WO2013068906A1

WO2013068906A1 - An ion exchanger and method of exchanging ions

Info

Publication number: WO2013068906A1
Application number: PCT/IB2012/056161
Authority: WO
Inventors: Guangwei Wang; Peixin Hu; Mei Shi
Original assignee: Koninklijke Philips Electronics N.V.
Priority date: 2011-11-10
Filing date: 2012-11-05
Publication date: 2013-05-16

Abstract

The present invention provides an ion exchanger and a corresponding method of ion exchange. The ion exchanger may comprise: a first electrode and a second electrode, a surface of the first electrode being coated with a first ion exchange material, the first ion exchange material comprising ions I_1A; a power supply being electrically connected with both the first electrode and the second electrode; wherein the first electrode coated with the first ion exchange material and the second electrode are to be inserted into an electrolyte solution for exchanging ions I_1A with ions I_3A comprised in the electrolyte solution; a voltage controller for controlling a voltage to be applied by the power supply to the first electrode and the second electrode according to data reflecting the requirement of the ion exchange. By way of the above design of the present invention, the velocity and the degree of the ion exchange in an electrolyte solution can be quantitatively controlled, i.e. it is made possible to exchange a target ion in the electrolyte solution in a desired concentration, thereby achieveing control of the ion exchange.

Description

AN ION EXCHANGER AND METHOD OF EXCHANGING IONS

FIELD OF THE INVENTION

The present invention generally relates to the field of ion exchange, and specifically to an ion exchanger and a method of exchanging ions.

BACKGROUND OF THE INVENTION

Ion exchange has been widely used in a number of fields, such as food & beverages, hydrometallurgy, metals finishing, chemical & petrochemical industry, pharmaceutical industry, sugar & sweeteners, ground & potable water, nuclear industry, softening & industrial water, semiconductors, power, etc..

The basic reaction mechanism of a current ion exchanger may be as described below. Let it be assumed that the ion exchanger uses an ion exchange material, such as an ion-exchange resin, that has greater affinity for ion B than for ion A. If the ion exchange material contains ion A, and meanwhile, ion B is dissolved in the water passing through the ion exchange material, then the following exchange takes place (E represents the ion exchange material):

AE + B^n± BE + A^n±

Because the ion exchange reaction depends on the affinity of the ion exchange material for ions, this means the exchange reaction will take place spontaneously and in one direction only when the exchangeable ions, e.g. ion B, contact the ion exchange material E until the exhaustion of the ion exchange material or the running out of ions. This natural process cannot be controlled now. However, for a lot of different ion-exchange applications, it is required to maintain the level of concentration of ions in solutions, like controlling pH in water, sweetness in beverages and strict composition control in pharmacy; therefore, this uncontrollable ion exchange causes many problems. Thus, there is an urgent need in the prior art to solve the above technical problems.

OBJECT AND SUMMARY OF THE INVENTION

In view of this, the present invention provides an improved ion exchange solution which is capable of solving or at least alleviating at least a part of the defects present in the prior art.

According to a first aspect of the present invention, an ion exchanger is provided, which may comprise:

- a first electrode and a second electrode, a surface of the first electrode being coated with a first ion exchange material, the first ion exchange material comprising ions I_IA;

- a power supply being electrically connected with both the first electrode and the second electrode;

wherein the first electrode coated with the first ion exchange material and the second electrode are to be inserted into an electrolyte solution for exchanging ions I_IA with ions I_3A comprised in the electrolyte solution;

- a voltage controller for controlling a voltage to be applied by the power supply to the first electrode and the second electrode according to data reflecting the requirement of the ion exchange.

According to an embodiment of the present invention, a surface of the second electrode may be coated with a second ion exchange material, the second ion exchange material comprising ions I_2A, the electrolyte solution further comprising I_4A.

According to another embodiment of the present invention, the controlling of the voltage to be applied to the first electrode and the second electrode may further comprise adjusting the voltage according to data reflecting the requirements with respect to velocity and/or degree of the ion exchange.

