PURPOSE: To grasp the reduction ratio of reduced ore on real time by providing a ramification tube in a product discharging tube in a fluidized bed reduction furnace for iron ore and measuring bulk density of the reduced ore with a weighting tube fitted to the ramification tube.
CONSTITUTION: Powdery and granular iron ores are supplied into the fluidized bed reduction furnace 1 from a raw material supplying hole 3, and also, reducing gas 2 is supplied from the lower part of the reduction furnace 1, and after reducing the iron ore in the fluidized bed condition, the reduced ore and the gas are separated with a solid-gas separator 4. The reducing ore is circulatively supplied to the lower part of the fluidized bed reduction furnace 1 through a downcomer 5 and a part thereof is collected to a product hopper 7 from a discharging hole for reduced ore as the product through the product discharging tube 6. In this case, the ramification tube is arranged in the product discharging tube 6 and the bulk density for the reduced ore is measured with the weighing tube 8 on the way of this ramification tube. As there is the fixed correlation between the reduction ratio of the reduced ore and the bulk density, by measuring the bulk density of the remained ore, the reduction ratio of the ore can quickly and precisely be estimated on the real time.
TAKAMOTO YASUSHI
EGASHIRA TATSUHIKO
