| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent clogging of passages or apparatuses in producing an aqueous solution of sodium hypochlorite by reacting a solution of caustic soda with chlorine to obtain an aqueous solution of sodium hypochlorite, cooling the aqueous solution to precipitate crystals of sodium hypochlorite and dissolving the separated crystals in water.SOLUTION: An aqueous solution of sodium hypochlorite supplied to a crystallizer 4 is cooled through first and second circulation passages 50A and 50B equipped with a cooler 5 to crystallize in a crystallization tank 42. Since the cooler 5 is arranged outside the crystallization tank 42 and the aqueous solution of sodium hypochlorite is cooled while circulated, the first and second passages 50A and 50B cause less clogging, allowing crystallization in a high concentration of crystals. Even when one circulation passage causes clogging, the cooling with a plurality of the circulation passages 50A and 50B allows continuing the treatment by using the other circulation passage while carrying out maintenance of the circulation passage in trouble.</p> |