According to a further embodiment of the present invention, the ion exchanger may further comprise: - a timer for timing the duration of applying the voltage to the first electrode and the second electrode.

According to an embodiment of the present invention, the ion exchanger may further comprise:

- a user interface for receiving the data reflecting the requirement of the ion exchange, wherein said data corresponds to at least one of the following data types:

- the voltage to be applied;

- the type of the electrolyte solution;

- the expected ion exchange velocity;

- the expected ion exchange degree.

According to another embodiment of the present invention, the ion exchanger may further comprise:

- a memory for storing a list of values for each type of data and the relations between the voltage values and the values of other types of data.

The ion exchanger according to the present invention may be applied in fields like water softening, water purification, catalysis production, juice purification, sugar manufacturing, pharmaceutical manufacturing, and so on.

According to a second aspect of the present invention, a method of exchanging ions is provided, comprising:

- setting a voltage to be applied to a first electrode and a second electrode of an ion exchanger according to data reflecting the requirement for ion exchange, wherein a surface of the first electrode is coated with a first ion exchange material comprising ions I_IA ;

- inserting the first electrode and the second electrode into an electrolyte solution comprising ions I_3A SO as to enable ion exchange between the ions I_IA and the ions I_3A;

- applying the set voltage to control the ion exchange process.

According to an embodiment of the present invention, a surface of the second electrode is coated with a second ion exchange material comprising ions I_2A and the electrolyte solution further comprises ions I_4A, and wherein the ion exchange between ions I_2A and ions I_4A is controlled by the set voltage.

According to another embodiment of the present invention, the setting of a voltage to be applied to the first electrode and the second electrode comprises adjusting the voltage according to the data reflecting the requirement with respect to velocity and/or degree of ion exchange.

According to a further embodiment of the present invention, it further comprises timing the duration of applying the set voltage to the first electrode and the second electrode.

According to an embodiment of the present invention, it further comprises receiving data reflecting the requirements for ion exchange via a user interface, wherein said data corresponds to at least one of the following data types:

- the voltage to be applied;

- the type of the electrolyte solution;

- the expected ion exchange velocity;

- the expected ion exchange degree.

According to another embodiment of the present invention, it further comprises pre-storing a list of values for each type of data and the relations between the voltage values and the values of other types of data in a memory.

According to still another embodiment of the present invention, the method of the present invention may be applied to fields such as water softening, water purification, catalysis production, juice purification, sugar manufacturing, pharmaceutical manufacturing, etc..

By way of the above design of the present invention, the velocity and the degree of ion exchange in a solution can be quantitatively controlled, i.e. by using the design of the present invention, it is possible to exchange a target ion in the solution in a desired concentration, thereby achieving control of the ion exchange. BRIEF DESCRIPTION OF THE DRAWINGS

Fig.1 A is a schematic view of an ion exchanger according to an embodiment of the present invention.

Fig. IB is a schematic view of an ion exchanger according to another

embodiment of the present invention.

Fig.1C is a schematic view of an ion exchanger according to a further

embodiment of the present invention.

Fig.2A is a schematic structural view of a voltage controller according to an embodiment of the present invention.

Fig.2B is a schematic structural view of a voltage controller according to another embodiment of the present invention.

Fig.3 is a schematic flowchart of a method of exchanging ions according to an embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Next, the present invention will be described in detail with reference to the accompanying drawings and in conjunction with the schematic embodiments of the present invention.

First of all, reference is made to Fig.lA. Fig. lA is a schematic view of an ion exchanger according to an embodiment of the present invention, wherein the ion exchanger 100a as shown may comprise: a first electrode 101 and a second electrode 102, a surface of the first electrode 101 being coated with a first ion exchange material 106 and the first ion exchange material 106 comprising ions I_IA. The first electrode 101 as referred to in the description of the present invention may be either an anode or a cathode. Also, the second electrode 102 as referred to in the description of the present invention may be either an anode or a cathode. The person skilled in the art is aware that in a case where the first electrode 101 is an anode, the second electrode 102 should be a cathode; and in a case where the first electrode 101 is a cathode, the second electrode 102 should be an anode. In the schematic diagrams of Figs. 1A to 1C, it is schematically shown that the first electrode 101 serves as a cathode and the second electrode 102 serves as an anode. Ion exchanger 100a may further comprise a power supply 103 that is electrically connected with both the first electrode 101 and the second electrode 102; wherein the first electrode 101 coated with the first ion exchange material 106 and the second electrode 102 are to be inserted into an electrolyte solution 104a for exchanging ions I_IA with ions I_3A comprised in the electrolyte solution 104a. Ion exchanger 100a may further comprise a voltage controller 105 for controlling the voltage to be applied by the power supply 103 to the first electrode 101 and the second electrode 102 according to data reflecting the requirement for the ion exchange. The data reflecting the requirement for the ion exchange, according to the present invention, corresponds to at least one of the following data types: the voltage to be applied; the type of the electrolyte solution; the expected ion exchange velocity; the expected ion exchange degree. These types of data will be described in detail hereinbelow.

Next, water softening is taken as an example. In the case of water softening, the electrolyte solution 104a may be tap water or underground water or the like, and in the process of ion exchange, the tap water or underground water or the like may be either flowing or stored in a container for some time, wherein the softened water will not be released from the container until after the ion exchange has been completed. In the case of water softening, the first electrode 101 may be a cathode, while the first ion exchange material 106 coating the surface of the first electrode 101 may be an ion-exchange resin comprising Na⁺ ions for example, and the tap water or underground water comprises Mg²⁺ and Ca²⁺ ions. As a certain voltage is applied, when the first electrode 101 operates as a cathode, the ion-exchange resin coating the surface of the first electrode 101 has a high concentration of Na⁺ ions, while Mg²⁺ and Ca²⁺ ions in the tap water or underground water are also high in concentration, and the first electrode 101 has a greater affinity for Mg²⁺ and Ca²⁺ ions than for Na⁺ ions, and accordingly, the Mg²⁺ and Ca²⁺ ions in the tap water or underground water are enabled for ion exchange with the Na⁺ ions in the ion-exchange resin. An ion exchanger according to the present invention may further comprise a timer 108 (with reference to Figs.2A and 2B) for timing the duration of applying the voltage to the first electrode 101 and the second electrode 102 so as to control the velocity and degree of ion exchange. The timer may be integrated into the voltage controller 105 or, alternatively, connected in the circuit as a separate timer, e.g. connected between the power supply 103 and the voltage controller 105 or connected to other positions, so long as it can achieve the object of timing, which is not difficult to understand for the person skilled in the art.

The following Table 1 shows relevant data of Test I conducted by the inventor taking tap water as the electrolyte solution 104a:

Table 1

The above Test I consists of four experiments conducted by the inventor. For example, in a first one of the four experiments, in which the applied voltage is 0V (which means that no voltage is applied to the first electrode 101 and the second electrode 102), it is measured that when the input water hardness is 9.6°d (lmmol/L=2.804°d, lmmol/L is equal to the concentration of l OOmg/L CaC03), given that the first electrode 101 whose surface is coated with the ion-exchange resin (comprising Na⁺ ions) and the second electrode 102 whose surface is not coated with any ion-exchange resin are both inserted into the tap water, the resultant output water hardness after ten minutes is 5.4°d. With the duration of applying the voltage held constant, the inventor conducts the remaining three experiments. For example, in the second experiment, in which the applied voltage is 5V, it is measured that when the input water hardness is 9.6°d, given that the first electrode 101 whose surface is coated with the ion-exchange resin (comprising Na⁺ ions) and the second electrode 102 whose surface is not coated with any ion-exchange resin, are both inserted into the tap water, the resultant output water hardness after ten minutes is 5.4°d. In the third experiment, in which the applied voltage is 10V, it is measured that when the input water hardness is 9.6°d, given that the first electrode 101 whose surface is coated with the ion-exchange resin (comprising Na⁺ ions) and the second electrode 102 whose surface is not coated with any ion-exchange resin are both inserted into the tap water, the resultant output water hardness after ten minutes is 6.1 °d. In the fourth experiment, in which the applied voltage is 15 V, it is measured that when the input water hardness is 9.6°d, given that the first electrode 101 whose surface is coated with the ion-exchange resin (comprising Na⁺ ions) and the second electrode 102 whose surface is not coated with any ion-exchange resin are both inserted into the tap water, the resultant output water hardness after ten minutes is 3.9°d.

It can be seen from a comparison of the four experiments that when a relatively low voltage, e.g. less than or equal to 10V, is applied to the first electrode 101 and the second electrode 102, the output water hardness increases (5.4→6.1) as the voltage increases, because the applied voltage is insufficient to break the dynamic balance established between the Mg²⁺ and Ca²⁺ ions in the tap water and the Na⁺ ions in the ion-exchange resin, which applied voltage, by contrast, attracts the Na⁺ ions more tightly to the ion-exchange resin. When a sufficiently high voltage, e.g. 15V, is applied, it breaks the dynamic balance established between the Mg²⁺ and Ca²⁺ ions in the tap water and the Na⁺ ions in the ion-exchange resin, thus allowing more Mg²⁺ and Ca²⁺ ions for the ion exchange with Na ions, which means more Mg²⁺ and Ca²⁺ ions are attracted to the surface of the ion-exchange resin while more Na⁺ ions enter the tap water, thereby reducing the output water hardness. The above experiment results have proved that the inventor's idea to control ion exchange by controlling the voltage applied by the power supply 103 to the first electrode 101 and the second electrode 102 is tenable. That is, the velocity of the ion exchange may be increased or decreased by controlling the value of the voltage applied by the power supply 103 to the first electrode 101 and the second electrode 102. Also, the degree of the ion exchange may be controlled in addition to the velocity of the ion exchange by timing, via the timer, the duration of applying the voltage to the first electrode 101 and the second electrode 102, which is not difficult to understand for the person skilled in the art. Even if the duration of applying the voltage to the first electrode 101 and the second electrode 102 for each of the four

experiments in Test I is 10 minutes, under the same voltage value of e.g. 15 V, the resultant output water hardness will differ as the duration of applying the voltage to the first electrode 101 and the second electrode 102 changes, because the degree of the ion exchange may be controlled by controlling the duration of applying the voltage, which is not difficult to understand for the person skilled in the art.

The following Table 2 shows relevant data of Test II conducted by the inventor taking tap water as the electrolyte solution 104a:

Table 2

The above Test II consists of another four experiments conducted by the inventor. As compared with the conditions in Test I, the input water hardness in Test II is different but the duration of applying the voltage and the applied voltage values are the same as in Test I. For example, in a first experiment, as the applied voltage is 0V (meaning that no voltage is applied to the first electrode 101 and the second electrode 102), it is measured that when the input water hardness is 10°d, given that the first electrode 101 whose surface is coated with the ion-exchange resin (comprising Na⁺ ions) and the second electrode 102 whose surface is not coated with any ion-exchange resin are both inserted into the tap water, the resultant output water hardness after ten minutes is 5.1°d. With the duration of applying the voltage held constant, the inventor conducts the remaining three experiments. For example, in the second experiment, as the applied voltage is 5V, it is measured that when the input water hardness is 10°d, given that the first electrode 101 whose surface is coated with the ion-exchange resin (comprising Na⁺ ions) and the second electrode 102 whose surface is not coated with any ion-exchange resin are both inserted into the tap water, the resultant output water hardness after ten minutes is 5.2°d. In the third experiment, as the applied voltage is 10V, it is measured that when the input water hardness is 10°d, given that the first electrode 101 whose surface is coated with the ion-exchange resin (comprising Na⁺ ions) and the second electrode 102 whose surface is not coated with any ion-exchange resin are both inserted into the tap water, the resultant output water hardness after ten minutes is 6.0°d. In the fourth experiment, as the applied voltage is 15V, it is measured that when the input water hardness is 10°d, given that the first electrode 101 whose surface is coated with the ion-exchange resin (comprising Na⁺ ions) and the second electrode 102 whose surface is not coated with any ion-exchange resin are both inserted into the tap water, the resultant output water hardness after ten minutes is 3.2°d.

