Coal Rotary Drying Machine
Improve the value of coal utilization
Improve calorific value and combustion efficiency: Wet coal will absorb combustion heat (1 kilogram of water needs consume 2.26 megajoules of heat), and after drying, heat loss during combustion can be reduced, and calorific value can be increased by 0%-30% (for example, the calorific value of coal after drying can be increased from 12-18 megajoules/kilogram to20-25 megajoules/kilogram), which is more suitable for power plants, boilers and other combustion scenarios.
Expand the range of applications High moisture coal (such as lignite) can only be used locally due to its spontaneous combustion and high transportation cost; after drying, it can be transported over long distances, it can also be used as the raw material for coal chemical industry (such as gasification, liquefaction), which can expand the industrial chain
The coal dryer is a dedicated equipment designed for the moisture removal and drying of wet coal (such asignite, bituminous coal, raw coal, washed coal, etc.), which can improve its combustion efficiency, calorific value, and economic value by removing the moisture and some internal moisture of the coal. The following details are introduced from core parameters, working principles, structural composition, and applicable scenarios:
I. Core Functions and ParametersDrying Target: To reduce the initial moisture content of coal (usually 20%-50%, lignite can reach more than 50%) to 815% (specifically adjusted according to the purpose, such as ≤12% for power generation coal).
Processing Capacity: The hourly processing capacity is0.5-500 tons, adapting to the different needs of small mines, coal washing plants to large coal processing bases.
Thermal Efficiency: Generally 0%-80%, depending on the type of heat source and equipment design (such as the dryer with a closed loop has a higher thermal efficiency).
Heat Sourceatibility: It can be compatible with coal, gas (natural gas, liquefied gas), biomass fuel, steam, industrial waste heat (such as power plant tail gas, etc. Some models support "coal drying with coal" (using low-quality coal as a heat source).
II. Working Principle
The thermal airflow technology is adopted, and the core process is as follows:
Feeding: The wet coal enters the dryer drum through the conveyor belt, the drum is inclined at 3-5°, and moves forward with the rotation.
Drying: The high-temperature hot air (150-350℃, adjusted according to the coal) generated by the heat source fully contacts with the coal in the drum — the coal is continuously lifted and scattered by the lifting plate, expanding the contact area, and the moisture quicklyates into steam.
Separation: The dried coal is discharged from the discharge port, and the dusty exhaust gas enters the dust removal system (cyclone separator bag filter, and is discharged after purification.
Temperature Control Key: By adjusting the hot air temperature (such as lignite needs ≤200℃ to prevent pylysis), drum speed (control the residence time of the material), to ensure that the coal is dried evenly without caking, carbonization.
III. Coreructural Composition
Drum Body: Horizontal cylindrical drum, with a special-angle lifting plate (such as lifting type, stirring type) installed on the inner wall, role is to turn over the material and extend the contact time with the hot air, the material is mostly Q235 steel plate or wear-resistant alloy (for high impurity).
Heat Source System: Combustion stove (coal / gas / biomass stove) or heat exchanger (steam / waste heat), which is responsible for stable hot air.
Transmission System: Motor reducer drives the drum to rotate, the speed can be adjusted by frequency conversion (usually 3-10r/), controlling the residence time of the material in the drum (10-30 minutes).
Dust Removal System: Standard cyclone separator (separating particle dust) bag filter (filtering fine dust), ensuring dust emission ≤30mg/m³ (compliant with national standards).
Control System: Manual for small equipment (temperature control, feed rate); large equipment is equipped with PLC automatic control system, which monitors the moisture content of the feed and discharge in real time, hot air temperature, and automatically adjusts the parameters to achieve precise drying.
IV. Key Features and Advantages
Targeted Design:
Anti-adhesion: angle of the lifting plate in the drum is optimized to avoid the adhesion and caking of wet coal (especially lignite).
Precise Temperature Control: The hot temperature is regulated according to the characteristics of the coal variety (such as lignite avoiding high temperature to prevent the loss of volatile matter, and bituminous coal can be slightly).
Energy Efficient: Continuous operation, hot air and materials flow in the reverse or forward direction (reverse heat exchange is more thorough), with low heat loss.Environmentally Compliant: In addition to the dust removal system, some machines... (the text seems incomplete here and requires further information to provide a full translation)
