PURPOSE: To efficiently perform the electrolysis of NaCl and the manufacture of NaOCl from NaOH and Cl2 obtd. by the electrolysis by using a Cl2-contg. gas in a preparation vessel for the electrolysis of an aqueous NaCl soln. to dilute the Cl2.
CONSTITUTION: An aqueous NaCl soln. in preparation vessel 7 is fed to electrolytic cell 1 composed of cathode chamber 14 and anode chamber 15 formed with cathode 11, anode 12 and cation exchange membrane 13, and the soln. is electrolyzed. NaOH and H2 formed in chamber 14 are introduced into catholyte vessel 2. The H2 is exhausted from line 45, and the NaOH is adjusted to a predetermined concn., passed through line 41, and supplied to NaOCl manufacturing reactor 6 kept under a reduced pressure slightly below the atmospheric pressure with suction pump 50. On the other hand, Cl2 gas generated in chamber 15 is passed through anolyte vessel 3, mixed with Cl2 gas-contg. air in vessel 7, fed to reactor 6 through line 42, and reacted with the NaOH. The resulting aqueous NaOCl soln. is drawn out of line 44.
KOIKE SEIJI
TAKAHASHI SANKICHI
MORITO NOBORU
