| 摘要 |
<p>1,232,032. Settling sewage sludge. SOC. GENERALE D'EPURATION ET D'ASSAINISSEMENT. 26 July, 1968 [28 July, 1967], No. 35903/68. Heading B1D. [Also in Division E1] A sewage settling tank comprises a clear water overflow 18, means 22 for removing deposited sludge and, for removing the less dense fraction, and a pipe 34 having its inlet movable near the tank bottom and feeding a syphon 35-37. The syphon contains air, to allow the suction effect to be controlled. A bridge 28 rotates in the tank and carries scraper/eductor elements 29 (see Fig. 5). The scraper blades 30 are concave and carry flexible flaps 31 which push the densest sludge into sump 13 to be withdrawn whenever an automatic valve 23 is actuated. The eductor inlets 33 are at such a height as to suck away the lighter sludge. The suction rate is controlled by letting air into the syphons by means of a balanced valve arrangement controlled by a fluid pressure line (51) (see Division E1 and Figs. 3, 4 (not shown)), thereby partially "spoiling" the syphoning effect. The syphons discharge into a basin 19 having an outlet channel 20. Should a syphon become choked, all the other syphons are shut off, and the resulting fall in the level in basin 19 produces an increased pressure drop so as to clear the blockage.</p> |
