| 摘要 |
1,142,542. Pneumatic conveyers. WISCONSIN ALUMNI RESEARCH FOUNDATION. 22 Nov., 1966 [1 Dec., 1965], No. 52302/66. Heading B8A. [Also in Divisions A2, B1 and B2] In treating particulate material the material is fed into one end of an elongated trough, divided into a central zone and two side zones by longitudinal divider plates spaced above the base of the trough, a fluidizing gas is passed upwardly through the central zone to lift the particles of the particulate material above said divider plates, a treating composition is dispersed within the trough, the treated particles are withdrawn from the other end of the trough and the rates of introduction and withdrawal of the particles and of the gas flow adjusted to cause the particles to move in a generally helical path around the divider plates. In the embodiment shown, trough 1 has a pair of side walls 2 and a base 3 and divider plates 4 to give a central zone 5 and side zones 6. The base beneath central zone 5 has a large number of small apertures 9 whilst the strips of the base beneath the side zones 6 have a much smaller number of similar apertures 10. Particulate material is fed in to the two side zones at one end of the trough from a hopper 11 via valve means 13 to control the rate of input and are withdrawn at the other end through conduit 15 with valve means 16 to control the withdrawal rate. Beneath the base 3 is a housing 17 to distribute fluidizing medium under pressure to the apertures 9, 10 from inlet valve 18 by means of which the flow can be regulated. Treating medium is contained in vats 19 and is supplied under pressure, via control valves 21, to nozzles 22a which are preferably positioned in the central zone near the feed end of the trough so that the remaining length of the trough may function as a drying zone. The base may be formed by removable separate perforated plates and they may be formed of superposed perforated plates longitudinally slidable with respect to each other so that the open area may be varied from a maximum to zero. Additional perforations may be provided along the corners between the base and the side walls to provide horizontal gas streams to prevent stagnation of particles in these corners. The treatment may consist in cooling seeds, tablets, cereals etc.; reacting particles chemically especially where the reaction requires contacting a solid in particulate form with one or two reactants in a dispersed liquid or gaseous phase. |
