GB793713A - Improvements in suspension type heat exchanger and method of heating finely divided solids - Google Patents

Abstract

793,713. Preheating furnace charges. KENNEDY VAN SAUN MFG. & ENG. CORPORATION. July 11, 1955 [July 23, 1954], No. 20038/55. Class 51 (2). [Also in Group XXXVII] In a heat exchange tower 12 for preheating cement raw materials being fed to a rotary furnace 10 in a generally counter-current direction to hot waste gases issuing therefrom, the raw materials from a hopper 14 fall successively through a series of chambers 17, 22 and 26 or 18, 23 and 27, and the waste gases are caused to traverse each chamber in the same direction as the falling materials. From the furnace the gases pass in turn up a central flue 30, down the chambers 26 and 27, up side flues 34 and 35, down chambers 22 and 23, up a central flue 37, down chambers 17 and 18, up flues 39 and 40, and out through openings 41 and 42 into cyclone separators 43 and 44 from which an extractor fan delivers them into a stack running parallel with the tower. If necessary, the hot gases can be diverted at the foot of the tower directly into the stack. The side walls of each chamber are formed with baffles 19 defining a circuitous path for the materials and the waste gases, and the sudden reversal of the waste gases at the foot of each chamber causes the bulk of the raw materials to separate out. Passage of the raw materials downwardly from the hopper 14 is controlled at each stage by rotary pocketed valves 16, 20, 21, 24, 25, 28 and 29 arranged as shown in pairs. Additional rotary valves 47 control the passage of fires from the separators 44 and 43 to points above the valves 20 and 21 respectively, and a further valve 51 discharges any material collecting in the central flue 37. The valves, shown in detail in Fig. 3, each comprise a cylindrical body formed with an axial passage for cooling air, and blade members 59 defining the intervening pockets. Above each valve is disposed a mounting comprising hollow side sections 60 and a grating 61. Driving motors for each set of valves and fans supplying the cooling air are disposed on platforms 55 mounted on the tower, and inspection doors 52 allow of access to the gratings 61 from these platforms. If the rotary valves jam they are automatically reversed by a motor-controlling circuit (see Group XXXVII).