Spiral Classifier

The Spiral Classifier is a mechanical classifier designed for separating materials based on particle size and density. It is available in multiple configurations with different spiral diameters, tank designs, and spiral submergence levels to suit various operational requirements.

Working / Selection Criteria

• Depends on tonnage of dry solids per 24 hours
• Based on required mesh size separation
• Depends on overflow density requirements
• Determined by settling rate of solids in pulp

Operational Guidelines

• Classifier slope affects pool area and capacity
• Lower speed → finer overflow and less agitation
• Higher speed → more capacity but coarser overflow
• Length of classifier depends on circuit design
• Closed circuit setup requires proper layout with grinding equipment

Capacity & Calculation

• Effective pool area = Volume overflow / Settling rate

Capacity depends on:

• Pool area
• Mesh size
• Pulp density
• Conveyor capacity must match circulating load requirements

• Closed circuit grinding with ball mill or rod mill
• Sand and slime separation
• Dewatering of sands and granular materials
• Continuous counter-current washing
• Mineral processing and classification operations

Feed size :

• Up to 2″ (50 mm)

Feed opening :

• 2.25″ x 3″ (55 mm x 75 mm)

Output size :

• 700 microns (28 mesh)
• 1400 microns (14 mesh)

Speed :

• 525 RPM (overhead eccentric)

Capacity :

• 25 lbs (12 kg) per hour

Machine weight :

• 35–36 lbs

Dimensions :

• 11″ (H) x 8″ (W) x 11″ (L)

Power requirement :

• Compatible with 1 HP motor (not included)

Design Components :

Shaft :

• Solid square steel or heavy steel pipe
• Reinforced at lower bearing

Flights :

• Hard cast iron or steel plate
• Replaceable sections
• Can be continuous or staggered

Drive System :

• Worm gear reducer or bevel gear drive
• Driven via motor with belts, chain, or gears
• Variable speed option available

Stand :

• Steel legs for support
• Designed for standard slope installation

Conveyor Rotation :

• Dual helical flights rotate in opposite directions
• Moves sand upward while allowing drainage

Additional Notes :

• Suitable for mesh separation from 20 to 325 mesh (depending on application)
• More efficient alternatives may be used for very fine separations (below 100 mesh)
• Requires proper layout design for closed circuit grinding

• High sand raking capacity
• Heavy plate tank with strong structural base
• Extra heavy shaft with improved submerged bearing
• Strengthened and improved drive unit
• Reducer design eliminates overhang/cantilever load
• Outboard bearing ensures proper gear alignment
• High-quality cast gears with smooth operation
• Quiet operation compared to other classifiers
• Flexible configurations for different applications
• Replaceable flights and wearing components
• Variable speed drive option available
• Easy installation with structural stand (in smaller sizes)