It can be seen from a comparison of the experiment results in Table 2 with the experiment results in Table 1 that since the input water hardness of 10°d in Test II is higher than the input water hardness of 9.6°d in Test I, while the same voltage is applied in Test II and Test I, the Mg²⁺ and Ca²⁺ ions in the tap water are higher in concentration in Test II than they are in Test I, due to the higher input water hardness in Test II, and consequently, while the same voltage and the same duration are applied, more Mg²⁺ and Ca²⁺ ions are enabled for the ion exchange with the Na⁺ ions in the ion-exchange resin, thereby reducing the output water hardness more, e.g. the output water hardness in the fourth experiment in Test I is 3.9°d, while the output water hardness in the fourth experiment in Test II is 3.2°d. Fig.lA illustrates a situation in which a surface of the first electrode 101 (serving as a cathode) is coated with the first ion exchange material 106. Alternatively, in the ion exchanger 100b according to another embodiment of the present invention as shown in Fig. IB, a surface of the second electrode 102 may also be coated with a second ion exchange material 107, wherein the second ion exchange material 107 comprises ions I_2A, and the electrolyte solution 104b further comprises ions I_4A. Fig. IB shows a situation in which the second electrode 102 operates as an anode. For example, in the water purification application, CI^" ions in waste water, for example, may need to be removed. Then the second ion exchange material 107 coating the surface of the second electrode 102 comprises the ions I_2A, such as OH^" ions. Subsequent to inserting the first electrode 101 and the second electrode 102 whose surface is coated with the second ion exchange material 107 into the water, the velocity and the degree of the ion exchange are controlled based on the requirement for removing the CI^" ions such that the CI^" ions (ions I_4A) in a higher concentration in the waste water serving as the electrolyte solution 104b are exchanged with the ions I_2A, such as OH^" ions, comprised in the second ion exchange material 107.

Figs.1 A and IB illustrates a situation where a surface of one of the first electrode 101 and the second electrode 102 may be coated with an ion exchange material. Alternatively, the surfaces of both the first electrode 101 and the second electrode 102 may be coated with ion exchange materials (first ion exchange material 106 and second ion exchange material 107). Such a situation is shown in Fig.lC. Fig.lC is a schematic view of an ion exchanger 100c according to a further embodiment of the present invention. In some applications, e.g. deionized water manufacturing, there may be a need for the surfaces of both the first electrode 101 and the second electrode 102 to be coated with ion exchange materials (first ion exchange material 106 and second ion exchange material 107), such that the ions I_IA comprised in the first ion exchange material 106 are exchanged with at least the ions I_3A comprised in an electrolyte solution 104c, and the ions I_2A comprised in the second ion exchange material 107 are exchanged with at least the ions I_4A comprised in the electrolyte solution 104c, e.g. such that Mg²⁺ and Ca²⁺ ions in an electrolyte solution 104c, such as water, are exchanged with Na⁺ ions in the first ion exchange material 106, and CI^" ions are exchanged with OH^" ions in the second ion exchange material 107.

Alternatively, an ion exchanger according to the present invention may further comprise a user interface 109 (with reference to Figs.2A and 2B) for receiving the data reflecting the requirement for the ion exchange. The user interface may be in the form of, for example, several soft keys mounted on a panel of the ion exchanger or a liquid crystal panel with touch-display function, such that the users can directly operate the soft keys or the liquid crystal panel with touch-display function to input corresponding data.

