Shaft furnace for reducing ores
AssigneeKobe Steel, Ltd.
InventorsHiroyuki Kohama, Masaru Tamiya, Sunichi Mizukami, Dentaro Kaneko, Yoshio Kimura
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Abstract
A shaft furnace for reducing ores with a gas, wherein the furnace is constructed to destroy the plug-flow state of ores in or above a plug-flow zone where a reduction ratio of the ores is 50 to 70%, in order to prevent the clustering by changing the plug-flow zone into a shear-flow zone. Further, the shaft furnace for reducing ores with a gas is so constructed that a hydraulic radius R (cm) of the furnace in the reduction zone in which the reduction ratio is greater than 50% is selected to be, R.ltoreq.120 exp(8.6-0.009T) wherein T denotes the temperature (.degree.C.) of the reducing gas, in order to prevent the clustering.
Claims1
A shaft furnace for reducing ores with a gas comprising:
- a reduction zone formed along a predetermined height of said furnace;
- a plug flow zone formed in an upper portion of said reduction zone of said furnace during reduction operation;
- a shear flow zone formed in a portion of said reduction zone of said furnace downstream of said plug flow zone;
- and
- means operatively connected to said furnace in said reduction zone for shifting said shear flow zone to a position upstream of a portion of said reduction zone where a reduction ratio of 50 to 70% occurs, wherein said means for shifting comprises a hydraulic radius in the reduction zone where a reduction ratio greater than 50% occurs, defined by the formula:
- R.ltoreq.120 exp. (8.6-0.009T),
- wherein R is the hydraulic radius and T is the temperature (.degree.C.) of the reducing gas.
Dependencies are inferred from the claim text.