Micro-magnetic filtering

As part of Mollart’s subcontract machining of customer parts, the PRB40 machine is used in-house for work including drilling and milling. The gundrilling and general machining centre, which is capable of machining 40mm diameters in exotic materials down to 5mm, has a 120 litre pump and auxiliary pumps of 200+ litres. As the high pressure pump can cost up to £5,000, prolonging its life and protecting it from damage is essential.

Ian Petitt, sales director for deep hole drilling systems at Mollart says: “The Micromag does an excellent job of polishing the oil. The set-up allows for continuous operation; the Micromag works at its own pace to polish the oil even if the machine isn’t working.”

Mollart was experiencing problems with the amount of fine particulate produced by the machine, which would quickly settle on the bottom of the tank and impair the functioning of the pump once it had accumulated. Despite using strainer filters as a method of protection for the pump, they quickly became thick with debris and subsequently blocked.

The build-up of debris required the pump to be washed manually, therefore causing downtime. Not only was this method of protection ineffective, it was also time consuming. The scavenge pump was in operation all the time, but Mollart needed to find an effective method of removing the dust from the oil before it had a chance to settle on the bottom of the clean tank.

Mollart now employ a system that consists of three levels of filtration: a conveyor to take out the largest particles; a paper filter to go down to 20µm, and a Micromag from Eclipse Magnetics to catch and collect the submicron particles. After the scavenge pump has been utilised the oil passes through the Micromag before reaching the heat exchanger in order to remove the particulate from the fluid and make the heat exchanger as efficient as possible in controlling the temperature of the fluid.

In this particular application, a single Micromag is fitted onto the machine to act as a polishing filter, which is in operation on a continuous basis. The Micromag basically acts as a clean-up filter that is employed after the base filtration methods have done their work, polishing the oil to a finer standard and removing submicron particles to achieve high levels of filtration.

The Micromag magnetic filter works by allowing contaminated fluid to enter the inlet port where it is dispersed by the innovative tapered radial flow channels. As the fluid passes down the outside of the centrally mounted rare earth, high intensity magnetic core, it captures contamination particles along its length. The geometry of the magnetic flux circuit means that the contamination builds up in a controlled way. This ensures that the filter will not block, regardless of how much contamination it holds, as the channels remain open allowing the fluid to continue to flow freely through the unit.

Mollart cleans the magnetic filter approximately every four to six weeks using the supplied cleaning tool which is a quick and simple process. The magnetic particles can be removed from the filter and easily disposed of, with no dirty cartridges and no consumables. The device is not only compact; it has a clear bowl which allows machine operatives to see the level of contamination building up around the magnet and maintain an effective cleaning schedule to keep the process running at maximum efficiency.

Ian Petitt concludes: “I honestly don’t believe that there is a true competitor to the Micromag on the market. It is a simple idea, and simple ideas are often the best.”

Mollart

http://mollart.com

Eclipse Magnetics www.eclipsemagnetics.com