PML
Magnetic Grill
Magnetic Grill
Starting from Rs.3,828
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Product Details
At a Glance
A magnetic grill (also called a hopper magnet) is a frame of magnetic rods fitted into a gravity chute or hopper outlet to remove iron contamination from dry, free-flowing products like grain, sugar, flour and powders in a single pass. PML's grills are built in Stainless Steel 304/316 with ferrite or high-intensity rare-earth NdFeB elements, rated up to 12,000 Gauss for continuous operation up to 250°C.
Dry, free-flowing products — grain, sugar, flour, plastic pellets, powders — pick up iron contamination somewhere between the field and the finished pack, usually from the machinery that processes them. The PML Magnetic Grill — also called a hopper magnet when fitted at a hopper outlet — traps that contamination in a single pass: a stainless steel frame (round, square or rectangular) fitted with magnetic rods, dropped straight into the product flow.
Every component is Stainless Steel 304/316, and the magnetic elements are either hard ferrite ceramic or high-intensity rare-earth NdFeB, built into a frame sized and shaped to your application.
Choosing the Right Intensity
Contamination size and type determine which grade you need — and the grill is only efficient if contamination stays within roughly 1–1.5% by weight of the product (for higher levels, look at our Drawer or Multi-Drawer Grills instead).
| Grade | Field Strength | Best For | Max. Operating Temp. |
| Low-Intensity | ≈2,500 Gauss | Nuts, bolts, screws, broken washers — large pieces from a distance | 250°C |
| Medium-Intensity | ≈6,500 Gauss | Particle contamination down to 150 microns, free-flowing/non-sticky material | 80°C |
| High-Intensity | ≈11,000 Gauss | Fine contamination down to 1 micron | 80°C (350°C with SmCo) |
| Super High-Intensity | ≈12,000 Gauss | Maximum-strength fine capture | 80°C |
Each grade is available in round diameters and square dimensions from 150×150mm to 600×600mm, in 50mm increments — tell us your duct or hopper opening and we'll match the frame to it.
Key Advantages
- Fits Any Opening
Round, square or rectangular frames sized to your hopper, chute or duct.
- No Power Cost
Permanent magnets — no electricity, no controls, nothing to maintain beyond periodic cleaning.
- Four Intensity Grades
From 2,500 to 12,000 Gauss, matched to your contamination size.
- Full Stainless Construction
SS 304/316 throughout, suitable for food, pharma and chemical environments.
Where It's Used
Plastics, food processing (sugar, coffee, tea, grains, pulses, flour, spices, milk), pharmaceutical, chemical, ceramic, colours and paints, pigments, ink, refractory and mineral processing. See dedicated pages for grain, flour & feed, plastics & chemical processing, and paint & pigments.
Keeping a Grill Effective
- Clean the grill thoroughly before every batch, or on a schedule matched to your contamination load.
- Iron accumulated over time reduces attraction — for the strongest capture, the grill needs to stay clean.
- Medium and high-intensity grills are also available rated to 200°C, and high-intensity to 350°C with Samarium Cobalt magnets, on request.
Frequently Asked Questions
Round or square — which should I choose?
It comes down to your existing opening — round for pipes and circular ducts, square or rectangular for hoppers and chutes. Both are available in the same intensity range.
How often does it need cleaning?
Before every batch is the safest baseline; some lines run on a schedule instead. More frequent cleaning means stronger, more consistent attraction.
Can you build a custom size?
Yes — customised grill and magnetic grid designs are available beyond the standard size range.
What sizes are available?
150×150mm to 600×600mm in 50mm increments, in round, square or rectangular format.
What's the finest contamination it captures?
High-intensity grades capture particles down to 1 micron at 11,000 Gauss; super high-intensity reaches 12,000 Gauss for maximum-strength fine capture.
In the Field: Rieco Magnetic Grill Installation
Why Buy From PML
- 65+ years of magnetic separation engineering — trusted by Hindustan Unilever, Cipla, Tata Tea and Pidilite Industries, among others.
- Made and tested in-house — every grill is manufactured and checked to its stated Gauss rating.
- Four intensity grades from 2,500 to 12,000 Gauss to match your exact contamination profile.
- Magnetic calibration and audit services available to verify performance over time.
Need a custom size, shape or intensity? Enquire now and our engineering team will size the right grill for your process.
Why Magnetic Strength Drops in Ferrous Separators (and When to Replace)
Separation efficiency falls as magnetic strength decreases. Below are the most common causes of reduced field strength in NdFeB (neodymium) magnetic separation equipment, along with the warning signs that indicate a magnet or separator needs replacing.
Causes of Reduced Magnetic Strength
- Thermal demagnetization: Standard Neodymium-Iron-Boron (NdFeB) grades lose magnetic strength when exposed to temperatures above their rating — often starting at 80°C / 176°F for standard grades. Exceeding these limits causes a permanent loss of magnetic flux.
- Corrosion and core oxidation: NdFeB is highly iron-rich and oxidizes quickly. If moisture, washdown liquids, or corrosive chemicals breach the outer stainless steel cladding, the magnet swells, crumbles, and loses field strength.
- Mechanical damage and internal cracking: NdFeB is brittle. Dropping magnetic tubes during cleaning, or subjecting them to heavy equipment vibration, causes internal micro-fractures that break the continuous magnetic circuit.
- Strong opposing magnetic fields: A sufficiently strong opposing field can overcome a material's coercivity and flip or randomize its magnetic domain polarity. High alternating current (AC) electric fields, in particular, create powerful local alternating magnetic fields that rapidly scramble domain alignment.
- Material buildup ("air gap" effect): Accumulated fine iron on the surface acts as a barrier, pushing the active magnetic field further away from incoming material. Because magnetic force decays exponentially with distance, even a few millimetres of buildup severely reduces capture rates.
- Increased process velocity or burden depth: Running material too fast, or in overly thick layers, prevents fine ferrous particles from spending enough time in the peak magnetic field zone to be pulled out of the flow.
Signs an NdFeB Magnet or Separator Needs Replacing
- Drop in gauss rating: Annual or semi-annual gauss testing shows a permanent drop of 10–15% or more from the baseline specification.
- Bulging or "pillow" swelling: The protective stainless steel tube cladding looks warped, swollen, or cracked — a sign of internal oxidation where rust has expanded inside the shell.
- Dead spots along the field: Measuring with a gauss meter reveals localised spots with zero or drastically lower magnetic pull across the grid or tube surface.
- Downstream metal contamination: Ferrous fines or tramp iron start showing up in final product testing or downstream machinery detectors despite the separator being clean.
- Structural casing punctures: Scratches, gouges, or pinhole leaks in the stainless steel jacket expose the internal magnetic circuit to moisture and process fluids.
Regular gauss testing (at least annually) is the most reliable way to catch strength loss before it affects downstream product purity — PML's own range of Gaussmeters and magnetic field meters covers this. If you're seeing any of the signs above, talk to our team about testing or replacing your separator.
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