GB715836A - Improvements relating to heat-exchange processes for heating or cooling powdered material - Google Patents

Abstract

715,836. Cooling and preheating furnace changes. SMIDTH & CO. AKTIESELSKAB, F. L. Dec. 13, 1951 [Dec. 13, 1950], No. 29282/51. Class 51 (2). [Also in Group XIII] Powdered fluidized material such as cement or aluminium oxide travels up and down in a sinuous path intersected by tubes through which the heating or cooling fluid passes. Raw cement meal is preheated in a chamber with eight compartments, four on each side of a central wall having a communication opening 8, Fig. 1. Partitions D", E" provide for up and down flow of the material entering at 121 and leaving by pipe 24 leading to a kiln 16. Hot gases from the kiln pass by conduit 18 into header 13 from which pipes 9 pass through the compartments on one side of the chamber to a central header O<SP>11</SP> and onwards to header 14 from which they return through a similar pipe system in the compartments on the other side of the chamber leading to an exhaust conduit and fan (not shown). The floor of the chamber is formed of porous ceramic plates 20 through which fluidizing air is passed by a pipe system 21, this air leaving the chamber by passage 28. Dust is removed by a screw-conveyer 25. The intensity of fluidization in the various compartments may be varied by automatically-operated valves in the pipe system 21. Aluminium oxide leaving a kiln 38 is cooled in a partitioned chamber 41, Fig. 7, as previous!y described. Combustion air impelled by fan 49 passes through tubes 52 and a conduit 55 having ports 53, 57 feeding the kiln and pipe 58 conveying air for injection by the pump 59 into the burner pipe 62. Surplus air escapes by the damper-controlled passage 56. The material may be further cooled in a chamber with partitions 47 forming a sinuous path, for the material which is traversed by cooling water in a pipe system 63.