JP2010142674A - Water softener and hot-water supply apparatus equipped with it - Google Patents

Abstract

In a conventional water softening device, salt is used to regenerate a cation exchange resin, and it is necessary to periodically replenish the salt according to the amount of water used, and it takes time to replenish the salt. There was a problem.
By controlling the voltage applied between the electrodes independently for each electrode pair during regeneration, hydrogen ions and hydroxide ions can be efficiently generated by electrolysis, and a cation exchanger and an anion The exchanger can be efficiently regenerated. This eliminates the need for supplying medicines and the like, reduces energy consumption, and makes it possible to obtain soft water by mentales.
[Selection] Figure 1

Description

  The present invention relates to a water softening device and a hot water supply device using the water softening device for continuously supplying soft water without supplying a medicine.

  Conventionally, many soft water generators using ion exchange resins, reverse osmosis membranes, and electrodialysis have been proposed.For example, cation exchange resins having sodium ions as exchange groups are used, and the raw materials are produced by cation exchange resins. It is known that soft water is obtained by ion exchange of calcium ions and magnesium ions, which are hardness components contained in water, with sodium ions.

  Then, after all the sodium ions, which are exchange groups of the cation exchange resin, are exchanged with calcium ions and magnesium ions, the ion exchange cannot be performed. Therefore, the cation exchange resin is regenerated so that the ion exchange can be performed again. There is a need.

In the regeneration of this cation exchange resin, salt or the like is used, and it is necessary to periodically replenish the salt according to the amount of soft water used, and there is a problem that it takes time to replenish the salt. Therefore, as a method for regenerating a cation exchange resin without using a salt, a method for obtaining soft water using a reverse osmosis membrane (see, for example, Patent Document 1), a method for obtaining soft water by electrodialysis, and an ion exchange resin between electrodes of electrodialysis. And a method of regenerating the cation exchange resin with hydrogen ions generated by the dissociation of water (see, for example, Patent Document 2).
Japanese Patent Laid-Open No. 7-68216 JP 2006-43149 A

  However, in the method of obtaining soft water using a reverse osmosis membrane or electrodialysis, there is a problem that when the flow rate of concentrated water is decreased, the hardness component is precipitated in the concentrated portion, and the membrane is clogged. Further, in the method of regenerating the cation exchange resin with hydrogen ions generated by the dissociation of water, there is a problem that much electric power is required to regenerate the cation exchange resin.

  In order to solve the above-described conventional problems, the water softening device of the present invention includes an anode chamber filled with a cation exchanger and a cathode chamber filled with an anion exchanger, and a cation exchange membrane surface and an anion exchange membrane surface. Separately formed with a bipolar membrane, and at least two electrode pairs are separately formed in the anode chamber and the cathode chamber, and the voltage applied to the electrode pair is independently controlled during regeneration of the cation exchanger and the anion exchanger. Thus, the cation exchanger and the anion exchanger are efficiently regenerated.

  The water softening device of the present invention can efficiently generate hydrogen ions and hydroxide ions by electrolysis by controlling the voltage applied between the electrodes independently for each electrode pair at the time of regeneration. The body and anion exchanger can be efficiently regenerated. This eliminates the need to supply chemicals and the like, reduces energy consumption, and enables soft water to be obtained with mentales.

In the water softening device according to the first aspect of the present invention, an anode chamber filled with a cation exchanger and a cathode chamber filled with an anion exchanger are separated by a bipolar membrane having a cation exchange membrane surface and an anion exchange membrane surface. Separating at least two electrode pairs in the anode chamber and the cathode chamber, and independently controlling the voltage applied to the electrode pair during regeneration of the cation exchanger and the anion exchanger, An anion exchanger is efficiently regenerated.

  With the above configuration, the voltage applied between the electrodes during regeneration can be controlled independently for each electrode pair, so that hydrogen ions and hydroxide ions can be efficiently generated by electrolysis. The exchanger can be efficiently regenerated. This eliminates the need to supply chemicals and the like, reduces energy consumption, and enables soft water to be obtained with mentales.

