GB111401A - Improvements in the Treatment of Sewage for the Purification thereof and the Production of Combustible Gas therefrom. - Google Patents

Abstract

111,401. Flicker, H. Feb. 27, 1917. Aerating; plant.-A process for purifying sewage comprises charging it with air, introducing the aerated sewage over the surface of sewage contained in a tank, the downward movement of the sewage in the tank while it is subjected to bacterial resolution, the continuous discharge of the effluent, and the periodical withdrawal of sludge. The combustible gases evolved may be collected for heating and lighting purposes. In the plant shown in Fig. 2, an aerating-device 2 charges the inflowing sewage in the pipe 1 with air, and the aerated sewage is sprayed by sprinklers 3 over the surface of the sewage in a chamber 5 formed by the wall of the tank and a baffle 7. The effluent leaves the chamber 5 by a passage 6, passes across the surface of the sludge deposited in a chamber 8 so as to facilitate the liberation of gas therefrom, and leaves the tank by a passage 9 and over a sill 11 where it is broken up to facilitate the liberation of gas from it. The leaving effluent is further aerated at 106. When the sludge reaches a gutter 14, as determined by the aid of a test pipe 105, some of it is drawn off by a pipe 101. Spray pipes 104, 102 facilitate cleansing the bottom of the tank and the pipe 101. The lower edges of the baffles are serrated to provide even distribution of the effluent. Gas may be drawn off by a pipe 20, and some of it is utilized in a heater 23 from which hot fluid is passed through a coil 24 in the tank to maintain the sewage at a temperature suited to the bacterial action. A circular tank is similarly arranged, annular baffles and a central discharge pipe being provided. In the circular tank shown in Fig. 4, the aerated sewage is supplied by sprinklers 304. The effluent flows downward in a chamber 302 and under a baffle 305 to an outlet 313, while the sludge is collected in a central chamber 308.