JP4292087B2 - Ion exchange resin life detection method and ion removal filter - Google Patents

Description

  The present invention relates to a lifetime detection method and an ion removal filter that detect the lifetime of an ion exchange resin that removes ions in a liquid.

  Fuel cells have been used as power sources for next-generation automobiles or as household power sources. The fuel cell converts chemical energy when hydrogen and oxygen are chemically reacted into electric energy. Since the chemical reaction between hydrogen and oxygen is an exothermic reaction, water is circulated to cool the fuel cell. At that time, water that conducts electricity, such as tap water, causes the fuel cell to short-circuit. For this reason, an ion exchange resin is used in order to remove ions in water and lower the electrical conductivity (electrical conductivity).

  The fuel cell is supplied with humidifying water for moistening hydrogen and oxygen. When an ionic component dissolves in humidifying water, it interferes with the chemical reaction between hydrogen and oxygen. For this reason, ions are also removed from the water for humidification.

  As described above, since the fuel cell does not accept ions, it is necessary to remove the ions with an ion exchange resin. The ion exchange resin has a predetermined amount of ions that can be exchanged. When a certain amount of exchange is performed, the ion exchange resin cannot be exchanged any more and loses the ability to lower the conductivity. This state is regarded as the life of the ion exchange resin. Ions cannot be visually observed, and since the color of the ion exchange resin does not change when the lifetime is reached, it is extremely difficult to determine the lifetime of the ion exchange resin.

  The purpose of the ion exchange resin is to lower the electrical conductivity in water. Currently, the most commonly used method for detecting the life is to incorporate a conductivity sensor into the circuit, measure the conductivity of the filtered water with the conductivity meter, and the conductivity does not drop below a certain value. This is a method of capturing the lifetime of the ion exchange resin (see, for example, Patent Document 1, paragraph 0011).

See JP-A-11-137799

  However, when the fuel cell system is not operated for a long period of time, a large amount of ions are eluted from the pipe in the water. However, when water with high conductivity suddenly comes into the filter, the ion exchange resin performs as set. Even if it exhibits, the conductivity after the filter may be high. In this case, in the life detection method for measuring the electrical conductivity in water after the filter, it may be determined that the ion exchange resin has a long life even though the ion exchange resin still has power. In addition, since the conductivity sensor for measuring the conductivity in water is expensive, there is also a problem that the merit in cost is small.

  At the laboratory level, the life of the ion exchange resin can be accurately measured by adding a certain amount of ion reagent to the circuit and measuring the state in which the ion exchange resin removes ions. However, when a car is actually used, the amount of ions generated varies greatly depending on the ambient environment conditions and running conditions of the car itself. For this reason, it is impossible to predict the lifetime of the ion exchange resin under certain conditions.

  Accordingly, an object of the present invention is to provide an ion exchange resin lifetime detection method and an ion removal filter that can easily and accurately grasp the lifetime of an ion exchange resin.

  The present invention will be described below. The inventor has paid attention to the fact that the ion exchange resin undergoes ion exchange and the resin itself shrinks. In conducting the experiment, it was found that the lifetime of the ion exchange resin can be easily and accurately grasped by detecting the lifetime of the ion exchange resin from the shrinkage of the ion exchange resin.

That the invention of claim 1, a method for detecting the life of the ion exchange resin for removing ions in liquids, wherein the ion exchange resin by utilizing the property of shrinking in volume when the ion exchange, the ion The life of the ion exchange resin is detected by measuring the amount of change in the volume of the exchange resin.

  The invention of claim 2 is a method for detecting the lifetime of an ion exchange resin for removing ions in a liquid, comprising a slide member that presses the ion exchange resin filled in the container and is slidable with respect to the container. The life of the ion exchange resin is detected by utilizing a change in position.

  The invention of claim 3 is a method for detecting the lifetime of an ion exchange resin that removes ions in a liquid, and utilizes a change in the load of a spring that applies a load for pressing the ion exchange resin filled in the container. The life of the ion exchange resin is detected.

Further, the invention of claim 4 is an ion removal filter for removing ions in a liquid, wherein the ion exchange resin has a volume shrinkage due to ion exchange, and the volume of the ion exchange resin is reduced . The life of the ion exchange resin is detected by measuring the amount of change .

