JP2006149714A - Electric water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric water heater which supplies reduced water (hot water) having ORP (oxidation-reduction potential) and having active oxygen erasing ability by increasing dissolved hydrogen (hydrogen ion) concentration by comparatively simple constitution. <P>SOLUTION: The electric water heater is provided with: a heater 4 for heating water in a water-storage container 2; a circulation path 5 for circulating the water in the container 2; a hot water flow-out path 6 for making the water flow out; a pump 7 for circulating the water or making the water flow out; a substance 8 provided in the circulation path 5 and having photocatalyst reaction; and an irradiation means 9 for irradiating the substance 8 having the photocatalyst reaction with light containing UV at least. Thus, by electrolyzing a small amount of the water with the photocatalyst without applying external voltage by comparatively simple constitution, the dissolved hydrogen (hydrogen ion) concentration is increased so as to supply reduced water (hot water) having ORP and having active oxygen erasing ability. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electric water heater for supplying hot water for drinking having an active oxygen scavenging ability by a photocatalyst at home or office.

  Conventionally, an electric water heater in which a water purification effect is maintained by using a photocatalyst is known (see, for example, Patent Document 1).

  This is provided with a photocatalyst substance / adsorbent complex and a water purification unit using a UV lamp for irradiating the complex with ultraviolet rays inside a lid attached to the electric water heater body. By irradiating the photocatalyst substance with a UV lamp and circulating the water to the water purification unit, the photocatalytic action decomposes the caustic components of tap water and microorganisms that cause water stains. Similarly, trihalomethane produced by the reaction of residual chlorine contained in tap water for sterilization and organic coloring substances such as humic substances, and trace amounts of organochlorine compounds (trihalomethaneethylene and trichloromethane) contained in tap water. Methane) is also decomposed and removed.

On the other hand, the utility of reduced water with a reduced oxidation-reduction potential (in the present invention, which is based on a hydrogen electrode and hereinafter referred to as ORP) has attracted attention in various fields. For example, although it is water for drinking or water for washing the body, it is widely known that about 60 to 70% of the human body is water. Has been shown to have a significant impact on health and beauty. This is due to the action of giving electrons to active oxygen, which is said to be the cause of many diseases and aging such as cancer, diabetes, arteriosclerosis, gastritis, atopic dermatitis, and brain dysfunction, and erases active oxygen. It is believed that. Tap water is oxidized water due to the effects of hypochlorous acid and free chlorine dissolved for sterilization. In addition, natural water such as groundwater that can be obtained from nature is generally lower in ORP than tap water and negative in ORP. However, ORP changes with the place of water intake and with time, and stable supply is difficult. Therefore, there is an attempt to make artificially in order to stably supply reduced water, and the main generation method is a method of electrolyzing water. This method has been known for a long time, and recently, an apparatus that has been devised in various ways based on the method has been proposed (see, for example, Patent Document 2).
Japanese Patent Laid-Open No. 10-211104 JP 2002-254078 A

  However, the conventional photocatalytic action has the following problems. First, since water is purified using only the photocatalyst, the water purification unit with the photocatalytic substance is very large, and the ultraviolet ray with a strong irradiation intensity is required, the UV lamp is also enlarged, the electric water heater itself is enlarged, There was a problem of cost. In addition, since the photocatalyst is mainly used for purification, it is hardly used for water electrolysis until the purification is completed, and there is a problem that it takes time to generate reduced water. Furthermore, since the circulation time becomes long, the electric pump has to be driven, and there are inconveniences such as increase in power consumption and generation of noise.

  On the other hand, the conventional electrolysis method in which voltage is positively applied from the outside has a problem that the apparatus is complicated and it is difficult to mount it on a small household appliance such as an electric water heater.

  The present invention solves the above-described conventional problems. Electricity that can supply reduced water (hot water) having a relatively simple configuration and increasing the dissolved hydrogen (hydrogen ion) concentration and reducing the ORP has an active oxygen scavenging ability. The object is to provide a water heater.

  This invention solves such a subject, the heater which heats the water in the water storage container, the circulation path | route which circulates the water in the water storage container, the tap water path | route which flows out water, and water A pump that circulates or flows out, a substance that has at least a photocatalytic action provided in the circulation path, and an irradiation means that irradiates the substance having a photocatalytic action with light containing at least ultraviolet rays.

  Thus, reduced water having a relatively simple structure, that is, an active oxygen scavenging ability in which the dissolved hydrogen (hydrogen ion) concentration is increased by electrolyzing water in a small amount with a photocatalyst without applying an external voltage and ORP is decreased. An electric water heater capable of supplying (hot water) can be realized.