  The water softening device according to the second invention is configured to separate and form the electrode pair in the water flow direction in the first invention and to control the applied voltage to the electrode pair to be higher on the upstream side of the water. . Since the ions in the water are sequentially exchanged with the ion exchanger in contact with the ion exchanger, more ions are exchanged in the ion exchanger on the inlet side in the water flow direction than the ion exchanger on the outlet side, and hydrogen ions required for regeneration And a lot of hydroxide ions are also needed. By forming the electrode pair separately from the water direction and controlling the voltage applied to the electrode pair on the inlet side to be higher on the inlet side, more hydrogen ions and hydroxide ions are required for regeneration. It is possible to generate a large amount of hydrogen ions and hydroxide ions on the inlet side, and to keep the applied voltage on the outlet side with less ion exchange low so that an unnecessary voltage is not applied and the ion exchanger can be efficiently Can be played.

  The water softening device according to the third invention is characterized in that the flow rate of water to the water softening device is intermittently changed during regeneration of the ion exchanger. By changing the water flow rate intermittently, the amount of waste water generated during regeneration is reduced, and regeneration can be performed without reducing the flow rate of water passed through the ion exchanger during regeneration. Clogging of the body can be prevented.

  The water softening device according to the fourth aspect of the present invention includes a water softening detection unit that detects the degree of water softening, and can regenerate the ion exchanger according to the degree of water softening detected by the water softening detection unit. .

  In the water softening device according to the fifth aspect of the invention, the ion exchanger is composed of a woven or non-woven fabric having an ion-exchange group or a processed product thereof, and the ion exchanger is made into a woven or non-woven fabric so that the ion exchanger is placed in the soft water chamber. It can be filled uniformly.

  6th invention is the hot-water supply apparatus provided with the water softening apparatus of the said 1st to 4th invention. By installing the water softening device in the water heater, scale generation formed on the heat transfer surface of the hot water heat exchanger can be suppressed. Thereby, the water circuit blockage of the heat exchanger can be prevented and the heat exchange efficiency can be increased.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each embodiment, the same reference numerals are given to portions performing the same operation and the same operation, and detailed description is saved. Note that the present invention is not limited to the present embodiment.

(Embodiment 1)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a water softener. The water softening device includes a water supply channel 1, a chlorine removing device 2 provided in the water supply channel 1, and a water softening device 3 for softening the water from which chlorine compounds in the water have been removed by the chlorine removing device 2 by ion exchange. A bipolar membrane 4 having a cation exchange membrane surface and an anion exchange membrane surface is separated into an anode chamber 5 and a cathode chamber 6. The anode chamber 5 is provided with a cation exchanger 7 and anodes 8a and 8b, and the cathode chamber 6 is provided with an anion exchanger 9 and cathodes 10a and 10b. The anodes 8a and 8b and the cathodes 10a and 10b are formed separately from each other in the water flow direction.

  As the cation exchanger 6, one having a functional group capable of exchanging cations such as a strong acid cation exchange resin or a weak acid cation exchange resin can be used. Moreover, as the anion exchanger 9, what has the functional group which exchanges anions, such as a strong basic anion exchange resin and a weak basic ion exchange resin, can be used. The ion exchanger is not limited to any functional group as long as it can be regenerated with hydrogen ions and hydroxide ions generated by dissociation of water, but weakly acidic cation exchange resins and weak bases are easy to regenerate. A combination of cationic anion exchange resins is desirable.

  The water supply channel 1 is connected to the cathode chamber inlet 11 provided in the cathode chamber 6 through the chlorine removing means 2, and the cathode chamber outlet 12 is connected to the anode chamber inlet 13. Furthermore, the anode chamber outlet 14 is connected to a soft water using device 15 that uses soft water. A regeneration switching valve 16 is provided in the flow path connecting the anode chamber outlet 14 and the soft water using device 15, and the regeneration switching valve 16 drains the flow path for supplying water to the soft water using device 15 during sampling and the waste water generated during the regeneration. The drainage channel 17 is configured to switch the channel. The drainage flow path 17 is provided with a pressure loss resistor 18 for adjusting the drainage flow rate.

  The chlorine removing means 2 is filled with a metal mixture or metal alloy containing either zinc or copper, and the shape of the filling body is a ring shape such as granular, Raschig ring, a saddle shape, or a honeycomb shape. It is possible to use.

