Apparatus for producing non-abrasive coke forms from brown-coal briquets

In apparatus for producing non-abrasive coke forms from brown coal briquettes, of the type in which the brown coal briquettes are preheated, dehydrated or dried, carbonized and subsequently cooled in an oven in at least three respective stages, and including gas recirculating circuits for recirculating gas consisting essentially of combustion lean gas obtained from carbonization of the brown coal briquettes, with the gas in the recirculating circuits for the carbonization being heated and the gas in the recirculating circuits for the cooling being cooled, the improvement wherein said oven comprises four oven chambers arranged in superposed aligned relation and including a preheating chamber, a dehydrating chamber, a carbonization chamber and a cooling chamber;

• each chamber having conically converging upper and lower ends;
• means interconnecting the conically converging ends of adjacent chambers, said interconnecting means and said conically converging ends defining transition zones between said oven chambers, the cross-sectional area of each of said transition zones decreasing from one chamber toward the next subjacent chamber to approximately one-half the cross-sectional area of the superjacent chamber and then increasing to the full cross-sectional area of the subjacent oven chamber;
• respective gas inlets for each oven chamber provided around the entire periphery of the conically converging lower end thereof;
• respective gas outlets for each oven chamber provided around the entire periphery of the conically converging upper end thereof;
• respective means connecting the gas outlet of each chamber to the gas inlet thereof to provide, for each chamber, a primary gas recirculating circuit respective to only that chamber and separate from the primary gas recirculating circuits respective to the other chambers;
• respective combustion chambers, supplied with such combustion lean gas and with air, connected in the primary gas recirculating circuits of said pre-heating and dehydrating chambers for separately heating the respective gases recirculating therein;
• and respective dust settling receptacles provided immediately adjacent the gas outlets of said oven chambers and surrounding the transition zones interconnecting said oven chambers;
• said dust settling receptacles effecting separate dedusting of the recirculating gases of the respective oven chambers while reducing the flow velocity of the respective recirculating gases to substantially 0.2 to 2.0 m/sec.