GB398980A - Apparatus for separating and recovering solid matter from liquid suspension - Google Patents

Abstract

398,980. Filters or strainers. THORNE, C. B., Hawkesbury, Ontario, Canada. July 6, 1932, No. 19127. Convention date, Dec. 3, 1931. [Class 46.] In paper making the longer fibres are separated from white water by a continuously moving screen of mesh which, unobstructed, passes the shorter fibres and wood flour, liquid being passed through the screen at one portion of its path, paddles or blades being reciprocated or oscillated relatively to the screen continuously to agitate the fibres on the inflow side of the screen to maintain the flow through it and delay the deposition of the fibres, and the longer fibres which do not pass through the screen being collected from another part of the screen and discharged. A drum 1, Fig. 2, rotated in bearings 2, 3 by reduction gearing 40, Fig. 3, has spiders 7 intermediate of end-plates 4, 5 supporting a coarse wire-screen or perforated drum 11 covered by a fine wire-screen 12 in sections clamped by rims 13 and, at their edges, by bars 6. The drum is divided by partitions 18 with openings 19 relatively 'displaced angularly and a hollow shaft 8 carries agitators 20 which may have spray jets 24 and are oscillated by an eccentric 42 &c., Fig. 3, the shaft 8 being also reciprocated endwise owing to a screw thread 45 &c. A spray pipe 36 above the drum may also be oscillated from an arm 46 on the shaft 8. White water &c. enters by a pipe 32 and compartment 28 having a weir 33 and passes through a float-controlled valve 30 to the drum, the fibre &c. being deposited and the water flowing through the screen into a compartment 26 and over a weir to an overflow box 50, the fibrous deposit being agitated in the successive compartments to cause the wood flour &c. to pass through the screen, the larger fibres being finally washed off by the spray 36 and passed into a shoot 25. In a modification the wood flour &c. passes from the outside to the inside of a drum, external agitators being used and the pulp removed by a collector roll which contacts with a scraper blade. In a further modification the white water is delivered to the lower run of a travelling wire-cloth and after agitation passes over an end roller and the fibre is washed off by a spray and collected in a trough ; deckles aiding in maintaining a pool of white water on the lower run of the wire-cloth.