  The invention according to claim 5 is an ion removal filter for removing ions in a liquid, the container filled with an ion exchange resin, the ion exchange resin filled in the container, and the container. It is provided with a slide member which can slide, and a detection part which detects a change of a position of the slide member.

  The invention of claim 6 is an ion removal filter for removing ions in a liquid, a container filled with an ion exchange resin, a spring for applying a load for pressing the ion exchange resin filled in the container, And a detector for detecting a change in the load of the spring.

As described above, according to the present invention, the ion exchange resin is measured by measuring the amount of change in the volume of the ion exchange resin by utilizing the property that the volume contracts when ion exchange is performed. Therefore, the lifetime of the ion exchange resin can be easily and accurately grasped.

  Hereinafter, an embodiment of an ion removal filter of the present invention will be described with reference to the accompanying drawings. The ion removal filter is incorporated in a circuit of a fuel cell that chemically reacts with hydrogen and oxygen, and is not particularly limited. However, a cooling circuit that cools the fuel cell or a humidification that humidifies the ion exchange membrane of the fuel cell. It is common to incorporate in a circuit. The ion removal filter removes ions in a liquid such as pure water or ethylene glycol to reduce the conductivity (electrical conductivity). The capacity of the ion exchange resin in the ion removal filter is variously set according to the flowing flow rate and the amount of ions.

  FIG. 1 shows a cross-sectional view of an ion removal filter according to an embodiment of the present invention. A case 3 having a fluid inlet 1 and an outlet 2 is divided into, for example, a lower case 3b on the inlet 1 side, an upper case 3a on the outlet 2 side, and a cylindrical intermediate case 3c. . A cartridge 5 as a container filled with an ion exchange resin is incorporated in the case 3 in a replaceable manner.

  2 and 3 are detailed views of the cartridge 5. FIG. 2 shows a perspective view and FIG. 3 shows a cross-sectional view. The cartridge 5 includes an outer cylinder 5a in which a large number of liquid inflow holes 11 are formed, an inner cylinder 5b that is disposed inside the outer cylinder 5a and in which a large number of liquid inflow holes 10 are formed, and an axial direction of the inner cylinder 5b. There is a bottom plate 5c that connects one end side and one end side in the axial direction of the outer cylinder, and an upper plate 5d that connects the other end side in the axial direction of the inner cylinder 5b and the other end side in the axial direction of the outer cylinder 5a. A part of the inner cylinder 5 b protrudes from the upper plate 5 d so that it can be connected to the outlet 2 of the case 3.

  A granular ion exchange resin is filled between the inner cylinder 5b and the outer cylinder 5a of the cartridge 5. The cartridge 5 is provided with an annular slide plate 6 as a slide member for pressing the filled ion exchange resin so as to be slidable with respect to the cartridge 5. Seal members 7 and 8 are provided on the outer periphery and the inner periphery of the slide plate 6 to prevent the liquid from leaking in contact with the inner periphery of the outer tube 5a and the outer periphery of the inner tube 5b. A coil spring 9 is disposed between the slide plate 6 and the upper plate 5d to apply a load that holds the ion exchange resin.

  As shown in FIG. 1, the liquid flowing in from the inlet 1 of the case 3 passes through the outer cylinder 5 a of the cartridge 5 and the annular passage 12 between the outer peripheral surface of the case 3 and the outside of the cartridge 5. It flows into the region filled with the ion exchange resin from the plurality of inflow holes 11 of the cylinder 5a. The fluid from which ions have been removed by the ion exchange resin flows into the inner cylinder 5b from the plurality of inlet holes 10 of the inner cylinder 5b, and then flows out from the outlet 2. Note that the fluid may flow from the outlet 2 toward the inlet 1 in the opposite direction.

  The ion exchange resin has a predetermined amount of ions that can be exchanged. When a certain amount of exchange is performed, the ion exchange resin cannot be exchanged any more and loses the ability to lower the conductivity. This state is regarded as the life of the ion exchange resin. Ion exchange resins have the property of shrinking when ion exchange is performed. When the lifetime of the ion exchange resin comes, the ion exchange resin shrinks by about 10% in volume ratio, for example. In the present embodiment, the lifetime of the ion exchange resin is detected by utilizing the property that the ion exchange resin shrinks by performing ion exchange.

