JPS6223992A - Electrolytic sodium hypochlorite producing device - Google Patents

Abstract

PURPOSE:To obtain the titled device which is extremely small-sized and simple in a structure by fixing a cathode and an anode performed with a coating consisting of both a platinum group metallic ternary mixture of Pt-PdO-RuO2 and TiO2 on Ti (alloy) in an under end part of a vessel cover. CONSTITUTION:In the above-mentioned electrolytic sodium hypochlorite producing device, an electric power source box 5 incorporated with both a rectifier 3 exchanging AC into DC and a timer 4 setting the electrolytic time therein is fixed to one part of the upper part of the vessel cover 2 fitted to a vessel 1. Furthermore a cathode 6 and an anode 7 which are wired to the rectifier 3 are hung and fixed to the under end part of the cover 2. The anode 7 is constituted by performing a coating consisting of both a platinum group metallic ternary mixture of Pt-PdO-RuO2 having the composition of 3-42wt% Pt, 3-34wt% PdO, 42-94wt% RuO2 and 20-40wt% TiO2 for this mixture on Ti or Ti alloy. Brine contg. NaClO can be obtained from dilute brine by the electrolysis in high-current efficiency in a batch system.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a sodium hypochlorite generator, and more particularly to a small-capacity, simple batch-type generator that generates sodium hypochlorite by electrolysis of saline water. It is something.

(Prior art) Chlorine treatment has been widely used in the past for disinfection of water and sewage systems, oxidation treatment of waste liquids, cleaning and bleaching of various textiles, and cleaning and sterilization of food-related products, and sodium hypochlorite solution was used as the chlorine source. It's here. However, this chlorine source has problems in handling, safety, economy, etc., and in recent years, a method of obtaining sodium hypochlorite by electrolyzing dilute salt water at the site of use has become popular.

Conventional electrolytic sodium hypochlorite generators electrolyze 3% salt water to produce an effective chlorine concentration of 6,000 to ILOOO.
Most of the equipment generates sodium hypochlorite solution containing ppn+, and most of the equipment generates it by continuously passing the solution, and most of the equipment is large-capacity equipment that generates a large amount of sodium hypochlorite. There are no small-capacity devices that generate less than 20g per hour. Furthermore, the conventional apparatus is considerably complicated and expensive because it is composed of a large number of devices such as a salt dissolution tank, an electrolytic cell, a rectifier, and a sodium hypochlorite solution storage tank.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned problems, and allows salt water containing 9 sodium hypochlorite to be obtained from dilute salt water by electrolysis in a batch manner with high current efficiency, and in an extremely small size. - The purpose is to provide a generator with a simple structure and low cost.

(Means for Solving the Problems) As a result of various studies, the inventor of the present invention has discovered that a container, a power supply box fixed to the upper part of the container lid of the container and equipped with a rectifier and a timer, and a lower end portion of the container lid. It consists of a cathode and an anode which are fixed to the surface and connected by a rectifier, and the anode has a composition of 3 to 42% by weight of platinum, 3 to 34% by weight of palladium oxide, and 42 to 94% by weight of ruthenium dioxide on titanium or a titanium alloy. A ternary mixture of platinum group metals of platinum-paralumum oxide-ruthenium dioxide having the following properties, and titanium dioxide in an amount of 20 to 40 percent based on the mixture. It has been concluded that the sodium hypochlorite generator is a sodium hypochlorite generator that achieves the objectives of the present invention.

Next, a specific example of the apparatus of the present invention will be explained with reference to the drawings. 1st
The figure is a schematic diagram showing a specific example of the present invention.

An electrical box 5 containing a built-in rectifier 3 for exchanging alternating current with direct current and a timer 4 for setting the electrolysis time is fixed to a part of the upper part of the container lid 2 attached to the container 1, and further to the lower end of the container lid 2. A cathode 6 and an anode 7 connected through a rectifier 3 are suspended and fixed to constitute an electrolytic sodium hypochlorite generator. The device is equipped with a power cord 8 connected to a timer 4.