Alternatively, the ion exchanger may further comprise a memory 110 (with reference to Figs.2A and 2B) for storing a list of values for each type of data and the relations between the voltage values and the values of other types of data. The data reflecting the requirement for the ion exchange may include data of the following types: the voltage to be applied, e.g. the four voltage values, 0V, 5V, 10V and 15V given above, in Test I and Test II. The data reflecting the requirement for the ion exchange may further include the type of the electrolyte solution, e.g. the user can directly select, on a user interface such as soft keys, a corresponding one of multiple applications such as water softening, water purification, catalysis production, juice purification, sugar manufacturing, pharmaceutical manufacturing, etc., or enter corresponding codes such as A, B, C, D, E, F, etc. to represent respectively the six applications mentioned above. The data reflecting the requirement for the ion exchange may further include the expected ion exchange velocity, which means that the ion exchange takes place at a fast or a slow rate and which reflects the number of exchanges per unit time between the ions in the ion-exchange resin and the ions to be exchanged in the electrolyte solution, wherein a larger number means a higher ion exchange velocity and a smaller number means a lower ion exchange velocity. The duration of applying the voltage in each of the eight experiments in Test I and Test II is 10 minutes, however, this is for the convenience of experimentation so as to obtain comparable experiment data. The skilled person in the art is aware that in the field of ion exchange, the duration of applying a voltage to the first electrode 101 and the second electrode 102 may be variable as required. For example, in the case of tap water softening, provided that the voltage applied to the first electrode 101 and the second electrode 102 is 15 V, the duration of applying the voltage may be only a few minutes or even less from the moment the tap water enters the water tank (start of the ion exchange) tillthe moment it leaves the water tank (end of the ion exchange) because the tap water is

continuously flowing in the water tank. In this case, since it is required to complete the ion exchange in a short time in order to achieve the object of water softening, it is necessary to adjust the applied voltage to achieve the exchange velocity, i.e. a sufficiently high velocity of the ion exchange is required. Thus, the data representing the expected ion exchange velocity includes the duration of applying the voltage.

The data reflecting the requirement for the ion exchange may further include the expected ion exchange degree, which relates to how many of the ions are exchanged and which reflects, upon completion of the ion exchange, specifically how many ions in the ion-exchange resin are exchanged into the electrolyte solution or specifically how many ions in the electrolyte solution are exchanged into the ion-exchange resin. For example, in the case of water softening in Test I and Test II, the higher the expected ion exchange degree is, the more ions are exchanged between the Na⁺ ions in the ion-exchange resin and the Mg²⁺ and Ca²⁺ ions in the tap water, i.e. the lower is the output water hardness with respect to the input water hardness; and the lower the expected ion exchange degree is, the fewer ions are exchanged between the Na⁺ ions in the ion-exchange resin and the Mg²⁺ and Ca²⁺ ions in the tap water, i.e. the higher is the output water hardness with respect to the input water hardness. Then, the data representing the expected ion exchange degree includes an input water hardness and an output water hardness or includes a percentage of an output water hardness with respect to an input water hardness. In other applications such as water purification, the data representing the expected ion exchange degree may include other relevant data, e.g. a concentration of CI^" ions in the input water and a concentration of CI^" ions in the output water, etc., which is not difficult to understand for the person skilled in the art.

The person skilled in the art should understand that although the above illustrative embodiments are described using tap water softening as an example, the ion exchanger according to the present invention may be applied to many fields such as water purification, catalysis production, juice purification, sugar manufacturing, pharmaceutical manufacturing, etc.. Also, the ion exchange material according to the present invention is not limited to an ion-exchange resin, which will be readily understood by a person skilled in the art. Ions to be exchanged in different applications may differ. The ions that are able to be combined into the ion exchange material may include:

• H⁺ (proton) and OH (hydroxide)

• Single-charged monoatomic ions like Na⁺, K⁺, and CI

• Double-charged monoatomic ions like Ca²⁺ and Mg²⁺

• Polyatomic inorganic ions like S0₄ ² and P0₄ ³

• Organic bases, usually molecules containing the amino functional group -NR₂HO⁺

• Organic acids, often molecules containing -COO- (carboxylic acid) functional groups

• Biomolecules that can be ionized: amino acids, peptides, proteins, etc.

