Lignite resources are abundant; however, raw lignite suffers from high moisture content, low calorific value, and a tendency for spontaneous combustion, while high long-distance transportation costs limit its large-scale industrial application. Specialized rotary dryers for lignite utilize a stable, low-temperature drying process to dehydrate and upgrade the fuel, serving as core equipment in the field of clean coal processing.
Raw lignite typically has a moisture content of 25%–40%, resulting in low efficiency during direct combustion. These dryers employ a rotary structure equipped with specialized lifting flights that disperse the lignite to form a uniform material curtain, ensuring thorough heat exchange between the hot air and the material. Dehydration occurs under safe operating conditions—below the lignite's ignition point—reducing the final moisture content to below 13%. This process significantly boosts the calorific value by 30%–50% and vastly improves combustion performance, facilitating storage, transport, and utilization in power plants and heating boilers.
The equipment features optimized designs to prevent wall adhesion and crusting, allowing it to handle lignite of varying particle sizes while ensuring stable, continuous, long-term operation. The integrated system incorporates waste heat recovery and bag-type dust collection units to ensure exhaust emissions meet standards, thereby reducing drying energy consumption and environmental risks. Equipped with an intelligent variable-frequency control system, the unit automatically adjusts temperature and drum rotation speed based on raw coal moisture and production requirements; it offers ease of operation and maintenance, with single-unit capacities ranging from 1 to 100 tons per hour. Complete single-drum or triple-drum drying production lines can be customized to meet specific project site requirements.
