GB733825A - Improvements in travelling scrapers for desludging sedimentation tanks - Google Patents

Abstract

733,825. Treating sewage; separating mixtures of liquids and solids by gravity. HARTLEY, C. J. March 19, 1954 [March 19, 1953], No. 7553/53. Classes 46 and 111. Travelling scraper apparatus for sedimentation tanks comprises a scraper blade which is automatically lifted and lowered at opposite ends of the tank by means of actuating mechanism from side tracks arranged along the side walls of the tank. Gantries 11 which support the scraper blades 29, run on side rails 43 and carry on depending brackets 15, 33 hinged arms 18 which support rollers 20 running on upper and lower tracks 27, 25. During the inoperative period they run on the upper track 27 and at the end of their passage run down a sloping end member 28 on to the lower rail 25. The sloping members 28 are hinged at 37 and counterweighted at 29 to return to the horizontal when freed from the weight of the rollers 20 which now return beneath them along the lower track 25 having lowered the scraper blade 29 to its operative position through a connecting link 35, the blade-supporting arm 18 being pivoted at 31 to the bracket member 15. At the opposite end of the tank, above a sludge-collecting trough, a hinged slope 26 is displaced by the roller 20 which on reversal of direction rides up the slope to the upper rail 27, lifting the scraper blade 29 clear of the floor of the tank. The rail 25 is parallel to the flow of the tank and both rails are arranged in recesses in the side walls of the tank. Stops may limit the drop of the scraper blades. In a modification, a division wall between two tanks supports a set of guide rails 27, 25 on each side and the running rails 43 support the gantries in cantilever fashion over the respective tanks. Specifications 482,379 and 483,582 are referred to.