Flexible Screw vs Pneumatic Vacuum VS Tubular Conveyors

Spiral conveyor, pneumatic vacuum conveyor, tubular conveyor…which is the best option for your bulk solids?

We break it down for you below.

Comparing Flexible Screw Conveyors, Pneumatic Conveyors and Tubular Conveyors

There are several options available on the market when it comes to conveying most materials. Spiral conveyors (also known as Spiralfeeder™ or flexible screw conveyors), pneumatic conveyors and tubular cable conveyors (sometimes called drag or disc conveyors.)  Choosing the best one for your specific use, however, requires three primary considerations:

  1. The type of materials you need to convey
  2. Physical parameters/environmental conditions
  3. Project budget

Most often, our customers have narrowed their choices down to either a flexible screw conveyor, pneumatic vacuum conveyor or a tubular conveyor. That’s why we are only going to compare these three options here. 

Flexible Screw Conveyors

  • Lower cost both in terms of initial purchase and maintenance
  • Designed to move a wide variety of materials, including those have fine particles or those that can cake or smear
  • Require materials to be dumped into a hopper; cannot select materials from containers
  • Prevent the separation of blended materials and maintain temperature and moisture content
  • Works best for shorter distances and/or mobile units. Multiple screw conveyors can be used to span longer distances
  • Are better for moving product from a lower point to an elevated one, straight or slightly curved path: however, they are not ideal for systems requiring a limited or tight turn space

Pneumatic Vacuum Conveyors

  • Cost-effective for very long conveyor systems, but have much higher initial & maintenance costs
  • Suitable for dry non-blended free- flowing products, and ideal for hazardous materials requiring containment
  • Able to pull materials from multiple containers, or work equally well with products from bulk bags
  • More difficult to clean than flexible screw conveyors, which may lead to longer downtime
  • Better for systems tasked with moving large volumes quickly
  • Can accommodate multiple changes in direction along a routing path, but may require more headroom within a factory setting

Tubular (drag) Conveyors

  • Cost effective for long distances, but have a higher initial cost over Flexible Conveyors
  • Cannot be started with a full head load of material
  • Inlet metering may be required, depending on the source of material
  • Materials that are fine, cake and/or smear, can lead to additional drag /wear on system components
  • Better for moving friable/ fragile material
  • Can accommodate multiple changes in direction

While this comparison chart can serve as a guide, we encourage you to contact Automated Flexible Conveyors directly about your project specifications. Our team can answer your questions and provide more detailed information that will allow you to make a well-informed decision.

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