US20020027070A1

US20020027070A1 - Apparatus for producing electrolyzed water

Info

Publication number: US20020027070A1
Application number: US09/947,899
Authority: US
Inventors: Shigeru Oyokota; Yuichi Sawada
Original assignee: Tominaga Manufacturing Co
Current assignee: NIHON DENKEN CO Ltd; Tominaga Manufacturing Co
Priority date: 2000-09-06
Filing date: 2001-09-06
Publication date: 2002-03-07
Also published as: JP2002079248A; KR20020020163A

Abstract

An apparatus for electrolyzing water has an electrolytic cell, a pipe having nozzles for admitting water into the cell, at least one anode plate disposed in the cell along a vertical plane, at least one cathode plate disposed in the cell substantially in parallel to the anode plate and facing it, and a pipe for letting out electrolyzed water from the cell. The cathode plate has many through holes. The anode and cathode plates have therebetween a small distance defining a narrow passage therebetween. Water issuing from the nozzles flows into the passage through the holes of the cathode plate.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to an apparatus for producing electrolyzed water which can be used for car washing and to wash agricultural products, sheeting, tableware, cooking utensils, toilets, etc. effectively without the aid of any detergent, or which can be used as water not causing oxidation.

2. Description of the Related Art

There is known an apparatus for electrolyzing water in a cell having an ion-permeable diaphragm disposed between the anode and the cathode to produce electrolyzed water. City or well water, which is an example of water to be electrolyzed, contains positive ions such as hydrogen, calcium and magnesium ions, etc. and negative ions such as hydroxide and chlorine ions, etc.

Hydrogen ions are attracted to discharge hydrogen gas at the cathode, and positive ions, such as calcium and magnesium ions, etc. are attracted to deposit scales of calcium, magnesium, etc. on the electrode surface. Alkaline water is produced around the cathode, since hydrogen ions decrease by receiving electrons from the cathode and changing to hydrogen gas.

On the other hand, hydroxide and chlorine ions are attracted to discharge oxygen and chlorine gases at the anode. Acid water is produced around the anode, since hydroxide ions decrease by releasing electrons to the anode and thereby changing to oxygen gas.

Alkaline water produced as described is generally said to prevent the oxidation of blood and body fluids, and used as drinking or cooking water. It is also considered suitable for washing, as it easily dissolves a detergent.

On the other hand, acid water is said to have a sterilizing action, and used for hand or face washing, or bathing. Acid water is, however, lower in diffusibility through lipids and other contaminant substances than alkaline or city water. It is, therefore, not suitable as water for washing away lipids containing bacteria, though it may be suitable for superficial sterilization.

Thus, the known apparatus produces not only alkaline water, but also acid water which is not suitable for washing purposes. Therefore, it is not an efficient or effective apparatus for producing washing water.

There is also known an apparatus which produces electrolyzed water as ionized water for car washing by reacting water with tourmaline sintered with a ceramic material. It is, however, actually impossible to use tourmaline for the treatment of a large amount of water, since it can be used to electrolyze only a very small amount of water.

SUMMARY OF THE INVENTION

It is, therefore, an object of this invention to provide an apparatus for electrolyzing water powerfully to produce electrolyzed water remaining neutral, but having a high washing power, instead of producing alkaline or acid water.

The above object is attained by an apparatus for producing electrolyzed water from water or an aqueous solution, the apparatus comprising an electrolytic cell (electrolytic bath), an inlet pipe for forcing water or an aqueous solution into the cell, an anode plate disposed along a vertical or inclined plane in the cell, a cathode plate disposed in the cell substantially in parallel to the anode plate and facing it, and an outlet pipe through which electrolyzed water produced in the cell is let out therefrom. The cathode plate has a multiplicity of through holes (at least 10, or preferably at least 20, or more preferably such a number of holes as covers substantially the whole surface of the cathode plate), and is so close to the anode plate that a narrow flow passage is formed between the electrode plates. The cell is provided with deflecting means by which water or an aqueous solution is directed from the inlet pipe to the holes of the cathode plate. The deflecting means causes the water, or aqueous solution to flow through the holes into the flow passage, so that the water or the solution flows through the flow passage.

