| 摘要 |
<p>457,756. Treating sewage; gravity-separation apparatus. DORR-OLIVER CO., Ltd., Abford House, Wilton Road, Westminster, and GIBBS, R. C., Ash House, Garrard Road, Banstead, Surrey. March 1, 1935, No. 6546. [Class 111] Liquid such as sewage is treated with coagulating agent, agitated by paddles to promote flocculation and allowed to drift horizontally to a settling-tank without such changes of direction as would cause disintegration of the flocks. The liquid is first thoroughly mixed with a coagulating agent such as lime by means of a high-speed agitating device, then passed through a tank 32, Fig. 3, with baffles 47 and rotating paddles 36, which cause the suspended matter to flocculate as described in Specification 407,807. From the tank 32 it passes along a channel fitted with paddles to a settling tank 13, and is distributed downwardly in the tank through a stationary cylindrical chamber 40 and a ring 42, carried by a rotating drum 18 to which sludge scrapers 16 are attached. Clear liquid overflows at the periphery and sludge collected by the scrapers 16 is directed into a depressed portion 12 of the tank fitted with an agitator 28 of the " picket fence " type, which is supported by and rotates with the drum 18 and to which scrapers 54 are attached. This subjects the sludge to a gentle disturbance which promotes further thickening. The thickened sludge is discharged through a pipe 61. In a modified form of apparatus the flocculating paddles are arranged in an extension of the settling tank on its inlet side. In another form, Fig. 8, the flocculating paddles 36 are arranged at the inlet side of a rectangular settling-tank, clear liquid flowing over a weir 85 at the opposite end. The sludge is moved laterally by scrapers 17 supported by swing arms from a carriage 22 which is reciprocated on tracks 23. The sludge thus collected is pushed into the compartment 12 by another scraper mounted on the carriage and arranged to operate only when the carriage moves towards the compartment 12. The agitator in the compartment 12 is attached to a shaft 29 driven by the motor which drives the paddles 36. A bar 88 suspended from the carriage 22 directs scum into a launder 87.</p> |
