GB758176A - Improvements in apparatus for heat exchange between gases and solid particles - Google Patents

Abstract

758,176. Centrifugal separators. SMIDTH & CO., AKTIESELSKAB, F. L. Oct, 13, 1954, No. 29535/64. Class 23. [Also in Group XII] In combined apparatus for feeding and preheating powdered or granular material charged into a rotary kiln of the type in which waste gases from the kiln pass in a generally countercurrent direction to the charge material through a series of cyclone separators, hot gases from the kiln 1 pass in turn through a duct 2, a cyclone 3, a duct 4 into which a screw 10 feeds charge material from a storage bin 9, and a second cyclone 5 disposed inside the cyclone 3. The gases are drawn by a fan 8 from the cyclone 5 through a duct 6 and a dust collector 7. Charge material from the dust collector 7 and the cyclone 3 are respectively fed through a duct 13 and a valve-controlled duct 12 to the furnace, and charge material from the cyclone 5 passing through a valve-controlled duct 11 is dispersed in the hot gases ascending the duct 2. The part of the duct 4 which is disposed inside the cyclone 3 is of stream-lined cross section. In a modification, Fig. 4 (not shown), the duct 2 leads to the inner cyclone 5, and in a further modification, Fig. 5 (not shown), the headroom required is reduced by making the feed from the cyclones wholly or in part of horizontal screw conveyers. Another modification, Fig. 6 (not shown), comprises successive pairs of cyclones generally similar to those of Fig. 5. Fig. 7 shows three cyclones 3, 5 and 19 mounted partially inside one another, charge material being fed from the bin 9 by the screw 10 into the duct 20 leading to the third cyclone 19 which discharges through a screw 21 driven by a shaft 23 and a duct 22 into the duct 4 leading to the cyclone 5. In yet another modification, Fig. 9 (not shown), the duct 20 is dispensed with and gases from the cyclone 5 pass to the cyclone 19 through a jacket surrounding the latter, the charge material being also fed into this jacket. A final modification, Fig. 10 (not shown), has a nest of four cyclones disposed within one another. The apparatus may also be applied to cooling hot granular &c. material with cool air.