Method and apparatus for producing electrolyzed water

An electrolytic cell capable of controlling the pH and the ORP independently to each other, comprising an electrolytic chamber (113) to which subject water to be electrolyzed are supplied, membranes (115, 115) provided on the both side walls of the electrolytic chamber, a pair of electrode plates (116, 117) respectively provided inside the electrolyzed chamber and outside the electrolytic chamber sandwiching the membrane therebetween, and wherein the electrode plate (116) is provided outside the electrolytic chamber in contact with the membrane (115) or leaving a slight space.

TECHNICAL FIELD
 The present invention relates to an electrolytic cell and an apparatus for
 producing reducing electrolyzed water and other electrolyzed water
 favorable to be used as potable water, drip solutions and other
 injections.
 BACKGROUND ART
 It has been reported that electrolyzed alkaline water derived by
 electrolyzing subject water produces the medical effects that
 extraordinary zymosis and indigestion in the stomach and intestines,
 diarrhea and gastric hyperacidity are suppressed. The medical effects have
 been considered to be produced principally by such mineral components
 contained in electrolyzed alkaline water and present as cations as
 calcium, sodium, magnesium and potassium. Electrolyzed alkaline water used
 for obtaining such medical effects is exclusively defined being subjected
 to metal ions contained therein and the pH, and produced by electrolyzing
 subject water to which calcium, and the like are added until the pH
 reaches about 9 or more.
 However, disease is mainly caused by the damage of biomolecules within an
 organism resulting from oxidation of the biomolecules with active oxygen
 formed therein, and such active oxygen can be reduced with hydrogen to
 form non-toxic water. By promoting the reaction, higher medical effects
 can be obtained, and the applicants of the present application found
 through their study that it is preferable to use electrolyzed water of a
 minus oxidation-reduction potential (ORP) and the absolute value is large
 (for example the ORP is
 300 mV or less).
 When using electrolyzed water having a reducing property of this kind as
 potable water, drip solutions, injections, dialysis solutions, etc., it is
 desired that the pH is maintained to be as neutral as possible. The
 conventional apparatus for producing electrolyzed water, however, was not
 able to produce electrolyzed water having a neutral pH and an
 oxidation-reduction potential in minus a little. Namely, when
 electrolyzing subject water by the conventional apparatus for producing
 electrolyzed water, a pH and an ORP correlationally changed. When the pH
 was heighten to about 10, the ORP fell to about -500 mV, while in the case
 of electrolyzed water having a pH close to neutral, such as 6 to 8, the
 ORP fell only to about
 150 mV even at minimum. Namely, in the conventional apparatus for producing
 electrolyzed water, the pH and the ORP were not able to be controlled
 independently to each other.
 DISCLOSURE OF INVENTION
 The present invention has been made in consideration of the above problem
 of the related art and has as an object thereof to provide an electrolytic
 cell and apparatus for producing electrolyzed water capable of controlling
 a pH and an ORP independently to each other.
 [1] To attain the above object, an electrolytic cell of the present
 invention, comprising:
 an electrolytic chamber to which subject water is supplied, and at least a
 pair of electrode plates respectively provided inside said electrolytic
 chamber and outside said electrolytic chamber sandwiching a membrane
 therebetween; and the electrolytic cell,
 wherein the electrode plate outside said electrolytic chamber is provided
 in contact with the membrane or leaving a slight space.
 In the electrolytic cell of the present invention, a pair of electrode
 plates sandwiching a membrane therebetween are respectively provided
 inside and outside the electrolytic chamber, and one of the electrode
 plates is provided outside the membrane being in contact with the membrane
 or leaving a slight space therebetween. Electrolysis is carried out by
 flowing a current to the pair of electrode plates, while feeding the
 subject water to the electrolytic chamber.
 Here, between the pair of electrode plates sandwiching the membrane,
 especially between the electrode plate outside the electrolytic chamber
 and the membrane, lies subject water due to water content characteristics
 of the membrane and capillarity between the electrode plate and the
 membrane, so that a current flows between the electrode plates.
 The chemical reaction at this time will be explained in a case where the
 electrode plate inside the electrolytic chamber is an anode and the
 electrode plate outside the electrolytic chamber is a cathode.
 First, when a direct current (DC) voltage is applied to the pair of
 electrode plates, the reaction of
EQU 2H.sub.2 O+2e.sup.-.fwdarw.2OH.sup.- +H.sub.2.uparw. (1)
 arises on the surface of the cathode plate inside the electrolytic chamber.
 And the reaction of
EQU H.sub.2 O--2e.sup.-.fwdarw.2H.sup.+ +1/2.multidot.O.sub.2.uparw. (2)
 arises on the surface of the electrode plate outside the electrolytic
 chamber over the membrane, that is, between the electrode plate and the
 membrane.
 In the electrolytic cell of the present invention, since the membrane and
 the electrode plate (anode) outside the electrolytic chamber are almost in
 contact with each other, H.sup.+ ion (actually, existing in the form of
 oxonium H.sub.3 O.sup.+) in the above formula (2) generated between them
 strongly react against on the anode plate. Therefore, relatively large
 electric power is applied in the membrane direction. As a result, the
 H.sup.+ ion passes the membrane as being permeated in the same, and a part
 of the H.sup.+ ion receives electron e.sup.- from the cathode plate,
 becomes hydrogen gas as in the formula (3) below, and dissolved into the
 produced electrolyzed water on the cathode side.
EQU 2H.sup.+ +2e.sup.-.fwdarw.H.sub.2.uparw. (3)
 As a result, the electrolyzed water produced on the cathode side (that is,
 inside the electrolytic chamber) has a lower oxidation-reduction potential
 (ORP) than ordinary cases (which is the electrolyzed water having a minus
 ORP of a high absolute value, and hereinafter also referred to as
 electrolyzed reducing water).