It is said that water molecules form a cluster (aggregation of molecules formed by aggregating molecules) by hydrogen bonding which behaves like a macromolecule. The electrolysis of water, however, forms oxygen gas, hydrogen gas and new water molecules as a result of chemical reactions shown by formulas (1) to (3) below.

H₂O→H⁺+OH⁻ (1)

2H⁺+2e ⁻→H₂ (2)

4OH⁻→4e ⁻+O₂+2H₂O (3)

These chemical changes destroy the clusters. As a result, water decreases its surface tension and increases its surface activity and thereby its diffusion through contaminant substances. Electrolyzed water contains a large number of fine bubbles, as of hydrogen and oxygen gases, etc. and owing to cavitation (an infinite number of fine and nearly vacuum cavities formed about the bubbles and producing an impact force when they are broken), the water facilitates the separation of contaminant substances from the material to be washed.

It has been confirmed that the electrolysis of city water lowers its surface tension from 0.0722 N/m to about 0.0716 N/m.

According to this invention, water or an aqueous solution is used as raw water. As raw water is required to be electrically conductive and contain ions in order to realize the chemical reactions according to formulas (1) to (3), city or well water is usually used as “water”, though pure (or distilled) water can also be used. An aqueous solution may contain salt, or citric acid.

The amount of water which can be electrolyzed is proportional to the amount of an electric current flowing to the electrodes. It is, therefore, necessary to raise the amount of the current as far as possible to perform electrolysis powerfully. According to this invention, the electrodes have a reduced distance therebetween to receive an increased current without relying upon the application of a very high voltage. The distance between the electrodes is usually required not to exceed 3.0 mm and is preferably from about 0.5 to 2.0 mm. In this connection, it is desirable to employ a plurality of electrode units to obtain a large total electrode surface area.

The anode plate and cathode plate are so disposed as to extend substantially in parallel to each other and face each other to thereby have a substantially uniform distance therebetween, so that the surface of each electrode plates may contribute to electrolysis uniformly

The “facing” each other of the electrode plates means that there is no diaphragm therebetween.

The reduced distance between the electrodes makes it difficult for water to flow into the space therebetween. According to this invention, therefore, the cathode plate has a multiplicity of through holes which make it easy for water to flow into the passage between the electrodes. Moreover, deflecting means is provided for directing raw water toward the holes of the cathode plate so that it may flow into the passage between the electrodes. The deflecting means is preferably defined by a multiplicity of nozzles formed in the inlet pipe.

Water entering the flow passage between the two electrode plates flows therethrough with bubbles and flows out through other holes and the top clearance between the two electrode plates. Therefore, the two electrode plates are disposed not horizontally, but along a vertical or inclined plane to facilitate the flow of the water containing bubbles therebetween.

The electrolysis of water produces fine bubbles of hydrogen and oxygen gases. These bubbles serve as nuclei for an infinite number of fine and nearly vacuum cavities which produce an impact force when they are broken. This phenomenon is called cavitation, and the energy which is produced when the bubbles are broken exhibits an effective washing action. According to this invention, therefore, the outlet pipe is open at the top of the cell for letting out electrolyzed water through the top of the cell, so that the bubbles may not stay in the cell, but may be let out with the electrolyzed water.

The deposition of scales of calcium, magnesium, etc. on the cathode plate gradually makes the flow of an electric current difficult and thereby lowers the efficiency of electrolysis. Therefore, it is necessary to remove such scales from the electrode surfaces by reversing the polarity of the voltage applied to the electrode plate automatically or manually after the apparatus has been in operation for a certain length of time (about 15 min.), or when it is not in operation. As the scales removed from the electrode collect at the bottom of the cell, the cell is provided at its bottom with a drain for removing the scales from the cell. Scales still adhering to the electrode surface can be removed by water flowing into the cell through the deflecting means.

