WO2014195831A1

WO2014195831A1 - Ion exchange resin container and method for treatment of a liquid

Info

Publication number: WO2014195831A1
Application number: PCT/IB2014/061799
Authority: WO
Inventors: Valiyambath Krishnan MOHANKUMAR.; Lanying Ji; David Jeanson; Ma NOBLEZA; Wee Ann Chong
Original assignee: Koninklijke Philips N.V.
Priority date: 2013-06-07
Filing date: 2014-05-29
Publication date: 2014-12-11
Also published as: CN205731286U; DE212014000137U1; RU171984U1

Abstract

The present invention relates to an ion exchange resin container, which is filled with resin beads, and which comprises an inlet through which the liquid to be treated flows into the ion exchange resin container, and an outlet through which the treated liquid flows out of the ion exchange resin container. The ion exchange resin container is made of a flexible sheet material, and the ion exchange resin container is able to collapse under a negative pressure at the outlet to enable the close contact of resin beads with the ion exchange resin container. With the ion exchange resin container, the liquid can be treated effectively and the resin can be utilized efficiently. The use of the ion exchange resin container as a package for shipment and/or storage of resin beads, as well as a method for treatment of a liquid, has also been disclosed.

Description

ION EXCHANGE RESIN CONTAINER AND METHOD FOR TREATMENT OF A LIQUID

FIELD OF THE INVENTION

The invention relates to the field of treatment of a liquid, and particularly to an ion exchange (IEX) resin container and a method for treatment of a liquid. BACKGROUND OF THE INVENTION

IEX resin is widely used for treatment of liquid, for example, to remove undesired ions, either cations or anions, or both, from water. IEX resin also finds applications in domestic appliances, such as steam irons, irons with separate steam generators, steamers, vacuum cleaners with steam generators, drinking water jugs, etc. In these applications, IEX resin is used to remove minerals from water so as to reduce the amount of scale when water is heated up to boil or to steam. If not handled properly, scaling may cause a lot of problems in these appliances, like less efficient heat transfer, clogging of flow path, discharge of scale particles and shorter product lifetime.

IEX resin becomes saturated or exhausted after certain amount of liquid treatment, and needs to be regenerated or replaced. In industrial applications, resin is usually regenerated by using chemicals such as salt, acid or alkaline under precise control by skilled users.

In domestic applications, normally, IEX resin is contained in a hard plastic cartridge. The cartridge itself is normally then sealed inside an aluminized film bag to prevent resin degradation due to exposure to sunlight or air. To replace the IEX resin, usually users have to discard the exhausted resin, the cartridge and the aluminized film bag, which is costly and not environmentally friendly. On the other hand, to only replace the resin, users have to deal with loose resin beads of a diameter as small as about 0.3 mm, which is messy and not convenient. In the course of water treatment, the resin undergoes volume change. While some types of IEX resins swell as water treatment progresses, a few other types shrink upon use. For the IEX resins of the type that swell upon use, normally, a free volume is provided in the hard casing cartridge to accommodate the volume expansion. As the resin beads are initially loosely packed, there is insufficient water-bead contact resulting in lower treatment effectiveness. In order to resolve this issue, normally, the cartridge is made larger or longer with more resin filled in. Alternatively, the water flow direction is restricted to a top-to- bottom flow design, limiting design freedom. In the case of IEX resins that shrink upon use, the resin bead packing becomes loose upon use, and the water quality deteriorates fast due to insufficient water contact. In order to resolve this issue, addition of water-swellable agents is known; the water swellable agents expand in volume by absorbing water and keep the resin beads in packed condition even though they shrink. In both the cases, the solutions are relatively more expensive.

US publication No. : US3180825, published on April 27, 1965, describes a filter for fluid treatment in industrial applications. The filter comprises an outer hard casing containing an inner flexible casing. The filtration bed is contained in the inner flexible casing. A variable volume chamber is hydraulically or pneumatically provided between the flexible casing and the hard casing, so that an external pressure is exerted on an outer surface of the flexible casing to keep the material of the filtration bed in a compact condition.

