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

Abstract

The coke forms are produced in four stages, each constituted by a respective oven chamber, and in which the briquets are, respectively, preheated, dehydrated or dried, carbonized and cooled. Hot gas circuits are provided, in which the hot gas is composed substantially of burnt lean gas of the carbonization, and, for each stage, the hot gases are recirculated in a separate respective circuit. In the preheating, dehydrating and carbonization stages, the hot gases are heated and produced, or supplemented, in a respective separate combustion chamber with the recirculating hot gas in the carbonization stage being supplemented with cooled lean gas from this stage. The recirculating hot gases are dedusted separately in a dust settling chamber in which their flow velocity is reduced to approximately 0.2 to 2.0 m/sec, with the dust being collected. Steam may be added to the recirculating hot gas of the preheating stage, drying stage, or both, and the pressure in the hot gas circuits is maintained at a level slightly higher than atmospheric pressure. The oven chambers are arranged as a vertical oven block plant and the oven chambers are interconnected with each other by transition zones which are conically narrowed to approximately one half of the cross section of the chamber and then widened up to the full cross section. The hot gas inlets are provided in the transition zones at the lower ends of the oven chambers, and the hot gas outlets are provided in the transition zones at the upper ends of the chambers. The dust settling chambers are provided immediately adjacent the hot gas outlets, and the carbonization chamber is surrounded by its combustion chamber to form an operating unit. SP