Effect of Rapid Heating Conditions on Crack of Coal Particle

Abstract

In the SCOPE21 coke making process, there is a preheating process which raise the temperature of coal particles up to about 400°C before coal charging. It is known that coal particles are broken into pieces when they are heated rapidly to over 1000°C in the DIOS process¹⁾. It is undesirable that coal particles break into fine powder in preheating process of the SCOPE21. Because fine powder causes various troubles in coke making process such as carry over phenomenon. Then, effect of rapid heating condition on crack of coal particles from room temperature up to 380°C was investigated. Down flow type experimental apparatus was used in this study, and 6 kinds of coals were investigated about heat crack. From this investigation, next results were obtained.
1) Crack of wet coal particles, in the case of direct rapid heating from room temperature up to 380°C, was remarkable.
2) Degree of the heat crack of wet coal samples that Ro were about 0.70.8 was low in rapid heating.
3) Degree of the heat crack of coal particles, in the case of rapid heating up to 380°C after heating and drying below 250°C, became lower.
Preheating process was divided to two stages in the SCOPE21 coke making process. The first stage is the drying and preheating process in which coal particle is heated and dried and fine coal powder is separated in the same time. The second stage is the rapid heating tower process after the drying process. Obtained results were applied to the heating condition in two preheating processes.