  The anodes 8a and 8b and the cathodes 10a and 10b use noble metal electrodes obtained by plating or sintering a noble metal such as platinum or iridium using titanium as a base material. As long as a predetermined electrode area can be ensured, the shape of the electrode is not limited. In addition, a direct current voltage is independently applied to each electrode pair by a direct current power source (not shown) between the anode 8a cathode 10a and between the anode 8b cathode 10b.

  The operation and action of the water softening device configured as described above will be described. When soft water is used in the soft water using device 15, the regeneration switching valve 16 is switched to the soft water using device 15 side. The water supplied from the water supply channel 1 is supplied to the water softening means 3 through the chlorine removing means 2. At this time, the chlorine compound in the water is removed by reacting with a metal body such as zinc or copper filled in the chlorine removing means 2, and water from which the chlorine compound deteriorating the ion exchanger is removed is supplied to the cathode chamber 6. Is done.

  The water supplied to the water softening means 3 is supplied to the anode chamber 5 after the anions such as carbonate ions and chlorine ions are ion-exchanged with hydroxide ions by the anion exchanger 9 filled in the cathode chamber 6. The cation exchanger 7 filled in the chamber 5 exchanges cations such as sodium and calcium with hydrogen ions. The soft water generated in this way is supplied from the anode chamber outlet 14 to the soft water using device 15.

  As the device 15 using soft water, it can be used as a washing device such as a washing machine or a dishwasher, a cooking device, a steam using device in which deposition of scale becomes a problem, a hairdressing barber device, or the like. In washing machines such as washing machines and dishwashers, the hardness component inhibits the function of the surfactant, so soft water can be used to increase detergency and suppress the formation of soap scum due to the hardness component. It can prevent the clothes from becoming wrinkled and the water drops remaining on the tableware, and can provide a high-quality finish.

Moreover, when it uses for a rice cooker etc. as cooking equipment, the water absorption to rice can be accelerated | stimulated by the effect of soft water, and the taste of rice, such as a rice grain collapse | crumble and the balance improvement of hardness, can be improved. Soft water also promotes extraction of umami components (amino acids) such as kelp, so that the taste of the cooked product can be improved by performing soft water cooking on a suitable soft water material.

  Next, the action during regeneration of the cation exchanger 7 and the anion exchanger 9 will be described. When the cation exchanger 7 and the anion exchanger 9 are regenerated, a DC voltage is independently applied to each electrode pair by a DC power source (not shown) between the anode 8a and the cathode 10a and between the anode 8b and the cathode 10b. While being applied, the regeneration switching valve 16 is switched to the drainage channel 17 side. The water supplied from the water supply channel 1 is supplied to the water softening means 3 through the chlorine removing means 2. At this time, the chlorine compound in the water is removed by reacting with a metal body such as zinc or copper filled in the chlorine removing means 2, and water from which the chlorine compound deteriorating the ion exchanger is removed is supplied to the cathode chamber 6. Is done.

  At the time of regeneration, the regeneration switching valve 16 is switched to the drainage channel 17 side, and the water used for regeneration is drained from the drainage channel via the pressure loss resistor 18. By providing the pressure drop resistance 18 in the drainage channel 17 in this manner, the flow rate of water to the water softening device can be changed during sampling and regeneration of the ion exchanger with a simple configuration. By reducing the water flow rate at the time of regeneration from that at the time of sampling, the amount of discarded water generated at the time of regeneration can be reduced.

  By applying a DC voltage between the anode 8a and the cathode 10a, and between the anode 8b and the cathode 10b, water is dissociated at the internal interface of the bipolar film 4, and hydroxide ions generated by the dissociation of water are generated in the cathode chamber 6. Then, ion exchange is performed with anions such as carbonate ions and chloride ions adsorbed on the anion exchanger 9, and carbonate ions and chloride ions are released from the anion exchanger 9. In the anode chamber 5, hydrogen ions generated by the dissociation of water are ion-exchanged with cations such as calcium adsorbed on the cation exchanger 7, and cations such as calcium are released from the cation exchanger 7.

  A voltage higher than that of the anodes 8b and 10b provided on the outlet side is applied between the anode 8a and the cathode 10a provided on the inlet side (that is, the upstream side) in the water flow direction. As a result, many hydrogen ions and hydroxide ions can be generated on the inlet side where a large amount of hydrogen ions and hydroxide ions are required for regeneration, and the applied voltage on the outlet side where ion exchange is small can be kept low. Thus, the ion exchanger can be efficiently regenerated without applying an unnecessary voltage.

