KR19980029456A - Electrolytic Sterilization System of Drinking Water - Google Patents

Abstract

The present invention relates to an electrolytic sterilization apparatus for treating bacteria present in water, such as vending machines or water purifiers. It is an improvement and development of the patents applied in connection with the prior art, and when applying electricity in water, it is possible to increase the efficiency of sterilization and minimize the amount of metal precipitation by installing a cathode and an anode or using a metal bucket itself as a reducing electrode. It is designed to solve various problems caused by oxidation from the electrode (anode). In addition, there is also a problem to increase the effect of sterilization by appropriately adjusting the generation of O ₂ and Cl ₂ generated from the electrode surface and the problem of oxygen overvoltage of the electrode used.

Description

Electrolytic Sterilization System of Drinking Water

1 is a cross-sectional view of a molding structure for preventing an oxidation problem in the electrode terminal portion when applying voltage to the electrode in the present invention.

2 is a structural diagram showing an embodiment for preventing oxidation of the electrode by coding platinum on the electrode as an example of the electrode used when the oxygen overvoltage is very high as an embodiment of the present invention.

3 is a principle diagram illustrating a reaction principle according to oxygen overvoltage of an electrode unit of FIG. 2;

4 is a structural diagram of an embodiment in which an electrode terminal part is made of a platinum coated electrode in order to solve the problem of oxygen overvoltage and the problem of oxidation of the terminal terminal part as an embodiment of the present invention.

Figure 5 is a principle diagram showing the reaction principle according to the structure of the terminal of Figure 4 and the oxygen overvoltage.

Figure 6 shows an embodiment in which the electrolytic sterilization apparatus of the present invention is installed in a metal water tank.

FIG. 7 is an enlarged view of a structure for improving water circulation by processing holes in a cylindrical metal electrode in the water tank of FIG. 8; FIG.

8 is a cross-sectional view showing an embodiment of a structure in which both the cathode and the anode are installed in the lid portion to facilitate installation and cleaning inside the water tank.

Figure 9 shows the results of the sterilization effect according to the electrode material and structure.

Figure 10 (a) (b) (c) shows the results of the sterilization effect according to the voltage applied amount per electrode.

Figure 11 (a) (b) (c) (d) shows the results of the sterilization effect according to the amount of water per electrode.

* Explanation of symbols for the main parts of the drawings

DESCRIPTION OF SYMBOLS 1 Ferrite Electrode 2 Electrode Fixture 3 Safety Cap

4 electrode fixing screw 5 sealing rubber 6 voltage applying terminal

7: wire 8: epoxy 9: water tank

9 ': metal water tank 10: metal cathode

The present invention is an apparatus for sterilizing waterborne bacteria. Improvement and expansion of domestic patent applications 95-36079, 96-21333 by devising a plan for steam sterilization devices that are generally used, for example, water storage tanks in apartments, drinking water in restaurants, or anywhere where sanitary germs are required. It is devised about application. In addition, the purpose of the present invention is to completely solve the problem of bacteria, such as a beverage vending machine that is particularly useful or a water purifier that is being actively distributed in recent years. In order to solve such problems in the related art, an attempt has been made by using an ultraviolet lamp or a method of detonating an oxidizing agent such as ozone, but problems of use and efficiency have emerged, and thus, they do not show a very good effect on sterilization. Therefore, the previous patent application 95-36079 was designed to solve this problem, but many problems and difficulties have been excluded in achieving its purpose. Although it can be seen without explanation, the results are very different depending on the water conditions, and there are various difficulties in overcoming various problems in the electrode at each time. This invention is for solving most of these problems, improving sterilization efficiency, securing reliability, lowering costs, and so on. The problem in the conventional electrolytic sterilization was that the problem occurred due to oxidation of the electrode during electrolysis. In order to solve this problem, in particular, platinum was coated on a non-oxidized material, that is, a titanium metal material, but the problem of oxidizing the electrode was greatly improved, but an efficient problem of sterilization occurred. There are very important problems such as the problem of the type of gas generated by the material and the problem of the size of the electrode. It occurs at the anode and cathode, and the anode is oxidized and the cathode is reduced. The problem of oxidation of the anode could be solved by using platinum material with high oxygen overvoltage, but the metal ions generated at the reduction electrode cling to the electrode. The problem of reducing precipitation to metal was very serious.

