JPH0244909B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a first method in which the inner surface of a cylindrical substrate made of titanium is coated with iridium dioxide or platinum.
The present invention relates to a water electrolyzer that can improve the production rate of acidic water based on the use of an electrode body.

[Background technology]

It has been known that alkaline water obtained through water electrolysis is effective for strengthening the gastrointestinal tract and maintaining health, as well as having antioxidant effects.
For example, in addition to being used for beverages and for long-term preservation of foodstuffs such as tofu, acidic water is also used for cosmetics, face washing, and washing tableware due to its bleaching and sterilizing effects due to its oxidizing action. Ta. Furthermore, when used in noodle making, etc., it is known that not only can the elution of noodle bodies be prevented to improve the yield, but also that the use of chemicals can be reduced due to the preservative effect.

However, in recent years, this acidic water has been desired to be used as water for pools, baths, etc. due to its effects on curing and preventing skin diseases, as well as its ability to reduce water turbidity. containers such as
Demand for industrial cleaning water, such as for sterilizing tableware, is also increasing.

On the other hand, in order to generate such alkaline water and acidic water, it is necessary to use a method between a rod-shaped positive electrode made of carbon, nickel ferrite, etc., and a cylindrical negative electrode made of rust-free metal such as stainless steel and inserted into the positive electrode. A water electrolyzer with an ion-exchange membrane interposed therein has been conventionally used, and by electrolyzing fresh water while flowing between the electrodes, acidic water is supplied to the inside of the diaphragm, which is the ion-exchange membrane, that is, on the anode side. Alkaline water was generated on the outside, that is, on the cathode side.

[Problem that the invention seeks to solve]

However, such water electrolyzers have a drawback in that the production rate of acidic water relative to alkaline water cannot be increased.

The cause of this is, for example, the flow rate of acidic water flowing inside the diaphragm.
When the flow rate of alkaline water is increased compared to the flow rate of alkaline water flowing outside, the internal pressure inside the diaphragm decreases as the flow rate increases, that is, the flow velocity increases, and this pressure difference between the inside and outside causes the diaphragm to move inward. You will be under pressure. Furthermore, because the acidic water outlet is provided near the center of the water electrolyzer due to its positional relationship with the alkaline water outlet, the acidic water draws a streamline toward the center near the outlet, thus pushing the diaphragm inward. It will be a drag.

Further, the limit value of the distance between each electrode, that is, the dischargeable distance is generally relatively small, about 7 mm, and therefore the diaphragm interposed inside the diaphragm is disposed close to each electrode. Furthermore, the diaphragm is a cylindrical sheet body and has low rigidity, so it is easily deformed inward by external forces such as the above-mentioned pressure difference and water flow. lead to deterioration and shorten its lifespan.

On the other hand, on the other hand, reducing the pressure outside the diaphragm allows the diaphragm to be stretched and is effective in preventing the shoot, so it increases the flow rate outside the diaphragm and applies a negative voltage to the positive electrode side and to the negative electrode side. It is conceivable to apply a positive voltage.

However, when a positive voltage is applied to the conventional negative electrode, i.e., the stainless steel side, the surface of the stainless steel becomes oxidized, reducing its durability and also tends to elute the chromium it contains, which poses a health problem. In some cases.

It is also possible to form a rod-shaped negative electrode with stainless steel and a cylindrical positive electrode with carbon or nickel ferrite;
Nickel ferrite is ceramic-like, easily cracked, difficult to process, and has inconsistent precision due to shrinkage due to baking, etc., and therefore it is difficult to form such an electrode.

As described above, in conventional water electrolyzers, it is not possible to increase the flow rate inside the diaphragm in order to prevent deterioration of the electrode, and it is difficult to form a positive electrode body that is easy to process, has a good discharge effect, and is harmless to the human body. Because it was not possible,
It was not possible to increase the production rate of acidic water, which sometimes led to excessive production of alkaline water, leading to an increase in costs.

[Purpose of the invention]

The present invention provides a first method in which the inner surface of a cylindrical substrate made of titanium is coated with iridium dioxide or platinum.
Basically, applying a positive voltage to the electrode body of
The object of the present invention is to provide a water electrolyzer that can easily and stably improve the production rate of acidic water, prevent excessive production of alkaline water, and contribute to reducing production costs and saving resources.

[Means for solving problems]

An embodiment of the present invention will be described below based on the drawings.

In the figure, a water electrolyzer 1 has a first electrode body 3 in which the inner surface of a cylindrical base body 2 made of titanium is coated with iridium dioxide or platinum.
A second electrode body 6 is inserted from the inner surface of the electrode body 3 in parallel with the first electrode body 3 across a water flow gap 5, and a positive voltage is applied to the first electrode body 3. There is.

The first electrode body 3 includes a cylindrical base body 2 made of titanium, and a connecting terminal 12 made of a conductive screw member is welded to the outer peripheral surface of the base body 2, and in this example, iridium dioxide is attached to the inner surface of the base body 2. coated. Note that iridium dioxide is applied to the inner surface of the base 2 by spraying, brushing, etc., and then subjected to a baking treatment.

