Innovative engineering from “super filtration” specialist Magnom in the UK employs patented magnetic flux gradients to combat one of the most vexing problems faced by OEM engineers and designers. In machinery as diverse as Formula 1 race cars, off-highway equipment and industrial process equipment, removing ferrous debris that can catastrophically damage their high-performance engines, transmissions and fluid power systems can make a huge difference in system performance and resiliency.
Magnom is a British engineering company which offers novel solutions to the cause of the majority of catastrophic failures in fluid systems by filtering out super hard and sharp ferrous particles irrespective of size. They can be the most dangerous contaminant in fluid systems, yet the failure of conventional filtration to remove them is not highlighted by traditional analysis which tends to focus on the size of a particle and not the threat it presents to a system. While they are often microscopic and small enough to be missed by conventional filtration, ferrous particles are the hidden assassins of fluid systems, effectively, bits of the system killing itself – mindful of the maxim “the worse things get, the faster they get worse”.
Magnom’s patented technology is used to produce inexpensive filtration units, typically fitted in addition to conventional mechanical barrier filters. Magnom units have exceptionally long life and a design which enables them to capture a surprisingly large mass of ferrous material, filtering particle sizes down to 0.07µ while not impeding fluid flow. They are even suitable for fitment on the inlet suction side of pumps, positioned to remove particles before they enter critical system components.
The core filtration technology was developed in collaboration with top Formula 1 race teams as well as the extremes of heavy industrial machinery and process equipment. Technical features and innovations were honed and tested on the racetrack, and in grueling, performance-demanding environments. The result was a highly innovative yet deceptively simple and effective filtration solution.
As explained to Magnetics Magazine by Jobey Marlowe, technical director at Magnom, the basic form of the technology consists of a permanent magnetic power source that is sandwiched between two specially developed low-impedance carbon steel flux plates.
“The steel plates are used for three reasons,” explains Marlowe. “The first is to intensify the magnetic flux field. Steel transmits magnetic flux up to 15 times more efficiently than the magnet itself. This is the underlying principle of why laminations of steel are used in the armatures of generators and motors. The second reason is to project and focus this increase in energy directly into the fluid flow. Finally, the steel plates provide a very secure three-dimensional trap to hold contaminants out of the fluid flow, preventing the captured contaminants from being washed back into the fluid system.”
Another important feature relates to the incorporation of fluid flow channels cut directly into the high-energy steel flux plates. The design of these flow channels ensures that the total cross-sectional area of the fluid flow channels exceeds the cross-sectional of any pipe or fitting connecting the Magnom products to fluid systems. Thus, no pressure differential is generated, even when full.
“The field effect flux lensing plates have ‘V’ shaped flow channels cut out around their circumference that exceed the feed pipe diameter and so cannot impede flow. Each high energy magnet and its two flux field plates are known as a Magnom core. The fluid can only flow through the ‘V’ channels, and is therefore forced to pass through regions of high magnetic gradient, thus accomplishing highly effective cleaning,” explains Marlowe.
“The magnetically susceptible contaminants are captured in the space between the plates where they are held out of the fluid flow, without risk of unwanted wash off. The patented magnetic cores are typically stacked in multiples on a central mandrel, and located inside a snug fitting polymer or nonmagnetic metal canister. The number of cores in a unit varies between two, such as in Formula 1 race cars, and 20 for heavy duty industrial process protection. The core diameter is designed and optimized to meet the flow conditions in the system.”
“To try to use a conventional barrier filter to achieve this level of performance would require a media so fine it would introduce massive restriction to fluid flow and pressure drop, and would very quickly fill, requiring a significant amount of costly replacement and maintenance,” he notes.
The Magnom core acts like a magnetic lens, focusing and magnifying the magnetic energy into the fluid flow stream. The flux gradient is very complex, and as such the energy generated by the core is amplified many times that of the surface of a magnet, including rare earth magnets.
“Our products’ principal difference,” says Jobey, “is that our design ensures that we drive all fluid/gas through a controlled high intensity magnetic flux field/gradient, thus ensuring that all contaminant is exposed to this very intense flux matrix, and removed from the flow into traps that ensure it is not re-entrained to the fluid once removed, so as to avoid any possibility of re-introduction into the system. Basic magnetic devices tend to leave any contaminant exposed to fluid flow, enabling it to be washed off the magnets and re-enter the systems fluid thus presenting an even greater threat to the system.”
Adoption of Magnom products by global OEMs started some 20 years ago as a protection against high system warranty claims for hydraulic valves, pump and motor failures and general system damage. Over the years, solutions have been developed for leading OEMs such as Ducati motorcycles, Ferrari Formula 1 cars, wind turbines, and JCB and Caterpillar off-highway equipment.
Today, the company has an extensive lineup of products that apply its technology in both standard and custom-designed formats. They can perform in high or low-pressure systems at a wide variety of temperatures, viscosities, flow rates and dynamics. A few examples of its standard units are highlighted here.
Headquartered in Oxfordshire, Magnom also has locations in the USA and ROW supplying more than 38 countries worldwide. For more info including a video and animations (https://www.youtube.com/channel/UCc3-pHjCO64TO9Z5JnQatqQ) that depict its technology in action, see www.magnom.com and www.magnom-filtration.com.