Technical Analysis on Lignite Drying Technology with High Temperature Flue Gas

The procedure and system of drum drying technology are introduced for lignite drying and upgrading with high temperature flue gas. The total moisture and inherent moisture of lignite decrease significantly after being dried and the lower heat value (LHV) increases greatly, which means that the quality of lignite is improved obviously. Both the moisture and air dried volatile of the dried product coal decrease gradually when increasing the drum inlet temperature. However, only the moisture decreases and the volatile varies little when increasing the drum outlet temperature.The rotating speed of drum will make a few impact on the drying degree. Because the combustion load and the drying output will affect each other, it is recommended that the independent pulverized coal system is added. The key factors affecting the system material balance are the ratio of fine-grained powder and lower heat value. The appropriate ratio of fine-grained powder is suggested. The inert atmosphere feeding system which can control the oxygen content independently must be designed.