SUPPLY OF RAW MEAL VIA SCOOP CHAMBER

1508840 Preheating granular material F L SMIDTH & CO AS 3 Sept 1976 [15 Oct 1975 19 Nov 1975 4 Feb 1976] 42221/75 47632/75 and 4362/76 Heading F4B In a kiln plant comprising a multistage preheater and a rotary kiln, material from a preheater stage other than the last is fed to a dispersing device mounted on the upper end of the kiln, and material from the last preheater stage is fed to the kiln beyond the dispersing device. In one embodiment, Figs. 3 and 6, a duct 4 leads preheated material into the kiln end, and a duct 5 leads material from the penultimate preheater to a scoop chamber 3 having lifters 9 scattering material into the gas flow, and air inlets 17 allowing the entry of cooling air. The supply duct 4 is located below the sloping floor 2a of the smoke box 2 leading to the preheaters thus reducing the cross-section and accelerating the gas flow. A by-pass pipe 16 for kiln gases may be provided. In another embodiment (Figs. 7 and 8) the upper end of the kiln carries scoops on its outer surface, a stationary chamber surrounding the kiln end receiving material from the penultimate preheater stage. The dispersing device may take the form of stationary plates 27a at the entry of the smoke box 2, Fig. 9. The Specification shows various arrangements of cyclone preheaters, coolers and calciners similar to those shown in Specifications 1,469,673 and 1,479,220. Specifications 763,837, 1,100,530, 1,375,566 and 1,453 215 are referred to.