grate magnet hopper magnet

Standard sizes only 1 week to ship! Special request only 2 weeks to ship!

Grate magnet Separators, sometimes called "magnetic grate" or "hopper magnet", are designed to remove medium and small-size ferrous tramp metal contaminants from dry, 

granular free-flowing product streams in gravity-fed vertical chutes, hoppers, housings, surge or catch bins and deliver ferrous tramp metal separation in bins, chutes, drawers, hoppers and circular enclosures.

GME Round Style grate magnets are constructed with one inch diameter magnetic tubes placed on SUS 304 or SUS 304 stainless steel framing. 

The round style hopper magnets are available in 16 standard diameters ranging from 4" to 36" with either Ceramic or Rare Earth magnetic construction. 

Special sizes are also available. Each round grate magnet can be equipped with diverters. See tech sheet for styles.

magnetic grate diameter	layer	magnetic grate height	bar center distance A	bar center distance B	magnetic bar QTY
Φ100	1	40	50mm	40mm	2
	2	80			3
Φ150	1	40			3
	2	80			5
Φ200	1	40			4
	2	80			7
Φ250	1	40			5
	2	80			9
Φ300	1	40			6
	2	80			11
Φ350	1	40			7
	2	80			13
Φ400	1	40			8
	2	80			15
Φ450	1	40			9
	2	80			17
Φ500	1	40			10
	2	80			19

GME Square Style grate magnet separators are also constructed with 1" dia. magnetic tubes placed on SUS 304 or SUS 304 stainless steel framing.

magnetic grate diameter	layer	magnetic grate height	bar center distance A	bar center distance B	magnetic bar QTY
100*100	1	40	50mm	40mm	2
	2	80			3
150*150	1	40			3
	2	80			5
200*200	1	40			4
	2	80			7
250*250	1	40			5
	2	80			9
300*300	1	40			6
	2	80			11
350*350	1	40			7
	2	80			13
400*400	1	40			8
	2	80			15
450*450	1	40			9
	2	80			17
500*500	1	40			10
	2	80			19

Standard models are often available to ship within 1 week. 

GME Grate Magnets are easy to install and clean. 

They offer efficient, economical magnetic protection of processing equipment such as milling, extruding, and mixing, while at the same time improving product purity.

Standard Features:

• Powerful Ceramic 8 permanent magnetic material
• Liquid tight, seam-welded end caps
• 100% stainless steel enclosed design
• 1" dia. magnetic tubes, mounted on 2" centers
• Rugged all-welded construction

Optional Features:

• High-energy rare earth magnetic material
• Three different types of product stream diverters
• Magnetic tube spacing other than 1"
• Quick-clean designs
• All-magnetic grate designs
• Custom grate sizes and mountings to meet design criteria

Construction:

• Highest grade of magnet material including Neodymium-Iron-Boron (rare earth), Samarium-Cobalt (rare earth), Ceramic and Alnico
• stainless steel support stringers welded to tubes
• Rugged, high strength designs
• Seam welded tube ends
• 100% stainless steel enclosed construction

How do grate magnets work?  How are grate magnets constructed?

Typical construction of a magnetic grate is shown.

Not shown is the 304 stainless steel tube in which this stack of magnets and steel washers (or pole pieces) is inserted.

Most of the grates are made with tubes of non-magnetic stainless steel with an assembly of magnets inside.

The stainless is sealed shut, usually with a weld, which keeps the magnets free from contamination.

The magnets inside the tube are usually arranged in a row, usually with ring magnets sitting on a shaft.

The magnetization direction each successive magnet is assembled in the opposite direction, so that the direction alternates with each magnet.

This specific arrangement is used to create a powerful magnetic field around the assembly.

It produces an extremely high magnetic field right at the steel “pole pieces,” and can exceed 10,000 gauss, even 12000 gauss!

Tiny bits of iron and steel are attracted to the magnet, with the most force in the locations where the magnetic field strength changes the most.

Near the pole pieces, this setup can exert a very strong hold onto even fairly small pieces of iron or steel.

Why are they constructed this way?
So many made with this sort of arrangement, its wide use is taken for granted. 

Strong magnetic field as far out as possible from the tube, to catch ferromagnetic particles from as far away as possible. 

This setup uses common, axially magnetized ring magnets to produce a magnetic field in a region around the cylinder.  

It is also strong all the way around the circumference of the cylinder, unlike a diamagnetic magnet, which is strongest at two points (the poles located 180° apart).

The second, it has to do with holding onto the bits of iron or steel to the magnet after they are caught. 

The force exerted on a tiny bit of iron depends on both the field strength and the field strength gradient at given location near the magnet.

The gradient is how much the field strength is changing with distance from the magnet.