| 摘要 |
<p>621,880. Aerating sewage. TRIGGS, W. W. (Dorr Co.). Sept. 16, 1946, No. 27690. [Class 111] In the method of treating sewage by the activated sludge process and by aeration, in which the air bubbles formed also produce agitation of the liquid, the air is supplied by water-jet injectors sumberged below the surface of the liquid. In one form the apparatus is supported by a vertical tube 1, Fig. 1. having a water inlet 3 and lateral pipes 6, the tube 1 being surrounded by a packet 4 having an air inlet 5 and lateral pipes 7, a water-jet injector 8 being connected to each pair of lateral pipes as shown. The apparatus may have alternatively one only, or a plurality, (e.g., four), of injectors, equally spaced radially about the central tube. When used in the arrangement of Fig. 3 the return sludge is used as water feed for the injectors. The sewage flows from a main 12 into an aeration tank 10 in which are installed one or more injector-aerators 11 connected to a sludge-return pipe 15 and air feed pipe 16 respectively. A settling tank 18 to which the sewage overflows, is provided with a chain-conveyer 19 which moves the settled sludge to a sump 21 whence it is pumped back to the aerators. The water feed to the injectors may alternatively be pumped directly out of the aerating tank, the return sludge then being mixed with the fresh sewage. For large tanks water or return sludge may be supplied through a pipe 21, Fig. 4, downcomer 22 and header 23 resting on supports 24 near the bottom of the tank, and connected at intervals to transverse feed pipes 28 having injectors 29. Air from inlet 25 is similarly fed to the injectors 29 by transverse feed pipes immediately below the pipes 28. In another arrangement the header 27 is vertically above the header 23.</p> |
