Introducing the Full-flow Magnetic Flux Filter

Tom Hulme, Fluid Conditioning Systems

The “Mag Oil Module”, or Magnom, is an innovative full-flow magnetic flux filter system recently patented by Jobey Marlowe and Harold Hall for use in machines with oil and water circulation and filtration requirements. It is now marketed globally through Fluid Conditioning Systems Limited based in the United Kingdom with offices in the United States.

The Magnom was designed to augment high-performance racing engines that themselves were designed and built by Hall and Marlowe.

While tuning and building engines for endurance racing, Harold found that he could produce far superior power outputs from his engines, though he was forced to limit the delivered power in these machines to improve their durability.

Hall refused to accept that this could not be remedied and he began investigating why previously healthy motors would suffer bearing failure almost without warning. Detailed analysis on piston thrust faces, bearing journals and shells from failed engines revealed high carbon steel fragments buried in inclusions in the softer sacrificial metal surfaces of the bearings, typically emanating from the oil feed holes.

The fragments produced tracks of circumferential wear in the steel journals. Further analysis showed that 5- to 20-micron high carbon steel or iron contamination was causing much of the wear and damage to these critical bearings and components.

The pair realized that improved oil filtering would remove the damaging build and wear debris before it had the opportunity to cause a chain reaction of wear and eventually catastrophic failure.

Hall had assumed that conventional oil filters being used by industry and automotive engineers alike were of adequate specification and performance for the protection of the system that they were designed to be fitted to.

Hall and Marlowe believed that a finer porosity filter, for example between 5 and 20 micron nominal, might, in certain cases restrict the flow to such a degree that oil starvation might be more problematic than the contamination itself. Size and cost constraints prevented the fitting of a fine filter of a size that would not incur too much of a pressure drop.

With this knowledge Hall and Marlowe considered magnetic sump plugs, but investigation and basic lateral thinking demonstrated some fundamental flaws with them.

Namely, magnetic field strength falls by the inverse of the cube when moving away from the magnet. If a magnetic plug is to attract contaminant, that contaminant must pass very close to the magnet. Particles don’t have to be too far removed from the magnet to negate any attraction, greatly limiting magnet efficiency.

Also, magnets suffer from particle wash-off, particularly in high-vibration environments (which cover most fluid systems) and high-velocity oil flows (which is why they are generally located in the center of a large sump). Despite these inherent problems, magnetic sump plugs are common to most vehicles and fluid systems.

Hall and Marlowe initially thought there might be a way to create an in-line magnetic solution that would handle the full flow of the fluid; the real question was how to eliminate the destructive wash-off problem.

They discovered that a number of designs had been tried by companies but they all had limitations, usually because designs relied on placing a magnetic surface area into the fluid. This surface area, like the sump plugs, was not close enough to most of the fluid and allowed contaminant to be washed off. These flaws were particularly evident at high flow rates and high viscosities.

To overcome these issues, they realized that they would have to focus strong magnetic flux gradients (fields) into the fluid at full flow. These would pull ferro-magnetic particles directly from the fluid flow instantly, without suffering contaminant wash-off.

The target solution was to ultra-efficiently remove large volumes of magnetic debris from a fast-flowing fluid without incurring a pressure drop. Over time they became skeptical that the objective could be achieved.

Figure 1. How a Magnetic Filter Works

The Eureka Moment

By chance, Hall was drawn to the small magnetic catch located in the top corner of his kitchen cabinet. It was a fairly standard one, comprising a flat magnet sandwiched between two small metal plates.

He recognized that the edges of the metal plates form the magnetic area, which secured the cupboard door. Hall began to consider the effect of the metal plates on the intensity of the magnetic field at the latch, and whether this could be incorporated into a magnetic filter design.

Hall and Marlowe experimented with various designs and realized that steel parts, especially low-impedance steel, will transmit magnetic flux up to 15 times more efficiently than the magnet itself. If the magnet was polarized appropriately, the steel plates could be used to focus and amplify the magnetic flux into the fluid.

With this concept in mind, they began to experiment with various shapes and designs, arriving at a prototype that had potential.

Take One

The first version built was rough, but they recognized that it was stronger than any magnetic solution that they had come across before. Ensuing refinements have produced a viable full-flow magnetic filtration.

A major adjustment along the way was to use the steel plates to create storage zones out of the fluid flow. Through fluid refraction, the fluid is harnessed to compact the debris in these zones and further reduce the chance of any wash-off at all.

Market Opportunities

Initial field testing was performed in a familiar and demanding environment: the racetrack. Hall and Marlowe conducted testing and refinement in high-output engines over a period of time. Engineers and racers were frequently surprised at the amount of debris removed from engines and transmissions, leading them to fear that the components were on the verge of failure.

Armed with the knowledge from the racetrack, some research and a bit of common sense, Marlowe found a ready audience for the technology with blue-chip companies in manufacturing, heavy commercial vehicle, hydraulic, transmission, power generation, automotive and water management operations.

Interests common to companies where this technology was welcomed included:

  • Protection of high-cost capital equipment

  • Reduction of downtime for machine repair or maintenance

  • Reduction in consumable costs (fluids and filters where they are used)

  • Reduction in disposal costs

  • Reduction of erosion on machine surfaces (from grinding wheels through to bearings)

The Magnom is entirely scaleable in that the diameter can be sized to accommodate different pipe and flow requirements and cores could simply be stacked together to increase the capacity for contaminant as required.

Generally, the Magnom’s flow channels tend to combine to a flow area equal to more than 110 percent of the feed pipe flow area. In this way, the pressure drop across the Magnom starts low and remains low even when it collects large amounts of ferro-magnetic contamination.

Given this low backpressure design, the Magnom could be fitted on the suction side of a pump without fear of creating cavitations due to a pressure drop. In many full-flow systems, the pump is often the most expensive component, and is devoid of effective filtration protection, until the Magnom!

FCS is currently focused on the transmission, machine tool, hydraulic and water heating and cooling markets, with any one of these being large enough to generate global business demand.

The MagnomTM technology has won a host of awards in the United Kingdom, including;

  • First prize in the Regional Merseyside Innovation Awards, accompanied by a check for $20,000.

  • First prize in the National Business Environment Awards, for the technology’s contribution to reduction of waste materials to the environment.

  • Silver prize in the Invention of the Year awards, a competition run by the Institute of Patentees and Inventors.

  • The technology was also accredited as an official Millennium product, a highly regarded accolade across Europe.

Since FCS was financed, the sales of the Magnom have increased approximately 20 times. FCS is presently building distribution across the United States, permitting North American partners to yield the benefits presented by the Magnom technology.

Recently, in a move that bucks a recent industry trend, the team planned to bring the manufacturing of the products to the United States, cutting out transport cost and any delay in supplying the end customer.

The company’s strap line says it all; that Magnom is removing the barriers to fluid cleanliness.

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