How to Operate a Coal Grinding Mill: Essential Training Guide for Operators

Introduction to Coal Grinding Mills

Coal grinding mills are critical equipment in power plants and cement industries, designed to pulverize coal into fine powder for efficient combustion. Proper operation ensures optimal performance, energy efficiency, and extended equipment lifespan. This guide covers fundamental principles, best practices, and maintenance tips for operators.

Operator monitoring coal grinding mill control panel

1. Pre-Operation Checks

Before starting the mill:

  • Inspect grinding components: Check wear on rollers, liners, and classifier blades.
  • Verify lubrication: Ensure all bearings and gears are properly lubricated.
  • Clear obstructions: Remove foreign materials from the grinding chamber.
  • Test safety systems: Confirm emergency stop and temperature alarms are functional.

2. Startup Sequence

  1. Engage the auxiliary drive to rotate the mill slowly for 2-3 revolutions.
  2. Start the dust collection system and classifier motor.
  3. Initiate main motor operation at 30% capacity for warm-up (5-10 minutes).
  4. Begin controlled coal feeding when motor current stabilizes.

Optimizing Grinding Performance

Key Operational Parameters

Parameter Optimal Range Monitoring Method
Mill Current 75-85% of rated load Ampere meter
Outlet Temperature 65-75°C (for bituminous coal) Thermocouples
Fineness (R90) 15-25% (power plant applications) Particle size analyzer

Real-time monitoring dashboard of coal mill parameters

Advanced Techniques

For operations requiring ultra-fine coal powder (D97 ≤ 5μm), consider our SCM Ultrafine Mill featuring:

  • Vertical turbine classifier for precise particle size control
  • 30% lower energy consumption compared to conventional mills
  • Pulse除尘系统 with >99.9% efficiency

Maintenance Best Practices

Scheduled Maintenance Tasks

  1. Daily: Check oil levels, inspect seals for leaks
  2. Weekly: Measure roller wear with depth gauge
  3. Monthly: Re-grease all bearings
  4. Annually: Replace wear plates and classifier blades

Troubleshooting Common Issues

Symptom Possible Cause Solution
High vibration Unbalanced rollers or material buildup Stop and inspect grinding elements
Low output fineness Worn classifier blades or excessive feed rate Adjust classifier speed or replace blades

Recommended Equipment

For large-scale coal preparation (15-45 TPH), our MTW215G Trapezium Mill offers:

  • Conical gear transmission with 98% efficiency
  • Curved air duct design reducing energy loss
  • Integrated PLC control system

MTW series trapezium mill in industrial installation

Safety Protocols

  • Always wear PPE including respirators when handling mill dust
  • Implement lockout/tagout procedures during maintenance
  • Monitor CO levels in enclosed grinding areas

Emergency Procedures

  1. Immediately activate emergency stop for excessive vibration (>10mm/s)
  2. Purge system with inert gas if temperature exceeds 90°C
  3. Follow plant evacuation protocol for dust explosions
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