Recently, Dutch goudsmit developed a permanent ultra-wideband magnet with a strong, deep-penetrating magnetic field. The magnet attracts standard rebar of Ø20x120mm at a distance of 550 mm (VDE 0580); something previously only possible with electromagnets.

goudsmit permanent overband magnet benefits

Compared to electromagnets, this new design offers clear advantages. The newly developed permanent overband magnet delivers performance equal to or even better than that of 10 kW overband electromagnets, while significantly reducing purchase costs and lowering ongoing energy costs. The design has also been improved. The magnet features better, more sealed shielding against blasted stainless steel. This makes the permanent overband magnet safer and reduces maintenance costs. Overband magnets are designed for installation above conveyor belts in bulk handling or recycling industries. They remove large quantities of ferrous metal parts from raw materials and process them automatically and continuously. See how it works.

goudsmit permanent overband magnet vs. electromagnet comparison

It is known that electric overband electromagnets provide stronger and deeper holding force than permanent overband magnets. However, there are disadvantages. Electromagnets heat up when switched on.

As the magnet heats up, the magnetic force decreases. Performance improves again once the magnet cools down. External cooling of the magnet is a solution, but this entails additional investment in purchase and higher energy consumption. In flammable or explosive environments, magnet heating also poses adverse risks. Therefore, electromagnets cannot obtain ATEX 21 certification.

goudsmit permanent overband magnet energy costs

Electromagnets also require a control cabinet, resulting in associated energy costs. The rated power of good electromagnets can easily reach 7 kW. This means ongoing energy consumption costs. Permanent ultra-wideband magnets do not require energy; only the drive motor needs power. Therefore, no control cabinet is needed, and energy costs remain low.

In short, permanent magnets do not have all these disadvantages, and with the advent of new magnet types, they offer equal or even better performance.

goudsmit permanent overband magnet applications

Ultra-wideband magnets are suitable for removing or separating large amounts of iron or steel and are suspended above flat or troughed conveyors. This type of magnet is self-cleaning and continuously separates (ferromagnetic) iron parts from the material flow. The iron removal efficiency of overband magnets ranges from 70% to 90%. This depends on the magnet design, product flow, and position. Automatic self-cleaning overband magnetic separators are suitable for the recycling of ferrous parts and the removal/elimination of impurities (iron contaminants).

These magnets are mainly suitable for coarser particles larger than 10 mm. Thanks to robust and reliable technology, these magnets are used in many industries. Using permanent ultra-wideband magnets requires only four suspension points, sufficient space, and power to drive the conveyor belt.