Ozonised Water Supply.

Ozonised Water Supply.

Nice, with its 105,000 inhabitants, and several smaller French cities not only filter their water supply, but, also, purify it by ozone. At Chat res, a city of 24,000 inhabitants, ozonisation of the supply is most successfully employed. The process is thus described: “The water is pumped from the river Eure into sendiincntation-basins. which are contained in a building of ferro-conCrete, with a double roof, which keeps the water fairly cool in summer and prevents it from freezing in winter. The building has windows of yel low glass, yellow light being unfavorable to the development of bacteria. In these basins about 1,600,000 gal. of water are clarified in twentyfour hours. The water flows thence through coarse coke-filters and fine sand-hlters to the ozonising apparatus. The coke tilterbeds are cleaned, when they become choked, by exposing them to the air and washing away the oxidised impurities with a current of water. The sand-lil ters are cleaned by powerful jets of compressed air and water, directed upward. The ozonising plant is constructed in duplicate, so that one section is always ready for use. The water trickles down through four beds of pebbles, which have an aggregate thickness of 14 ft., and are supported by perforated floors in a tower, at the hot tom of which ozonised air enters under pressure. The ozone generator is a cell of glass 6 ft long. :i ft. wide and 6 ft. high. It contains five elements. each composed of three cast-iron plates. The middle plate is connected with a transformer, which furnishes an alternating current of 20,000 volts; the outside plates are connected to earth Between the iron plates are glass nlatcs covered with tinfoil. Ozone is produced by the alternating electric discharges between the plates. The outer iron plates are perforated to allow the ozone to escape, and the middle olate is cooled by a current of water from a tank insulated by triple bells of porcelain. Air is forced into tingenerator under a pressure sufficient to carry it. iaden with ozone, through the water tower. One grain of ozone is used for 8½ gal. of water. The primary circuit of the transformer is connected with an alternator, which produces a monophase current of 250 volts and 500 cycles. It is of in terest to note that the price charged for water— about 1 cent for 44 gal., has not been increased since the installation of the ozonising plant.”

Nice, with its 105,000 inhabitants, and several smaller French cities not only filter their water supply, but, also, purify it by ozone. At Chat res, a city of 24,000 inhabitants, ozonisation of the supply is most successfully employed. The process is thus described: “The water is pumped from the river Eure into sendiincntation-basins. which are contained in a building of ferro-conCrete, with a double roof, which keeps the water fairly cool in summer and prevents it from freezing in winter. The building has windows of yel low glass, yellow light being unfavorable to the development of bacteria. In these basins about 1,600,000 gal. of water are clarified in twentyfour hours. The water flows thence through coarse coke-filters and fine sand-hlters to the ozonising apparatus. The coke tilterbeds are cleaned, when they become choked, by exposing them to the air and washing away the oxidised impurities with a current of water. The sand-lil ters are cleaned by powerful jets of compressed air and water, directed upward. The ozonising plant is constructed in duplicate, so that one section is always ready for use. The water trickles down through four beds of pebbles, which have an aggregate thickness of 14 ft., and are supported by perforated floors in a tower, at the hot tom of which ozonised air enters under pressure. The ozone generator is a cell of glass 6 ft long. :i ft. wide and 6 ft. high. It contains five elements. each composed of three cast-iron plates. The middle plate is connected with a transformer, which furnishes an alternating current of 20,000 volts; the outside plates are connected to earth Between the iron plates are glass nlatcs covered with tinfoil. Ozone is produced by the alternating electric discharges between the plates. The outer iron plates are perforated to allow the ozone to escape, and the middle olate is cooled by a current of water from a tank insulated by triple bells of porcelain. Air is forced into tingenerator under a pressure sufficient to carry it. iaden with ozone, through the water tower. One grain of ozone is used for 8½ gal. of water. The primary circuit of the transformer is connected with an alternator, which produces a monophase current of 250 volts and 500 cycles. It is of in terest to note that the price charged for water— about 1 cent for 44 gal., has not been increased since the installation of the ozonising plant.”