초록 |
With the continuous increase of energy demand, low-grade coal is regarded as a new energy source. However, due to the high water content, the utilization efficiency of low-grade coal is not good to be used in recent conversion plants. Therefore, it requires a drying process to lower the water content in low-grade coals. Although a variety of drying experiments were conducted, drying characteristics in accordance with the pressure change has not been progressed. In this study, the flash drying characteristics of coals (A : 14.7%, B: 21.5%) were determined in a pressurized micro-riser. The micro-riser consisted of M.F.C., disk type feeder, rolled tube with oven, cyclone, back filter and back pressure regulator. The effect of operation conditions such as pressure (1-40bar), drying temperature (200-600oC), and particle size (212-300um and 300-355um), tube length (2-6m) on drying ratio were investigated. |