| 摘要 |
A method and apparatus for increasing hydrocarbon input to a direct reduction shaft furnace while controlling the temperature uniformity of the center portion of the burden within the furnace wherein the hydrocarbon gases used in the direct reduction may be preheated, which increases the temperature of the hydrocarbon gees, and therefore increases the resultant temperature of the upflowing gas as it rises from the lower section of the furnace into the center of the burden. Alternatively, a portion of the uptlowing gas may be removed before it enters the reduction zone of the furnace. The removed upflowing gas, known as hot bleed gas, may be dueled to the top gas scrubber of the furnace or may be mixed with the main reducing gas stream of the furnace for reintroduction to the furnace. Alternatively, hot reducing gas may be directly injected into the center portion of the burden, offsetting the cooling effect of the upflowing gas. The centrally injected hot reducing gas may be split off from the main reducing gas stream or may be generated by a partial oxidation reactor.
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