 Note that the residual H.sup.+ ion passed through the membrane is reduced
 to water by reacting with OH.sup.- ion in the electrolytic chamber
 (2H.sup.+ +OH.sup.-.fwdarw.H.sub.2 O), so that the pH of the electrolyzed
 reducing water produced in the electrolytic chamber becomes a little close
 to neutral.
 [2] In the electrolytic cell of the present invention, when the membrane
 and a pair of electrode plates are provided at least two sets, at least
 two electrode plates are provided inside the electrolytic chamber, thus,
 the reaction of the above formula (1) is proceeded also between the
 electrode plates of the same polarity. Accordingly, comparing with the
 case of providing a pair of electrode plate sandwiching the membrane
 therebetween, the electrolysis reaction area per unit volume increases.
 Therefore, the efficiency of the electrolysis improves and the
 electrolytic cell can be configured to be compact.
 Also, in the electrolytic cell of the present invention, the membrane and
 the electrode plate (anode) outside the electrolytic chamber are provided
 being almost in contact with each other and only the water lies between
 the membrane and the electrode plate outside the electrolytic chamber
 becomes conductive medium. Therefore, the oxygen gas generated in the
 above formula (2) is emitted into the air as it is. Accordingly, comparing
 with a so-called non-membrane type electrolysis, dissolved oxygen content
 in the produced electrolyzed water becomes remarkably small, and,
 furthermore, the oxidation-reduction potential becomes low.
 At the same time, when the H.sup.+ ion and oxygen gas on the right side of
 the equal sign in the above formula (2) are discharged from between the
 membrane and the electrode plate outside the electrolytic chamber, there
 is a tendency that the reaction in the right direction of the formula (2)
 becomes active in terms of chemical balancing. As a result, an electron
 supplying capacity from the cathode plate to water molecules H.sub.2 O and
 an electron receiving capacity to receive water molecules H.sub.2 O of the
 anode plate are activated, so that the conductive capacity is not reduced
 even when the electrolysis is carried out for a long time and stabilized
 electrolyzed water can be obtained.
 In the electrolytic cell of the present invention, when the membrane and a
 pair of electrode plates are provided at least two sets, at least one of
 the electrode plates outside the electrolytic chamber provided at least
 two is preferably provided in the second electrolytic chamber.
 Electrolysis is carried out by respectively flowing a current to the
 respective two pairs of electrode plates while supplying the subject water
 (electrolyte may be added in accordance with need) to the second
 electrolytic chamber and supplying the same to the above original
 electrolytic chamber (hereinafter, also referred to as a first
 electrolytic chamber for convenience).
 Here, a case where the electrode plate in the first electrolytic chamber is
 a cathode plate and the electrode plate outside the first electrolytic
 chamber is anode plate will be explained as an example. In the
 electrolysis carried out between the anode plate provided inside the
 second electrolytic chamber and the corresponding cathode plate making a
 pair, since sufficient subject water is supplied to both the electrolytic
 chambers, the pH rises, the ORP lowers, and furthermore, mineral
 components are condensed in the electrolyzed water produced near the
 cathode plate.
 Contrary to this, in the electrolysis carried out between the other anode
 plate and the corresponding cathode plate making a pair, since the chamber
 provided with the anode plate is open to the air, although the pH of the
 electrolyzed water produced near the cathode plate does not rise much and
 the mineral components are unchanged, the ORP reduces due to the reasons
 above.
 Generally, since an ORP of electrolyzed water can be made lower more
 easily, when a pH is higher, it is advantageous to make the pH higher when
 producing electrolyzed water having a larger reduction potential is
 desired.
 Since a pair of electrode plates having different property values exist
 within one electrolytic chamber for producing electrolyzed water, by
 properly controlling the pair of electrode plates in accordance with need,
 a pH and an ORP can be controlled without being affected by difference of
 water quality (the pH and ORP) of the subject water.
 In this case, a degree of free combination of a pH and an ORP can be
 heightened by providing an electrolytic cell, comprising: a first
 electrolytic cell having a first electrolytic chamber and a second
 electrolytic chamber filled in by subject water and separated by a
 membrane and at least a pair of electrode plates sandwiching the membrane
 therebetween respectively provided in the first electrolytic chamber and
 the second electrolytic chamber; a second electrolytic cell having a third
 electrolytic chamber to which electrolyzed water produced in the first
 electrolytic chamber of the first electrolytic cell, at least a pair of
 electrode plates sandwiching a membrane therebetween respectively provided
 inside of the third electrolytic chamber and outside of the third
 electrolytic chamber; and the electrolytic cell wherein the electrode
 plate outside of the third electrolytic chamber is provided in contact
 with the membrane or leaving a slight space.
 [3] It is not limited to the electrolytic cell of the present invention,
 however, as a reverse descaling method, for example, it is preferable that
 the power source circuit has a reverse electrolysis descaling circuit for
 carrying out a first reverse electrolysis descaling by applying a voltage
 of either one of an anode or a cathode to one of the electrode plates
 provided outside of the electrolytic chamber, and simultaneously applying
 a voltage of the other one of the anode or the cathode to the other one of
 the electrode plates, and thereafter, carrying out a second reverse
 electrolysis descaling by reversing the polarity of the applying voltage
 to the electrode plates. At this time, it is not specifically limited,
 however, it is preferable that a voltage is not applied to the electrode
 plate outside the electrolytic chamber during the first and second reverse
 electrolysis descaling.
 An ordinary method of reverse electrolysis descaling is to simply reverse
 the applying polarity, and an anode polarity is applied to the electrode
 plate, to which a scale is adhered by being applied a cathode polarity
 till then, in order to electrically flow out the adhered scale.
 Accordingly, such a method of reverse electrolysis descaling can be
 adopted to the above electrolytic cell of the present invention.
