21 May Screw & Belt Conveyors: Design, Types & Applications
In bulk material handling, screw and belt conveyors stand out for their versatility and cost-efficiency, but the way they function, their very design, and use cases vary quite a bit. Even so, these systems bring unique strengths for different applications.
Let us break down how these conveyors work, key configurations, and what to consider when selecting one for your facility.
How Screw Conveyor work
Screw conveyors use a rotating screw blade to move materials.
A screw conveyor—also known as an auger conveyor—uses a rotating helical blade (screw) inside a trough or pipe to move bulk material. When in use, the screw rotates and pushes material forward in a controlled, enclosed flow.
Screw conveyors designs come in two types:
- Shafted screws: The spiral blade is fixed to a central shaft that is driven at one end and held at the other. This is suitable for most bulk materials.
- Shaftless screws: A flexible spiral blade without a shaft, often used for sticky or fibrous materials that could clog a shafted system.
These conveyors can be installed horizontally, vertically, or at an incline. However, their efficiency typically drops once inclination increases beyond 45°.
In practice, screw conveyors are used for precise flow control in batching or feeding operations, as their design allows for a variable feed rate by adjusting the screw’s rotational speed. They’re also fully enclosed, minimising dust emissions and contamination risks.
Common applications:
- Wastewater sludge, cement, flour, and feedstock
- Dosing and metering systems in agriculture and food production
- Inclined transfer in compact layouts
How belt conveyors work
Belt conveyors use moving belts to transport goods and materials.
Belt conveyors move materials using a continuous belt—typically made of rubber, PVC, or fabric—stretched over rollers or pulleys. The belt is supported by idlers (rollers) and driven by a motorised pulley or drum at one end.
Key components of belt conveyors include:
- Drive pulley: Transfers power from the motor to the belt
- Return pulley: Redirects the belt back for continuous motion
- Idler rollers: Provide belt support and reduce friction
- Tensioning systems: Maintain consistent belt tension for optimal operation
As they can move large volumes of free-flowing or packaged materials efficiently, belt conveyors are ideal for bulk material handling and transport. They’re customisable for width, belt type, and loading conditions. Cleats or sidewalls can also be added for inclined transport.
Common applications:
- Aggregates, coal, and grain handling
- Warehousing and logistics for carton or pallet movement
- Manufacturing lines in packaging, electronics, and automotive sectors
Key configurations and when to use them
| Configuration Type | Screw Conveyor | Belt Conveyor |
|---|---|---|
| Horizontal | Ideal for general-purpose bulk transfer | Best for continuous movement over long distances |
| Inclined | Widely used; performance varies by angle | Limited to low angles without cleats |
| Vertical | Requires specific design (vertical flighting) | Not recommended (due to the nature of how it works) |
| Enclosed | Standard design; ideal for dusty, corrosive, or hazardous materials | Optional (costlier) |
| Multi-point discharge | Easily implemented using intermediate outlets | Possible with diverters |
Design considerations for choosing the right system
When selecting between a belt or screw conveyor, consider key factors like:
1. Material characteristics
Sticky, dusty, or semi-solid materials are better handled by enclosed systems that offer controlled flow and minimise spillage. Dry, free-flowing, or fragile goods benefit from gentler, continuous movement provided by open-belt configurations.
2. Volume and feed rate
For consistent high-volume throughput, long-distance runs, or bulk transfer, a wide, fast-moving belt offers efficiency. If your operation involves metering, batching, or intermittent flow, a helical screw allows for precise rate control.
3. Layout and space constraints
Compact or vertical layouts favour systems that can operate at inclines or within enclosed channels. Conversely, facilities with ample space or longer conveying distances can accommodate linear belt systems more easily.
4. Maintenance and durability
Applications involving abrasive loads or heavy-duty usage may lead to faster wear, so consider the durability of internal components and ease of part replacement. Belt-driven systems offer standardised components, while helical designs require more specialised upkeep.
5. Environment and sanitation
Enclosed conveyors are best for dusty, hazardous, or regulated environments where spillage or exposure is a concern. For cleanroom, washdown, or food-grade settings, stainless steel open-belt systems are often preferred for hygiene and accessibility.
There can be quite a few variables and factors to consider for conveyors, especially when you have specific needs and layouts, so check out our guide to choosing the right conveyor system for making an informed decision.
Trust in SJEC for your conveyor system needs
Here at SJEC, we are a trusted manufacturer for designing and fabricating both belt conveyors and screw conveyors for various industries, from manufacturing to chemical processing. Our systems are available with flexible delivery options, including FOB, EXW, and CIF terms for international buyers.
Work with a reliable supply partner committed to quality, precision, and global readiness by contacting us today. Let us build your next industrial solution with confidence.
FAQ
What’s the difference between a belt and screw conveyor?
Belt conveyors move materials along a flat or trough belt, ideal for long, horizontal runs. Screw conveyors use a helical blade to push materials through a tube or trough, better suited for enclosed, precise, or vertical transport.
Where are screw conveyors used?
Screw conveyors are often used in industries needing dust control, such as chemicals, food, or wastewater as these systems can transport bulk materials like powders, grains, or sludge efficiently.
What factors need to be considered in designing a conveyor system?
Key design factors include material type, flow rate, angle of inclination, trough size, and screw pitch. These elements affect performance, capacity, and energy efficiency.