How Do Magnetic Drum Pulleys Work?
Magnetic drum pulleys are mounted at the head of the conveyor belt where the discharge takes place and remove metal contaminants from the product on the conveyor belt. It is integrated into the system for automatic continuous separation and attracts the metal parts during the roller rotation while the cleaned product emerges. As soon as the conveyor belt leaves the roller, the effect of the magnet wears off and the undesired impurities fall from the underside of the belt into a separate collecting container. This type of magnet serves as additional protection against metal parts that have penetrated deep into the product and were not extracted during the first separation by a hanging magnet. This improves the quality and purity very much of the processed material.
The industrial applications are processes with dry materials such as plastics, powders, grains, wood waste, rubber, and so on.
Magnetic drum pulleys are available with the required connecting shafts according to customer specifications. If the customer asks for, the roller offers special features such as spherical surfaces that can be integrated into the design. The production of the roller in the form of a barrel has the additional advantage that the conveyor belt keeps the direction on the roller more precisely. Particularly, this is very important if there is no tensioning system in the conveyor that controls the sideways movement of the belt. The roller can also be supplied with a rubber coating that is glued to the surface, which prevents the rubber conveyor belt from sliding over the roller.
A magnetic drum pulley can be integrated as part of a completely new system or as a custom-made product into existing conveyor systems. In both cases, assembly is very easy. A lot of rollers are made of 304 SS stainless steel with strong corrosion resistance. The ferrite roller usually has a thickness of 1,500 – 2,000 Gauss. The strongest rare earth magnet for this application with high energy density has a strength of 3,500 Gauss and can remove the smallest particles from the material.
The magnetic drum pulley at the material outlet of the conveyor belt has another great advantage: thanks to its self-cleaning system, no or only minimal maintenance is required. The cleaned material falls directly from the magnetic drum pulley while the metal is still held on the belt. The belt moves away from the magnetic drum pulley as soon as possible, the metal parts are released, into a waste chute. That makes the conveyor belt a self-cleaning magnet.
The stable and permanent properties of the magnetic drum pulley mean that no external energy source is required for operation and the average loss of magnetic field strength of less than 5% over the course of a year is negligible (unless the roller is exposed to heat, shock or vibration) . In order to ensure a better end product, the roller will be a cost-effective solution