In domestic applications, a mesh bag is proposed for replacement of resin. The resin beads together with the mesh bag are inserted in a hard plastic cartridge. To make insertion into the hard plastic cartridge easy, the mesh bag is typically made slightly smaller. As the mesh bag does not make full contact with the hard casing throughout, water finds an easy path to flow through the hard plastic cartridge and consequently, the resin is not fully utilized. For example, water may leak past or short-circuit around the mesh bag. Instead of pressing through the resin beads, the water flows through the gap between the hard plastic cartridge wall and the mesh bag. Thus water is not treated effectively, and also, the resin is not utilized fully.

In both cases, the hard casing renders a complicated and costly system. There is a need in the art for solutions that would enable to efficiently utilize the IEX resin and conveniently replace the IEX resin in a simple manner. SUMMARY OF THE INVENTION

It is an object of the invention to at least partly overcome the problems of the prior art, and to provide an improved IEX resin container and a method for treatment of a liquid.

This and other objects of the invention that will be apparent from the following description are achieved by means of an IEX resin container, the use of the IEX resin container, and a method for treatment of a liquid according to the appended claims.

According to a first aspect of the invention, it is disclosed an ion exchange resin container which is filled with resin beads, and which comprises an inlet through which the liquid to be treated flows into the ion exchange resin container, and an outlet through which the treated liquid flows out of the ion exchange resin container, wherein the ion exchange resin container is made of a flexible material, preferably a flexible sheet-like material, and wherein the ion exchange resin container is able to collapse under a negative pressure at the outlet, thus shrinking the overall size to conform to the resin volume, thus enabling the close contact of resin beads with the ion exchange resin container. Thereby, the liquid to be treated is forced to flow through the resin beads. There is no void between beads and container available for the liquid to take short-cut. Thus, the liquid is treated effectively and the resin is utilized efficiently. In the course of water treatment, the ion exchange resin undergoes a volume change, some types expand and other types shrink as water treatment progresses. As the resin container is flexible and is able to collapse under negative pressure, both the types of ion exchange resins, those that expand as well as those which shrink upon use, are easily accommodated and always kept conformed to resin volume during use, whereby, the liquid to be treated is forced to flow through the resin beads. This results in maximal effectiveness and efficiency in water treatment. In this manner, an ion exchange resin container, which is simple in structure and low in cost, can be achieved.

In embodiments of the invention, the flexible sheet may be selected from materials that are substantially impermeable to light and/or gas. These selected materials prevent shortening of shelf life of the resin, without requiring additional protective packaging. This further has the benefit of reducing the waste disposal of packaging materials and plastic, and thus is more environmentally friendly.

In embodiments of the invention, the flexible sheet is selected from materials that are sealable, preferably by heating, or friction welding. Thus, the ion exchange resin container may be fabricated in a relatively simple and cost effective process. Besides, an airtight sealing can be easily realized for the ion exchange resin container.

In embodiments of the invention, the sheet material may comprise a metallic layer. Preferably, an aluminized layer is used because it is impermeable to light, air, carbon dioxide, and water moisture. Other alternative metallic films, like copper film and zinc film, can also be used. The metallic layer is coupled with plastic film.

Embodiments of the flexible sheet are combination of metallic film with polymeric film; such as polyethylene, polypropylene, polyester, etc., to enhance the mechanical strength.

The flexible sheet may be selected from an elastomeric material iiiatjs substantially

impermeable to light and/or gas.

In embodiments of the invention, the ion exchange resin container may be provided with internal divisions to create a longer flow path and a smaller flow cross area.

The resin column is preferably as slim as possible, so as to have an optimum performance of resin. To this end, one or more internal division is created to increase the length of liquid flow path and reduce the flow cross area. Besides, this also gives more flexibility for the selection of height, length and width of the resin container, for a certain amount of resin beads. These internal partitions can be created by sealing the opposite sheets to form channels.

In embodiments of the invention, the inlet and/or outlet may be provided with a filter to avoid leakage of resin beads through the inlet and/or outlet. The filter, for example, can be mesh, sponge, fabric, filter paper or other porous material. Preferably, the filter may be a mesh. The size of the mesh or pores is such that no resin bead is allowed to seep outside the ion exchange resin container, e.g. to seep into a connection tube which is connected to a pump.

