Sterilization by Ozone at Baltimore
Baltimore sterilizes its water by the use of ozone generated by electricity. The plant has been erected at its Herring Run station and consists of a raw water chamber, aspirator heads, ozone chambers, ozone generator and a timecontact basin or mixing well. The ozone generator consists of a boiler-plate shell and head 30 inches high by 33 inches diameter. In this shell is a large number of aluminum tubes containing micanite tubes, serving as insulators for metallic tubes connected to one terminal of a transformer. The other terminal of the transformer, which gives from 10,000 to 15,000 volts, is connected to the ozone-generator shell. When the current is closed a continuous violet discharge occurs between the inner and outer tubes, producing ozone in the air passing through. By means of the time-contact basin or mixing cell the water is made to move horizontally as well as vertically in contact with the ozone, so as to give it a long time of action. Current is supplied to the transformer at about 2,000 volts, and there is a separate 5-kilowatt transformer for each mixing cell or basin. The capacity of each basin is 1,000,000 gallons of water in 24 hours.