 However, even during the reverse electrolysis descaling, scale adheres to
 the electrode plates which is being applied a cathode polarity. In the
 above electrolytic cell of the present invention, it is difficult to
 remove the once adhered scale because the subject water is not supplied to
 the electrode when transferred to the regular electrolysis, and the anode
 polarity is applied to the electrode. Therefore, by using the at least two
 electrode plates provided in the first electrolytic chamber, the scale
 adhered to the electrode plates is removed by flowing a current for
 reverse electrolysis descaling only to these electrode plates.
 In this way, scale is not adhered to the electrodes provided outside the
 first electrolytic chamber and the reverse electrolysis descaling can be
 conducted by flowing a current only to the electrode plates provided
 inside the first electrolytic chamber. Therefore, half amount of power
 becomes sufficient, or the duration for reverse electrolysis descaling can
 be reduced to half with the same amount of current.
 [4] The above electrolytic cell of the present invention can be used
 independently, however, it may be configured as an apparatus for producing
 electrolyzed water, comprising: a plurality of electrolytic cells, a water
 supply system for letting in the subject water in parallel to the
 respective electrolytic chambers of the electrolytic cell, and a water
 sluice system for letting out in parallel the electrolyzed water generated
 in the respective electrolytic chambers.
 In the electrolytic cell and an apparatus for producing electrolyzed water
 of the present invention, electrode plates outside the electrolytic
 chamber are provided being in contact with the membrane or leaving a
 slight space. This idea includes forming the electrode plates on the
 surface of the membrane.
 The membrane used in the electrolytic cell and an apparatus for producing
 electrolyzed water of the present invention is not specifically limited,
 however, a porous membrane, an ion-exchange membrane (cation-exchange
 membrane or anion-exchange membrane) etc. can be raised. To sum up, the
 membrane of the present invention may be anything as far as it has porous
 characteristics and water content characteristics to allow water molecules
 to pass through it.
 Also, in the electrolytic cell and an apparatus for producing electrolyzed
 water of the present invention, other conductor and semiconductor can be
 stacked on the principal surface facing to the membrane of the electrode
 plates. The electrode plates of the present invention also includes these.
 Purpose for using the electrolyzed water produced by the electrolytic cell
 and an apparatus for producing electrolyzed water of the present invention
 is not specifically limited, and can be applied for a wide range of
 various fields of medical treatment, foods, agriculture, industry, etc. in
 addition to potable water and medical use.
 Note that the electrolyzed water obtained by the electrolytic cell and an
 apparatus for producing electrolyzed water of the present invention is
 characterized in that the value of the oxidation-reduction potential does
 not depend on a pH. Therefore, in the present specification, the
 electrolyzed water produced by the cathode side will be referred to as
 electrolyzed reducing water not as alkaline electrolyzed water and the
 electrolyzed water produced by the anode side will be referred to as
 electrolyzed oxidizing water not as acidic electrolyzed water.

BEST MODE FOR CARRYING OUT THE INVENTION
 Below, the preferred embodiment of the present invention will be explained
 based on the drawings.
 [First Embodiment]
 FIG. 1 is a vertical cross-sectional view of a first embodiment of the
 present invention which shows the basic configuration of the electrolytic
 cell of the present invention.
 In the electrolytic cell 11 of the present invention, an inlet 111 for
 letting in the original water and an outlet 112 for letting out the
 electrolyzed water are formed and an electrolytic chamber 113 is formed
 between the inlet 111 and the outlet 112. In the electrolytic cell 11 of
 the present example, the inlet 111 is formed in order that the subjected
 water flows in the vertical direction with respect to the illustrated
 paper surface at the bottom of a casing 114, and the outlet 112 is formed
 in order that the electrolyzed water is sluiced out in the vertical
 direction with respective to the illustrated paper surface at the top
 surface of a casing 114.
 Also, porous films 115 are provided on the right and left side walls of the
 electrolytic chamber 11, and electrode plates 116 are respectively
 provided for the porous films 115 outside the electrolytic chamber in a
 contact state. The other electrode plates 117 are provided inside the
 electrolytic chamber 113 in order that the primary surfaces respectively
 face to each of the electrode plates 116.
 The two sets of electrode plates 116 and 117 are connected with a direct
 current (DC) power source 12. An anode polarity is applied to one of the
 one pair of mutually facing electrode plates 116 and 117 sandwiching the
 membrane 115 therebetween and a cathode polarity is applied to the other
 electrode plate. For example, when generating electrolyzed reducing water
 in the electrolytic chamber 113, as shown in FIG. 1, the cathode of the DC
 power source is connected to the electrode plate 117 provided in the
 electrolytic chamber 113, and the anode is connected to the electrode
 plate 116 provided outside the electrolytic chamber 113.
 Note that when generating electrolyzed oxidizing water in the electrolytic
 chamber 113, the anode of the DC power source may be connected to the
 electrode plate 117 provided inside the electrolytic chamber 113 and the
 cathode may be connected to the electrode plate 116 provided outside the
 electrolytic chamber 113.
 The membrane 115 used in the present embodiment is preferably has
 characteristics that it easily permeates the water flowing into the
 electrolytic chamber 113, at the same time, the permeated water is hard to
 drip. Namely, in the electrolytic cell 11 of the present embodiment,
 during the electrolysis, a water film is formed in the membrane 115 itself
 and in the slight space S between the membrane 115 and the electrode plate
 116, and the current flows to both the electrode plates 116 and 117 via
 the water film. Accordingly, it becomes important for improving the
 electrolysis efficiency that the water composing this water film is
 successively exchanged. Also, if the water permeated in the membrane 115
 leaks from between the membrane 115 and the electrode plate 116,
 processing to deal with it is required. Therefore, it is preferable that
 the membrane 115 has water content characteristics to a degree that the
 permeated water does not leak.
 As one example of the membrane 115, a porous film formed by unwoven
 polyester or polyethylene screen as a core part and chlorinated ethylene
 or poly-fluorinate bynilyden and titanium oxide or poly-vynil chloride as
 film materials, having the thickness of 0.1 to 0.3 mm, an average diameter
 of the porous being 0.05 to 1.0 .mu.m, and the permeable water amount of
 not more than 1.0 cc/cm2.multidot.min. can be raised as an example.