It should be noted that the memory stores a list of values for each type of data and the relations between the voltage values and the values of other types of data. As mentioned above, each type of data includes the voltage to be applied, the type of electrolyte solution, the expected ion exchange velocity, the expected ion exchange degree, etc., and these types of data may all be stored in the memory in certain value forms (including various symbols, codes, etc.). The memory may also store a list of the relations between the voltage values, e.g. those in the form shown in Tables 1 and 2, and the values of other types of data. These values of other types of data include, for example, the duration of applying the voltage, the input water hardness and output water hardness in the case of water softening, and so on. The list of relations between the voltage values and the values of other types of data may be a list in the form shown in Tables 1 and 2 or a list in any other form that reflects the relations between the voltage values and the type of electrolyte solution, the expected ion exchange velocity as well as the expected ion exchange degree.

The voltage control may be realized, for example, by means of the Pulse- Width Modulation (PWM) technology; it can be an adjustable power amplifier with variable resistance, etc. Next, Figs.2A and 2B are introduced. Fig.2A is a schematic structural view of a voltage controller according to an embodiment of the present invention, in which the timer 108, user interface 109, memory 110 are integrated with a voltage controller 105, to facilitate user use. The user may directly operate the user interface 109 and store data that reflects the requirement for the ion exchange in the memory 110, and subsequently, the voltage controller 105 and timer 108 apply a corresponding voltage having a certain duration according to the stored data that reflects the requirement for the ion exchange. Fig.2B is a schematic structural view of a voltage controller according to another embodiment of the present invention, in which the timer 108, user interface 109, memory 110 and voltage controller 105 are separate components, and the user may operate the user interface 109 and store data that reflects the requirement for the ion exchange in the memory 110, and subsequently, the voltage controller 105 and timer 108 apply a corresponding voltage having a certain duration according to the stored data that reflects the requirement for the ion exchange. The person skilled in the art may understand that the aforesaid timer 108, user interface 109, memory 1 10 and voltage controller 105 may be arranged otherwise, so long as it is possible to achieve the object of applying a voltage having a certain duration according to the stored data that reflects the requirement for the ion exchange.

Then Fig.3 is introduced. Fig.3 is a schematic flowchart of a method of exchanging ions according to an embodiment of the present invention. The method in Fig. 3 starts from S301 and then, in S302, a voltage to be applied to a first electrode 101 and a second electrode 102 of an ion exchanger is set according to data reflecting the requirement for ion exchange, wherein a surface of the first electrode 101 is coated with a first ion exchange material 106 comprising ions I_IA. Preferably, the setting of a voltage to be applied to the first electrode 101 and the second electrode 102 comprises adjusting the voltage according to data reflecting the requirement with respect to velocity and/or degree of ion exchange. As mentioned above, the data reflecting the requirement for ion exchange includes data that corresponds to at least one of the following types: the voltage to be applied; the type of the electrolyte solution; the expected ion exchange velocity; the expected ion exchange degree; as the meanings and expressions of the various data have been described above in detail, these will not be repeated here. These data reflecting the requirement for ion exchange may be received via a user interface and stored in a memory, or alternatively, the

manufacturer may pre-store a list of values for each type of data and the relations between the voltage values and the values of other types of data in a memory, for ease of use. Then, the method proceeds to S303, where the first electrode 101 and the second electrode 102 are both inserted into an electrolyte solution 104a comprising ions I_3A, thus enabling ion exchange between the ions I_IA and the ions I_3A. Subsequently, the method proceeds to S304, where the set voltage is applied for controlling the ion exchange process. Preferably, the duration of applying the set voltage to the first electrode 101 and the second electrode 102 is timed.

