D-C power for the chlorine-caustic industry

The second largest consumption of d-c power in the United States for electrochemical use is by the chlorine-caustic industry which is expected to have a capacity of about 494,000 kw before the end of this year. Two major types of electrolytic cells — the diaphragm type and the mercury cathode type — are used to produce chlorine and either potassium or sodium hydroxide. Since 1936 most of the conversion equipment installed for supplying these cells has been mercury-arc rectifiers.