 On the other hand, a distance between a pair of mutually facing electrode
 plates 116 and 117 arranged to sandwich the membrane 115 is 0 mm to 5.0
 mm, more preferably, 1.5 mm. Here, the distance between the electrode
 plates 116 and 117 being 0 mm indicates the case of using a zero gap
 electrode, for example as shown in FIG. 14, wherein the electrode films
 are directly formed respectively on both primary surfaces of the membrane
 115, and it means that substantially there is a distance of the thickness
 of the membrane 115. In the zero gap electrode, electrode may be formed
 only on one primary surface of the membrane 115. Also, when adopting such
 a zero gap electrode, it is preferable that holes or a space is provided
 on the electrode plates 116 and 117 for letting out the gas generated on
 the electrode surfaces to the back side which is the opposite of the
 membrane 115.
 The distance between the electrode plates 117 and 117 provided inside the
 electrolytic chamber 113 is not specifically limited, however, it is 0.5
 mm to 5 mm, more preferably, 1 mm.
 When generating electrolyzed reducing water by using such an electrolytic
 cell 11, first, the cathode (-) of the DC power source 12 is connected to
 the two electrode plates 117 and 117 provided inside the electrolytic
 chamber 113, the anode (+) of the DC power source 12 is connected to the
 electrode plates 116 and 116 outside the electrolytic chamber 113, and a
 voltage is applied to two pairs of the mutually facing electrode plates
 116 and 117 sandwiching the membrane 115. Then, when water, such as tap
 water, is supplied from the inlet 111, the tap water is subjected to
 electrolysis in the electrolytic chamber 113, and the reaction of the
 above formula (1) occurs on the surface of the electrode plates 117 and
 the around. The reaction of the above formula (2) occurs on the surface of
 the electrode plate 116 outside the electrolytic chamber 113 over the
 membrane 115, that is, between the electrode plates 116 and the membrane
 115.
 This H.sup.+ ion passes the membrane 115 as being permeated therein, and a
 part of it receives the electron e.sup.- from the cathode plate 117 to
 become hydrogen gas and dissolved in the generated electrolyzed water on
 the cathode side. Due to this, the electrolyzed water generated on the
 cathode side (that is, inside the electrolysis chamber 113) becomes
 electrolyzed reducing water having a lower oxidation-reduction potential
 (ORP) than ordinary cases.
 Since the residual H.sup.+ ion passed through the membrane 115 reacts with
 OH.sup.- ion in the electrolytic chamber 113 and is reduced to water, the
 pH of the electrolyzed reducing water generated in the electrolytic
 chamber 113 becomes a little close to neutral. Namely, electrolyzed
 reducing water having a not very high pH and a low ORP can be obtained. In
 this way, the electrolyzed reducing water including the generated
 hydroxide ion is supplied from the outlet 112.
 When continuing the electrolysis by using tap water as electrolyzing
 subject water, calcium ion and magnesium ion included in the tap water
 precipitate on the surface of the cathode plate 117, becomes a scale and
 causes deterioration of the electrolysis efficiency. Therefore, so called
 reverse electrolysis descaling is carried out to remove the scale
 precipitated on the cathode plate 117 after performing electrolysis for a
 certain period of time. In the electrolytic cell 11 of the present
 embodiment, the reverse electrolysis descaling is carried out in certain
 intervals.
 As the simplest method of the reverse electrolysis descaling, it is
 considered to simply reverse the polarity applied hithereto. Namely, to
 explain in the above case of generating the alkaline electrolyzed water,
 while, connecting the anode (+) of the DC power source 12 to the two
 electrode plates 117 and 117 provided inside the electrolytic chamber 113,
 connecting the cathode (-) of the DC power source 12 to the electrode
 plates 116 and 116 provided outside the electrolysis chamber 113, and a
 voltage is applied to the two pairs of mutually facing electrode plates
 116 and 117 sandwiching the membrane 115. As a result, at the electrode
 plates 117 being adhered by scale due to the application of cathode, the
 adhered plus metal ion is flown out in the tap water by being applied an
 anode and discharged from the outlet 112.
 In the electrolytic cell of the present invention, the explained reverse
 electrolysis descaling method can be of course adopted, as well, however,
 when applying a cathode to the electrode plate 116 provided outside the
 electrolytic chamber 113, scale is precipitated on the electrode plate 116
 during the reverse electrolysis descaling. Therefore, in the electrolytic
 cell having the configuration shown in FIG. 1, it becomes difficult to
 remove the scale precipitated on the electrode plate 116 during the
 regular electrolysis performed next. If this is continued, the scale
 precipitated on the electrode plate 116 gradually increases to bring a
 fear that the electrolysis efficiency declines.
 Therefore, the reverse electrolysis descaling of the present embodiment is,
 as shown in FIGS. 2 and 3, carried out by applying a voltage only to the
 two electrode plates 117 and 117 provided inside the electrolytic chamber
 113 to remove the scale. Namely, as shown in FIG. 2, the polarity of one
 of the two electrode plates 117 and 117 provided inside the electrolytic
 chamber 113 (the electrode plate 117 on the left here) is kept to be
 minus, while the polarity of the other (the electrode plate 117 on the
 right here) is reversed to be applied a plus voltage first. As a result, a
 current flows between the two electrode plates 117 and 117 inside the
 electrolytic chamber 113, so that the scale precipitated on the electrode
 plate 117 on the right being applied a plus voltage is flown into the tap
 water.
 After continuing this for a certain period of time, as shown in FIG. 3, the
 application polarity of the two electrode plates 117 and 117 are reversed
 in turn. Namely, a plus voltage is applied to the electrode plate 117 on
 the left, a minus voltage is applied to the electrode plate 117 on the
 left, and by flowing a current between the two electrode plates 117 and
 117, the scale precipitated on the electrode plate 117 on the left in turn
 is removed.
