Maxtech Industries

Coal Mill

When to use membrane filter bags:

  • High-moisture present in fuel
  • Reduce pressure drop, and increase the airflow
  • Capacity enhancement with existing baghouse
  • Reduce fuel cost by using low-cost low-calorific value coal
  • Less maintenance and longer bag life

Two types of coal firing are used: 1. Direct Firing 2. Indirect Firing. Direct firing is when coal is milled and is directly fed to the kiln. In indirect firing system, coal is milled and stored and fed to the kiln as needed. Most new plants have indirect firing. 

Operating Data

  • Nature of dust: Explosive, Free Flowing

  • Dust Load: 30-500 g/Nm3

  • Design Temperature: 127 deg C for Polyester and 135 deg C for Acrylic 
  • Surge Temperature: 140 deg C for Acrylic and 150 deg C for Polyester

Coal fineness has a direct relationship with its reactivity. Hence, in the cement plant, a special significance has been given to the milling behaviour of coal. It has been observed that low volatile matter in coal can be compensated by finer grinding. In order to reduce high fuel cost associated with cement production, many cement plants are using petcoke as their primary fuel. Depending upon fuel used dust can be very fine and sticky in nature. A higher percentage of sulfur in the fuel with moisture can accelerate corrosion in a baghouse. When using petcoke, the dust size is much finer and membrane filter bags are recommended. 

Filter MediaAnti-Static Polyester FeltAnti-Static Acrylic Homopolymer Felt
 

When To UseLow moisture and temperature combinationHigh moisture and temperature combination

Downloads

References

Case Study 1: Gore Anti Static Bags Vented Two Coal Mill Simultaneously at 2.0 m/min Air to Cloth Ratio

Case Study 2: Gore Filter Bags in Operation with Below 10mg Emission Level & 85 mmwg Pressure Drop

Case Study 3: Gore Bag Filter Completed 60 months of Bag Life, Below 15 mg Emission in a New Coal Mill Baghouse

Case Study 4: Gore Filter Bags Helped to Achieve Full Mill Production Capacity Making One Bag Filter Redundant