Due to the problem of metal deposition, there are problems such as deterioration of electrode efficiency and appearance, which are attached to the surface of the electrode and unsatisfactory appearance. In order to solve this problem, the current polarity applied to the anode and the cathode was alternately applied at regular time to remove the attached metal by the oxidation process according to the oxidation phenomenon of the anode. Various problems occurred due to the discoloration of water due to oxidation of metals stuck to the electrode surface. Therefore, in order to solve the above problems at once, research and research on the structure and installation of the electrodes were inevitable, so the best condition was devised based on the results of the study. That is, the size of the positive electrode and the negative electrode is proportionally increased, so that the negative electrode is much larger than the positive electrode, so that the maximum contact area between the electrode, bacteria and bacteria is maximized, and the voltage is minimized for safety.

In other words, in order to reduce the amount of metal reduced in the cathode as much as possible, the material of the cathode is used as a cathode, which is cheaper than platinum, and the size thereof is maximized, and the low oxygen ferrite is used as the anode. It can be achieved. Of course, it is possible to use platinum-plated titanium or other materials with high oxygen overvoltage as the material of the anode, but precious metals are very expensive and are not easy to handle during mass production due to coating and oxygen overvoltage. The use of ferrite, which has a good surface reaction of the electrode rather than the platinum-plated material alone, is very effective in sterilization due to the problems that the actual sterilization, such as the generation of oxygen on the electrode surface, is not very good. It is cheap and not easy to be coated because the raw material itself is ferrite. In particular, the ferrite surface generates a large amount of Cl ₂ gas required for sterilization compared to platinum coating, which is very good as an anode material for electrolytic sterilization. This does not mean that platinum-coated electrodes are not available and can be used as well.

That is, in the case of Cl occurs by anodic oxidation is Cl ^- + H ₂ O-2e = ClO ^- + 2H ⁺ C1o ^by-two and the production of 2H ⁺ happening 2H ⁺ is 2H ₂ O generated in the cathode + 2e = H ₂ + 2OH ^- is neutralized with ^- 2OH to be generated. Cl ₂ generated at the anode in transplantation 2C1 ^- -2e = Cl ₂ as a bun disproportionated distribution _{Cl 2 + H 2 O = HCIO} + H 2 + Cl -, Cl 2 + H 2 O = ClO - + 2H + + Cl ^-by will. I.e. positive in the generation of _{H 2 O-2e = 1 /} 2O 2 + 2H + and HClO in the sub-reaction caused by oxidation of the O ₂ generated in the main reaction by the current and H ₂ O that is _{^{Cl - + H 2 O-2e}} = Partitioned into HClO + H ⁺ . In addition, the production of HClO at the anode must suppress the generation of O ₂ in water and induce the production of HClO necessary for sterilization. In other words, the average potential of oxygen generation is theoretically +1.23 (V) chlorine surface potential in the solution of PH = O, the surface potential of +1.36 (V) in parallel, O ₂ generation is preferred over Cl ₂ in parallel. Therefore, the anode material is made of ferrite material rather than platinum plated material in order to efficiently generate C1 ₂ . This is because ferrite has a superior surface electrode catalyst function than an electrode made of metal such as platinum. In this case, if the purpose of the generation of O ₂ is to use a high oxygen-type anode material, and if the purpose of the generation of Cl ₂ is not to use a low-oxygen anode is not good effect. Also using the positive electrode of the other when the electrode catalyst function of the Cl ₂ occurs better than ferrite and low O ₂ generated PdO system is capable Theoretically, the realization of the 100% of Cl ₂ generating efficiency (available actually chaesu ClO ^- The extraction efficiency is not 100% because of the reduction loss by the cathode)

According to the above theoretical basis, even if ferrite (N: system or Mn system, etc.) which is cheaper than other materials and excellent in surface electrode catalyst function is used, there is no problem.

