Overband Magnet Facts, Figures and Tips
The Overband Magnet is one of the most common Magnetic Separators used in the world today. Also known as the Cross Belt Magnet or Suspended Permanent Magnet, the Overband Magnet is a workhorse used in nearly all industries and especially in recycling, aggregates and bulk handling.
In operation, the Overband Magnet is suspended over a conveyor transporting material and attracts ferrous metal up and out of the material. There are 2 positions in which the Overband Magnet can be suspended:
- Position 1 – Across the conveyor belt;
- Position 2 – Over the head pulley of the conveyor;
Position 2 enables better levels of separation, although the head pulley does need to be non-magnetic.
The performance of the Overband Magnet is influenced by:
- Suspension height above the conveyor;
- Design of the magnetic field (Twin Pole, as supplied by Bunting, or the more common Single Pole);
- Strength of the Magnetic Field (the Twin Pole design has a higher force density and, therefore, magnetic pull, at the same suspension height as a Single Pole design);
The range of Bunting Twin Pole Overband Magnets are available with both hydraulic and electric drives and include two models with different frame specifications:
- Model CBS – Constructed out of stainless steel to prevent ferrous metal being attached to the Overband Magnet frame. This is ideal for applications where metal is long and thin such as nails and screws in woodchips;
- Model CBSV – Standard steel frame
All the Models are designed for suspension at 300mm above the conveyor belt with a magnetic block wide enough to suit a range of conveyor widths including:
- CBS/CBSV-60-60: 600mm wide conveyor belt;
- CBS/CBSV-60-80: 800mm wide conveyor belt;
- CBS/CBSV-60-100: 1000mm wide conveyor belt;
- CBS/CBSV60-120: 1200mm wide conveyor belt;
Selecting the right Overband Magnet for a specific application is difficult for most customers as the outward appearance is very similar for very different designs and strengths. When asking for companies to quote for an Overband Magnet, ask some key questions including:
- Does the Magnet block have a single or twin pole?
- What is the recommended suspension height above the conveyor for the Overband Magnet?
- What metal test piece will the Overband Magnet lift up from the conveyor? The could be a specific size of nail or bolt and will enable a test to be undertaken to confirm that the Overband Magnet that has been supplied is the same as that quoted;
For further information on the Bunting range of Overband Magnets or to discuss an application with a member of the Technical Sales Team, please contact us on: