Is a Magnetic Field Even Along the Surface of a Tube Magnet?

By buntingeurope | 09 December 2016

6th of 10 Magnetic Separator Myths

On a typical Cartridge or Tube Magnet, the magnetic field on the surface is not even along the whole length.  As shown on the photograph, magnetically attracted materials agglomerate at specific points along the length.  So why is that?


A Cartridge or Tube Magnetic Separator is constructed by placing an alternating series of magnet slugs and steel discs inside a stainless steel tube.  Each magnet slug has a North and South pole and is inserted into the tube so that the South Pole faces another South pole and visa-versa.  When the magnet slugs are very strong, as in the case of the Bunting Cartridge Magnetic Separators which use high strength Neodymium Iron Boron or Rare Earth Magnets, the assembly requires a great deal of skill and knowledge.  In between each magnet slug is a steel disc which acts as a magnetic pole, intensifying the magnetic field.  As shown on the photograph below, the magnetic field is drawn into each steel pole positioned between each magnet slug, with magnetic field lines arcing from the North to the South Pole.


Any magnetically susceptible particle moving into the lines of magnetic field will be attracted to the point of highest intensity, which is at the nearest pole.  Hence why magnetically captured particles are then seen to agglomerate at specific points along the surface of a Cartridge or Tube Magnetic Separators.  They have been held at the point of the highest magnetic field, which is between the magnet slugs and actually on the steel pole piece.

Hence why a magnetic field is not uniform along the surface of a Magnetic Separator like the Tube Magnet.

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Other Magnetic Myths reviewed in this series include:


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