Novel filter gives new oil water separator the edge

Dean Palmer reports on a novel system for removing water from hydraulic oils, that uses a peristaltic pump and sensors to monitor the moisture content of oil

An innovative oil water separator has been developed that uses a sealed filter/purifier, a peristaltic pump, differential pressure gauge and power supply, plus sensors that can be added to monitor the moisture content, particulate size and number for condition monitoring of oils. The new system works by gently pumping oil through a filter and filter medium (patent applied for) which absorbs moisture present in the oil without changing the characteristics of the hydraulic oil. A by-product of this system is the removal of particulate down to around 30 microns. The system was developed by Leslie Selsdon of Selsdon Filtration, an expert on the removal of water from oil with more than 25 years' experience in the industry, in conjunction with Autoclude, a UK manufacturer of peristaltic pumps. The system is lightweight, portable and can be powered from 12/24V DC or 110/230V AC. The separator can be used as a service aid, taken to site or to a machine, where the presence of moisture in oil may be a problem. Alternatively, the system can be used as a static installation next to a holding tank, where the oil can be continually recycled through the filter medium. The equipment can also be scaled up to meet higher flow requirements or larger capacities and, because of the peristaltic action of the pump, there is no potential for frothing of the oil and the entire system operates at pressures of less than 2 bar. The new system will be a welcome solution for many companies. Water contamination can change the physical properties of hydraulic oil by increasing oil acidity, changing viscosities, forming sludge and promoting corrosion and the growth of bacteria. Also, the growing trend towards biodegradable oils will add to these problems, since they are more hydroscopic than mineral oils, so contamination produces more water and CO2. Having accepted water is present in hydraulic oil, either in a dissolved or free state, the problem is how to remove it before components fail in hydraulic systems. Autoclude and Selsdon's system offers a solution.