Magnetic Separators Get Rid of Tramp Iron

March 15, 2011
Magnetic separators remove tramp iron from material lines processing powdery plastics, abrasives, or glass cullet.
Resources:
Eriez, en-us.eriez.com
Edited by Leslie Gordon


Magnetic separators from Eriez, Erie, Pa., use ceramic or AlNiCo magnets and an electric circuit to generate magnetic fields that remove tramp iron from lines processing powdery bulk materials such as plastics, abrasives, or glass cullet.

The company also makes drum separators that use its proprietary Erium 3000 rare-earth (RE) permanent magnets. In these magnets, the lines of flux concentrate in each internal pole, creating a high–gradient magnetic field. According to the company, Erium 3000 generates magnetic fields up to 25 times stronger than conventional ceramic or AlNiCo units — with no increase in size. The magnets grip contaminants so tightly that wipe-off caused by product flow is almost eliminated.

The RE magnets remove exceedingly fine iron particles, which are difficult to attract and hold because of their small mass. They also separate out weakly magnetic particles such as rust or iron oxide, which are not strongly attracted to conventional ferrite magnets, as well as stainless-steel particles rendered paramagnetic through work hardening.

Separators with RE magnets work like this: As the material to be cleaned goes into the rotating drum, the magnetic field attracts and holds ferrous particles to the drum shell. Cleaned, nonmagnetic materials fall freely into a chute, while ferrous particles stick to the drum until its rotation carries them past the magnetic field, where they fall into another chute to be dumped or sold as scrap.

All RE magnets are not created equal, according to Eriez. It conducted studies of RE compounds and magnetic circuits, which showed that some were only slightly better than ferrite-ceramic magnetic circuits, while others were much stronger. The research led to the development of Erium 3000.

REs’ magnetic strength falls in the medium-intensity range — 4,000 to 10,000 gauss. Previously, it took high-intensity electromagnets to generate fields this strong. But high-intensity electromagnets are bulky, expensive, and costly to operate. RE magnets economically fill the gap between high-intensity electromagnets and low-intensity conventional magnets.

© 2011 Penton Media, Inc.

Sponsored Recommendations

Altech's Liquid Tight Strain Relifs Catalog

March 13, 2024
With experienced Product Engineers and Customer Service personnel, Altech provides solutions to your most pressing application challenges. All with one thought in mind - to ensure...

Industrial Straight-Through Cable Gland

March 13, 2024
Learn more about Altech's cable glands and all they have to offer for your needs!

Smooth Sorting with SEW-EURODRIVE!

Feb. 22, 2024
Sorting systems are essential when it comes to warehouse automation, material handling, and distribution. SEW-EURODRIVE’s automated sorting solutions increase capacity, reliability...

Setting the Agricultural Industry in Motion

Feb. 22, 2024
Agricultural products go through specialized processes of harvesting, storing, conveying, cleaning, drying, sorting, and handling to ensure that seasonal products reach the processing...

Voice your opinion!

To join the conversation, and become an exclusive member of Machine Design, create an account today!