Trommel Screen

Design Parameters of Trommel Screens

1. Drum Dimensions

• Diameter (D): Typically ranges from 1 m to 3 m
• Length (L): Usually 3 m to 12 m
• A higher L/D ratio improves screening efficiency by increasing residence time.

2. Screen Aperture Size

• Defines the cut size of separation
• Can vary along the drum length in multi-fraction designs

3. Rotational Speed

• Operates at 12-15 rpm
   

4. Inclination Angle

• Typically between 3° and 5°
• Affects material flow rate and retention time

5. Screening Area

• Effective area determines throughput capacity
• Calculated based on drum circumference and length

Capacity of Trommel Screens

General Capacity Range

• Small units: 5–30 TPH
• Medium units: 30–100 TPH
• Large industrial units: 100–500+ TPH

Factors Affecting Capacity

• Feed gradation and particle size distribution
• Moisture content and material stickiness
• Screen open area percentage
• Rotational speed and inclination
• Uniformity of feed

Types of Trommel Screens

1. Single Fraction Trommel

• One screen size
• Produces fine and oversize fractions

2. Multi-Fraction Trommel

• Multiple screening sections
• Produces 3 or more size fractions in one operation

3. Mobile Trommel Screens

• Mounted on wheeled or tracked chassis
• Suitable for on-site and temporary operations

Applications of Trommel Screens

• Mining and mineral processing (ore classification)
• Municipal solid waste (MSW) separation
• Composting and biomass processing
• Sand and gravel industries
• Construction and demolition waste recycling

Advantages of Trommel Screens

• Efficient handling of wet and sticky materials
• Low maintenance and simple mechanical design
• Continuous operation capability
• Customizable for multi-stage screening