Seal structure of solid feeding screw, and method of manufacturing reduced metal using the seal structure

A method for producing a reduced metal by heating and reducing a metal oxide containing a carbonaceous reducing material, comprising the steps of;

• feeding the metal oxide into a heating furnace for heating the metal oxide;
• leveling the metal oxide fed into the heating furnace in the feeding step with a material-leveling screw;
• and
• heating the metal oxide evenly laid in the leveling step for reducing;
• wherein
• the material-leveling screw comprises a driving shaft and a helical blade fixed on the driving shaft;
• the driving shaft passes through through-holes for screw-driving shaft which are formed in the side walls of the heating furnace, each of the through-holes having a vertical size which is larger than the diameter of the driving shaft by at least a lifting range of the solid-transferring screw, the driving shaft being supported by liftable supporting devices which are disposed at the outsides of the heating furnace;
• sealing blocks are attached on the outer edges of the through-holes for the screw-driving shaft so as to surround the periphery of the through-holes at the outsides of the heating furnace;
• and
• sliding panels are disposed at the outer sides of the sealing blocks of the furnace, each of the sliding panels having a sliding hole for sliding the screw-driving shaft so that the driving shaft extends through the sliding hole, each of the sliding panels being slidable in the vertical direction while airtightness between the sliding panel and the sealing block is retained.

A method for producing a reduced metal by heating and reducing a metal oxide containing a carbonaceous reducing material, comprising the steps of:

• feeding the metal oxide into a heating furnace for heating the metal oxide;
• heating the metal oxide fed into the heating furnace in the feeding step for reducing;
• and
• discharging the resulting reduced metal in the heating step with a product-discharging screw;
• wherein
• the product-discharging screw comprises a driving shaft and a helical blade fixed on the driving shaft;
• the driving shaft passes through through-holes for screw-driving shaft which are formed in the side walls of the heating furnace, each of the through-holes having a vertical size which is larger than the diameter of the driving shaft by at least a lifting range of the solid-transferring screw, the driving shaft being supported by liftable supporting devices which are disposed at the outsides of the heating furnace;
• sealing blocks are attached on the outer edges of the through-holes for the screw-driving shaft so as to surround the periphery of the through-holes at the outsides of the heating furnace;
• and
• sliding panels are disposed at the outer sides of the sealing blocks of the furnace, each of the sliding panels having a sliding hole for sliding the screw-driving shaft so that the driving shaft extends through the sliding hole, each of the sliding panels being slidable in the vertical direction while airtightness between the sliding panel and the sealing block is retained.