System Overview
This system uses a combination of a vacuum pump, (venturi type), compressed air to drive the vacuum pump, and a gear pump to drive the centrifuge. De-watering is accomplished by heating the oil to 180 degrees f and applying a vacuum of approximately 17 inches of mercury. The water can be removed under these conditions in 20 to 30 minutes.
The oil is stored in 2 - 275 gallon totes.
By using 2 tanks, the oil is allowed to settle for around 2 to 3 weeks prior to being processed. This helps settle a large amount of particulate and water to the bottom of the tank. The pickup tubes are set to the 75 gallon level, leaving plenty of room to collect the undesirable material. The water and sediment is pumped out periodically and disposed of.
The heating tank is filled by drawing a vacuum of 25 inHG, then opening the fill valve on the bag filter and allowing the pressures to equalize. The rate of flow will be dependent on the temperature of the oil, and the condition of the 100 micron bag filter.
The tank holds 32 gallons, and with oil temperature around 50 degrees f, it can take 15 to 20 minutes. The oil is being drawn through approximately 20 feet of 3/4 inch pipe.
The centrifuge is a Dieselcraft OC-20.
The centrifuge is driven by a 110 volt 100 psi, 1 gallon per minute gear pump.
The pump is connected to the centrifuge using high temperature, high pressure 1/4 inch id flexible lines. This was changed from the original design which included 1/4 inch od aluminum lines that failed due to vibration.
Running for 3 to 4 hours will filter down to less then 0.5 micron, which is cleaner then any nominal fuel filters available. A standard Wix, will filter down to 6 microns.
The oil is tested for water content by taking a 400 milliliter sample, weighing the sample on a scale capable on an accuracy of 1/10 of a gram and recording the weight. Next the sample is heated in a 1600 watt microwave for 6 minutes and then weighed again. The difference in weight is the weight of the water that has boiled out. A 400 ml sample will have a weight of +- 400.0112 grams. If there is 0.2 grams removed from the sample that will equate to 0.199994 ml of water, or 0.08 percent of water by volume.
The finished fuel is then pumped through a 110 volt transfer pump, with a Goldenrod 10 micron filter before the nozzle hose.
The final filter is in place to catch any debris that may have been generated among the pumps, valves, and piping.
