Sawdust dryer machine-important equipment in sawdust pellet production

  Lignite is a low-rank coal with a low degree of coalification, it has high moisture content and high volatility, combustible in the air. Lignite upgrading can reduce ash and sulfur content, increase calorific value. The processed lignite can be directly used as a power coal, bituminous coal, and anthracite in thermal power plants. The lignite dryer is a key equipment in the lignite upgrading process. So, how does lignite dryer work to improve lignite quality?

  The lignite dryer is a rotary dryer primarily composed of a rotating cylinder, exhaust air equipment, high-speed dispersion equipment, lifting plates, and a hot blast furnace, designed for continuous drying of wet lignite materials. Developed specifically for the unique properties of lignite, this dryer employs a four-stage drying process to reduce lignite moisture content to below 15%.

  Primary Drying: Lignite has a low ignition point and begins to self-ignite at 270°C. During this stage, the lignite undergoes rapid evaporation of most surface moisture at high temperatures of 400°C while ensuring its inherent composition remains unchanged.

  Secondary Drying: Utilizing a high temperature of 300°C close to the lignite ignition point, along with the assistance of a high-velocity induced draft fan, to remove surface moisture from the lignite while ensuring it does not burn.

  Three-stage drying: As the lignite flows through this zone, it is continuously broken and dispersed by the crushing device inside the lignite dryer drum, forming a material curtain. It is then fully dried again within the drum temperature range of 120-210°C.

  Fourth-stage Drying: Due to the high moisture content discharged after lignite drying, this stage employs low temperatures of 60-80°C under the action of the induced draft system to remove moisture, ultimately yielding finished lignite products to prevent rehydration.

  Besides lignite, the lignite dryer is also suitable for drying materials such as coal slurry, raw coal, flotation concentrate, and mixed concentrate in the coal industry, offering a wide range of applications. For further technical inquiries, you may consult us at any time.