The skilled person in the art may understand that in the method of the present invention there may be also a situation like that shown in Figs. IB and 1C, where a surface of the second electrode 102 is coated with a second ion exchange material 107 comprising ions I_2A, and where electrolyte solutions 104b, 104c may also comprise ions I_4A, and an ion exchange between the ions I_2A and ions I_4A is controlled via the set voltage.

The person skilled in the art may understand that the method of the present invention may also be applied in applications such as water softening, water purification, catalysis production, juice purification, sugar manufacturing, pharmaceutical manufacturing, etc..

Although the present invention has been described with reference to the currently considered embodiments, it should be understood that the present invention is not limited to the embodiments as disclosed. On the contrary, the present invention aims to cover various modifications and equivalent arrangements comprised within the spirit and scope of the appended claims. The scope of the following claims conforms to the widest interpretation so as to include all such modifications as well as equivalent structures and functions.

Claims

CLAIMS:

1. An ion exchanger comprising:

- a voltage controller for controlling a voltage to be applied by the power supply to the first electrode and the second electrode according to data reflecting the requirement for the ion exchange.

2. The ion exchanger according to claim 1, wherein a surface of the second electrode is coated with a second ion exchange material, the second ion exchange material comprising ions I_2A¾nd the electrolyte solution further comprising ions I_4A.

3. The ion exchanger according to any one of claims 1 to 2, wherein the controlling of the voltage to be applied to the first electrode and the second electrode further comprises adjusting the voltage according to the data reflecting the requirement with respect to velocity and/or degree of the ion exchange.

4. The ion exchanger according to any one of claims 1 to 2, wherein the ion exchanger further comprises:

- a timer for timing a duration of applying the voltage to the first

electrode and the second electrode.

5. The ion exchanger according to claim 4, wherein the ion exchanger further comprises:

- a user interface for receiving the data reflecting the requirement for the ion exchange, wherein said data corresponds to at least one of the following data types:

- the voltage to be applied;

- the type of the electrolyte solution;

- the expected ion exchange velocity;

- the expected ion exchange degree.

6. The ion exchanger according to claim 5, wherein the ion exchanger further comprises:

7. The use of an ion exchanger according to any one of the preceding claims in any one of water softening, water purification, catalyzing products, juice purification, sugar production and pharmaceutical applications.

8. A method of exchanging ions, comprising:

- inserting the first electrode and the second electrode into an electrolyte solution comprising ions I_3A SO as to enable the ion exchange between the ions I_IA and ions I_3A;

- applying the set voltage to control the ion exchange process.

9. The method according to claim 8, wherein a surface of the second electrode is coated with a second ion exchange material comprising ions I_2A ¾nd the electrolyte solution further comprises ions I_4A, and wherein the ion exchange between ions I_2A and ions I_4A is controlled by the set voltage.

10. The method according to any one of claims 8 to 9, wherein the setting of a voltage to be applied to the first electrode and the second electrode comprises adjusting the voltage according to the data reflecting the requirement with respect to velocity and/or degree of ion exchange.

11. The method according to claim 8, further comprising timing a duration of applying the set voltage to the first electrode and the second electrode.

12. The method according to any one of claims 8 to 9, further comprising receiving data reflecting the requirement for ion exchange via a user interface, wherein said data corresponds to at least one of the following data types:

- the voltage to be applied;

- the type of the electrolyte solution;

- the expected ion exchange velocity;

- the expected ion exchange degree.

13. The method according to claim 12, further comprising pre-storing a list of values for each type of data and the relations between the voltage values and the values of other types of data in a memory.

14. The method according to any one of claims 8 to 13, wherein the method is performed in any one of water softening, water purification, catalyzing products, juice purification, sugar production and pharmaceutical applications.