DRAG CHAIN CONVEYOR

Drag Chain Conveyor

A Drag Chain Conveyor is a robust mechanical conveying system designed to transport bulk materials by dragging them along a trough or enclosed housing using one or more chains. It is widely used in industries such as waste-to-energy, power plants, cement, mining, and agriculture for handling bulk materials like ash, coal, biomass, clinker, granules, and powders.

Key Features of Drag Chain Conveyors

1. Chains:
   • Heavy-duty chains equipped with attachments or paddles (drag flights) to push materials.
   • Made of durable materials like alloy steel for high wear resistance.
2. Drag Flights (Scrapers):
   • Attached to the chains to drag material along the conveyor trough.
   • Available in various materials (steel, cast iron, or UHMW polyethylene) depending on the application.
3. Trough or Housing:
   • An enclosed or open channel where the material is dragged.
   • Enclosed designs prevent dust emissions and spillage.
4. Drive System:
   • Includes a motor, gearbox, and sprockets to power the conveyor.
   • Drives the chain and scrapers along the length of the trough.
5. Material Inlet and Outlet:
   • Allows material to be fed into and discharged from the conveyor.

Working Principle

1. Loading:
   • Bulk material is fed into the conveyor via a chute, hopper, or directly from another piece of equipment.
2. Dragging:
   • The chain with attached flights moves along the trough, dragging the material with it.
3. Discharge:
   • Material is released through discharge outlets positioned along the conveyor’s path or at the end.
4. Return Path:
   • The chain returns along the empty side of the trough, completing the cycle.

Types of Drag Chain Conveyors

1. Single Chain Drag Conveyor:
   • Uses a single chain with flights for lighter materials and smaller capacities.
2. Double Chain Drag Conveyor:
   • Features two parallel chains for heavier loads and longer spans.
3. En-Masse Conveyor:
   • Material is moved in a dense, compact layer with minimal agitation, making it suitable for delicate or fragile materials.
4. Flat-Bottom Drag Conveyor:
   • Ideal for horizontal conveying over long distances.
5. Round-Bottom Drag Conveyor:
   • Designed for self-cleaning operation, reducing material buildup.

Advantages

• Durable and Reliable:
  • Suitable for abrasive, hot, or heavy materials.
• Enclosed Design:
  • Prevents spillage and minimizes dust emissions.
• Versatile Configuration:
  • Can handle horizontal, inclined, or even vertical conveying.
• High Efficiency:
  • Capable of moving large volumes of material with minimal energy consumption.
• Customizable:
  • Trough shape, chain type, and flight materials can be tailored to the application.

Disadvantages

• Higher Maintenance:
  • Chains and flights are subject to wear and need periodic inspection and replacement.
• Energy Usage:
  • More power-intensive compared to lighter conveying systems like belt conveyors.
• Slower Speed:
  • Typically operates at slower speeds, which may not be ideal for time-critical operations.

Applications

1. Waste-to-Energy Plants:
   • Handling bottom ash, fly ash, and refuse-derived fuel (RDF).
2. Power Plants:
   • Coal and biomass feeding or ash removal.
3. Cement Plants:
   • Conveying clinker, limestone, and gypsum.
4. Steel Plants:
   • Handling slag, coke, and other byproducts.
5. Agriculture:
   • Transporting grains, seeds, or fertilizers.
6. Mining:
   • Moving ores, coal, and aggregates.

Design Considerations

1. Material Characteristics:
   • Bulk density, abrasiveness, and moisture content.
2. Capacity Requirements:
   • Volume of material to be transported per hour.
3. Conveyor Layout:
   • Horizontal, inclined, or vertical movement.
4. Operating Environment:
   • Temperature, dust levels, and corrosion resistance.
5. Chain Type and Flight Material:
   • Must match the material being conveyed to reduce wear and tear.

Maintenance Tips

1. Regularly inspect chains, flights, and sprockets for wear or damage.
2. Lubricate chains and bearings to prevent friction.
3. Ensure proper chain tension to avoid slack or excessive strain.
4. Clean material buildup in the trough to maintain smooth operation.
5. Check alignment of chains and drive components to prevent premature wear.

Why Choose a Drag Chain Conveyor?

Drag chain conveyors are particularly suited for heavy-duty applications where durability, reliability, and low spillage are critical. Their ability to handle a wide range of materials, including hot, abrasive, and dense substances, makes them ideal for demanding industrial environments.