The electrode, the anode, and the anode are made of platinum-palladium oxide, which has a composition of 3 to 42% by weight of platinum, 3 to 34% by weight of palladium oxide, and 42 to 94% by weight of ruthenium dioxide, on titanium or titanium alloy, as proposed by the applicant. a ternary mixture of platinum group metals of ruthenium dioxide;
"Electrode coated with a mixture consisting of 0% by weight of titanium dioxide" (Special Publication No. 35473/1983) was used.
Titanium is mainly used for the cathode 6.

The coating of the anode used in the present invention is adjusted as follows. After the titanium surface is degreased, it is treated with hexachloric acid or oxalic acid, and a coating liquid is applied thereon by coating or dipping. For the coating solution, platinum tetrachloride, palladium dioxide, and ruthenium trichloride were selected so that the platinum-palladium oxide-ruthenium dioxide ratio was within the range of the present invention, and a small amount of hydrochloric acid was added, followed by n-butyl alcohol to completely dissolve them. let This is adjusted by adding a predetermined amount of butyl titanate. After drying, heat in air at a heating temperature of 450 to 600°C for 10 to 30 minutes. Coating and heating are repeated several times to obtain a coating of desired thickness.

Is the distance between the anode and cathode 3~? +nm, a protective tube is attached around the electrode to protect it if necessary. A rectifier 3 consisting of a transformer and a rectifying element and a timer 4 are built into the power supply box 5, which is mainly made of plastic, and are connected to a cathode 6 and an anode 7 from the rectifying element terminal. Further, the set knob of the timer 4 may be mounted on the surface of the power supply box 5 along with a power switch and a lamp to serve as an operation panel.

The capacity of the container 1 is determined by the required amount of sodium hypochlorite, but 1 to 2 OR is usually selected for use in small quantities, and commercially available plastic containers are mainly used from an economical standpoint.

A timer is usually selected that can be set within one day, preferably within 12 hours. Once the container capacity and electrolysis time using a timer are determined, the maximum amount is 1.3 t 000 p.
The electrolytic current that should reach pm is determined, and a rectifier with a capacity that matches this electrolytic current is set. The electrolytic box is mainly sized according to the rectifier capacity. When the salt water 9 whose concentration has been adjusted is put into the device manufactured in this manner and electrolysis is started, the concentration of sodium hypochlorite increases almost linearly with the electrolysis time, reaching a maximum of 13+000 ppm. The concentration can be freely selected depending on the electrolysis time using a timer.

To adjust the concentration of the salt water 9, a predetermined amount of table salt (refined salt, table salt, ordinary salt, etc. can be used as the type of salt) is measured from a measuring cup, and the container lid 2 is opened and the container 1 is poured into the container 1. Pour a specified amount of water into the container 1 and stir well to adjust. In this case, if the container 1 is marked with a capacity scale, the concentration can be easily adjusted.

(Functions and Effects) The sodium hypochlorite generator of the present invention can be operated by simply preparing and charging about 3% dilute salt water and then setting the timer and turning on the power switch. 3% salt water is electrolyzed for the time set by the timer, and when the time is up, the electrolysis is automatically stopped and the time is 6,000~'1.3.
OOOp p Sodium hypochlorite is produced. Combined with the use of a high-performance anode, the current efficiency is over 90% even when exceeding 10,000 pp+n due to batch electrolysis.

The device of the present invention has an extremely simple structure, and the components are simple and can be assembled together. In other words, since there are no driving parts and no complicated control parts for automatic control are required, there is no failure. Furthermore, the structure of the electrolytic cell is simple, and since everything including the power supply box is integrated, it is extremely compact, and can be easily carried and placed anywhere. Since the device of the present invention is constructed of plastic materials except for the titanium electrodes, there is no problem of corrosion and it is extremely advantageous in terms of maintenance. In addition, compared to conventional devices, the electrode is an open type that is immersed, so there is no problem such as a decrease in current efficiency due to electrolyzed gas, and the current concentration (electrolytic current relative to the salt water capacity) is small5, so there is no problem with temperature rise. .

