In modern power plants, coal is finally pulverised to about 200 mesh for boiler firing using which comminution device?

Introduction / Context:
Pulverised coal-fired boilers require fine coal (commonly around 200 mesh) for efficient combustion. The size reduction path ends with dedicated pulverisers capable of producing this fineness consistently.

Given Data / Assumptions:

• Target product: approximately 200 mesh.
• Continuous, high-throughput operation.
• Compatibility with classifier systems and burners.

Concept / Approach:
Ball-tube mills (pulverisers) or bowl mills are widely used for final pulverisation. Crushers (hammer, roll, gyratory) serve upstream, generating feed for the pulveriser but cannot achieve 200 mesh economically. The pulveriser integrates grinding and classification to deliver uniform fineness to the burners.

Step-by-Step Solution:
Distinguish crushing (cm–mm) from pulverising (sub-millimetre to microns).Match 200 mesh requirement to mill-based pulverisers.Select ball mill (pulveriser).

Verification / Alternative check:
Plant P&IDs show coal mills with classifiers feeding PF burners, confirming device choice.

Why Other Options Are Wrong:
Crushers: insufficient fineness.Pebble mill: less common in utility coal pulverisation compared with dedicated designs.

Common Pitfalls:
Assuming a single-stage crusher can meet PF fineness targets.

Final Answer:
Ball mill (pulveriser)