In other words, a special structure must be designed to fix the ferrite in water and apply voltage. Because it is a phenomenon caused by anodic oxidation, general terminal terminals contacting ferrite electrode such as Guangdong, tin, iron, stainless steel, copper, etc. are easily oxidized in water, causing sediment, floatation and discoloration of drinking water. Therefore, you must pay special attention.

In order to solve such a problem, a strong airtight is required, and since water absorption penetrates after the airtight, it is necessary to use a platinum coating or an iridium oxide or the like. Of course, there is no particular problem when the terminal for applying the electrode voltage is installed out of the water, but in most cases it is necessary considering that it is installed inside the drinking water tank. As a result of the study for about two years for the present invention, the penetration of water is so powerful that it was conceived that a problem occurs in the terminal part when used for a long time. Another embodiment Figures 2 and 4 connect the terminals of platinum or metal to the ferrite with the terminals before and after the metal to be in contact with water in some water, thereby solving problems such as the life of the electrode or the generation of oxides. If the low oxygen electrode and the high oxygen electrode is installed at the same time, the electrode itself by the material of the electrode itself in different electrode materials can be solved the problem of electrode wear and oxide formation. At the positive electrode, OH ^- ions are generated at the H ⁺ cathode, where two ions react to form H ₂ O. _{^{4OH - + 4H + → 4H 2}} O The OH generated in the ^{anode-cathode} to move toward the anode is oxidized on the surface. Therefore, electrode reaction is very important in electrolytic sterilization. This is because the purpose of electrolysis cannot be achieved unless electricity is applied in water for a long time. For example, applying very high voltage in very small space may be possible in a short time, but for practical use, proper voltage and safety must be considered. Can not achieve the purpose. However, it is very important at this time that the material of the electrode used in the water is very important. Since the electrons flowing through the electrolyte called water are related to the movement and reaction of the ions contained in the tank, the oxidation and reduction of the ions occur and the oxidation and consumption of the electrodes occur in water. The choice of material is very important. For example, a material such as stainless steel is suitable as a reduction electrode (cathode), but it is absolutely impossible to use a water purifier or drinking water as an oxidation electrode (anode).

As a material used to solve the problem of oxidation, the oxidation of the electrode can be minimized by coating platinum or platinum on titanium, or by using IrO ₂ or iron oxide, that is, a ferrite electrode. However OH of electrodes when using a ferrite ^electrode, thereby causing problems such as an increase of the fill of the electrode consumption by elution of ions and water discoloration of the iron ions in water according to the discharge. Another electrode used to solve this problem is a platinum electrode (platinum coating on titanium, of course). This can minimize oxidation due to significant oxygen overvoltages in water, but it is expensive and the electrode needs less electrode response. As a result, there is a significant problem in being used as an actual sterilization electrode due to a decrease in sterilization ability. Another problem, in particular, is to select the structure and material of the terminal connected to the electrode in order to apply voltage to the electrode in water vapor. Because it is confirmed that a significant problem such as rust caused by the oxidation of the terminal portion due to the absorption of the ferrite or platinum coated electrode itself. Therefore, the present invention is to solve the problem that even if used for long time electrolysis in the water, it does not generate harmful substances in drinking water and provides no oxidation phenomenon and rust occurs in the water due to the oxidation problem caused by absorption penetration of the electrode and wire connection. Its purpose is to enhance the disinfection effect while completely solving what it has done. For example, titanium platinum coated electrode which can be used for OH ^- discharge can be combined with ferrite to maximize oxygen overvoltage as much as possible to solve the problem of oxidation in the platinum part and use ferrite electrode with high sterilization effect. The present invention relates to a method for increasing the disinfection effect while minimizing the problem of electrode oxidation and eliminating the oxidation of the terminal part by adjusting the ratio of CI and OH ⁻ generated at the electrode surface according to the difference. In other words, in order to control the generation of oxygen and hydrogen generated at the anode, the equilibrium potential of oxygen generation is +1.23 (V) based on the hydrogen electrode for PH = 0. The standard potential of chlorine generation is +1.36 (V). In parallel, O ₂ generation takes precedence over Cl ₂ . So that so as to efficiently generate a Cl ₂ to inhibit the O ₂ generated by giving a selectivity in the catalytic properties of the Anode electrodes (positive electrodes) and the generated increase the Cl ₂ is required.