As mentioned above, this device has simple components and uses commercially available ready-made products, and since there are no connecting pipes, it is easy to manufacture and is therefore extremely economical. Conventionally, it was considered extremely difficult to achieve ultra-miniaturization that satisfies both economic efficiency and performance, but this device has a batch type and integrated structure, so even if it is ultra-compact, it has high current efficiency, is inexpensive, and has one of the lowest running costs. Mainly, highly concentrated sodium hypochlorite is obtained. In addition, cathode scale does not form easily and maintenance is easy.

(Example) As shown in Figure 1, the amount of sodium hypochlorite generated is 10g/h
Actual capacity 13I as a device for use! A commercially available polypropylene container is marked with an actual capacity scale of 101, and the top of the lid attached to the container is marked with a scale of approximately 9. A hard vinyl chloride resin power supply box that incorporates a rectifier (transformer and rectifying element) and a 12-hour timer that allows the direct current of the OA to flow is mounted and fixed, and the timer inside the power supply box supplies 100 AC via a fuse.
I pulled out the V power cord. Furthermore, one side of the electrode made of a titanium plate with a thickness of 2 mm was coated with a mixture of 25% by weight of platinum, 20% by weight of palladium oxide, 55% by weight of ruthenium dioxide, and 30% by weight of titanium dioxide. of anode and uncoated thickness of 2
One cathode made of a titanium plate having a diameter of 1 mm was opposed to the cathode with a distance of 5 I between the electrodes, and the upper ends of both electrodes were fixed to the lower part of the container lid, and both electrodes were connected to the positive and negative electrodes of a rectifier, respectively. The external dimensions of the container are 300 mm wide x 205 mm wide x 220 mm long.
The power supply box was 135 mm wide x 195 mm wide x 150 mm long.

300 g of ordinary salt weighed using a measuring cup was put into a container, and after pouring clean water to the capacity scale of 10, the mixture was well stirred with a stirring rod to prepare a 3% diluted salt solution. After covering the power supply box and the lid with fixed electrodes and immersing the electrodes in 3% F6 dilute salt water, connecting the power cord to a 100 AC power source, setting the timer to 12 hours, and then turning on the power switch.

As a result of electrolysis by passing a direct current of 9 A and 4.3 ■, the concentration of sodium hypochlorite increased over time and reached 1 in 12 hours.
A dilute brine containing 3,200 pp+n was obtained.

At this time 1. LOOOppm was reached in about 9 hours. Although the water temperature (19° C. at the start) and current increased slightly with the electrolysis time, no problems such as increased sliding voltage or decreased current efficiency occurred. The current efficiency is 90.7%, and the required power is 1 liter of sodium hypochlorite as the average value of 12-hour electrolysis repeated 8 times.
．． It was 3.6 ku+l+ per kg. Once a day12
The device was operated smoothly without any problems until the electrodes were cleaned after about 7 months of operation.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a specific example of the present invention. 1. Container 2. Container lid 3. Rectifier 4. Timer 5. Power supply box 6. Cathode 7. Anode

Claims (1)

[Claims] A power supply box 5 fixed to the upper part of the container lid 2 of the container 1 and equipped with a rectifier 3 and a timer 4, and a cathode 6 fixed to the lower end of the container lid 2 and connected to the rectifier 3. and an anode 7, the anode 7 having a composition of 3 to 42% by weight of platinum, 3 to 34% by weight of palladium oxide, and 42 to 94% by weight of ruthenium dioxide on titanium or a titanium alloy. a platinum group metal ternary mixture of ruthenium;
An electrolytic sodium hypochlorite generator characterized in that it is coated with a mixture comprising 40% by weight of titanium dioxide.