DE1607694

1,214,872. Separating solid particles from gas; cyclone separators. DEUTSCHE GOLDUND SILBER SCHEIDEANSTALT. 9 Feb., 1968 [11 Feb., 1967], No. 6439/68. Headings BIT and B2P. Solid particles are removed from gas, in chemical plant, by passing the gas through cyclone separators 1, 2, 3, which operate in series, then through filters 4, 5, 6, which operate in parallel, each filter comprising a plurality of outward-flow filter tubes which are cleaned periodically by reverse flow of filtered gas, drawn from outlet manifold 12 by blower 15, after closing valve 10a, 10b or 10c and opening valve 4f, 5f or 6f a short time later. During the changeover of each filter from filtering to reverse flow and back, a valve 19 is opened and gas flows through conduit 17, a valve 18 creating the same pressure drop as would a filter on reverse flow. This arrangement limits pressure surges which might damage the filter tubes or chemical plant upstream of the cyclones. Blower 15 delivers the reverse flow gas and the agglomerated solids from the filter tubes to the upstream side of cyclone 2 where they attract fine particles to assist the separation in the cyclone. Alternatively (Fig. 2, not shown) the blower may deliver the solids into an agglomerator (7), in series between two cyclones, in which the same process occurs. Agglomerator (7) may be a mechanical whirler or use electrostatic or ultrasonic effects. The filter tubes are glass cloth and held under tension by adjustable upper fastenings. Synthetic fabrics and fabrics impregnated to resist heat and/or chemicals are mentioned. The cyclones, filters and connecting conduits are all heated by means 20, 21 to prevent condensation.