Before you buy a screw conveyor, it’s worth taking a moment to think about your exact requirements. You might, in actual fact, need no more than a standard transfer conveyor. Or, in fact, a screw feeder. The naming is similar, which often leads to confusion.
How exactly are screw conveyors and screw feeders different? The critical difference is in how the system is loaded. Depending on your plant applications and existing equipment, there might be a clear winner for you.
By the end of this article, you’ll know whether a screw conveyor or screw feeder is suitable for you.
What’s a Screw Conveyor?
Screw conveyor systems are frequently used in the automotive industry to unload materials from cars, bins, hoppers or piles. They are used in grain storage plants, chemical plants, cereal processing and feed mills.
A screw conveyor will move your material from one point to another. It can be used in various applications and positions and moves material from other conveyors, airlocks, bucket elevators and more. The screw conveyor can be placed vertically, horizontally or at an incline. It can also cool or heat materials and mix materials during the transfer.
The Benefits of Screw Conveyors
- Screw conveyors are flexible and can move product horizontally, vertically, or at an incline.
- They can effectively speed up bulk handling and automatically transport product.
- Screw conveyors can handle mixing, cooling and heating of material whilst in transit.
- Screw conveyors can transport sluggish or semi-liquid materials. They can also transport complex or irregular material if the central pipe is taken out.
- Screw conveyors can come with drop bottoms and self-cleaning capabilities for easy maintenance.
- Screw conveyors can have several inlets and discharge points to service multiple locations within the plant.
- They can be designed to work with your plant layout and make effective use of space
What’s a Screw Feeder?
A screw feeder is used to control how much product moves through your system and dispensed at any given time. This makes it ideal for metering or packing product in specific quantities. The feeder is usually mounted at the base of a bin or hopper and controls the flow.
The screw feeder doesn’t move material over a distance. It simply feeds material into the following mechanism at a calculated rate. It adjusts the speed at which material flows into the system according to your processes.
The Benefits of Screw Feeders
- Control how much product enters the process stream
- Adjust the rate and speed at which product is dispensed
- Screw feeders don’t take up much space – they are placed directly underneath bins and hoppers
The Key Differences:
- Screw feeders are normally placed at the beginning of a process, whereas screw conveyors move product from A to B anywhere it is required
- Screw feeders are designed to meter product, whereas Screw conveyors are designed to move it
- Screw conveyors can be used to mix, heat or cool product. The screw feeder doesn’t do this.
- Screw feeders generally control the down-flow of the product onto another mechanism. They can’t move the product up vertically. Screw conveyors can move the product up at an incline.
- Screw conveyors are typically control loaded, whereas screw conveyors are always flood-loaded
Buying The Right Screw Conveyor or Screw Feeder
Screw feeders and screw conveyors come in useful at different stages of processing, and might therefore both be an asset to your plant.
When it comes to buying a screw feeder, the pitch, diameter, and torque are crucial aspects. Make sure you know the exact specifications to get the correct size.
When choosing a screw conveyor, you should consider what type of material you will be handling and how many inlets and discharge points it needs. You should also make a list of functional requirements, like maintenance features or the ability to cool or heat material. Depending on what you are transporting, you may require a wider diameter of screw conveyor or remove the central shaft. Finally, screw conveyors take up more space in your plant, so have the dimensions at hand to plan your space carefully.