Screw feeders versus screw conveyors: what’s the difference?

Bulk material handling industries including construction, food processing, mining and pulp and paper depend heavily on industrial bulk material handling equipment such as screw feeders and screw conveyors. 

From transporting grains to microscopic powders, screw feeders are mistakenly dubbed as screw conveyors because their functions are near identical.

But, there is a fine line between what is conveyed and what is fed when it comes to this staple piece of equipment.  

Feed your mind by comparing and contrasting the subtle differences between screw conveyors and screw feeders as bulk material handling systems.

What is a screw feeder anyway?

Screw feeders are used specifically to deliver finer, granular types of substances accurately from one part of the feeder mechanism to the other.

Not to be confused with a screw conveyor, which moves bulk materials from one part of a machine to another, a screw feeder for all tense and purposes does the same job, but at a different rate.

Comparing apples to oranges

The main distinction between screw conveyors and screw feeders is that the latter is capable of adjusting the speed of the bulk material flowing from the hopper (or bin or storage container), which matches the pace of the screw feeder when in operation.

In other words, the volumetric rate of material flow that is discharged from a screw feeder can be controlled. While screw conveyors are capable of handling free-flowing materials, they are unable to regulate the speed at which they discharge material.

Another distinction between screw conveyors and screw feeders is that screw conveyors run at a moderately full capacity. Typically, the materials in screw conveyors can range anywhere from 15 to 50% capacity, versus screw feeders, which run at a flooded 100% full capacity.

The difference in capacity lies in that screw conveyors cannot vary its operational speed (which tends to be a fixed high speed) compared to screw feeders that can alter its dispensing speed and flow control of materials from the inlet.

One more difference: flighting (i.e. the diameter and pitch) can also be modulated on screw feeders depending on the type of materials that are transported.

We’re always free-flowing with expert advice on industrial conveyor solutions for our clients

Continental Conveyor & Machine Works Ltd. is a designing, engineering and manufacturing force capitalizing on our mechanical bulk materials handling equipment and systems expertise since 1963.

We deliver countless solutions for industries seeking high-quality bulk material handling machinery, including belt and screw conveyors, apron, weight feeders and vibrating feeders, as well as bucket elevators.  

Let us convey to you why we’re your number one source for all your conveyor equipment and accessory needs.

Contact us for more information or browse through our comprehensive virtual catalogue at www.continentalconveyor.ca.  

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