Steelmaking. Characteristics of Scrap Preheating by Shaft-type Preheater.

A new scrap preheater, named MSP(Multistage Super Preheater),has been developed by Daido Steel Co., Ltd. MSP is a kind of shaft-type Preheater and has two chambers, upper stage and lower stage. Steel-maded fingers which support the load of scrap are provided in both chambers. To investigate the basic functions of shaft-type preheater, experimental equipment was installed and scrap preheating experiments were carried out. The experimental results are as follows. (1) After 30 minutes heating by about 1200; gas, the average scrap temperature is 500~600;, and preheating efficiency is 35~45%. (2) Scrap oxidation proceeds by the heating at the temperature of more than 6 0 0 ;,and its rate reaches as much as 10%/hour by the heating at the temperature of 1200;.