 By applying this reverse electrolysis descaling method, the power
 consumption during the reverse electrolysis descaling becomes half, or
 time for the reverse electrolysis descaling becomes half when with the
 same power consumption. Also, since a current does not flow to the
 electrode plates 116 provided outside the electrolytic chamber 113 during
 the reverse electrolysis descaling, only anode voltage is applied to the
 electrode plates 116. Accordingly, it is not necessary to use an expensive
 plate material able to be used as both polarities in terms of endurance,
 or in the case of performing precious metal coating, it is possible to
 make the thickness of the film thinner.
 Note that in the above embodiment, a case of generating electrolyzed
 reducing water was raised as an example for explaining the electrolytic
 cell 11, however, the electrolytic cell 11 of the present invention can be
 applied to the case of generating electrolyzed oxidizing water, as well.
 In the case, it is attained by connecting an anode (+) to the DC power
 source 12 of the two electrode plates 117 and 117 provided inside the
 electrolytic chamber 113, connecting a cathode (-) of the DC power source
 12 to the electrode plates 116 and 116 provided outside the electrolytic
 chamber 113, and applying voltages to the two pairs of mutually facing
 electrode plates 116 and 117 sandwiching the membrane 115.
 Then, when water, such as tap water, is supplied from the inlet 111, the
 tap water is subjected to electrolysis in the electrolytic chamber 113,
 and the reaction of the above formula (2) occurs on the surface of the
 electrode plate 117 and the around, while the reaction of the above
 formula (1) occurs on the surface of the electrode plate 116 outside the
 electrolytic chamber 113 over the membrane 115, that is, on the water film
 between the electrode plate 116 and the membrane 115.
 This OH.sup.- ion passes the membrane 115 as being permeated therein, and a
 part of it delivers the electron e.sup.- to the cathode plate 117 to
 become oxygen gas and dissolved in the generated electrolyzed water on the
 anode side. Due to this, the electrolyzed water generated on the anode
 side (that is, inside the electrolysis chamber 113) becomes electrolyzed
 reducing water having a lower oxidation-reduction potential (ORP) than
 ordinary cases.
 Since the residual OH ion passed through the membrane 115 reacts with H+ion
 in the electrolytic chamber 113 to be reduced to water, the pH of the
 electrolyzed reducing water generated in the electrolytic chamber 113
 becomes a little close to neutral. Namely, electrolyzed reducing water
 having a not very high pH but a low ORP can be obtained. The electrolyzed
 oxidizing water including the hydrogen ion generated in this way is
 delivered from the outlet 112.
 The electrolytic cell of the present embodiment will be explained more
 specifically.
 By using the electrolytic cell 11 having the basic configuration shown in
 FIG. 1, wherein tap water having the pH of 7.9 and the ORP of +473 mV was
 flown by four litters per minute, a voltage was applied to electrode
 plates 116 and 117, each having an area of 24 cm.sup.2, and a constant
 current of 14 A was provided to carry out electrolysis.
 As a membrane 115, a porous film formed by unwoven polyester as the
 aggregate, poly-fluorinate bynilyden and titanium oxide as the film
 material, having the thickness of 0.12 mm, an average porous diameter of
 0.4 mm, and the permeable water amount of not more than 0.3
 cc/cm.sup.2.multidot.min. was used. The distance between the electrode
 plates 116 and 117 was set to be 1 mm and the distance between the
 electrode plates 117 and 117 was set to be 1 mm.
 As a result, electrolyzed reducing water having the pH of 9.03 and the ORP
 of -550 mV was obtained immediately after the generation. Also, when
 measuring the pH and the ORP of the electrolyzed reducing water being kept
 still for 5 minutes and 10 minutes and 30 minutes, the results became as
 shown in Table 1.
 According to this, the pH exceeded 9 at the initial stage of the
 electrolysis, however, it soon lowered and was stabilized at pH=8. The
 reason for this can be considered that the H.sup.+ ion generated at the
 water film between the membrane 115 and the anode plate 116 passed through
 the membrane 115 and moved to the electrolytic chamber 113 to have
 neutralizing reaction with OH ion inside the electrolytic chamber 113.
 TABLE 1
 immediately 5 10
 after minutes minutes 30 minutes
 electrolysis later later later
 pH 9.03 8.14 8.11 8.02
 ORP (mV) -550 -562 -570 -571
 [Second Embodiment]
 The electrolytic cell of the present invention has the basic configuration
 shown in FIG. 1, however, when making it fit for practical use, a variety
 of embodiments can be considered. FIG. 4 is a vertical cross-sectional
 view of a second embodiment of the present invention, wherein the common
 members as those in the basic configuration of the electrolytic cell 11 of
 the present invention shown in FIG. 1 are indicated by the same reference
 numbers.
 In the electrolytic cell 11 of the present embodiment, the different point
 form the above first embodiment is that one of the electrode plates 116
 and 116 provided outside the electrolytic chamber 113 (here, it is the one
 on the left) is provided in a second electrolysis chamber 118. The second
 118 is formed on one side wall of a casing 114 and to which electrolyzing
 subject water is supplied. The supply of the electrolyzing subject water
 to the second 118 may be water flowing water or simply filled water
 subjected to be electrolyzed.
 According to the electrolytic cell 11, the electrolyzed reducing water
 generated by a pair of electrode plates 116 and 117 on the right can be
 made to have the ORP of peculiarly low in minus without making the pH very
 high as explained above. Contrary to this, the electrolyzed reducing water
 generated by the pair of electrode plates 116 and 117 on the left has a
 high pH and an ORP of largely low in minus.