  The electric water heater of the present invention can generate reduced water (hot water) that has a relatively simple structure and has a function of eliminating active oxygen, and is provided as drinking water or cooking water that is considered to be good for health. be able to.

  A first invention is a water storage container, a heater for heating water in the water storage container, a circulation path for circulating water in the water storage container, a tapping water path for discharging water, and circulating water or Comparison is made by using an electric water heater comprising an outflow pump, a substance having a photocatalytic action provided at least in the circulation path, and an irradiation means for irradiating the substance having a photocatalytic action with light containing at least ultraviolet rays. Simple structure, that is, reduced water (hot water) having an active oxygen scavenging ability that increases the dissolved hydrogen (hydrogen ion) concentration by reducing the ORP by electrolyzing water in a minute amount with a photocatalyst without applying an external voltage. Can supply.

  In the second invention, in particular, in the first invention, since the substance having photocatalytic action is anatase type titanium oxide, anatase type titanium oxide has higher photocatalytic action than other substances having photocatalytic action. Thus, it is possible to provide reduced water having an active oxygen scavenging ability with a reduced amount of ORP in a small amount of time.

  According to a third invention, in particular, in the first or second invention, the substance having a photocatalytic action is caused by the smell of hot water by being supported on a carrier containing an adsorbent having a physical adsorption action. In order to adsorb free chlorine, which is a cause of increasing ORP, it is possible to provide reduced water having an active oxygen scavenging ability with lower ORP.

  In a fourth aspect of the invention, in particular, in the first aspect of the invention, the irradiation means is a light emitting diode having a peak wavelength between 350 nm and 400 nm, thereby having a low energy, high efficiency and low ORP active oxygen scavenging ability. Reduced water can be supplied.

  In particular, the fifth invention is characterized in that in any one of the first to fourth inventions, a mineral addition filter containing a compound containing at least magnesium is added, so that minerals necessary for the body such as calcium and magnesium are added. In addition, it is possible to provide reduced water having an active oxygen scavenging ability with improved extractability of tea or the like by adding calcium or the like.

  According to a sixth aspect of the invention, in particular, in any one of the first to fifth aspects of the invention, water having an ORP that is too low is said to have an adverse effect on the body due to the provision of a sensor for measuring the oxidation-reduction potential. However, since ORP can be measured by a sensor, reduced water having almost the desired ORP can be obtained.

  In particular, in a seventh aspect of the present invention, in any one of the first to sixth aspects, by providing hot water having an active oxygen scavenging capacity higher than that of tap water, the active oxygen is erased with a relatively simple configuration. It is possible to produce reduced water (hot water) that is said to work, and to provide drinking water and cooking water that are considered to be good for health.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment)
FIG. 1 shows an electric water heater according to an embodiment of the present invention.

  As shown in the figure, the electric water heater in the present embodiment includes a casing 1, a water storage container 2 that is housed in the casing 1 and stores hot water therein, and steam that covers the top of the casing 1 so as to be openable and closable. A lid 3 having a mouth, a donut-shaped heater 4 for heating the water in the water storage container 2, a circulation path 5 for circulating the water in the water storage container 2, and a hot water supply path 6 for allowing the water to flow outside. A photocatalyst is provided with a pump 7 provided at the bottom between the housing 1 and the water storage container 2 for circulating or flowing out water, a substance 8 having photocatalytic action provided in at least the circulation path 5, and light containing at least ultraviolet rays. Irradiation means 9 for irradiating the substance 8 having

  At least the vertical part of the circulation path 5 is transparent, and serves as a water level pipe that displays the water level in the water storage container 2. The water level can be confirmed from the outside through the slit of the housing 1. Further, a mineral addition filter 10 with a water purification function (hereinafter simply referred to as filter 10) is connected to the water storage container 2 of the circulation path 5 so as to purify the circulating water and add minerals. A part of the circulation path 5 branches from the hot water supply path 6 so that water can flow out from the discharge port 11 to the outside. Switching between the circulation path 5 and the hot water path 6 is appropriately controlled by the switching valve 12.

  When the pump 7 is driven, the water (hot water) in the water storage container 2 is discharged from the discharge port 11 through the circulation path 5 in which the photocatalytic substance 8 is installed, or It passes through the filter 10 and circulates to the water storage container 2. The installation position of the substance 8 having a photocatalytic action may be provided in the hot water supply path 6 at least as in the circulation path 5 in the present embodiment. In this embodiment, the circulation path 5 also serves as the hot water discharge path 6, but may be switched by a valve as an independent structure.

  Next, the substance 8 having a photocatalytic action will be described.