  At this time, it is known that not only hydrogen ions but also hypochlorous acid is generated in the anode chamber. In the present embodiment, the cathode chamber 6 filled with the anion exchanger 6 is passed through and then the anode chamber 5 is passed through, so that the chlorine compound generated in the anode chamber 5 flows into the cathode chamber. Can be prevented. Since the functional group of the anion exchanger 6 is weaker and more susceptible to deterioration than the functional group of the cation exchanger 7, the anode chamber 5 is allowed to flow after passing through the cathode chamber 6. Deterioration of the ion exchanger can be prevented.

  In this way, cation exchangers and anion exchangers can be regenerated using hydrogen ions and hydroxide ions generated by applying a voltage between the electrodes during regeneration, eliminating the need for supplying chemicals, etc. It becomes possible to obtain soft water.

  In this embodiment, the configuration for controlling the voltage applied to the electrode pair is shown. However, the same effect can be obtained by controlling the current flowing between the electrodes so that a large amount of current flows through the electrode pair on the inlet side. Can be obtained.

In this embodiment, the pressure drop resistor 18 is provided as the water flow rate variable means. However, the amount of waste water generated at the time of regeneration can be reduced by intermittently changing the water flow rate without using the pressure drop resistor. In addition to being reduced, regeneration can be performed without reducing the flow rate of water flowing through the ion exchanger during regeneration, so that the ion exchanger can be prevented from being clogged during regeneration.

  As the form of the ion exchanger, granular, woven cloth, non-woven cloth or processed product thereof can be used. However, the ion exchanger can be provided in the soft water chamber 5 by making the ion exchanger into the form of woven cloth or non-woven cloth. It can be filled uniformly and processing becomes easy. Furthermore, by mixing conductive fibers and the like in the ion exchanger, the electrical resistance in the soft water chamber can be reduced, and power consumption can be reduced.

  As a timing for performing regeneration, a method of performing regeneration every predetermined time, a method of performing regeneration after passing a predetermined water flow rate, or the like can be used. The amount of hardness component contained in the treated raw water by providing water softening detection means, detecting the degree of water softening of the treated water, and regenerating when the degree of water softening falls below the predetermined water softening degree Even when the amount of water changes or when the adsorption amount of the ion exchanger decreases, stable soft water can always be supplied without leaking the hardness component. As the softening detection means, a method of applying an AC voltage between the anode 8a and the cathode 10a and between the anode 8b and the cathode 10b and measuring the impedance between the electrodes can be used.

(Embodiment 2)
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a configuration diagram in which the soft water device is used in a heat pump hot water supply device. In FIG. 2, the hot water supply apparatus includes a hot water storage tank 20, a heat pump unit 22 including a heat exchanger 21, a heat exchange water supply path 23, a hot water storage tank water supply path 24, and a hot water supply circuit 25. The heat pump unit 22 includes a refrigerant circuit 27 having a refrigerant therein, and the refrigerant circuit 27 includes an evaporator 28 that collects atmospheric heat, a compression unit 29, and an expansion unit 30 in that order.

  As the refrigerant, a natural refrigerant such as CO2 is used. The refrigerant circulates in the refrigerant circuit 27, takes in the heat in the atmosphere by the evaporator 28, and is compressed by the compression means 29 to become a higher temperature. Is used by the heat exchanger 21 to heat the water in the heat exchanger water supply passage 23, and the refrigerant whose temperature has been lowered is sent to the evaporator 28 through the expansion means 30 and takes in atmospheric heat again.

  A heat exchanger water supply passage 23 and a hot water storage tank water supply passage 24 are connected to the lower part of the hot water storage tank 20, and a water softening device 31 and a circulation pump 32 are provided in the heat exchanger water supply passage 23. In the hot water supply circuit 25, hot water mixed with hot water and adjusted in temperature by a hot water mixing unit 34 provided in the bathroom unit 33 is supplied into the bathroom unit 33 from a currant 35 or the like.

