GB798885A - Improvements relating to the pneumatic separation of mixed discrete materials - Google Patents

Abstract

798,885. Separating solid materials. MCINTYRE, R. C. Nov. 9, 1956 [Jan. 18, 1956; Oct. 2, 1956], Nos. 1772/56 and 30037/56. Class 117 A pneumatic separator includes frustoconical casings 1, 2 defining between them an annular space 3 for the upward flow of an air current which carries away the lighter particles of a material flung from a centrifugal disc 6, the heavier material falling into a hopper 10. Means are provided to vary the speeds of the air current and disc, and the rate of material fed to the disc from a shoot 7. Air is drawn through the apparatus by a suction unit 5a, Fig. 3, and via a cyclone separator 5b, and the air current may be adjusted by the unit or. by moving the outer casing axially relative to the inner one thereby varying the width of the space 3. Fig. 3 shows pins 1a on the outer casing adjustably engaging slotted pillars 2a extending from the base of the inner casing. In the embodiment of Fig. 4, louvres 11 are provided around the periphery of the inner casing for the overflow of air to assist the separation, said outflow being adjustable if desired by a rotatable louvred sleeve. Fig. 5 shows an alternative arrangement in which surfaces 13 and 14 extend from the inner casing and disc, and provide a diverging outlet for an air current, the outlet being adjustable by relative movement between the disc and inner casing. The air may be heated before and during its passage through the apparatus, and its linear speed may be kept substantially constant over a vertical distance below and up to the disc level. For the latter purpose the space 3 is arranged to have a substantially constant cross-sectional area over that distance i.e. the inner and outer casings may have different apex angles or a skirt 2a, Fig. 6a may be provided. The disc may include a conical member with flutes, vanes &c. centrally positioned thereon. In Fig. 7 the material is fed through a duct 7a which has a conical member 7b providing, in effect, a continuation or the inner casing.