Settling tank with rotary scrapers

摘要

A cylindrical settling tank has scrapers 22 carried on radial arms 20 which scrape settled solids across the inclined floor to a central sump. There may be two or four radial arms, supported at their inner ends for rotation about an upstanding inlet pipe and each provided at their outer ends with a low friction wheel 24 running on a peripheral track 14 round the tank floor and with a hydraulic ram whose piston 32 engages successive upstanding lugs 26, ratchet fashion, to push the arm around the tank. In a tank with four arms 20, arranged at 90 degree intervals (Fig. 1), the respective rams are connected in pairs which operate antiphase so that the arm assembly moves continuously.