| 摘要 |
<p>442,458. Treating sewage. DORR CO., Inc., 247, Park Avenue, New York, U.S.A. Sept. 27, 1934, No. 27708. Convention date, Dec. 30, 1933. [Class 111] A tank for the digestion of sewage sludge is fitted withpaddle blades which move in a substantially vertical plane. They may extend for part of their movement above the level of the sludge so as to break up scum and cause it to be submerged. The tank 1 is divided by vertical walls 2, 3, into compartments in each of which paddles 10 are mounted on a shaft 5 driven from an electric motor 7. Each compartment has a sludge inlet 14 and the paddles near the inlet end mix the freshly introduced sludge with digesting sludge. The sludge settles at the further end where there is a valved outlet pipe 15 for sludge and an overflow for supernatant liquid. Heating coils or pipes 17 are associated with the shafts 5 and paddles. The tank may have covers 11 with gas-collecting domes 13. One only of the three compartments may be used as a sludge digester the others being used as settling tanks.</p> |