  This is because a substance having a photocatalytic action such as titanium oxide may be used as it is. However, titanium oxide and the like are mostly supplied in a powder form and are accompanied by an operation of separating water and titanium oxide after the treatment. It is desirable to carry it. For example, a honeycomb structure with a photocatalyst such as titanium oxide bonded and supported by an action such as an anchor effect or physical bonding or chemical bonding, or in the vicinity of the surface of silica gel, activated carbon or the like by a similar bonding method There is something that is carried on the. At this time, a binder may be added. However, if the amount is large, an appropriate amount is desirable because it causes a decrease in photocatalytic activity.

  In addition, since it is difficult to irradiate light inside the honeycomb structure in water, it is desirable to fill the surface having a photocatalytic action in the vicinity of the surface such as silica gel or activated carbon, and irradiate light from the outside. What has a certain light transmittance like silica gel is the best. Furthermore, the material of the carrier is not particularly limited, but it is desirable to use an inorganic material such as ceramics that is not decomposed by the photocatalytic action. At this time, it is desirable to reduce as much as possible the components that tend to become cations such as sodium and potassium, which reduce the photocatalytic action.

  The substance 8 having photocatalytic action is not particularly limited, but titanium dioxide is desirable in terms of cost, safety and availability, and anatase type having high photocatalytic activity particularly considering the performance aspect of photocatalytic action. Is the best.

  There are many methods for supporting the photocatalytic substance 8 on the carrier, such as a sputtering method, a sol-gel method, and a dip method. The method is not particularly limited, but in general, the dip method is used for supporting the honeycomb structure. Desirably, the sol-gel method is desirable for loading on silica gel or activated carbon.

  In addition to the photocatalyst, a substance having a physical adsorption action such as zeolite, silica gel, sepiolite, alumina, activated carbon or the like is added to the carrier, or the carrier itself is a substance having a physical adsorption action, so that the adsorbent The organic matter in the water is adsorbed and the reduced water production rate is improved. The organic matter adsorbed by the adsorbent is oxidatively decomposed by radicals generated when excited by light irradiation to the photocatalyst. In this embodiment, photocatalytic silica gel in which titanium oxide is supported on silica gel is used.

  When titanium oxide is used as the substance 8 having a photocatalytic action, the wavelength of light of the irradiation means 9 is preferably about 400 nm or less. This is because when the irradiation intensity is the same at different wavelengths, the photon number increases as the wavelength increases, so that the photocatalytic activity increases. On the other hand, from the band gap energy of titanium oxide, it does not show photocatalytic action at wavelengths of 400 nm or more, so wavelengths of 400 nm or less are desirable. Furthermore, sunlight, commercially available lamps and LEDs have a wide range of wavelengths. Therefore, it is desirable to use the irradiation means 9 having a peak wavelength of 350 to 400 nm. Furthermore, if the wavelength is 373 nm or more, it is not necessary to take special measures against light leakage according to the law. Therefore, the irradiation means 9 is preferably a black light, an ultraviolet lamp having a peak wavelength of about 350 nm to 400 nm, or an LED from the viewpoints of environmental and health considerations and prevention of resin degradation.

  There are two types of lamps, a hot cathode type, a cold cathode type, and an electrodeless type. Any one of them may be used, but a cold cathode type or an electrodeless type is desirable in consideration of durability. In addition, when an LED is used, it can be used for a long time because deterioration of the LED can be suppressed by increasing and decreasing the temperature of the resin that normally covers the light emitting element by repeatedly turning on and off. In the present embodiment, an LED having a peak wavelength near 380 nm is used.

  The switching valve 12 is not particularly limited as long as water can be shut off, and an openable / closable stopper or the like may be used in the vicinity of the discharge port 11 instead of the switching valve 12. The pump 7 is not particularly limited as long as water can be sent out.

  For the purpose of measuring the ORP of hot water, it is desirable to provide an oxidation-reduction potential sensor (not shown) at an appropriate location such as the circulation path 5 or the water storage container 2 so as to monitor the ORP so as not to decrease too much. . In addition, when the ORP becomes almost the set value or becomes a predetermined value or less, it can be monitored more reliably by interlocking with the notification means for notifying the user.

  The filter 10 contains an adsorbent for water purification, calcium or magnesium carbonate such as calcium carbonate or magnesium oxide, oxide, hydroxide, alloy or the like. The adsorbent is not particularly limited as long as it has a physical adsorption action or a chemical adsorption action, but activated carbon is desirable for the purification of tap water. Calcium or magnesium carbonate compounds, oxides, hydroxides, alloys, and the like may be contained in the form of grains, or the powders may be solidified with a binder or the like. Moreover, you may enter in the state of what contains calcium carbonate, such as coral sand. ORP can be further reduced by the dissolution of calcium, magnesium, etc., and can be reduced water to which minerals necessary for the body such as calcium and magnesium are added. Furthermore, extractability of tea and the like can be improved by reducing ORP and adding calcium or magnesium. In addition, as described above, the installation location is not limited to the one shown in the figure. However, if calcium or magnesium is excessively dissolved, the taste of water changes or the pH shifts to the alkali side. Therefore, it is necessary to set a place and amount that do not melt more than necessary.

