Fundamentals of Coal Handling Plant
A coal handling plant (CHP) is an essential facility in thermal power stations that manages the receipt, processing, storage, and feeding of coal to boilers. The primary objective of a CHP is to ensure a continuous supply of coal while maintaining efficiency and minimizing environmental impact. Below are the key components and operational principles of a coal handling plant.
1. Coal Unloading System
Coal is transported to power plants via rail, road, or ship. The unloading system varies depending on the mode of transportation:
- Wagon Tipplers: Used for unloading coal from rail wagons by rotating them to discharge the material onto conveyor belts.
- Truck Unloaders: Employed when coal arrives by road, typically using hydraulic or mechanical systems for tipping.
- Ship Unloaders: Large grab cranes or continuous unloaders extract coal from ships and transfer it to storage yards or bunkers.
2. Coal Crushing and Screening
Raw coal often contains oversized lumps and impurities that must be reduced in size for efficient combustion. Crushers break down large chunks into smaller particles, while screens separate fine coal from debris. Common crushers include:
- Ring Granulators: Suitable for high-capacity crushing with minimal fines generation.
- Roll Crushers: Used for secondary crushing to achieve uniform particle size.
3. Conveyor Belt Systems
Conveyors transport coal between different stages of the CHP, ensuring seamless movement with minimal spillage. Key features include:
- Idlers and Pulleys: Support belts and maintain tension for smooth operation.
- Dust Suppression Systems: Reduce airborne particles using water sprays or chemical additives.
4. Coal Storage and Stacking
Proper storage prevents degradation and ensures fuel availability during shortages:
- Stockyards: Open areas where coal is stacked in layers using stacker-reclaimers for blending consistency.
- Bunkers/Silos: Short-term storage units near boilers that maintain a steady supply during peak demand periods.
5. Coal Feeding System
Controlled feeding mechanisms regulate coal flow into pulverizers or boilers:
- Gravimetric Feeders: Measure weight-based feed rates for precise combustion control.
- Vibratory Feeders: Ensure consistent flow without clogging or spillage issues.
6.Dust Control & Safety Measures