The apparatus of this invention electrolyzes water powerfully, destroys clusters of its molecules, lowers its surface tension and raises its surface activity, as stated above. The apparatus produces electrolyzed water which is abundant in fine bubbles of hydrogen and oxygen gases, etc., and which can be used as excellent water for washing owing to cavitation, as well as surface activity, even without the aid of any detergent.

Moreover, the electrolyzed water is not divided into acid and alkaline water, but remains neutral with the pH of the original water.

Moreover, the electrolyzed water produced by the apparatus of this invention ensures the rustproofing of any washing apparatus and pipeline, since it has a an oxidation-reduction potential of as low as about −300 mV

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1([0027] a) is a top plan view of an apparatus for producing electrolyzed water according to a first preferred embodiment of this invention;
FIG. 1([0028] b) is a front elevational view thereof;
FIG. 1([0029] c) is a front elevational view of a modified form of the apparatus shown in FIG. 1(b);
FIG. 2([0030] a) is a top plan view of an apparatus according to a second preferred embodiment of this invention;
FIG. 2([0031] b) is a front elevational view thereof;
FIG. 3([0032] a) is a top plan view of an apparatus according to a third preferred embodiment of this invention;
FIG. 3([0033] b) is a front elevational view thereof;
FIG. 4 is a perspective view of the electrode units in the apparatus shown in FIGS. [0034] 3(a) and 3(b);
FIG. 5 is an exploded perspective view of the electrode units shown in FIG. 4; [0035]
FIG. 6([0036] a) is a front elevational view of an apparatus according to a fourth preferred embodiment of this invention; and
FIG. 6([0037] b) is a side elevational view thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

