Apparatus and method for introducing hot reducing gases into a shaft furnace

摘要

1488976 Injecting reducing gas into a shaft furnace CENTRE DE RECHERCHES METALLURGIQUES - CENTRUM VOOR RESEARCH IN DE METALLURGIE 20 March 1975 [29 March 1974] 11733/75 Heading F4B [Also in Division H5] Apparatus for injecting hot reducing gas into a shaft furnace comprises a duct 4 that supplies reducing gas or a gas consisting of a mixture of hydrocarbon gas to be reformed and oxidizing gas to a tuyÞre 6 via an injection tube 5 that is coaxial with the tuyÞre. The injection tube is either wholly or only partly constituted by a plasma arc furnace enclosure 9, in which heat is supplied by a plasma arc generated by plasma arc torches 15. The injection tube may have two plasma arc furnaces in series with the reducing gas being produced by one plasma arc furnace and heated by the other. The plasma arc furnace enclosure 9 may have three radial plasma arc torches spaced at 120 degrees from one another with each torch connected to one phase of a three-phase electrical supply the neutral point of which is on the common longitudinal axis 10, 11 of the tube 5 and tuyÞre 6. The stability of the electric arcs may be assisted by adding compounds that can be easily ionized such as alkali metal or alkaline-earth metal compounds to the plasma generating gas.