower in a pure water production apparatus.

It is a schematic block diagram of the conventional ion exchange tower. It is a schematic block diagram of another conventional ion exchange tower. It is a schematic block diagram for demonstrating the problem in the conventional ion exchange tower. It is a schematic block diagram of the ion exchange tower which concerns on the 1st embodiment of this invention. It is a schematic block diagram of the ion exchange tower which concerns on the 2nd embodiment of this invention. It is a schematic block diagram of the ion exchange tower which concerns on the 3rd embodiment of this invention. It is a schematic block diagram of the ion exchange tower which concerns on the 4th embodiment of this invention. It is a cross-sectional view of the backwashing room which illustrated the swirl flow in this invention. It is a schematic see-through perspective view of an ion exchange tower showing an example when a plurality of fluid water supply pipes are provided in the present invention. It is a schematic see-through | perspective perspective view of the ion exchange tower which shows another example at the time of providing multiple fluidized water supply piping in this invention. It is a schematic block diagram at the time of changing the ion exchange tower of FIG. 4 to an upward circulation water downward flow regeneration system.

Explanation of symbols

21, 31, 41, 51 Ion exchange tower 22 Ion exchange resin 23, 32, 42, 52 Fixed packed bed 24, 33, 43, 53 Fixed packed chamber 25, 34, 44, 54 Backwash chamber 26 Plate 27, 35 , 45, 55 Valves 28, 36, 46, 56 Communication pipe 29 Swirling flow 30, 37, 47, 57 Flowing water supply pipe 38 as resin fluidizing means Backwash drain outlet pipe 48, 58 Second resin chamber 61, 64 Fluidized water supply pipes 62, 65 Backwash chambers 63, 66 Swirl 71 Fixed filling chamber 72 Backwash chamber 73 Raw water inlet pipe 74 Treated water outlet pipe 75 Communication pipes 76, 77 Fluidized water supply pipe

Claims (5)

  A countercurrent ion exchange tower that regenerates the ion exchange resin by passing the stock solution to obtain a treatment liquid and passing the regenerative liquid to face the stock solution so as to form a fixed bed in the tower. The fixed filling chamber for filling the exchange resin, the backwashing chamber for backwashing the ion exchange resin in the fixed filling chamber by drawing the ion exchange resin upward from the fixed filling chamber, and the fixed filling chamber and the backwashing chamber. In an ion exchange tower equipped with a communication pipe that transfers the ion exchange resin through a valve, backwashing is performed by locally injecting water into the backwashing chamber with ion exchange resin in the backwashing chamber. An ion exchange tower characterized in that a resin fluidization means capable of fluidizing an ion exchange resin by forming a water flow in a room is attached.   The ion exchange tower according to claim 1, wherein at least a part of the injected water is used as water for transferring a resin from the backwashing chamber to the fixed filling chamber.   The ion exchange tower according to claim 1 or 2, wherein the resin fluidizing means comprises means for forming a swirling flow in the backwash chamber.   The ion-exchange tower in any one of Claims 1-3 by which the fixed filling chamber is arrange | positioned through the eyeplate below the backwashing chamber.   The ion exchange tower according to claim 1, wherein the stock solution is passed in a downward flow and the regenerated solution is passed in an upward flow.

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