Cable Drag Conveyor Problems: Keeping Material Moving

by Steve Simmons

What are the problems with cable drag conveyors? I know why you’re asking. Adding a cable drag conveyor to your process is an investment. You want to make sure you get the m­ost out of this machine. I can reassure you that these conveyors deliver exactly what they promise when ran properly. That’s what this article is all about.

Here at Spiroflow, we’ve been in the bulk material handling industry for more than 45 years. Our team has designed and supplied thousands of installations all over the planet. It’s been our goal since day one to provide quality products and to help educate our customers.

What Cable Drag Conveyors Do

A tubular cable drag conveyor uses a cable and disc assembly to drag material inside a totally enclosed tube. These types of conveyors can be designed to have multiple inlets and outlets. Material can be stream or meter fed into the conveyor.

More specifically, a motor driven sprocket within the tube pulls the cable and disc assembly in a continuous loop through the circuit. The conveyor can operate within multiple planes which provides great layout flexibility. If one isn’t enough, they can be linked together to cover greater distances.

How to Avoid Cable Drag Conveyor Problems

Do you want to make sure your cable drag conveyor is delivering the rate your process needs? Do you want to avoid spending a fortune on conveyor maintenance and replacement parts? Do you want to shorten system downtime? If you have any these questions or just want to know how to get the most out of a cable drag conveyor, the solutions are right here.

There’s nothing inherently flawed or faulty with tubular drag conveyors. Issues generally arise when operator mistakes are made. These errors are easy to fix and/or avoid. All you need to do is keep the following information in mind.

  • Every part of the circuit must be dent free
  • All internal moving parts must be in alignment with the exit and entry points
  • It is helpful to utilize available options that provide system feedback (level sensors, rotation sensors, and tension position indicators).

Mind the Material

Make sure the material you are conveying is appropriate for this type of conveyor. Anything abrasive, hygroscopic, cohesive, or slurries should stay out of a cable drag. Utilize a test lab if you have any questions about what should be conveyed.

Another tip, do not overfeed the conveyor. Trying to max out the capacity of a tubular cable drag conveyor may be tempting but it can put too much strain on its components. If you find yourself overfeeding a cable drag, you should consider a larger or different type of conveyor. An experienced supplier will make sure you get the right type and size of conveyor to meet all of your application parameters.

Keep the Conveyor Running Smoothly

The conveyor circuit must be supported with the included brackets to prevent circuit deflection during operation. The circuit is not self-supporting so particular care must be taken where changes in direction occur. This is normally achieved using bent tubes. In these areas, there’s more internal force present to change the direction of the conveyor path.

The circuit is constructed from multiple tube sections of varying lengths. These are joined with sleeved clamps at the joints between each section. It is very important that the joints are in alignment with the mating section and form a continuous uninterrupted circuit. The connection between circuit members must be flush without any burrs produced during cutting. This is critical for correct operation.

Maintain Proper Tension

To keep the cable and disc engaged on the drive and idler sprockets it is necessary to keep it taught. We always recommend the use of a tensioning device which applies a constant force to the system to ensure the discs engage correctly onto the sprockets. The applied force from the tensioner is variable depending on the circuit layout, length, and the material being conveyed. It is necessary to adjust this during commissioning to achieve optimal system performance.

Have any more questions?

Help is a phone call away. Our team in the United States or the United Kingdom is always willing to answer any questions you may have.

Here at Spiroflow, we have a wide variety of mechanical conveyors to choose from if a cable drag conveyor isn’t right for your process. We also design and supply bulk bag fillers and dischargers. If you’re interested in control systems integration, we do that as well. Give us a call.