GB842172A - Improvements relating to methods and apparatus for hardening briquettes by coking - Google Patents

Abstract

842,172. Carbonizing fuel briquettes. DIDIER-WERKE A.G. July 5, 1957 [July 7, 1956], No. 21441/57. Class 55 (1). Fuel briquettes are coked by direct heating with hot gases in three zones, in the first of which the gases at a high coking temperature form a thin coked layer on the briquettes so that they retain their form when, in the second zone, under the action of somewhat cooler gases, most of the volatile matter is extracted, the third zone being supplied with gases at a high coking temperature to complete the coking process. Briquettes from hopper 9 pass through hopper 8 on to an endless belt conveyer 6. Gases supplied from a gas reservoir pipe 28 are burnt in a combustion chamber 25, mixed with more gas and supplied at a temperature of 550‹ to 600‹ C. through passage 17 and roof recess 13 to the briquettes. The gases pass through the layer of briquettes, are reversed in chamber 10, and pass again through the layer to the roof recess 14 leading through passage 18 and fan 36 to the gas reservoir pipe 28. In the second zone, gases at a temperature below 550‹ C. pass from a mixing chamber 26 through inlet 19 and roof recess 15 to pass downwardly through the layer of briquettes and then upwardly to the roof recess 14. The mixing chamber 26 may be constructed as a combustion chamber. In the third zone gas from a combustion chamber 27, mixed with gas direct from the pipe 28, passes at a temperature of 700‹ to 800‹ C. through the passage 20, roof recess 16 and layer of briquettes to the reversal chamber 12 and then through the layer again to the roof recess 15. The gases evolved from the briquettes mix with the heating gases and are partially recycled to the mixing and combustion chambers, partially sent to shaft 21, where the briquettes are cooled before passing to a coke-quenching arrangement 23, below a grid 22, and partially withdrawn from the system through pipe 45.