A screw-type coal sample crushing machine is a specialized device used in laboratories or industrial settings to crush coal samples into fine particles for analysis (e.g., calorific value, ash content, or chemical composition). Here’s a detailed breakdown of its features, working principle, and applications:
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Key Features:
1. Screw Mechanism:
– Uses a rotating screw (auger) to feed and crush coal samples uniformly.
– Adjustable screw speed controls the crushing rate and particle size.
2. Crushing Components:
– Hardened steel or tungsten carbide blades/jaws for durability.
– Interlocking teeth or grinding plates for efficient pulverization.
3. Particle Size Control:
– Adjustable gap settings or screens to achieve desired fineness (e.g., ≤3mm or ≤0.2mm).
4. Safety & Design:
– Sealed enclosure to prevent dust leakage.
– Overload protection to avoid motor burnout.
5. Automation:
– Some models include automatic feeding and discharge systems for continuous operation.
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Working Principle:
1. Coal samples are fed into the hopper.
2. The rotating screw conveys the material toward the crushing zone.
3. Coal is compressed and sheared between the screw and fixed liner/blades, reducing it to smaller particles.
4. Crushed coal exits through a sieve or outlet for collection.
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Applications:
– Laboratory Testing: Prepares samples for proximate/ultimate analysis, sulfur content, etc.
– Quality Control: Ensures consistency in coal batches for power plants or coke production.
– Research & Development: Studies coal properties like grindability or reactivity.
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Advantages Over Other Crushers:
– Uniform Output: Screw feed ensures steady, even crushing (vs. hammer mills, which may produce uneven sizes).
– Low Dust Generation: Enclosed design minimizes airborne particles.
– Energy Efficient: Gual crushing reduces power consumption compared to impact crushers.
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Popular Models/Manufacturers:
1. Sealed Hammer Crusher (alternative for fine crushing).
2. Roll Crusher (for coarse-to-medium crushing).
3. Custom screw-type crushers from lab equipment suppliers like:
– Labtech Africa (coal sample preparators).
– Glen Mills