GB812822A - Apparatus for treating compressed fuel briquettes and materials of similar character - Google Patents

Abstract

812,822. Tunnel ovens for treating fuel agglomerates. HOUILLERES DU BASSIN DU NORD ET DU PAS-DE-CALAIS. July 25, 1955 [July 24, 1954], No. 21435/55. Addition to 716,537 and 722,495. Classes 51 (1) and 51 (2). In a tunnel oven for the treating of fue agglomerates by the three-stage process disclosed in the parent Specification in which the charge is conveyed through a plurality of zones each having inlets and outlets for circulating gases through the agglomerates, co-operating sealing devices on the outer wall surfaces of the trucks or a conveyer and the inner wall surfaces of the tunnel confine the circulating gases to their respective circuits. Charge trucks 15 with a perforated base 16 have sand seals 20 near the wheels and lower trough-shaped, flexible steel seals 32 packed with glass wool or other insulating material engaging shoulders on the truck base plates 17. Side flanges 36 of the truck base 16 slide over flexible seatings packed with glass wool &c. and a top seal comprises truck flanges 37 sliding on an S-shaped element 38 disposed in a trough 39 packed with glass wool &c. A modified upper and lower side seal, Fig. 5 (not shown), comprises spring-pressed channel members, engaging the truck sides, and disposed in recesses in the tunnel walls packed with glass wool &c. The various zones may be isolated by pivoted plates 42 depending from a roof section 41 and engaging a labyrinth seal formed between two trucks. Vertically extending resilient seals 46 on the truck ends engage the tunnel wall and define the lateral extent of a treatment zone. The supply of heating gases and air through sectional side flues 4 and 5 corresponding with each zone, and the circulation of the gases in each zone by a fan 25 is similar to that disclosed in the parent Specification. Some of the exhaust gases may be re-cycled to the external combustion chamber, Fig. 8 (not shown). An additional combustion chamber directly feeding one or more of the zones may be incorporated in the heating system, the spent gases being recycled to both combustion chambers. Passage of air and gases to and from the inlet end of the oven is prevented by providing an extra zone, Fig. 6, at this end, having a blower 54 controlled by a valve 55 and an exhaust fan 50 controlled by a valve 51, the valves and/or the fan motors being controlled from differential gauges 52 and 56 recording pressure differences between adjacent zones. A similar extra zone is disposed at the exit end of the oven, Fig. 7 (not shown).