3 Overband Magnet Installation Problems

By buntingeurope | 14 July 2016

Common Problems Installing an Overband Magnet

The Cross Belt Overband Magnet is one of the most commonly used Magnetic Separators.  The simple design of two pulleys mounted on a frame with a magnetic block in the middle has been manufactured for decades.  As the name suggests, the Cross Belt Overband Magnet is positioned above a conveyor, either over the head pulley, or more, commonly across the belt.

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Unfortunately, the separation performance is often poorer than expected simply because the installation is not correct.  Here are 3 typical installation issues that can be easily remedied to improve the level of separation:

  1. Being suspended too high

    Every Cross Belt Overband Magnet will be designed to operate at a specific height above the conveyor.  To accommodate an occasional surge of material, the Overband Magnet can be temporarily raised and then, as the magnetic field is further away from the conveyor belt, the separation performance falls.  Often, when the Overband Magnet is raised it is not then lowered back to the original position resulting in an ongoing poor separation performance.  If surges are common, a larger Cross Belt Overband Magnet suspended at a higher height may be the solution;

  2. Being too narrow for the conveyor

    This can occur from day one, with the Cross Belt Overband Magnet not being wide enough for the conveyor width or when the Overband Magnet has been relocated within a plant.  This results in material being lifted out of the material and then dropped back onto the conveyor as the magnetic block is not wide enough to transfer and discharge the metal outside of the belt and framework.  The only solution is often to invest in a wider Magnet;

  3. Incorrectly positioned over the conveyor belt

    Many Cross Belt Overband Magnets have a single pole in the centre of the magnet block.  The maximum level of attraction and separation is achieved directly under this centre line.  Often, and especially when the Cross Belt Overband Magnet is too narrow for the conveyor belt, the centre line is positioned to one side of the conveyor nearer the area of discharge.  However, this means that it is less likely that any ferrous metal on the opposite side of the conveyor will be separated as the magnetic field is significantly lower.  This is not such an issue with the Bunting design of Cross Belt Overband Magnet as they are all designed with two magnetic poles instead of just one

Contact Us

For free advice and help with maximising the performance of any Cross Belt Overband Magnet, please contact the Bunting sales team and we can arrange to visit your site and assess the installation.  For further details on the Bunting Cross Belt Overband Magnets, please contact our technical sales team on:

Other relevant articles include:

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