In embodiments of the invention, the resin beads may be at least one of a cationic or anionic ion exchange resin for treatment of water or aqueous solution. Resin described herein is not limited to mixed bed resin. The resin can be of any type, as long as it is replaceable and is used in a liquid medium. Preferably, additives for example, activated carbon or odorizing/de-odorizing agent may be provided inside the resin bag along the water path. Preferably, the additives may be fixated as a thin layer to the resin bag wall by means of a deposition process or by means of chemical or physical or heat bonding. For ease of processing, the additives may be pre-fixated to the resin bag material when the bag material is in the raw sheet material state (prior to manufacture of the bag).

According to an embodiment of the invention, the foregoing ion exchange resin container can be used as a package for resin beads. Thereby, the hard-case plastic cartridge as commonly used in the art is eliminated. Product details and instructions for use may be printed on the resin bag itself. As mentioned above, the ion exchange resin container is able to protect resin beads from exposure to sunlight and air during shipment and storage. This reduces the waste disposal of packaging materials and plastic, and thus is more

environmentally friendly.

According to a second aspect of the invention, it is disclosed a method for treatment of a liquid by using an ion exchange resin container, which is filled with resin beads, and which comprises an inlet through which the liquid to be treated flows into the ion exchange resin container, and an outlet through which the treated liquid flows out of the ion exchange resin container, wherein the ion exchange resin container is made of a flexible sheet material, wherein during treatment of a liquid, a negative pressure is produced at the outlet, so that the liquid to be treated flows through the ion exchange resin container in a state in which resin beads are in close contact with the ion exchange resin container. According to

embodiments of the method of the present invention, the liquid to be treated is forced to flow through the resin beads. There is no void available for the liquid to take short-cut. Thus, the method for treatment of a liquid can treat the liquid effectively and utilize the resin efficiently.

In a preferred embodiment, the inlet and/or outlet may be provided with an air-tight sealing that prevents degradation of the resin during storage. The sealing may be removed or punctured prior to usage of the resin container, or preferably, it is punctured when the resin container is inserted in the appliance (which is provided with puncturing means, for example, a sharp protrusion or a knife edge like structure) allowing water to flow through the resin container for treatment during operation. In a further embodiment, the seal is formed by the resin container itself, wherein the inlet or outlet is embedded at the designated portions inside the resin container during manufacturing. This way, a separate sealing is avoided, simplifying operations and reducing cost.

The conventional resin beads in a loose form may be applied to the ion exchange resin container according to embodiments of the present invention. Alternatively, the resin beads may be bonded by a binder into a block form of certain shape and size according to need. The resulting one-piece resin block is packed into the resin container. The resulting resin container, having the advantage of shape and dimensional stability, can be easily inserted into the receiving portion of the appliance to replace the exhausted resin bag.

In a further embodiment, the binder is selected from a water soluble polymer. Once water starts flowing through the resin container, the binder dissolved, and the beads become loose, and the resin container becomes soft and flexible, retaining the operational advantages mentioned earlier.

In embodiments of the invention, the binder may be any one or any combination of the following: synthetic polymer, a natural polymer, or a modified natural polymer. In preferred embodiments, polyacrylamide, polyvinyl alcohol, starch, synthetic starch, modified cellulose, or any other types of polyacid, polyelectrolyte may be used. For example, carboxy-methyl-cellulose sodium (CMC-Na), hydroxyl-propyl-cellulose (UPC), or methyl cellulose (MC) may be used as the modified natural polymer. Starch and cellulose may be used as the natural polymer.

In embodiments of the invention, the resin beads in a block form may be prepared by mixing an aqueous solution of the binder with resin beads, molding it into a required shape and size and drying out the mixture of the aqueous solution and resin beads. According to the present invention, the resin block may be fabricated in a simple manner.

In embodiments of the invention, the concentration of the binder in the aqueous solution may be between 0.1 wt% and 20 wt%, preferably 8 wt%. With these concentrations, the mixture is flowable and neither too thin nor too thick. Further, it is possible to ensure the quick release of the bonding polymer and thus the efficiency of resin beads.

It is noted that the present invention relates to all possible combinations of features recited in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention will now be described in more detail, with reference to the appended drawings showing embodiment(s) of the invention.

Fig. 1 shows a first example of an ion exchange resin container according to the invention. Fig. 2a shows a second example of an ion exchange resin container according to the invention.

Fig 2b shows a third example of an ion exchange resin container according to the invention.

Fig. 3 shows a first example of a resin block according to the invention.