This invention will become more apparent from the following description of its preferred embodiments based on the accompanying drawings. It is, however, to be understood that the following description and the drawings are merely illustrative, and that the scope of this invention is defined by the appended claims. In the drawings, a plurality of figures employ the same reference numerals to denote the same, or corresponding parts. [0038]
The preferred embodiments of this invention will now be described with reference to the drawings. [0039]
FIGS. [0040] 1(a) and 1(b) show an apparatus for producing electrolyzed water according to a first preferred embodiment of this invention. An electrolytic cell 1 contains a pair of electrode units U. Each electrode unit U comprises a cathode plate 2 a or 2 b having a multiplicity of through holes 50 and an anode plate 3 a or 3 b facing the cathode plate 2 a or 2 b and having a certain distance Δ therefrom. Each pair of electrode plates 2 a and 3 a (or 2 b and 3 b) face each other and are disposed in parallel to each other substantially along a vertical plane. An inlet pipe 4 is located between the two cathode plates 2 a and 2 b facing each other and introduced into the cell 1 from its bottom portion. A drain pipe 5 is connected to the bottom of the cell 1 for discharging water therefrom. An outlet pipe 6 is situated at the top of the cell 1 for letting out electrolyzed water therefrom.
The [0041] inlet pipe 4 has a multiplicity of nozzles 4 a ejecting water toward the surfaces of the cathode plates 2 a and 2 b, and when water is forced into the cell 1 through the inlet pipe 4, water is jetted out from the nozzles 4 a toward the surfaces of the cathode plates 2 a and 2 b. The water jetted out from the nozzles 4 a flows through the holes 50 of the cathode plates 2 a and 2 b into passages 51 defined between the cathode plates 2 a and 2 b and the anode plates 3 a and 3 b. Then, it flows up through the passages 51 along the electrode plates, or flows out through other holes 50 into the space between the cathode plates 2 a and 2 b. The inlet pipe 4 has a closed upper end.
If a voltage is applied across the [0042] cathode plates 2 a and 2 b and the anode plates 3 a and 3 b when the cell 1 is filled with water, while the nozzles 4 a are jetting out water, water is electrolyzed to yield oxygen gas at the anode plates 3 a and 3 b and hydrogen gas at the cathode plates 2 a and 2 b. These gases rise in the cell 1 through the holes 50 of the cathode plates 2 a and 2 b and the flow passages 51 and are let out through the outlet pipe 6 with the electrolyzed water.
When city water (raw water) is used, city water contains metal ions, such as calcium and magnesium ions, etc. Calcium and magnesium ions, etc. receive electrons from the [0043] cathode plates 2 a and 2 b to become calcium and magnesium atoms, etc. that are deposited as scales on the cathode plates 2 a and 2 b. That is, water has a lower oxidation-reduction potential as a result of a reduction of the calcium and magnesium ions which it contains. According to an experiment conducted by the inventor of this invention, city water having an oxidation-reduction potential of about +350 mV had an oxidation-reduction potential of about −300 mV as a result of its electrolysis carried out by supplying city water at a flow rate of 15 liters per minute and passing an electric current of 24 A to the electrodes. Thus, the use of electrolyzed water produced according to this invention is effective for the rustproofing of any washing apparatus and pipeline.
The scales deposited on the surfaces of the [0044] cathode plates 2 a and 2 b, however, bring about a gradually rising electrical resistance between the electrodes. It is, therefore, desirable to reverse the polarity of voltage applied across the electrode plates, when required. Upon application of the reverse voltage, the scales directly contacting the electrode surfaces are deprived of electrons and begin to be dissolved again by ionization. Thus, the scales are separated from the cathode plates 2 a and 2 b and settle in the bottom of the cell 1. After the ending of such voltage application, a valve 7 in the drain pipe 5 is opened automatically or manually to remove the scales with water from the cell 1.
The water supplied through the [0045] inlet pipe 4 is drained water off in a zone spaced above the bottom of the cell 1.
The [0046] cathode plates 2 a and 2 b are full of electrons hereby the cathode plates 2 a and 2 b are hardly oxidized, as long as the application of voltage thereto continues. On the other hand, in the state when a voltage is applied, the anode plates 3 a and 3 b are deficient in electrons hereby the anode plates 3 a and 3 b easily undergo oxidation (rusting). Therefore, it is advisable for the anode plates 3 a and 3 b to be formed from a material of high rusting resistance, such as titanium, etc. and coated with platinum, iridium, etc. A similar material and surface treatment are recommended for the cathode plates 2 a and 2 b, too, in view of the possible application of reverse voltage thereto for scale removal.
It is desirable that the [0047] nozzles 4 a provided on the side face of the inlet pipe 4 have a total open area which is larger than the cross sectional area of the inlet pipe 4, so that water may be jetted out at a uniform pressure from all the nozzles 4 a.
It is effective to have a stirring device, such as a fin for stirring, in the [0048] cell 1 to ensure that electrolyzed water and the resulting gases be mixed uniformly with raw water jetting out from the inlet pipe 4 to the electrode plates.
According to FIG. 1([0049] b), the cathode plates 2 a and 2 b are electrically connected, while the anode plates 3 a and 3 b are likewise connected, so that a DC voltage may be applied from a single power source. It is, however, likely that a different amount of electric current may flow from one electrode unit U to the other, if there is any difference in the distance A between the electrode plates, their surface conditions, etc. It is, therefore, desirable that an independent source of constant voltage is connected to each electrode unit and a function for controlling voltage is provided in the apparatus to ensure that the two electrode units be capable of electrolyzing a substantially equal amount of water.
