JP4354050B2 - Bleached powder molding - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a novel bleached powder molded body, and more specifically, an organic acid salt that forms a water-soluble metal complex by combining with a hardness component in an inorganic bleached powder mainly composed of calcium hypochlorite. It relates to a blended bleaching powder molding.
[0002]
[Prior art]
Conventionally, water treatment such as tap water, pool water, sewage and wastewater from sewage treatment facilities, and slime control of the cooling water system of machinery and equipment are made of plastic such as vinyl chloride and polyethylene attached to the water treatment facility. It is carried out by dissolving calcium hypochlorite-based bleaching powder in a tank and introducing the dissolved water into the equipment.
[0003]
When calcium hypochlorite-based bleaching powder is dissolved in a plastic dissolution tank such as vinyl chloride or polyethylene, the calcium concentration of the dissolved water increases, so a chemical injection pump or dissolved water is introduced into the pool. Calcium scale containing calcium carbonate as a main component is generated in the piping to make the flow of dissolved water worse. In severe cases, troubles such as blocking the piping may occur, which is a problem. .
[0004]
Previously, measures to prevent failures with calcium scale, such as periodically removing calcium scale generated in melting equipment and piping using hydrochloric acid, were regularly implemented. There are problems such as the generation of highly toxic chlorine gas due to the reaction between calcium hypochlorite and hydrochloric acid remaining in the scale, and the possibility of hydrochloric acid corroding the metal parts of processing equipment and machinery. In order to avoid these problems, the present applicant has already proposed a bleaching powder composition in which a polyphosphoric acid compound is blended with an inorganic bleaching powder mainly composed of calcium hypochlorite (Japanese Patent Laid-Open No. Hei 3-). No. 42094).
[0005]
[Problems to be solved by the invention]
As described above, it has become possible to substantially achieve calcium scale control by using a bleaching powder composition containing a polyphosphoric acid compound in an inorganic bleaching powder mainly composed of calcium hypochlorite. It was found that the scale control action over a long period of time in the chemical injection pump of the dissolution tank with the highest calcium concentration and the piping near the outlet was not sufficient. An object of the present invention is to provide a bleached powder molded body capable of preventing the generation of scales over a long period of time in a chemical injection pump and a water conduit of an inorganic bleaching powder dissolution tank mainly composed of calcium hypochlorite. There is.
[0006]
[Means for Solving the Problems]
As a result of intensive studies to solve the above-mentioned problems, the present inventors have conducted exposure in order to stably prevent scale generated in an inorganic bleaching powder solution containing calcium hypochlorite as a main component over a long period of time. Acquired knowledge that it is necessary to maintain the concentration of bleaching powder and scale control agent in the powder solution in the specified concentration range, using organic acid salt as the scale control agent, and using inorganic bleaching powder By using a mixture with an organic acid salt as a molded body, the concentration of the inorganic bleaching powder and the scale control agent in the bleaching powder solution can be maintained within a predetermined concentration range. The inventors have found that the generated scale can be stably prevented over a long period of time, and have completed the present invention.
[0007]
That is, the present invention is a tartaric acid, citric acid, malic acid, gluconic acid, EDTA, acrylic that forms a water-soluble metal complex with an inorganic bleaching powder mainly composed of calcium hypochlorite and a hardness component. Acid or methacrylic acid polymer, polymaleic acid, itaconic acid, crotonic acid, fumaric acid, malonic acid and the like, a salt of one or more organic acids, preferably tartrate, for example, organic acid salt The blending amount is 0.1 to 20% by weight with respect to the inorganic bleaching powder, and such a blend or a blend obtained by adding other optional components to the blend is formed into a tablet or the like. It relates to a featured bleached powder molded body.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The inorganic bleaching powder containing calcium hypochlorite as a main component in the present invention may be any one as long as it contains calcium hypochlorite as a main component. Specific examples may include (anhydrous calcium hypochlorite, monohydrate, dihydrate, trihydrate), 60% highly bleached powder and blended compositions thereof.
[0009]
In the present invention, the organic acid salt that forms a water-soluble metal complex by combining with a hardness component is an organic acid salt that can combine with a hardness component such as calcium or magnesium to form a water-soluble metal complex. There is no particular limitation as long as it is specifically, tartaric acid, citric acid, malic acid, gluconic acid, EDTA, acrylic acid or methacrylic acid polymer, polymaleic acid, itaconic acid, crotonic acid, fumaric acid, Examples include alkali metal salts and alkaline earth metal salts of malonic acid, preferably sodium salts and potassium salts, and these may be used alone or in combination of two or more. Among these organic acid salts, tartrate is preferable in that it has an excellent scale-inhibiting action, and as such tartrate, sodium tartrate, sodium hydrogen tartrate, potassium tartrate, potassium hydrogen tartrate, potassium sodium tartrate, and their Specific examples include hydrates such as monohydrate, dihydrate, and 1/2 hydrate, and these may be used as a mixture of two or more.
[0010]
