Partly closed electric redn. furnace - where outer part of roof forms ring channel in which redn. gases are burnt with air and fed to exit chimneys

摘要

The furnace has a round roof contg. holes through which three electrodes can be fed, and profiled holes through which the charge is fed. The profiled holes have vertical inlet pipes so the latter are steeper than the natural sloping surface of the charge. Roof only covers part of the furnace, and is located in a ring-shaped exhaust gas collection channel forming the remainder of the roof. Channel also forms a combustion chamber for the redn. gases, and has inlets for air of combustion. Channel is lined, and is also cooled, esp. by pipes forming a heat exchanger reclaiming heat from the exhaust gases. The combustion of the redn. gas can be controlled in a specific part of the surface of the charge, which can be fed continuously through the roof.