To improve the efficiency of preheating of scrap by regulating a charging position of the scrap in relation to the whole scrap so that an exhaust gas passage be ensured in preheating equipment, on the occasion when the scrap charged in the preheating equipment provided at the furnace top of a melting furnace is preheated by exhaust gas produced in the melting furnace.
In the top part of a melting furnace 11, preheating chambers 41 and 42 are formed by partitioning the inside of a shaft 21 above and below. A bypass 51 is provided between the lateral lower part of the shaft 21 and the lateral upper part of the shaft 21 forming the preheating chamber 41 and an exhaust gas duct 61 is connected to the lateral upper part of the preheating chamber 42 of the shaft 21. In large-piece scrap charged in the preheating chambers 41 and 42, small-piece scrap layers 71 and 73 of the upper layers and small-piece scrap layers 72 and 74 of the lower layers are made present by charging small-piece scrap in the large-piece one in layers and with spaces left between the upper and lower layers. However, the small-piece scrap layers 71-74 are not present in all the preheating chambers 41 and 42 in the direction of the width thereof and exhaust gas passes, in a meandering manner, through the parts in the preheating chambers 41 and 42 wherein the small-piece scrap is not charged.
NIWA YUKIO
KATO MASASHI