Further, in order to undergo electrolysis with an equivalent amount in each electrode unit, the use of an independent source of constant current instead of that of constant voltage is more desirable, since it eliminates the necessity for any voltage control. It is effective to provide the [0050] outlet pipe 6 or inlet pipe 4 with a flow sensor not shown, so that voltage may be applied to the electrode units only when the supply of water from the inlet pipe 4 to the cell 1 has been detected by the flow sensor.
The [0051] holes 50 of the cathode plates 2 a and 2 b are intended for facilitating the flow of water into the flow passages 51 and the flow of the resulting hydrogen and oxygen gases from between the electrode plates. Therefore, they may be of any shape, such as round, cross, square or elongated, and for example, the cathode plates 2 a and 2 b may be of an expanded metal.
The apparatus of this invention is primarily used for electrolyzing city or well water. It is, however, also applicable to an aqueous solution of salt, sodium hypochlorite or citric acid, so that a large quantity of chlorine gas may occur from the [0052] anode plates 3 a and 3 b to produce water having a sterilizing or bleaching power. If a solution of sodium hydrogen carbonate or the like is employed, sodium hydroxide (caustic soda), as well as carbon dioxide, is produced at the anode plates 3 a and 3 b to produce alkaline water having a still higher washing power. The electrolysis of any such solution, however, requires the utmost care for waste water disposal so that no environmental problem may occur.
A modified apparatus is shown in FIG. 1([0053] c). Its inlet pipe 4 does not have any nozzle as shown at 4 a in FIG. 1(b), but is provided with a V-shaped deflector 52 which directs water from the inner end of the inlet pipe 4 to the cathode plates 2 a and 2 b.
Another possible modification may be a cell having a cyclonic structure for producing an upwardly whirling stream of water. [0054]
FIGS. [0055] 2(a) and 2(b) show an apparatus according to a second preferred embodiment of this invention.
An [0056] electrolytic cell 8 contains an anode plate 9 and a pair of cathode plates 10 a and 10 b each facing one of the opposite surfaces of the anode plate 9 and having a certain distance Δ therefrom. A pair of inlet pipes 11 a and 11 b face the cathode plates 10 a and 10 b, respectively, and are introduced into the cell 8 from its bottom portion. A drain pipe 12 is connected to the bottom of the cell 8 for discharging water therefrom. The cell 8 is provided at its top with an outlet pipe 13 for letting out electrolyzed water therefrom.
Otherwise, the apparatus is similar in construction to what has been described with reference to FIGS. [0057] 1(a) and 1(b). The same reference numerals are, therefore, used in FIGS. 2(a) and 2(b) to denote the same or corresponding parts, and no detailed description thereof will be repeated.
FIGS. [0058] 3(a), 3(b), 4 and 5 show an apparatus according to a third preferred embodiment of this invention.
The apparatus has two [0059] anode plates 15 and 16, a pair of cathode plates 17 a and 17 b disposed on the opposite sides, respectively, of the anode plate 15 and spaced apart from each other by a set of first insulating spacers 21 and another pair of cathode plates 18 a and 18 b disposed on the opposite sides, respectively, of the anode plate 16 and spaced apart from each other by another set of first insulating spacers 21, whereby a pair of electrode units U and U are constructed, as shown in FIG. 5. The electrode units U and U, or the adjoining cathode plates 17 b and 18 b are spaced apart from each other by a plurality of elongated second insulating spacers 22, and the plates 17 a, 15, 17 b, 18 b, 16 and 18 a are held together in a mutually spaced apart relationship by a plurality of insulating bolts 23 and 24. The cathode plates 17 a and 17 b are secured to a cathode connecting rod 27 by a conductive bolt 26 via a conductive spacer 25. Likewise, the cathode plates 18 a and 18 b are secured to a cathode connecting rod 30 by a conductive bolt 29 via a conductive spacer 28. The anode plate 15 is secured to an anode connecting rod 31 by a conductive bolt 33 and is spaced apart therefrom by a conductive spacer 32. Likewise, the anode plate 16 is secured to an anode connecting rod 35 by a conductive bolt 36 and is spaced apart therefrom by a conductive spacer 34.
An [0060] inlet pipe 4 is situated under an electrolytic cell 14 and has a pair of portions 19 a and 19 b inserted in the cell 14 and facing the cathode plates 17 a and 18 a, respectively, as shown in FIGS. 3(a) and 3(b). Another inlet pipe 20 has an upper end which is open at the bottom portion of the cell 14. An outlet pipe 40 is situated at the top of the cell 14 for letting out electrolyzed water therefrom.
The [0061] inlet pipe 20 performs the function of the drain pipe 5 shown in FIG. 1(b) when reverse voltage is applied for scale removal.
Water is electrolyzed if a voltage is applied across the [0062] cathode plates 17 a, 17 b, 18 a and 18 b and the anode plates 15 and 16 when the cell 14 is filled with water, while nozzles 4 a are jetting out water. For further details of electrolysis and important aspects of construction and operation, reference is made to what has already been stated with reference to FIGS. 1(a) and 1(b).
The apparatus shown in FIGS. [0063] 3(a) to 5 is featured by the compactness of the electrode units U and the use of a large number of electrode plates which enable even a small apparatus to produce a large quantity of electrolyzed water.
A modified apparatus may have four electrode units U so arranged that every two adjoining units U may have a pair of cathode plates facing each other in an appropriately spaced apart relation. [0064]
FIGS. [0065] 6(a) and 6(b) show an apparatus according to a fourth preferred embodiment of this invention.
The apparatus has a horizontally mounted [0066] electrolytic cell 1 and an inlet pipe 4 extending horizontally in the cell 1 near its bottom portion.
While the invention has been described by way of its preferred embodiments with reference to the drawings, it is to be understood that variations or modifications may be easily made by those skilled in the art. [0067]
For example, the anode and cathode plates may be disposed along an inclined plane in the cell, though they have been described above as being disposed substantially along a vertical plane. [0068]
Thus, any and all such variations or modifications are interpreted as falling within the scope of this invention which is defined by the appended claims. [0069]

