GB401864A - Improvements in sedimentation devices - Google Patents

Abstract

401,864. Gravity-separation apparatus. TRIGGS, W. W., 57, Lincoln's Inn Fields, London.-(Dorr Co., Inc. ; 247, Park Avenue, New York, U.S.A.) Oct. 7, 1932, No. 27929. [Class 111.] Settled solids are collected by lateral displacement from the base of a rectangular or elongated settling-chamber by rakes or scrapers, adjustably suspended from a travelling carriage which reciprocates longitudinally of the cham. ber. A settling-tank, shown in plan in Fig. 1 and in vertical section in Fig. 2, has its bottom sloping from either side towards a central longitudinal sump or channel 14, into which settled solids are directed by scrapers 30, 31, suspended from a carriage 15 which is moved to-and-fro on rails on the sides of the tank by a motor 20, automatically reversed at either end of the tank. The scrapers are in pairs inclined in opposite directions to the channel 14 and supported from frames 35 so that the lower edge of each is parallel to the portion of the tank beneath it. The frames 35 are attached to members 36, 37 pivoted about a number 40 and are connected by a cable 42 passing round sheaves on a shaft 44. The shaft 44 is oscillated automatically when the carriage reaches either end of the tank, so that one pair of scrapers 30, 31, is raised and the other lowered into effective position to push the settled matter to the channel 14 as the carriage moves in the opposite direction. The sludge collecting in the channel 14 is raised through a pipe 47<1> by a pump 47 on the carriage and delivered into a tank 55 with an inclined bottom, the upper part of which serves as a drainage deck, and an overflow lip 57. Grit settles and is pushed over the drainage deck by paddles on a wheel 59 to an outlet 56', whence it is directed into a hopper 67. As the carriage reaches the end 12 of the tank, rollers on the hopper engage inclined members 71 and tilt the hopper so as to discharge the grit therein down a shoot 72. Both the pump 47 and the wheel 59 are operated from a motor 38. The ends of the tank are shaped in conformity with the scrapers so that dead spaces in which grit would collect are avoided. Fig. 5 shows modified apparatus comprising a tank with a flat floor and two sets of scrapers 79, the members of which are connected by links 82. As the carriage reaches one end of the tank the outer scrapers 79 contact with curved surfaces 83 and each set is turned so as to move the sludge to the central channel 78 as the carriage moves towards the other end of the tank.