Magnetic Coolant Filter
Magnetic filter for coolants, oils and wash liquids, built to order
Magnetic Filters Compared with Other Filters
Most industrial filters work by blocking. The fluid passes through a mesh, a paper, a bag or a cartridge, and the particles are held back. A magnetic filter works by attraction. The fluid passes over magnets, and iron particles are pulled out of the flow and held on the magnet surface.
This guide compares the two approaches for coolants, oils, wash liquids and process fluids.
How a magnetic filter works
A magnetic filter is a housing fitted into a pipeline. Inside are one or more high strength magnetic rods. Fluid enters, passes over and around the rods, and leaves. Iron and steel particles in the fluid are drawn to the rods and held there.
The rods are cleaned by lifting them out of the housing and wiping off the collected material. Nothing is consumed. The magnets keep their strength for many years.
What each type catches
Bag, cartridge and paper filters catch anything larger than their pore size. They catch iron, aluminium, plastic, dirt and fibres alike. They cannot catch anything smaller than the pore size, and a very fine filter blocks quickly and restricts the flow.
Magnetic filters catch iron and steel of any size, down to particles of a few microns, with no restriction to the flow. They do not catch aluminium, brass, plastic or dirt.
In practice, most contamination in a metalworking or steel processing fluid is iron. A magnetic filter removes that, and a coarser barrier filter handles the rest.
Comparison
| Barrier filters | Magnetic filter | |
|---|---|---|
| Catches | Everything above pore size | Iron and steel, all sizes |
| Very fine particles | Only with a fine, slow filter | Yes, at full flow |
| Flow restriction | Increases as the filter loads | None |
| Consumables | Bags, cartridges, paper | None |
| Waste | Wet filter media plus contamination | Dry iron only |
| Cleaning | Replace the element | Wipe the rods |
| Life | Weeks or months per element | Years |
Where a magnetic filter helps most
Grinding and machining coolant. Fine steel swarf shortens coolant life, blocks nozzles, scores machine slideways and marks the finished surface. A magnetic filter removes it before it circulates, so the coolant lasts longer and the finish improves.
Hydraulic and lubricating oil. Wear particles from pumps, gears and bearings are mostly iron. Removing them slows further wear.
Wash and rinse liquids. Iron particles from washed parts build up in the tank and are redeposited on the next batch.
Process fluids in steel and pipeline systems. Rust, scale and black powder are iron compounds and are held by a magnet.
Where a barrier filter is still needed
Non-magnetic contamination needs a barrier. Aluminium and brass swarf, plastic, fibres and general dirt pass over a magnet. In a system with mixed contamination, fit the magnetic filter first. It removes the bulk of the load, so the barrier filter downstream lasts far longer and can be coarser.
Sizing a magnetic filter
Three things decide the size:
- Flow rate. The fluid must spend enough time near the rods for particles to be drawn out. A larger housing for a higher flow.
- Contamination load. More iron means more rods, or more frequent cleaning.
- Particle size. Fine particles need higher strength rods. SMAG rods are made up to 13,500 gauss.
The SMAG range
Santosh Magnetic Works builds the magnetic coolant filter to order in Mumbai, with connection sizes and magnetic strengths matched to the line, and in-line and housed magnetic liquid traps for process pipelines. Every unit is supplied with a tested certificate of magnetic strength. Contact us with the flow rate and the fluid.