  Next, the operation of the electric water heater in this embodiment will be described. Water is poured into the water storage container 2 and the heater 4 is operated to start boiling water. At this time, the path to the discharge port 11 is closed by the switching valve 12 and the pump 7 and the irradiation means (LED in the present embodiment) 9 are operated, so that the water 8 in the water storage container 2 has a photocatalytic action 8. , The circulation path 5 and the filter 10 are formed to return to the water storage container 2. At this time, the photocatalytic substance 8 increases the dissolved hydrogen (hydrogen ion) concentration by electrolyzing water in a minute amount, or decomposes organic substances such as trihalomethane and trace components such as hypochlorous acid contained in water. Alternatively, free chlorine is adsorbed on the activated carbon by the filter 10 or magnesium or calcium is dissolved, resulting in reduced water having a reduced ORP. Then, the boiling of the water is finished and the mode is shifted to the heat retention mode. During the heat retention, when hot water is taken out, the path to the filter 10 is closed by the switching valve 12 and the pump 7 is operated to take out the hot water from the discharge port 11.

  Next, the experimental procedure will be described.

  The electric water heater (hereinafter referred to as electric water heater A) in the present embodiment, the electric water heater (hereinafter referred to as electric water heater B) obtained by removing the irradiation means (LED) 9 from the electric water heater A, and further the filter 10 from the electric water heater B. A removed electric water heater (hereinafter referred to as an electric water heater C) was prepared.

  A predetermined amount of tap water having an ORP of 700 mV was put into each electric water heater, and the water was heated. Thereafter, 50 mL of hot water from each electric water heater was put into a sealed container and allowed to stand for 5 hours to lower the temperature to room temperature. And ORP was measured with the oxidation-reduction potentiometer (product made from HORIBA, pH / ION METER F-23), and it converted into the hydrogen electrode reference | standard by adding 200mV. Electric water heaters A, B, and C were 200 mV, 350 mV, and 500 mV, respectively.

Next, the active oxygen (hydroxy radical) scavenging ability of each sample obtained in the above experiment was measured. Hydroxyl radicals generated in the hydrogen peroxide-Fe ²⁺ system were supplemented by a spin trapping method using DMPO, and the erasing ability of each sample was measured. The results are expressed in terms of mM (mmol / L) equivalent of hydroxy radical scavenging substance (mannitol) per 1 mL of the sample, and were 148, 114, 113 for electric water heaters A, B, C, respectively.

  Therefore, the electric water heater which can provide the reduced water (hot water) which has the active oxygen elimination capability which reduced ORP more than tap water is realizable from these using the electric water heater of this Embodiment.

  As described above, the electric water heater according to the present invention has a relatively simple configuration and can generate reduced water (hot water) that works to eliminate active oxygen, and is considered to be good for drinking water and cooking. Because it can be used as drinking water and cooking water, it can be used for applied products such as water heaters, water purifiers, washing machines, and dishwashers. As a bath water that can be used as well as highly washable wash water and wash water, it is possible to provide reduced water. Furthermore, it can be supplied to residential water pipes, hot water pipes, industrial pipes in factories, etc. It can be done.

Schematic configuration cross-sectional view showing an electric water heater in an embodiment of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Case 2 Water storage container 4 Heater 5 Circulation route 6 Hot water supply route 7 Pump 8 Photocatalytic substance 9 Irradiation means 11 Discharge port

Claims (7)

A water storage container, a heater for heating the water in the water storage container, a circulation path for circulating the water in the water storage container, a hot water discharge path for flowing out the water, a pump for circulating or flowing out the water, An electric water heater comprising a photocatalytic substance provided in the circulation path, and irradiation means for irradiating the photocatalytic substance with light containing at least ultraviolet rays. The electric water heater according to claim 1, wherein the substance having a photocatalytic action is anatase type titanium oxide. The electric water heater according to claim 1 or 2, wherein the substance having a photocatalytic action is supported on a carrier containing an adsorbent having a physical adsorption action. The electric water heater according to claim 1, wherein the irradiation means is a light emitting diode having a peak wavelength between 350 nm and 400 nm. The electric water heater of any one of Claims 1-4 provided with the mineral addition filter containing the compound containing at least magnesium. The electric water heater of any one of Claims 1-5 provided with the sensor which measures an oxidation reduction potential. The electric water heater of any one of Claims 1-6 which provides the hot water which has the active oxygen scavenging ability more than a tap water.

Images