The bleached powder molded body of the present invention is obtained by molding a molded body material containing a blend of the inorganic bleaching powder and the organic acid salt. The blending amount of the organic acid salt in the blend composed of the inorganic bleaching powder and the organic acid salt is 0.1 to 20% by weight, particularly 0.3 to 10% by weight with respect to the inorganic bleaching powder. It is preferable for effectively maintaining the scale prevention effect over a period. Moreover, the dissolution rate from a molded object can also be adjusted by selecting suitably the particle size of the calcium hypochlorite and organic acid salt to mix | blend. In addition to the inorganic bleaching powder and the organic acid salt, the bleaching powder molded body of the present invention can be blended with a dissolution rate adjusting agent, a lubricant, a corrosion inhibitor, and the like, if necessary. The dissolution rate modifier is added to adjust the dissolution rate of the organic acid salt and the like in the bleached powder molded body. For example, a water-repellent fine powder such as calcium stearate, magnesium stearate, and talc is preferably used. It is done.
[0011]
It is also effective to prevent the scale for a long period of time by molding a molding material such as a blend consisting of the above-mentioned inorganic bleaching powder containing calcium hypochlorite and an organic acid salt into a molding such as a tablet. It is preferable to maintain, and examples of the shape of the molded body such as a tablet include a spherical shape, a cubic shape, a cylindrical shape, a disk shape, a bowl shape, and a holed disk shape. In addition, specific examples of the molding method of the molded body include a pressure molding method and a tableting molding method in which the inorganic bleaching powder and the organic acid salt are uniformly stirred and then the compound is filled in a mold and then pressed. can do.
[0012]
【Example】
EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
Example 1
1 part by weight of sodium tartrate was added to 100 parts by weight of granular 70% highly bleached powder (“Nisso Hycron” manufactured by Nippon Soda Co., Ltd.), mixed using a ribbon mixer, and then molded at a tableting pressure of 60 t, and 200 g The bleached powder molded body (tablet with a diameter of 65 mm) of the present invention was obtained.
[0013]
Comparative Example 1
1 part by weight of sodium hexametaphosphate is added to 100 parts by weight of granular 70% highly bleached powder (“Nisso Hycron” manufactured by Nippon Soda Co., Ltd.), mixed using a ribbon mixer, and then tableted to form 200 g of bleached powder. A molded body (tablet) was obtained.
[0014]
Comparative Example 2
A granular 70% highly bleached powder (“Nisso Hycron” manufactured by Nippon Soda Co., Ltd.) was subjected to tableting to obtain 200 g of a bleached powder molded body (tablet), which was used as a control.
[0015]
(Dissolution test)
Using the bleached powder molded body dissolution apparatus shown in FIG. 1, a continuous dissolution test using the bleached powder molded bodies (tablets) of Example 1 and Comparative Examples 1 and 2 was performed, and the amount of calcium scale adhered to the piping Was measured. The bleached powder molded body (1) composed of 200 g of tablets is put into a 4 kg dissolver (2) once a day, and water of 27 ° C. with a calcium concentration of 200 ppm is used to dissolve the bleached powder molded body (1). It was poured at a rate of 8 hours / day at a liter / minute, and the bleached powder compact (1) was added every day for the test period and continued for 30 days. The dry weight before and after the test in the complex-shaped pipe (3) having corners and curved parts was measured, and the difference was taken as the amount of scale adhesion. Moreover, it was confirmed by X-ray diffraction that the deposit on the pipe (3) was calcium scale.
[0016]
The amount of calcium scale adhered when using the bleached powder molded body containing sodium tartrate of Example 1 was 20.0 g, and the amount of calcium scale deposited when using the bleached powder molded body containing sodium hexametaphosphate of Comparative Example 1 was 42. .2 g, the amount of calcium scale deposited when the control bleached powder molded body of Comparative Example 2 was used was 204.9 g. These results indicate that the use of the bleached powder molded body of the present invention can effectively suppress the generation of calcium scale.
[0017]
【The invention's effect】
The bleached powder molded body of the present invention is formed by adding an organic acid salt that forms a water-soluble metal complex by combining with a hardness component to an inorganic bleached powder mainly composed of calcium hypochlorite. Thus, the generation of calcium scale can be significantly suppressed, and therefore, it can be suitably used in place of conventional products for circulating disinfection of pool water in which a bleaching powder dissolving facility is installed, disinfection of drainage, and the like.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic longitudinal sectional view of a bleaching powder molded body dissolving apparatus used for a dissolution test.
[Explanation of symbols]
(1) Bleached powder molding (tablet)
(2) Dissolver
(3) Complex piping

Claims (3)

Tartaric acid, citric acid, which forms a water-soluble metal complex by combining with an inorganic bleaching powder containing calcium hypochlorite as a main component, and a hardness component of 0.1 to 20% by weight based on the inorganic bleaching powder ; bleached powder compact, characterized in that a molded material containing a blend of the salt of one or more organic acids selected from the group consisting of malic acid and gluconic acid. Bleaching powder molded body according to claim 1, wherein the organic acid salt characterized in that it is a tartrate salt. 3. The bleached powder molded body according to claim 1 or 2, wherein the molded body is a tablet.

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