Common Coal Grinding Problems in Power Plants and Effective Solutions

Common Coal Grinding Problems in Power Plants and Effective Solutions

Introduction

Coal grinding is a critical process in power generation, directly impacting combustion efficiency and emissions. However, operators frequently encounter technical challenges that reduce equipment lifespan and increase maintenance costs. This article analyzes prevalent issues in coal pulverization systems and presents advanced solutions leveraging modern grinding technology.

1. Frequent Problems in Coal Grinding Systems

1.1 Excessive Wear of Grinding Components

The abrasive nature of coal causes rapid deterioration of rollers and grinding tables, particularly with high-sulfur or high-ash coals. Traditional mills require component replacement every 1,500-2,000 hours, causing unplanned downtime.

1.2 Inconsistent Particle Size Distribution

Poor fineness control (R90>25%) leads to incomplete combustion, increasing unburned carbon in fly ash by 3-8%. Overly coarse particles also accelerate burner nozzle erosion.

1.3 System Vibration & Imbalance

Irregular feed rates or moisture fluctuations (>15%) generate harmful vibrations exceeding 8mm/s, damaging bearings and drive trains.

2. Advanced Solutions Through Modern Grinding Technology

2.1 Wear-Resistant Material Solutions

Our LM Series Vertical Roller Mill incorporates chromium-molybdenum alloy rollers with 4-5x longer service life compared to conventional materials. The patented roller refurbishment system allows in-situ hardfacing, reducing replacement downtime by 60%.

2.2 Precision Particle Control

The SCM Ultrafine Mill features:

• Vertical turbine classifier with 0.1-5μm adjustment precision
• Real-time particle size monitoring via laser diffraction
• Automatic feedback to grinding pressure system

This ensures stable fineness at R90<18% even with variable coal hardness (HGI 45-80).

2.3 Vibration Mitigation Systems

Our mills integrate:

3. Case Study: Performance Improvement

A 600MW plant using our MTW215G Trapezium Mill achieved:

• 38% reduction in specific power consumption (from 23.7 to 14.6 kWh/t)
• Maintenance intervals extended from 1,800 to 4,500 hours
• NOx emissions reduced by 12% through optimized fineness

4. Recommended Equipment Selection

For different capacity requirements:

4.1 High-Capacity Solutions (50-250t/h)

LM280K Vertical Mill provides:

• 1250kW main motor with planetary gearbox
• 50-170t/h capacity at 80-325 mesh
• Integrated drying for coals with ≤25% moisture

4.2 Precision Grinding Solutions

SCM1680 Ultrafine Mill delivers:

• 5-25t/h capacity at D97≤5μm
• 315kW main motor with 30% energy saving
• Noise levels below 75dB

Conclusion

Modern grinding systems with advanced materials, intelligent controls, and robust designs can resolve 90% of common coal grinding issues. Power plants adopting these technologies typically see ROI within 18-24 months through energy savings and reduced maintenance.