In this example, the second electrode body 6 includes a hollow base tube 15 whose openings at both ends are sealed with disk bodies 13, 13, and each disk body 13 has a central part and an outer part at the tip. A core shaft 16 for threading a screw is provided protrudingly.

The disk bodies 13, 13, the base tube 15, and the core shafts 16, 16 are each made of titanium material, and are fixed integrally and hermetically by argon gas welding, and around them are covered with iridium dioxide. is coated.

Further, the second electrode body 6 is formed with an outer diameter smaller than the inner diameter of the first electrode body 3, and has an inner diameter that is concentric with the first electrode body 3 and inside the first electrode body 3. By inserting them in parallel, a gap 5 is formed between the base body 2 and the base cylinder 15, and both ends thereof are connected to the lid member 1.
It is closed by 9 and 20.

The lid members 19, 20 consist of cover bodies 21, 22 and retaining plates 23, 24 attached to the inner ends thereof, respectively.

The holding plates 23 and 24 have a cylindrical shape with a center hole passing through the core shaft 16, and a water passage hole 25 is provided around the center hole, and a groove 26 is formed on the outer peripheral surface. will be established. Further, the outer diameters of the holding plates 23 and 24 are set to be larger than the outer diameter of the second electrode body 6 and smaller than the inner diameter of the first electrode body 3, and one of the holding plates 23 has a lower surface. Boss part 2 protruding from
7 is placed in contact with the upper end of the second electrode body 6, and the other holding plate 24 is disposed with an elastic ring 29 made of silicone rubber or the like interposed between the lower end of the second electrode body 6.

Further, in this example, a partition 31 is provided between the holding plates 23 and 24, and is attached to the outer peripheral surface thereof and surrounds the base cylinder 15.
A larger amount of water is allowed to flow through the outer gap 5B than the inner gap 5A. Note that the partition cylinder 31 is
When the elastic ring 29 is compressed, the groove 26
The partition tube 31 is tightened using a string or the like wrapped around the tube, and the partition tube 31 is stretched as a result of the repulsion of the elastic ring 29. Note that the partition tube 31 is made of a so-called ion exchange membrane such as a nonwoven fabric that allows ions generated by electrolysis of water to pass through but prevents water molecules from passing through.

The cover bodies 21 and 22 have a step 35 around a circular substrate 33 into which the first electrode body 3 is fitted.
The base plate 33 has a cap shape with a peripheral wall 36 having a circumferential wall 36, and a boss 37 protruding from the center of the base plate 33. The boss 37 has a hole through which the tip of the core shaft 16 is inserted.

Further, the cover bodies 21 and 22 fit the first electrode body 3 while keeping the first electrode body 3 moist by an O-ring that fits into an inner circumferential groove provided on the outside of the step 35, and By screwing a nut fitting 39, for example, a nut, onto the outer thread of the core shaft 16 that protrudes from the substrate 33 through the boss 37, the cover bodies 21, 22 can attach the step 35 to the end surface of the first electrode body 3. It is pressed and installed.

Further, the lower cover body 22 passes through the water passage hole 25 between the peripheral wall 36 and the boss 37 to form an inner gap 5A.
An inflow path 40 that communicates with the outer gap 5B through the space between the partition tube 31 and the first electrode body 3.
is formed, and the inlet passage 40 communicates with an elbow 41 screwed into the peripheral wall 36.

The other cover body 21 is, as shown in FIG.
An intermediate wall 42 is provided between the peripheral wall 36 and the boss 37, and the end surface of the intermediate wall 42 comes into contact with the outer peripheral edge of the retaining plate 23 when the cover body 22 is attached. Therefore, between the boss 37 and the inner wall 42, an inner flow path 45 can be formed which passes through the water passage hole 25 and communicates with the inner gap 5A, and between the inner wall 42 and the peripheral wall 36, a partition can be formed. 31 and the first electrode body 3, an outer flow path 46 communicating with the outer gap 5B is independently configured. The outer flow path 46 is connected to an elbow 47 screwed into the peripheral wall 36, and the inner flow path 45 passes through a bridge piece 49 connecting the inner wall 42 and the peripheral wall 36 and is screwed into a guide hole opened in the inner wall 42. It leads to elbow 48 where it will be worn.

In addition, in the water electrolyzer 1, an electric cord 51 on the positive electrode side extending from the power supply box is screwed to the connection terminal 12 welded to the first electrode body 3 using an end fitting. An electrical cord 53 on the negative electrode side extending from the power supply box is electrically connected using an end fitting that is inserted over the core shaft 16 and compressed by a nut 52. Note that the first electrode body 3, the second
For example, a DC voltage of 30V to 100V is applied between the electrode bodies 6. Further, in this example, by connecting one of the electric cords 53 to the upper end side of the core shaft 16, dew attached to the surface of the base body 2 is prevented from dripping to the connecting portion.

