What Is a Magnetic Separator?
Grinding machines produce metal debris. The cutting of castings also generates a fine sludge in addition to chips.
These are discharged out of the machine together with the coolant and collected in a coolant tank. To maintain the heat transferring performance of the cooling fluid, it is necessary to remove these impurities as much as possible. A magnetic separator is installed in the coolant tank to counteract this problem.
This device uses magnetic force to absorb metallic swarf, such as the grinding debris and sludge mixed in the coolant, and it discharges these impurities outside after sufficient water is removed by a squeezing roller.
Uses of Magnetic Separators
Magnetic separators are installed on grinding, shaving, honing, and other types of metalworking machines that cut castings.
When tainted coolant returns from the machine to the coolant tank, metallic swarf and sludge are collected and removed as they pass throuugh a magnetic seperator.
Coolant can be both water-soluble and oil-soluble. In addition to the type of coolant, the processing capacity size of the magnetic separator is selected based on the coolant flow rate and the amount of metallic debris discharged.
The type of magnet installed inside the magnet drum and the material used in the squeezing roller are also selected according to the type of metal particles or sludge suspended in the coolant.
Principle of Magnetic Separators
Metallic detritus is sucked in by the magnetic drum, sandwiched between the squeezing rollers, and then scraped off by the scraping plate to collect only metal-laden particles and sludge sludge, such as grinding swarf.
The magnetic materials used in the magnet drum are mainly ferrite and rare earth. Rare earths have 10 times more magnetic energy than ferrite, making them more expensive. Rare earths are selected when working with difficult-to-magnetize materials, fine sludge particles, or oily coolants.
SK and FC materials and workpieces after hardening have difficulty being absorbed by magnets, so rare earths can be selected for efficient recovery.
If a filter is used in the secondary filtration system, the selection of rare earths will have the effect of reducing the amount of filter used.
To maintain functionality, it is important not to scratch the surface of the magnet drum. In some cases, a hardening treatment on the surface can be used as a countermeasure.
Unlike the build-up of flinty metallic debris from abrasive grinding, the conventional, easily damaged rubber squeezing rollers used to clear those impurities may experience breakage due to the shape of the debris collected. In such cases, the roller materical can be changed.