Magnetic Separators

An Introduction to Magnetic Separators

Magnetic Separators use Separator Magnets to pull and remove ferromagnetic contamination from the material being processed. Such materials include most mild steels, a few stainless steels, iron, nickel, cobalt and manganese. “Non-magnetic” materials such as aluminum, silver, gold, many stainless steels and copper, will not be moved by magnets (ignoring paramagnetic and diamagnetic effects, which are very weak).

To separate ferrous material from nonferrous material, the principle of open gradient magnetic separation is applied, where the material is passed through a region of strong magnetic field gradient within the Magnetic Separator. Material with the greatest permeability will be deflected the most by the magnetic field towards the poles of the Separator Magnets.

The Magnetic Separators are placed in line with the flow of material. The trapped ferrous material will be kept not on the side of the Separator Magnet in first contact with the material but instead on the other side (this would be the underside if a Magnetic Separator is part of a gravity fed system). This method does not slow down the rate of passage of material through the Magnetic Separator (unless it is not regularly inspected and cleaned and a build-up occurs).

The Separator Magnet Rods are food quality stainless steel encased and contain rare earth magnets. By having a food quality stainless steel casing, the Separator Magnet Rods are corrosion resistant and easy to clean. The magnets provide a field strength of 10,000 Gauss (1 Tesla) on the magnet surface. The magnets are held in repulsion within the Separator Magnet Rods to maximize the magnetic field projected outside of the Separator Magnet Rods. The ends of the Separator Magnet Rods are tapped to allow either assembly onto other components or for assembly onto other Separator Magnet Rods to create even longer rods. The Separator Magnet Rods can therefore be used to make bespoke sized and shaped Separator Magnet Grid Assemblies. The applications of Separator Magnet Rods are varied but a popular method is to place the Separator Magnet Rod at the end of a conveyor belt. The 25mm diameter Separator Magnet Rods can be bought in 50mm increments in sizes ranging from 50mm up to 750mm long.

The Magnetic Separator Grids or Hopper Magnets exist in Circular and Square designs. Commonly refered to as Hopper Magnets as they fit within either Square or Round Hoppers In-Line within production lines. They are manufactured to the highest possible standards using food quality stainless steel. All the welds are cleaned and polished. Consistent performance of the Magnetic Separator Grids over a long life is assured. The Magnetic Separator Grids are easy to install and simple to clean. They are also highly cost effective

The Circular Magnetic Separator Grids / Hopper Magnets exist in sizes ranging from 100mm diameter up to 500mm diameter in 50mm increments. Stainless steel plates are used to hold the Separator Magnet Rods in optimum positions to give optimum straining effect. To increase the effectiveness of ferrous particle collection, the Magnetic Separator Grids can be stacked. There may be advantages in efficacy of ferrous material collection by rotating the Magnetic Separator Grids in the stack to increase turbulence so as to increase the chances of collecting all the ferrous material.

The Square Magnetic Separator Grids / Hopper Magnets exist in sizes ranging from 100mm x 100mm up to 500mm x 500mm in 50mm increments. Stainless steel plates are used to hold the Separator Magnet Rods in optimum positions to give optimum straining effect. To increase the effectiveness of ferrous particle collection, the Magnetic Separator Grids can be stacked. There may be advantages in efficacy of ferrous material collection by rotating the Magnetic Separator Grids in the stack to increase turbulence so as to increase the chances of collecting all the ferrous material.

e-Magnets UK Magnetic Separator Grids can be put into inline channel and chute systems, particularly hoppers. They can be used to remove ferrous contamination from free flowing dry materials such as sugar, rice, animal feed, plastic granulates, shredded paper, tea, chemicals, powders, shredded copper, flour, etc.

If a very high field is required within a circular channel and the channel is not to have Separator rods in the way, a Halbach Array may be a possible alternative. This array is a ring made up to permanent magnet arc segments. The directions of magnetisation within the arcs are such that a highly uniform, homogenous magnetic field traverses diametrically across the circular channel. It is possible to design the Halbach array to produce magnetic fields between 10,000 and 20,000 Gauss across the entire channel (subject to available space for magnets and the channel size). The Halbach array is better suited for smaller diameter channels and the channel needs to be removable to allow cleaning. Halbach arrays are usually supplied as complete magnet rings.

Types of Magnetic Separators

Circular Separator Grids
Square Separator Grids
Magnetic Rods

How to buy Magnetic Separators

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