The water electrolyzer 1 is also connected to a water supply source, which is a water pipe in this example, via a water purifier, for example.

The water purifier is, for example, a filter with a well-known configuration that stores activated carbon, calcium sulfite, etc. inside, and supplies clean water to the water electrolyzer 1 through the elbow 41 while purifying clean water such as tap water that is being fed. do.

In addition, there is an on-off valve between the water purifier and the water pipes.
In addition to turning on and off the fresh water supply, the elbows 47 and 48 communicate with an alkaline water outlet and an acidic water outlet, respectively, via metering valves of well-known construction.

For example, a flow switch (not shown) may be provided between the elbow 47 on the acidic water side and the faucet, and an electromagnetic valve that is opened and closed by the flow switch may be provided on the elbow 48 on the alkaline water side. At this time, alkaline water can be discharged at the same time as acidic water is taken out. Also, turn on the power switch for electrolysis by operating the flow switch.
Then, a voltage is applied to the first and second electrodes 3 and 6.
In addition, at that time, in the elbow 41 for fresh water intake,
A fresh water supply pipe, such as a water pipe, is directly connected via a backflow prevention valve.

[Effect]

However, tap water flows into the water purifier by opening the on-off valve, is filtered and purified, and then passes through the elbow 41.
It flows into the inflow path 40 through the flow path. Further, the metering valve adjusts the flow rate ratio of the water flowing through the inner gap 5A and the outer gap 5B to, for example, 1:5, so that the water flowing through the inflow path 40 has the desired flow rate. While changing the flow velocity according to the ratio, the inner gap portion 5A,
The outer gap 5B is raised.

Further, the water flowing between the inner and outer gaps 5A and 5B is electrolyzed by the voltage applied between the first electrode body 3 and the second electrode body 6, and the first electrode body 3 to which a positive voltage is applied is Acidic water is generated in the side, ie, outer gap 5B, and alkaline water is generated in the inner gap 5A.

Note that during generation, the pressure inside the outer gap 5B is reduced as the flow rate of the acidic water increases, so the partition 31 is stretched outward in the radial direction, and therefore the water electrolyzer 1 is Water can be stably electrolyzed without bringing 31 into contact with each electrode body 36.

Note that when titanium is used alone as a positive electrode, it usually forms an oxide film on its surface and can be insulated, but the water electrolyzer 1 of the present invention is coated with iridium dioxide, so it is suitable as a positive electrode. It can be used for

Furthermore, unlike stainless steel and the like, titanium forms a non-conductive oxide film on its surface with electric current, and titanium itself does not elute. Therefore, safety can be improved. Furthermore, even when the layer portion of iridium dioxide, platinum, etc. is peeled off, the above-mentioned titanium oxide film is formed at the peeled portion, thereby preventing the layer from being attacked.

In addition to iridium dioxide, platinum can be used for the first electrode body 3, and in such a case, the inner surface of the base body 2 can be coated by plating, vapor deposition, metallic coating, or the like.

The second electrode body 6 may be coated with platinum like the first electrode body, or may be a conventional electrode body made of carbon, nickel ferrite, or even made of stainless steel. It is also good to use a shaft body of

〔Effect of the invention〕

As mentioned above, the water electrolyzer of the present invention applies a positive voltage to the first electrode body, which is made of a cylindrical base made of titanium and whose inner surface is coated with iridium dioxide or platinum. By increasing the flow rate compared to the inside, the production rate of acidic water can be easily improved without bringing the septum into contact with the first electrode body and the second electrode body, and the alkaline water obtained together with the acidic water can be can prevent surplus generation.

In addition, if no partition is provided and the second electrode body is made of titanium as a base material and coated with iridium trioxide or platinum on the surface, or if it is made of carbon or nickel ferrite, the first electrode body By applying an alternating current voltage between the electrode body and the second electrode body, active water can be continuously generated along with electrolysis. Further, when applying an alternating current voltage, the water electrolyzer of the present invention can exhibit many effects such as being able to prevent the generation of scale.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention, and FIG.
The figure is an exploded perspective view, FIG. 3 is a partially sectional plan view showing the lid member, and FIG. 4 is a sectional view showing another embodiment of the present invention. 2... Base body, 3... First electrode body, 5... Gap, 6... Second electrode body.

Claims (1)

[Claims] 1. The first electrode body is placed inside a first electrode body whose inner surface is coated with iridium dioxide or platinum on the inner surface of a cylindrical base made of titanium, with a gap for water flow separated from the inner surface of the first electrode body. A second electrode body is inserted in parallel with the ion exchange membrane, and the gap is divided into an inner gap on the second electrode side and an outer gap on the first electrode side. The invention is characterized by providing a partition, applying a positive voltage to the first electrode body, and increasing the amount of water flowing through the outer gap compared to the inner gap to increase the production rate of acidic water. water electrolyzer.