For example by combining the easy oxide is oxygen-prone metal electrode and Cl ₂ vocalization (for example ferrite, carbon or the like) electrode OH according to the current ^{flow-discharge} is performed on the metal electrode portions, and Cl ₂ generated at the electrodes of the oxide-based In order to solve the problem of rust generation occurring at the connection part of the electrode by eliminating wear of the electrode, improving sterilization efficiency. Therefore, the problem that the present invention has to solve is to minimize the precipitation of metal ions due to the reduction action of the negative electrode so that it can be used for a long time and to maximize the Cl ₂ generation of the electrode in order to maximize the sterilization efficiency and To solve the problem of the occurrence of oxidation phenomenon at the connection part of the electrode and the wire when applying the power voltage applied to the electrode. In addition, in order to achieve the purpose of sterilization with voltage within the acceptable safety range of human body voltage, the size before and after reduction is significantly larger than that of the anode, and a cheap material is selected. Referring to the present invention as described above in more detail based on the drawings, the electrode reaction occurs in water vapor when the electrode having a structure as shown in Figure 1 is installed in a water bath and a voltage is applied to the electrode. At this time, the surface reaction of the electrode is different depending on the material of the electrode. Therefore, in the present invention, an oxygen-containing electrode such as an oxide-based ferrite or a carbon-treated graphite electrode, which is more likely to generate Cl ₂ than an oxygen-containing electrode such as an electrode of Pt, Iro ₂ or Pt or Ti-Pt, is used. It is. At this time, as the electrode and the cathode, a very large value is cheaper than that of the anode, and a good material such as stainless steel or other corrosiveness is used, and all the problems to be solved by the present invention can be solved by using a metal material. In addition, the installation structure of this electrode should not be sealed enough to eliminate oxidation of the connection between the ferrite electrode and the wire. An example of the structure is shown in FIG. In this case, it is again clarified that sterilization of the water after the purified water filtered by the filter rather than the condition of directly using tap water. Because tap water contains a large amount of chlorine and a mineral component that promotes the electrode reaction, the point of the present invention is somewhat different. Of course, the present invention can also be applied for sterilization of tap water, photoelectric water and the like. However, tap water that has passed through the membrane and carbon has little chlorine in the water.