 Accordingly, since mixture of the two kinds of electrolyzed reducing water
 is delivered from the outlet 112 of the electrolytic cell 11, the
 combination of the pH and the ORP can be adjusted freely by controlling
 the current to flow respectively into the pair of the electrode plates 116
 and 117 on the right and the pair of the electrode plates 116 and 117 on
 the left.
 This is effective especially when the quality of the electrolyzing subject
 water is different. For example, the balance of the pH and the ORP of the
 electrolyzing subject water often largely changes depending on regions and
 seasons. If the electrolytic cell 11 of the present embodiment is used for
 such a case, the balance of the pH and the ORP can be controlled to be
 desired values.
 The electrolytic cell 11 of the present embodiment will be further
 specifically explained.
 By using the electrolytic cell 11 having the basic configuration shown in
 FIG. 4, tap water having the pH of 7.9 and ORP of +473 mV was flown by
 four litters per minute to the electrolytic chamber 113, while by one
 litter per minute to the second 118, a voltage was applied to electrode
 plates 116 and 117, each having an area of 24 cm.sup.2, and a constant
 current of 7 A was provided to carry out electrolysis.
 As a membrane 115, a porous film formed by unwoven polyester as the
 aggregate, poly-fluorinate bynilyden and titanium oxide as the film
 material, having the thickness of 0.12 mm, an average porous diameter of
 0.4 .mu.m, and the permeable water amount of not more than 0.3
 cc/cm.sup.2.multidot.min was used. The distance between the electrode
 plates 116 and 117 was set to be 1 mm and the distance between the
 electrode plates 117 and 117 was set to be 1 mm.
 As a result, electrolyzed reducing water having the pH of 9.57 and the ORP
 of -657 mV was obtained immediately after the generation. Also, when
 measuring the pH and the ORP of the electrolyzed reducing water being kept
 still for 5 minutes and 10 minutes, the results became as shown in Table
 2.
 Next, the current value flowing to a pair of electrode plates 116 and 117
 provided in the second 118 was made to be 3 A and 5 A to generate
 electrolyzed water under the same condition as above. The result is shown
 in Table 2.
 According to this, by appropriately adjusting the current value flowing to
 the pair of electrode plates, electrolyzed water having the desired pH and
 ORP can be generated.
 TABLE 2
 Immediately
 after 5 minutes 10 minutes
 current electrolysis later later
 7A pH 9.57 9.50 9.46
 ORP -657 -670 -659
 5A pH 9.45 9.21 9.15
 ORP -620 -565 -610
 3A pH 9.16 8.86 8.80
 ORP -530 -539 -539
 As a modified example of the above second embodiment, it is considered to
 connect two or more electrolytic cells in series. For example, the
 electrolytic cell 11 shown in FIG. 15 is a serially connected electrolytic
 cell wherein a general electrolytic cell of water flowing type 11A (first
 electrolytic cell) and the electrolytic cell of the first embodiment 11B
 (second electrolytic cell) are connected in series.
 An inlet 111A is formed to which the electrolyzing subject water, such as
 tap water, is fed at one end of the casing 114A of the first electrolytic
 cell 11A, and a pair of mutually facing electrode plates 116A and 117A are
 provided in the casing 114A sandwiching the membrane 115A therebetween. In
 this example, the membranes 115A and a pair of the electrolytic plates
 116A and 117A are provided two sets on both sides of the casing 114A. By
 this, an electrolytic cell 113A is formed between the two membranes 115A
 and 115A, and the second electrolytic cells 118A and 118A are formed
 outside the membranes 115A and 115A.
 Note that an outlet 118Aa is provided for letting out the electrolyzed
 water generated at the second electrolysis chamber 118A at the casing 114A
 positioned in the downstream side of the second electrolysis chamber.
 The electrolytic cell 11B of the above first embodiment (refer to FIG. 1)
 is connected in the downstream side of the first electrolytic cell 11A.
 The same reference numbers are used for the same members.
 As shown in FIG. 15, the first electrolytic cell 11A and the second
 electrolytic cell llB are connected in series. When generating
 electrolyzed reducing water having a small ORP in the electrolytic cell
 11, (alkaline) electrolyzed water having a high pH in the first
 electrolytic cell 11A. And when supplying the generated electrolyzed water
 as electrolyzing subject water to the second electrolytic cell 11B, it is
 possible to mainly make the ORP low in minus in the second electrolytic
 cell 11B. Namely, the pH can be adjusted in the first electrolytic cell
 11A and the ORP can be adjusted in the second electrolytic cell 11B.
 Therefore, the electrolyzed water having a high degree of free combination
 of a pH and an ORP can be obtained.
 [Third Embodiment]
 FIG. 5 is the system configuration of an embodiment of the apparatus for
 producing electrolyzed water 1 configured by using the electrolytic cell
 11 of the present invention, wherein the electrolytic cell 11 of the above
 first and second embodiments are connected in series, and a water supply
 system 13 for supplying the electrolyzing subject water is provided at the
 respective inlets 111 of the electrolytic cell 11.
 The water supply system 13 is composed of a main water 46 pipe 131 and a
 plurality of branch water pipes 132 branching therefrom. A strainer 133
 for filtering any impure ingredients in the electrolyzing subject water is
 provided in the main water pipe 131, and a manual valve 134 is provided at
 the end to form a drain.
 The respective branch water pipes 132 are provided with a decompressor
 valve 135 and an electromagnetic valve 136. The branch water pipes are
 further branched ahead of the valves, to which a constant flow amount
 valves 137 and manual valves 138 are provided.
 On the other hand, a water take-in system 14 is provided at the outlet 112
 of the electrolytic cells 11 arranged in parallel. The water sluice system
 14 is composed of a main water sluice pipe 141 for putting the respective
 outlets 112 of the electrolytic cells 11 together, an electronic valve 142
 provided at the end thereof, drain pipes 143 branched from the main water
 take-in pipe 141, and an electronic valve 144 provided to the drain pipe
 143.
 Note that a DC power source 12 shown in FIG. 1 or 4 is connected to the
 respective electrolytic cells 11, illustration of which is omitted.