Claims

What is claimed is:

1. An apparatus for producing electrolyzed water from water or an aqueous solution, comprising:

an electrolytic cell;

an inlet pipe for forcing water or an aqueous solution into the cell;

at least one anode plate disposed substantially along a vertical plane in the cell;

at least one cathode plate disposed in the cell substantially in parallel to the anode plate and facing it, the cathode plate having at least 10 through holes;

an outlet pipe through which electrolyzed water produced in the cell is let out therefrom; and

means for deflecting the water or the solution to direct the water or the solution from the inlet pipe to the holes of the cathode plate;

wherein the cathode and anode plates have therebetween a distance of 3.0 mm or less and define therebetween a flow passage extending along the vertical plane; and

the means cause the water or the solution to flow through the holes into the flow passage, so that the water or the solution flows upward through the flow passage.

2. The apparatus according to claim 1, wherein the inlet pipe has at least one portion inserted in the cell and having a plurality of nozzles for jetting out the water or the solution toward the holes of the cathode plate, the nozzles defining the means.

3. The apparatus according to claim 2, wherein one of the nozzles correspond in position to at least the lower end of the cathode plate and the outlet pipe is open at an upper position than the top of the cathode plate in the cell.

4. The apparatus according to claim 1, further comprising:

another cathode plate having at least 10 through holes and disposed in the cell substantially in parallel to the anode plate and facing it, and defining one of a pair of cathode plates;

wherein the another cathode plate and the anode plate have therebetween a distance of 3.0 mm or less and define therebetween another flow passage extending along the vertical plane, the anode plate is interposed between the cathode plates, the anode and cathode plates define an electrode unit.

5. An apparatus for producing electrolyzed water from water or an aqueous solution, comprising:

two electrode units defined in claim 4;

wherein one of the cathode plates in one of the electrode units faces one of the cathode plates in the another electrode unit in a mutually spaced apart relation.

6. An apparatus for producing electrolyzed water from water or an aqueous solution, comprising:

an electrolytic cell;

an inlet pipe for forcing water or an aqueous solution into the cell;

at least one anode plate disposed along a inclined plane in the cell;

wherein the cathode and anode plates have therebetween a distance of 3.0 mm or less and define therebetween a flow passage extending along the inclined plane; and

the means cause the water or the solution to flow through the holes into the flow passage, so that the water or the solution flows obliquely upward through the flow passage.