In addition, most of the minerals that promote electrode reactions are eliminated, which is fundamentally different from the mechanism that occurs during electrolysis of tap water. In other words, in the conventional conventional electrolytic sterilization, the reaction by the production of Cl ₂ by the low oxygen electrode was mainly related to the sterilization of bacteria. However, in the present invention, it was found that sterilization by OH radicals revealed by the study of the present invention acts more strongly. In general, there is a patent application in Japan and the like to generate sterilized water by oxidizing a small amount of Cl ⁻ of hydrophobic water to an anode. The present invention has been solved in order to solve the problem of bacteria occurring in the purified water storage tank after the purified water of the domestic water purifier recently. In other words, recent membrane type water purifiers usually go through a four-stage filter, which removes sand, soil, and other suspended matter from tap water from the first MICR0 filter, and the color, taste, Odors, chlorine and the like are raised. In addition, the third membrane filter completely removes minerals such as hardness (calcium, magnesium, etc.) and taste, turbidity, chlorine, and other suspended substances in the tap water. In the fourth filter, odors that may remain in the water, It's supposed to treat taste, turbidity, color, chlorine, and other substances, and in fact it's not filtered out of mineral content--mineral balance of water, pH, etc. In this regard, the results of our research shows that tap water, mineral water, and bottled water are best sterilized when electrolytically sterilized by a common electrode method, because Cl ^- ions contained in trace water is oxidized at the anode is made of the number of sterilized i.e. _{^{Cl -. + H 2 O -}} 2e = ClO - + 2H - by the ClO ^- it is only However, in the case of mineral water or salt-free water, the sterilization effect is not very good.Moreover, the above method also raises about 90% of the minerals in the water to promote the electrode reaction with chlorine present in the tap water. In water purification, the sterilization effect is not much expected, of course, you can expect a slight effect by increasing the voltage very much, but at this time, the electrode reaction theory of Faraday due to the lack of safety due to excessive voltage and the electrode reaction in drinking water However, the method of disinfecting drinking water over a long period of time has not been beneficial because of problems such as elution of the oxidatively altered electrode of water, but the present invention solves this problem and solves this problem. Perfect sterilization neck even in water Method is that though the object of the present invention provides to achieve caused by the electrode reaction and OH ^-. And H ⁺ electrolytic production by the in H ₂ O reduction at the cathode (Cathode) H ₂ produced that is 2H ₂ O in + 2e = H ₂ + 2OH ^- and dissolved oxygen reduction 1/20 ₂ + H ₂ O + 2e → formation of 0H ^- by 2OH ^- and O ₂ formation by oxidation of H ₂ O at anode H ₂ The production of H ⁺ by O − 2e = 1 / 2O ₂ + 2H ⁺ occurs. The hydroxyl radical (Hydrozyl Radical) generated at the cathode means that OH ^- is produced. It has considerable oxidation power in water and it is several times stronger than chlorine. Therefore, in order to induce such an electrode reaction, it is impossible to efficiently achieve the effect of sterilization unless the size of the negative electrode is made large. Referring to FIG. 6, the water tank of the metal material is made of stainless steel (9 ') and the electrode 1 coated with platinum on anode ferrite or ditan is installed at the center of the water tank to achieve the purpose of sterilization. . At this time, in consideration of the convenience of use, cleaning, and the problem of contacting the water of the wire when voltage is applied, the electrode holder 2 is installed on the upper lid and completely sealed so that the power is applied from the outside. 9 ') connected to ground. At this time, the electrode reaction is sterilized as the oxidation reaction and the reduction reaction occur between the metal water tank 9 'and the anode electrode 1, respectively. In another embodiment, the plastic bucket 9 shown in FIG. 8 has a metal electrode, such as a cylindrical stainless steel, as the reduction electrode 10 in the lid portion, and the anode 1 is installed at the middle point thereof. The metal cylinder (10) of the water to improve the circulation of water to improve the efficiency and to achieve the purpose of sterilization according to the electrode reaction without difficulty.

Claims (7)

For electrolytic sterilization where drinking water or hygiene is required, install an electrode with excellent oxidation resistance in water so that it can be sterilized by electrode reaction when applying proper voltage continuously. At this time, wear and durability of electrode and oxidation of water In order to solve the problem, after applying a certain amount of time, it is electrically designed to stop the operation for a certain time and have a rest time. An embodiment of the present invention is characterized in that a low oxygen electrode such as ferrite carbon or the like is used as the positive electrode and a metal material such as stainless steel or the like is used as the negative electrode. As an embodiment of the present invention, the size of the negative electrode is greatly increased compared to the size of the positive electrode, thereby increasing the electrical safety, greatly improving the effect of sterilization, dispersing the amount of metal precipitation generated on the electrode surface by the reduction reaction, and using for a long time. Characterized by being enabled. As an embodiment of the present invention, in order to solve the oxidation of the anode and the oxidation of the terminal at the same time by making the terminal portion combined with the ferrite platinum and part of the platinum terminal to contact the water with the ferrite to increase the oxygen overvoltage of the electrode and the It is designed to solve the wear and oxidation problems and to prevent the occurrence of oxidation between ferrite and terminals. As an embodiment of the present invention, when bonded to the plastic to secure the anode electrode of the ferrite or platinum coating in the bucket, it has a suitable structure to maintain sufficient airtightness of the electrode, the terminal and the plastic body, such as an epoxy, which is harmless to the human body. Characterized by molded of solid material. In the embodiment of the present invention, when the water tank itself is a stainless steel, the cathode is connected to or grounded on the stainless steel bucket, and the anode is installed in the center of the water tank. As an embodiment of the present invention, other than the above examples, for example, the anode and the cathode can be used only in the place where the purpose and special requirements, for example, the sterilization efficiency does not have to be very high, only by ferrite or platinum-coated titanium. Characterized by being.