Fig. 4 shows a second example of a resin block according to the invention. Fig. 5 shows the conductivity measurement on water treated by a resin block of the invention.

DETAILED DESCRIPTION OF THE INVENTION

As illustrated in the figures, the sizes of layers and regions are exaggerated for illustrative purposes and, thus, are provided to illustrate the general structures of embodiments of the invention. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. Like reference numerals refer to like elements throughout.

Reference is made to Figs. 1, 2a, 2b, in which the first, second, and third examples of an ion exchange resin container of the invention are described, respectively.

In an embodiment of the invention shown in Fig. 1, the replaceable ion exchange resin container 100 comprises an inlet 101, an outlet 102, and ion exchange resin beads 103. The inlet 101 and/or the outlet 102 can be provided with a sealing (not shown) to prevent degradation of the resin during storage. Preferably, a connection tube 106 is attached to each of the inlet 101 and the outlet 102, respectively. A filter 104 may optionally be attached to each of the connection tube 106. Size of the filter 104 is selected so that no resin bead is allowed to seep into the connection tube, which may be connected to a pump (not shown).

Air-tight sealing must be ensured in every joint area or joint point. In an embodiment, the ion exchange resin container 100 is made of a flexible sheet material.

Accordingly, sealed areas 105 may be developed preferably by heating, gluing, metal-wire soldering, or welding. The sealed areas 105 provide air-tight sealing for the ion exchange resin container 100.

During usage, the ion exchange resin container 100 is connected via the connection tubes 106 to a pump at the outlet 102 and a water tank to at the inlet 101. When the pump starts to work, the ion exchange resin container 100 is under lower pressure than ambient pressure. The ion exchange resin container 100 starts to collapse and compress the resin beads 103 inside it. Thus, the water is forced to flow through the resin beads 103. No void is available for water to take short-cut. In this manner, the water can be treated

effectively and the resin can be utilized efficiently.

The ion exchange resin container 100 is preferably made of aluminized film. It serves two purposes. One purpose is to hold resin beads 103 for water treatment. Another purpose is to serve as a package for shipment and storage. Aluminized film is non-permeable to sunlight and non-permeable to air. In this way, the ion exchange resin container 100 protects resin from exposure to sunlight and air, and thus ensures the shelf life of resin.

The aluminized film consists of layers of plastic film on both sides. The plastic films ensure that the Aluminized film is heat sealable. It also strengthens the aluminized film such that it is not easily torn. Such flexible materials are commonly used in liquid packaging and food packaging. The plastic film can be polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), or other types of materials. Alternatively, an elastomeric material can be used.

A solid connection tube 106 may be inserted into the ion exchange resin container 100 and sealed on the inlet/outlet 101, 102. To prevent resin beads 103 from leaking into the water delivery system, the filter 104 may be sealed to one end of the connection tube 106. The mesh size of the filter 104 depends on the requirement of the water delivery system.

Normally the bead size is from 0.3 mm to 1.2 mm. The mesh size has to be as low as 0.3 mm. If the delivery is critical on finer particles, even smaller mesh size can be considered. The mesh can be as small as 40 μπι, or even smaller, like 20 μπι, if a filter paper is used. The mesh should have sufficient strength to resist the pump suction strength.

A second example of the ion exchange resin container 200 is shown in Fig. 2a.

As illustrated, an internal division 207 is added to optimize the performance of resin in terms of better output water quality and higher resin capacity utilized. To have an optimum performance of resin, the resin column is preferably as slim as possible. To do so, the internal division 207 is created to increase the length of water flow path and reduce the flow cross area. This also gives design freedom for certain amount of resin, namely, the selection of height, length and width of the resin block. The internal division 207 shown in Fig. 2a is only exemplary. The number and shape of the internal division 207 can be envisaged by the skilled in the art. The internal division may for example be created by a similar process as used for sealing the resin container.

A third example of the ion exchange resin container 200' is shown in Fig. 2b.

As compared with Fig. 2a, the resin container 200' in Fig. 2b is modified in the inlet and outlet. In this example, the inlet and outlet 20 Γ, 202' are embedded inside the resin container 200'. The resin container 200' can form at least a part of the sealing for the inlet and outlet 20Γ, 202'. As an example shown at 208, the inlet and outlet 20Γ, 202' is sealed by the resin container 200' itself. Prior to or during insertion of the resin container 200' onto an appliance, the resin container 200' is pierced at positions corresponding to the inlet and outlet 20 , 202', so that is possible to make fluid connections 208' to and from the resin container 200'.