 To generate the desired electrolyzed water by using such an apparatus for
 producing electrolyzed water 1, first, the manual valve 134 at the end of
 the main water pipe 131 is closed and the manual valves 138 of the
 respective branch water pipes 132 are left open. Then, the original water
 is supplied to the main water pipe 131, the electromagnetic valve 136 of
 the respective branch water pipes 132 and the electronic valve 142 of the
 water sluice system 14 are controlled.
 Though it is not especially limited, as an example of an operation method,
 it is preferable that the reverse electrolysis descaling is carried out to
 any one of the electrolytic cells 11 one by one. Namely, when being
 controlled that always one of the electrolytic cell 11 is to be carried
 out the reverse electrolysis descaling, and the remaining electrolytic
 cells 11 are to be generating electrolyzed water, the water quality of the
 electrolyzed water taken from the water sluice system 14 becomes always
 constant.
 [Fourth Embodiment]
 FIG. 6 is a cross-sectional view of a fourth embodiment of the electrolytic
 cell 11 of the present invention, wherein the common members to those in
 the basic configuration of the electrolytic cell 11 shown in FIG. 1 are
 indicated by the same reference numbers. The present example is different
 from the first embodiment in the point that only one set of the membrane
 115 and the electrode plates 116 and 117 are provided.
 Basically, the same effectiveness can be obtained as in the above first
 embodiment by using such an electrolytic cell 11. The present embodiment
 will be further specifically explained.
 As an example 1, by using the electrolytic cell having the basic
 configuration shown in FIG. 6, electrolysis was carried out by flowing tap
 water having the pH of 7.2 and the ORP of +450 mV by four litters per
 minute, and applying a voltage of 30V. A current flown to both the
 electrode plates 116 and 117 was 4 A (120 W). As a membrane 115, a porous
 film formed by unwoven polyester cloth as the aggregate, poly-fluorinate
 bynilyden and titanium oxide as the film material, having the thickness of
 0.12 mm, an average porous diameter of -0.4 .mu.m, and the permeable water
 amount of not more than 0.3 cc/cm.sup.2.multidot.min. was used. The
 distance between the electrode plates 116 and 117 was set to be 1 mm.
 As a result, electrolyzed reducing water having the pH of 8 to 9 and the
 ORP of -220 mV was obtained. Also, the electrolysis was continued for one
 hour, however, the values of the pH and ORP hardly changed as shown in
 FIGS. 7 and 8 (refer to the example 1). Note that the electrolyzed water
 having the pH exceeding 9 was obtained at the initial stage of the
 electrolysis as shown in FIG. 7, however, it soon lowered and became
 stable at the pH of 9. The reason for this can be considered that the
 H.sup.+ ion generated at the water film between the membrane 115 and the
 anode plate 116 passed through the membrane 115 and moved to the
 electrolytic chamber 113 to have neutralizing reaction with OH ion inside
 the electrolytic chamber 113.
 As a comparative example 1 to this, an electrolyzing cell having an
 electrolytic chamber 113' also on the side of the electrode plate 116 and
 wherein the distance between the electrode plate 116 and the membrane 115
 is long (0.5 mm) as shown in FIG. 9 was prepared to carry out electrolysis
 by flowing tap water having the pH of 7.2 and the ORP of +450 mV by four
 litters per minute and applying a voltage of 12V. A current flown to both
 the electrode plates 116 and 117 was 10 A (120 W). The same membrane 115
 as in the embodiment 1 was used, the distance between the electrode plates
 116 and 117 was set to be 1 mm, and the membrane 115 was set to be
 positioned at the center.
 As a result, alkaline electrolyzed water having the pH of 8 to 9 and the
 ORP of -220 mV was obtained at the initial stage of the electrolysis.
 However, when the electrolysis was continued for one hour, the pH and the
 ORP began to fluctuate after 20 minutes and the electrolysis was not able
 to be continued furthermore as shown in FIGS. 7 and 8. It is considered
 that the reason is that inside the electrolytic chamber 113' became
 saturated with the electrolyzed oxidizing water.
 Note that as an example 2, electrolysis was carried out under the same
 conditions as in the example 1 except that the polarity of the applied
 voltage to the electrode plates 116 and 117 was reversed and that tap
 water having the pH of 7.4, the ORP of +350 mV and the DO (dissolved
 oxygen content) of 6.4 ppm was used as the electrolyzing subject water.
 The electrolysis was continued for one hour and the stable electrolyzed
 oxidizing water having the pH of 6.9, the ORP of +560 mV and the DO of
 10.0 ppm could be obtained.
 When practically using the electrolytic cell of the fourth embodiment, a
 variety of forms can be considered. FIG. 10 is a vertical cross-sectional
 view of an example thereof, and FIG. 11 is a vertical cross-sectional view
 of another example, wherein the common members to those in the basic
 configuration of the electrolytic cell of the present invention shown in
 FIG. 1 are indicated by the same reference numbers.
 The electrolytic cell 11 shown in FIG. 10 has a casing 114 formed to have a
 rectangular parallelepiped vertical cross-section, wherein an inlet 111
 for electrolyzing subject water (specifically, a pipe for letting in the
 original water) is provided extending in the vertical direction with
 respective to the paper surface at the low end, and in the same way, an
 outlet 112 for the electrolyzed water (specifically, a pipe for letting
 out the electrolyzed water) is provided extending in the vertical
 direction with respective to the paper surface at the upper end.
 Also, in the electrolytic cell 11, a pair of electrode plates 116 and 117
 are fixed, further, a membrane 115 is installed on the electrode plate
 116, for example, as if the two are united as one. Between the electrode
 117 and the membrane 115 becomes an electrolytic chamber 113, and a space
 S is formed between the membrane 115 and the electrode plate 116
 configured as if being united, wherein the water exists, as well.
