| 摘要 |
<p>512,513. ' Treating sewage ; gravity-separation apparatus. AMERICAN CENTRIFUGAL CORPORATION. Jan. 6, 1938, No. 425. Convention date, Jan. 6, 1937. [Class 111] Sewage sludge is treated centrifugally to separate heavier solids and a greasy effluent from which the grease is separated while the effluent is in an aerated state. The sludge may be aerated initially or the effluent may be aerated in the centrifuge or as it passes from the centrifuge to the grease-separating means. The de-greased effluent may be filtered. The solid matter from the centrifuge, the grease and the solid matter retained by the filter may be passed together to an incinerator. With the apparatus shown the sludge is withdrawn from a thickener or storage tank 80 through an automatically controlled valve 11 and lifted by a bucket elevator 13 to a centrifuge 81. Solid matter separated by the centrifuge is delivered by a conveyer belt 21 and a bucket elevator 24 to an incinerator 82. The effluent from the centrifuge is passed through a pipe 19, which may be fitted with a spiral fin 76, serving to agitate the liquid, to a setting-tank 27. Staggered baffles 31 cause the liquid to take a sinuous course through the settling-tank and grease rising to the surface is collected and pushed over an arcuate plate 43 into a tank 27a by angle bars 34 on an endless belt or chain. The liquid flows up a narrow passage 45, Fig. 8, and over an adjustable weir 46 to a pipe 50, by which it may be returned to the tank 80 or passed to a tank 71 containing a rotary vacuum filter 70. Solid matter separated by the filter is delivered by an endless band 75 to the belt 21. In the tank 27a more liquid settles out of the grease and the grease is pushed by skinner bars 34 over a plate 28 on to the belt 21. The frame 57 of the skinning mechanism may be pivoted and counter-balanced so that the bars 34 can be brought into position to scrape away matter settling on the sloping floor of the tank. The valve 11 may be operated by mechanism as described in Specification 477,898, [Group II]. The centrifuge is preferably of the type described in Specification 453,651, [Group II]. Specification 478,977 also is referred to.</p> |