Reference is made to Figs. 3-5 to describe a resin block according to the invention. Fig. 3 shows a first example of a resin block 310: (a) as produced before placing in resin container, on the left side, and (b) after water flows through the resin container, on the right side. Fig. 4 shows a second example of a resin block 410: (a) as produced before placing in resin container, on the left side, and (b) after water flows through the resin container, on the right side. Fig. 5 shows the conductivity measurement on water treated by the resin block 310 shown in Fig. 3. In Fig. 5, the horizontal axis represents the amount of hard water (16.8 dH German) in Liters, and the vertical axis represents the conductivity of treated water in μ8/αη.

A mould (not shown) is made according to the dimension of the cartridge that the resin block is supposed to be inserted for water treatment. For example, water-soluble polymers 311 are dissolved in DI water under constant stirring. Depending on the type of polymer, molecular weight of the polymer, viscosity of the aqueous solution, the

concentration varies, from 0.01 wt% to 20 wt%, preferably 8 wt%. To ensure the quick release of the binder (bonding polymer) 311 and thus the efficiency of resin beads 303, the molecular weight and concentration are preferred to be as low as possible, as long as the bonding strength is enough. Resin beads 303 are mixed with the polymer solution under stirring. The mixture should not be too thin, like water. It should also not be too thick and hard to flow, like butter. The mixture should be fluid enough to allow easy pouring into the mould. When the mixture is poured into the mould, it should also not have phase separation. It should be able to be solidified or dried at a slightly elevated temperature, say, 50 °C. For resins, which are able to resist high temperature, the drying temperature can be higher than 50 °C. After the mixture is solidified, the resin block 310 is released from the mould, as shown on the left side of Fig 3. The resin block 310 is packed in the resin container 312, preferably under vacuum, to ensure the shelf life of resin.

As shown on the right side of Fig. 3, when the resin block 310 is inserted in the resin container 312 and water flow into/out of the resin container 312 via the inlet/outlet 301, 302, the binder 311 and resin beads 303 start to absorb water. The beads are loosened and the initial gap between the wall of the resin container 312 and the resin block 310 disappears. Water is pressed through pores of the resin beads 303. Tests showed that the treated water quality is comparable to that treated with normal loose resin beads. The effective amount of treated water is also comparable to that of normal loose resin beads.

In a second example of the resin block 410 shown in Fig. 4, the above mentioned binder is applied in the inner wall of the mould. Resin beads 403 are filled in the mould. The resin beads 403 are dried under temperature not more than 50 °C for several hours till the resin block 410 is able to be released from the mould. As a result, the resin beads 403 are bonded by the binder 411 only on the outer surface of the resin block 410.

As shown on the right side of Fig. 4, when the resin block 410 is inserted in the resin container 412 and water flow into/out of the resin container 412 via the inlet/outlet 401, 402, the binder 411 is dissolved at least partially and resin beads 403 are loosened.

Resins described in the present invention are not limited to mixed bed resin. It can be any type of resin, as long as it is replaceable and is used in water medium. The resin container may be provided with other additives, like activated carbon or de- odorizing/odorizing chemicals, for additional functions. These may be applied as a layer on the resin container material on the side facing the resin.

The binder can be a water-soluble polymer, e.g. polyacrylamide, polyvinyl alcohol, starch, synthetic starch, modified cellulose, or any other types of polyacid, polyelectrolytes. These polymers are soluble in water. The resin block is moulded in the dimension of the cartridge. The water is allowed to flow through the void between beads, and the pores inside the resin beads. Once in contact with water, polymer starts to dissolve. The beads loosen and rearrange such that it is able to fill up the gap between the original resin block and the cartridge wall. The binder covering the outer surface of resin block is removed gradually with water flow. Test is conducted to verify the efficiency of the resin block 410 shown in Fig. 3. 15 cc mixed bed resin is moulded from a syringe. The standard hard water, with German hardness of 16.8 dH, is flowing through the resin column in a syringe by gravity. Treated water is collected and conductivity is measured for every 1 liter, until the resin column color is fully changed from original blue to brown. The full color change indicates the exhaustion of resin. The test result is shown in Fig. 5. The total effective amount of water is 4.2 L. The treated water conductivity remains low, below 50 μ8/αη. These results are comparable to those of the loose resin beads. No reduction in performance is observed, either in water quality or in water amount.