  The operation and action of the above configuration will be described. Since the operation at the time of water softening and regeneration in the water softening device 31 is the same as that in the first embodiment, the description thereof is omitted. The soft water supplied to the heat exchanger 21 from the lower part of the hot water storage tank 20 through the heat exchanger water supply path 23 by the circulation pump 32 is heated to a high temperature by the heat exchanger 21 and sent to the hot water storage tank 20 through the hot water supply circuit 25. It is done. When the user uses the hot water of the hot water supply device, hot water adjusted to an appropriate temperature by hot water mixing or the like is supplied from the upper part of the hot water storage tank 20 to the user's use location (kitchen, washroom, bathroom, etc.). When the hot water in the hot water storage tank 20 is used, water is replenished to the hot water storage tank 20 from the hot water storage tank water supply path 24 below the hot water storage tank 20.

  In the heat exchanger 21, since water is rapidly heated, calcium or magnesium contained in the water adheres to the heat transfer surface as a scale to reduce heat exchange efficiency and block the water circuit of the heat exchanger 21. There was also sex. However, scale supply formed on the heat transfer surface of the heat exchanger can be suppressed by supplying soft water generated by the water softening device 31 to the heat exchanger 21 as in the present embodiment. Thereby, the water circuit blockage of the heat exchanger can be prevented and the heat exchange efficiency can be increased.

  Furthermore, it is known that the use of soft water during bath cleaning such as bathing can suppress the formation of soap scum, and it is known that allergy suppression and beauty effects can be obtained. Soft water is used as washing water for skin and hair. By using this, it is possible to obtain these soft water effects, to suppress the formation of soap scum and adhesion of scales, and to obtain the effect of reducing the trouble of cleaning around water.

  In addition, when a large amount of water is used like a heat pump water heater, and when a conventional water softener is combined with a hot water supply device installed outdoors, the frequency and amount of salt replenishment increases, and space is saved in apartment buildings and the like. However, it is possible that maintenance work such as salt replenishment will cause poor workability, but the use of this embodiment makes it unnecessary to use salt and reduces the work of replenishment. be able to.

  Further, by combining with a heat pump hot water supply apparatus having a hot water storage tank 20 as in the present embodiment, even when there is a time during which soft water cannot be collected in order to regenerate the ion exchanger in the water softening apparatus, Can be supplied to the user, so that soft water cannot be obtained and inconvenience can be eliminated.

  The water softening device according to the present invention does not require the supply of chemicals and continuously supplies soft water. As the device that uses soft water, water such as a washing machine, a dishwasher, a hot water supply device, and a cooking device is used. It can be applied to equipment.

The block diagram of the water softening apparatus in Embodiment 1 of this invention Configuration diagram of a heat pump water heater equipped with the water softening device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Water supply path 3 Water softening means 4 Bipolar membrane 5 Anode chamber 6 Cathode chamber 7 Cation exchanger 8a, 8b Anode 9 Anion exchanger 10a, 10b Cathode 16 Regeneration switching valve 17 Drain flow path 18 Pressure loss resistance 20 Hot water storage tank 21 Heat Exchanger 22 Heat pump unit 28 Evaporator 29 Compression means 30 Expansion means 31 Water softening device 33 Bathroom unit

Claims (6)

A cathode chamber filled with a cation exchanger and a cathode chamber filled with an anion exchanger are separately formed by a bipolar membrane having a cation exchange membrane surface and an anion exchange membrane surface, and electrodes are provided in the anode chamber and the cathode chamber. Soft water that regenerates the cation exchanger and the anion exchanger by hydrogen ions and hydroxide ions generated by applying a voltage between the electrodes during regeneration of the cation exchanger and the anion exchanger A water softening device, wherein the electrodes are separated and formed as at least two electrode pairs, and energization to the electrode pairs is controlled independently. The water softening device according to claim 1, wherein the electrode pair is separated from the water flow direction, and the voltage applied to the electrode pair is controlled to be higher on the upstream side of the water flow. 3. The water softening device according to claim 1, further comprising a water softening detecting unit configured to detect a degree of water softening, and controlling an applied voltage at the time of regeneration based on the detection result. 5. The water softening device according to claim 1, wherein the water flow rate is intermittently changed during regeneration of the cation exchanger and the anion exchanger. 5. The water softening device according to claim 1, wherein the cation exchanger and the anion exchanger are made of a woven fabric, a nonwoven fabric, a fiber having an ion exchange group, or a processed product thereof. A hot water supply apparatus comprising the water softening apparatus according to claim 1.