 To combine the electrode plate 116 and the membrane 115 as if being united
 as one, as well as to secure the water tightness with a gas chamber 119
 which will be explained later on, a packing 151 is fitted around the
 electrode plate 116 and the membrane 115. Also, in order to fix the
 electrode plate 117 to the casing 114 of the electrolytic cell 11, a
 packing 152 is fitted around the electrode plate 117.
 Especially in the electrolytic cell 11 of the present embodiment, a gas
 chamber 119 is formed outside the electrolytic chamber 113 and the gas
 generated on the surface on the side of the electrode plate 116, that is
 in the space S, can be collected effectively to the gas chamber 119. The
 reference number "119a" indicates an outlet for letting out the gas
 emitted to the gas chamber 119 to the desired part.
 Note that a chamber 119' is formed on the back surface of the electrode
 plate 117 being out of contact with the membrane 115, which is not
 essential and can be omitted. However, by making the electrolytic cell 11
 in a symmetric form, it can be preferably used to heighten the
 compatibility of the anode and the cathode. For example, when preparing an
 apparatus which can generate both electrolyzed reducing water and
 electrolyzed oxidizing water, it is sufficient to provide a circuit for
 reversing polarity to an applying circuit to the electrode plates 116 and
 117. When such a circuit cannot be provided, it can be handled by
 exchanging the unit of the electrode plate 116 and the membrane 115 with
 the electrode plate 117 shown in FIG. 7. Note that in this case, the
 outlet 119a' opened at the upper portion of the chamber 119' is not
 necessary, so that it may be closed with a plague 153, etc.
 On the other hand, a cylinder-shaped casing 114 is applied in the
 electrolytic cell 11 shown in FIG. 11. In accordance with the
 cylinder-shaped casing 114, the electrolytic cell 11 has a cylinder-shaped
 electrode plate 116 the upper and lower ends thereof are open and a
 cylinder-shaped membrane 115 the upper and lower ends thereof are open in
 the same way and in contact with the electrode plate 116. Further, an
 electrode bar 117, for example, in the shape of solid (not hollow) is
 provided at the center of the electrolytic chamber 113.
 An inlet 111 for the original water to be electrolyzed is provided at the
 lower end of the electrolytic cell 11, an outlet 112 for electrolyzed
 water is provided at the upper end. The original water to be electrolyzed
 fed from the inlet 111 passes thorough the cylinder-shaped electrolytic
 chamber 113 formed between the electrode bar 117 and the cylinder-shaped
 membrane 115, to be electrolyzed, and then taken out from the outlet 112.
 A gas chamber 119 which is the same as in the above example shown in FIG.
 10 is formed outside the electrolytic cell 11 to entirely surrounding it,
 and the gas generated at the cylinder-shaped space S (water film is formed
 here) formed by the cylinder-shaped membrane 115 and the cylinder-shaped
 electrode plate 116 is collected to be discharged from the outlet 119a.
 The same effectiveness can be obtained by such a cylinder-shaped
 electrolytic cell 11.
 [Fifth Embodiment]
 The above first to fourth embodiments are examples wherein the present
 invention were applied to a water flowing type electrolytic cell, while
 the present invention can be applied to a batch type electrolytic cell, as
 well. FIG. 12 is a schematic view of the basic configuration of when the
 electrolytic cell of the present invention is applied to a batch type
 electrolytic cell, wherein the common members to those in the basic
 configuration shown in FIG. 1 are indicated by the same reference numbers.
 The electrolyzed reducing water or electrolyzed oxidizing water having the
 aimed properties, especially, a large absolute value of the ORP without
 depending on the pH value can be also generated for a long time by this
 kind of batch type electrolytic cell.
 [Sixth Embodiment]
 The apparatus for producing electrolyzed water having the electrolytic cell
 of the present invention can be applied to the case of generating a large
 amount of electrolyzed water by circulating the original water to be
 electrolyzed fed in a storage tank in addition to supplying electrolyzed
 water on the real-time.
 FIG. 13 is a view of a sixth embodiment of the apparatus for producing
 electrolyzed water of the present invention, which is an application of
 the present invention for a portable water. The electrolyzed reducing
 water can be used as a replacement of portable water for domestic use and
 industrial use. In this case, tap water is stored in a storage tank 50 as
 shown in the same figure, supplied to the apparatus for producing
 electrolyzed water 1 of the present invention by a pump P, electrolyzed to
 generate the electrolyzed reducing water as explained above and returned
 to the storage tank 50. When continuing this circulation for a certain
 period of time, the electrolyzed reducing water having a pH close to
 neutral and a low ORP can be obtained.
 To explain more specifically, electrolysis was carried out by supplying 20
 litters of tap water having the pH of 7.2, the ORP of +450 mV and the DO
 of 7.0 to the storage tank 50, operating the pump for 25 minutes by using
 the apparatus for producing electrolyzed water having the electrolytic
 cell explained in the fourth embodiment, and circulating the water in the
 storage tank 50 to the electrolyzed water generating apparatus 1. The
 generating amount by the electrolyzing water generating apparatus 1 was
 four litters per minute and the current flown between the electrode plates
 was 10 A (constant). When measuring the pH, ORP (mV) and DP (ppm) of the
 electrolyzed water stored in the storage tank 50, the result shown in
 Table 3 was obtained and the electrolyzed water having a low ORP, which
 affects cleaning capability, was generated.
 TABLE 3
 Electrolyzing 0 5 10 15 20 25
 time minute minutes minutes minutes minutes minutes
 pH 7.20 8.33 8.44 8.85 8.85 8.80
 ORP +450 -250 -330 -367 -420 -450
 DO 7.00 2.70 2.60 2.14 2.20 1.76
 Note that the embodiments explained above are described for easier
 understanding of the present invention and not to limit the present
 invention. Accordingly, the respective elements disclosed in the above
 embodiments includes every modification in designing and equivalent
 subjects belong to the technical range of the present invention.