The invention also relates to a method for treatment of a liquid by using an ion exchange resin container as described. During treatment of a liquid, a negative pressure is produced at the outlet, so that the liquid to be treated flows through the ion exchange resin container in a state in which resin beads are in close contact with the ion exchange resin container.

In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements. In the device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Reference numerals in drawings:

100: ion exchange resin container

101 : inlet

102: outlet

103 : ion exchange resin beads

104: filter

105: sealed area

106: connection tube

200: ion exchange resin container 201 : inlet

202: outlet

203 : ion exchange resin beads

204: filter

205: sealed area

206: connection tube

207: internal division

200': ion exchange resin container

201^*: inlet

202': outlet

208: sealing

208': fluid connections

301 : inlet

302: outlet

303 : resin beads

310: resin block

311 : binder

312: ion exchange resin container 401 : inlet

402: outlet

403 : resin beads

410: resin block

411 : binder

412: ion exchange resin container.

Claims

CLAIMS:

1. An ion exchange resin container (100, 200, 200', 312, 412), which is filled with ion exchange resin beads (103, 203, 303, 403), and which comprises an inlet (101, 201, 20Γ, 301, 401) through which the liquid to be treated flows into the ion exchange resin container, and an outlet (102, 202, 202', 302, 402) through which the treated liquid flows out of the ion exchange resin container,

wherein the ion exchange resin container is made of a flexible material, and wherein the ion exchange resin container is able to collapse under a negative pressure at the outlet, thus shrinking the overall size to conform to the resin volume, to enable the close contact of resin beads with the ion exchange resin container.

2. The ion exchange resin container of claim 1, wherein the flexible material is preferably a sheet and substantially impermeable to light and/or gas.

3. The ion exchange resin container of claim 1, wherein the flexible material is sealable, preferably by heating, or friction welding.

4. The ion exchange resin container of claim 1, wherein the flexible material comprises a metallic layer, preferably an aluminized layer.

5. The ion exchange resin container of claim 1, wherein the ion exchange resin container is provided with internal divisions (207) to create a longer flow path and a smaller flow cross area, said divisions being created by sealing opposite sheets of the ion exchange resin container.

6. The ion exchange resin container of claim 1, wherein the inlet and/or outlet is provided with a filter (104, 204) to avoid leakage of resin beads through the inlet and/or outlet.

7. The ion exchange resin of claim 1, wherein the inlet and outlet are provided with sealings (208) to prevent degradation of the resin during storage.

8. The ion exchange resin of claim 7, wherein the inlet and/or outlet is embedded inside the ion exchange resin container, and the ion exchange resin container itself forms at least a part of the sealing, and wherein the ion exchange resin container is pierced at the inlet and/or outlet portions prior to or during insertion of the ion exchange resin container onto an appliance to make fluid connections to and from the ion exchange resin container.

9. The ion exchange resin container of claim 1, wherein the internal surface of the ion exchange resin container is covered with an additive layer, for instance, activated carbon or de-odorizing/odorizing agent.

10. The ion exchange resin container of claim 1, wherein the resin beads are in a block (310, 410) form bound by a binder (311, 411).

11. The ion exchange resin container of claim 10, wherein the binder is water- soluble, for instance, polyacrylamide, polyvinyl alcohol, starch, synthetic starch, modified cellulose, or any other types of polyacid, polyelectrolytes.

12. A method for treatment of a liquid by using an ion exchange resin container (100, 200, 200', 312, 412), which is filled with resin beads (103, 203, 303, 403), and which comprises an inlet (101, 201, 20Γ, 301, 401) through which the liquid to be treated flows into the ion exchange resin container, and an outlet (102, 202, 202', 302, 402) through which the treated liquid flows out of the ion exchange resin container, wherein the ion exchange resin container is made of a flexible sheet material,

wherein during treatment of a liquid, a negative pressure is produced at the outlet, so that the liquid to be treated flows through the ion exchange resin container in a state in which resin beads are in close contact with the ion exchange resin container.