  Since the granular ion exchange resin is filled in the elongated cylindrical cartridge 5, the area filled with the ion exchange resin is relatively long in the height direction of the cartridge 5 as the ion exchange resin contracts. Shrink. As a result, the slide plate 6 disposed on the top surface of the ion exchange resin slides with respect to the cartridge 5 and changes its position. As shown in FIG. 1, a detection unit 13 such as a micro switch is provided in the vicinity of the slide plate 6 of the cartridge 5 in order to detect a change in the position of the slide plate 6. When the slide plate 6 changes its position by a predetermined amount or more, the detection unit 13 detects a change in the position of the slide plate 6 and generates an electrical signal that is electrically turned on or off. This electric signal is used as a signal for detecting the life of the ion exchange resin, and is transmitted from the detection unit 13 to a meter or the like. The detection unit 13 is not particularly limited to a micro switch as long as it can detect a change in the position of the slide plate, and various sensors such as an optical sensor can be used.

  FIG. 4 shows another example of the detection unit. In this example, the cartridge is provided with a visible window as the detection unit 14 so that the position of the slide plate can be seen from the outside of the cartridge. In this way, a change in the position of the slide plate 6 over a predetermined amount may be detected by visual observation, and the lifetime of the ion exchange resin may be used. Since the structure other than the detection unit 14 is the same as that of the ion removal filter of the above embodiment, the same reference numerals are given and the description thereof is omitted. In addition, a visible window may be provided in the case 3 so that the position of the slide plate can be directly recognized from the outside of the case 3. Further, if necessary, a scale may be written in the vicinity of the visible window so that a change in the position of the slide plate 6 by a predetermined amount or more, that is, the life of the ion exchange resin can be detected from the scale.

  As the ion exchange resin contracts, the coil spring 9 that applies a load that holds the ion exchange resin gradually expands to reduce the applied load. In addition to the detection by the micro switch and the detection by the visible window, such a load change of the coil spring 9 is measured by a strain gauge as a detection unit, and the converted electric signal is used as a signal for detecting the life of the ion exchange resin. It may be used. The detection unit 14 such as a strain gauge may be provided on the coil spring 9 or may be provided on the slide plate 6.

  Moreover, the ion removal filter of this embodiment can also be applied to the ion removal filter of a wire cut machine, without being limited to automobiles and household fuel cells.

Sectional drawing of the ion removal filter in one Embodiment of this invention. The perspective view of a cartridge. Sectional drawing of a cartridge. Sectional drawing which shows an ion removal filter (The other example of a detection part is shown).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Inlet 2 ... Outlet 3 ... Case 5 ... Cartridge (container)
6 ... Slide plate (slide member)
9 ... Coil spring (spring)
13 ... Detection unit 14 ... Detection unit

Claims (6)

A method for detecting the lifetime of an ion exchange resin that removes ions in a liquid,
The ion-exchange resin by utilizing the property of shrinking volume by ion exchange, by measuring the amount of change in volume of the ion-exchange resin, and detecting the life of the ion-exchange resin How to detect the life of ion exchange resin. A method for detecting the lifetime of an ion exchange resin that removes ions in a liquid,
The life of the ion exchange resin is characterized in that the life of the ion exchange resin is detected by using a change in the position of a slide member that is slidable with respect to the container while pressing the ion exchange resin filled in the container. Detection method. A method for detecting the lifetime of an ion exchange resin that removes ions in a liquid,
A method for detecting a life of an ion exchange resin, comprising: detecting a life of the ion exchange resin by using a change in a load of a spring that applies a load for pressing the ion exchange resin filled in a container. An ion removal filter for removing ions in a liquid,
The ion-exchange resin by utilizing the property of shrinking volume by ion exchange, by measuring the amount of change in volume of the ion-exchange resin, and detecting the life of the ion-exchange resin Ion removal filter. An ion removal filter for removing ions in a liquid,
A container filled with ion exchange resin;
While holding down the ion exchange resin filled in the container, a slide member that is slidable with respect to the container,
An ion removal filter comprising: a detection unit that detects a change in the position of the slide member. An ion removal filter for removing ions in a liquid,
A container filled with ion exchange resin;
A spring for applying a load for pressing the ion-exchange resin filled in the container;
An ion removal filter comprising: a detection unit that detects a change in the load of the spring.

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