Adjustment and Transformation of Lignite Drying Technology with High Temperature Flue Gas

The schemes including igniting after large air purging and the establishment of master fuel trip logic have been proved helpful to reduce the autoignition and explosion of coal powder, and improve safety operation in lignite drying process. Adjustment principle of several important parameters was proposed, such as inlet flue gas temperature, exit gas temperature,and oxygen. Based on primary air duct reconstruction in burner, electric heating transformation in bunker, and strictly pre-warming before wet lignite drying, continuous operation on drying-system reached. According to the coal analysis, as the total mositure content of wet lignite decreases, the total mositure content of the block coal and pulverized coal also decreases, but the increasing extent of net calorific value of the block coal decreases, and net calorific value of the pulverized coal maybe decreases with the rise of ash content. The total moisture and ash content of product coal should be controlled reasonably, to avoid over-drying and damage the system mass balance.