GF-25 Centrifuge

Green Fuels, GF Series Oil Centrifuges

Excellent quality 'Centrifugal Oil Cleaners', which remove water and all heavier-than-oil particle contamination from oils. Designed for use with Diesel, Bio Diesel, Vegetable Oil, Gear Oil, and Lubricating Oil, the centrifuges will work more efficiently if the oil is heated prior to introduction to reduce viscosity to that similar to water, this is particularly important when used with vegetable oil

Used in conjunction with a pump of the correct pressure, the oil centrifuge uses pressurised oil as a wet seal to prevent wear, and turns the incoming liquid flow into a fine jet which propels the rotor at speeds of up to 9000 RPM, creating centrifugal forces of 2000 times gravity. At this point all heavier-than-oil particles such as soot, dirt, glycerine, fat, grease and water, are forced to the outside wall of the rotor, where they mass into a solid layer, clean oil then flows outward into your storage vessel. Multiple passes (up to 3) may be required to gain the highest purity when sub-micron contamination is present.

The centrifuge will require emptying of contaminants periodically, although regularity will depend upon how contaminated your oil is, the better you strain your oil beforehand, the longer the centrifuge will operate before cleaning is required

Oil must be pre-filtered down to a maximum of 250 microns prior to introduction to the centrifuge, failure to do this will result in blocking of one or both propulsion jets, this will either reduce rotor speed and flow rate, or prevent the device from functioning at all. If this happens the jets will need to be removed using a spanner and cleaned. The device is fully user-serviceable

For cleaning of lubrication oil that has been used in a combustion engine, please note that whilst the centrifuge will remove all heavier-than-oil particles, it will not reverse changes that have occurred to the oil at a molecular level - for example the black colour of used engine oil is not only caused by carbon deposits i.e soot (which will be removed) but by a change in the molecular structure of the oil caused by the combustion of hydrocarbons around and within it, and this colouring cannot be removed by using a centrifuge or any other means of fitration

All of our centrifuges are priced complete with a steel wall mounting bracket

WHAT TO EXPECT FROM A CENTRIFUGE & GENERAL GUIDANCE

Due to a large number of enquiries following supply, we have enhanced the information and manuals provided, and summarise what to expect (in workshop conditions) from a centrifugal oil cleaner below;

Purpose - A Centrifuge is a fuel-polishing device, it is not intended to purify foul oil in one pass, moreso to remove the contaminants from oil that cannot be removed by the lowest rating of washable filter (this being 80 micron), and particles that are too small to be removed by any filter (smaller than 1 micron), by combining washable filters with a centrifuge you can eliminate the need for disposable filter elements

Particles - A Centrifuge will remove heavier-than-oil particles, but it will find it more difficult to seperate any particles if the main body of oil is heavily contaminated with material of the same Specific Gravity, in this case the oil will require more than one pass, or for the oil to be filtered to a better standard before pumping into the centrifuge, the cleaner the main body of oil is, or gets, the faster the rate of separation will be

Liquids - A Centrifuge will remove heavier-than-oil liquids by the same means as it removes particles, but it will not remove "miscible" liquids, for example liquids that have the same "Specific Gravity" as the oil, or contaminants that are bonded to the oil molecules chemically. It is worth noting particularly with liquids that the maximum capacity of the centrifuge rotor cap (where dirt is held) is approximately 295 Grams, if you pump a lot of water, glycerol, or animal fat through the centrifuge then it will become full very quickly and this will prevent further separation

Number Of Passes -A centrifuge is not designed to purify oil in a single pass, unless the oil is very clean. The speed at which the centrifuge separates contaminants from oil is determined by the cleanliness of the main body of oil and the RPM (not the RPM alone). The centrifuge rotor is driven by jets of oil squirting out from the rotor, creating a propulsional force away from the outer wall of the centrifuge, without the jets the rotor will not spin, so to spin at all it needs to pass oil at a rate of about 3 lpm... if your oil is too contaminated then most oil will go straight through the centrifuge to provide the propulsion, and only a small amount of contamination will be separated in the initial pass/es, if your centrifuge fails to remove anything after repeated passes then your oil may need to be filtered to a better standard beforehand

Perseverance -Centrifuges take a bit of getting used to, some people expect too-much-too-soon and get frustrated without investigating their problems properly. Most problems are experienced by those who use a centrifuge for purifying waste vegetable oil, and are mostly caused by excessive animal-fat in the oil (this is white in colour at room temperature) Animal Fat makes the oil cloudy and, being almost the same SG as the oil, makes it extremely difficult to separate. We recommend passing a small amount of oil through an ion-exchange or cellulose media to determine if any cloudiness is caused by animal fat

How We Do It - We purify our own oil like this;

1. Heat waste oil to 40c and filter through a 200 micron washable filter bag
2. Pour oil into a conical HDPE tank (reactor tank) in a room at 20c+ (do not heat the tank as this causes convection and mixing currents) allow oil to settle over a few days
3. Via a tap in the bottom of the conical tank, drain off all settled waste solids and liquids and discard completely
4. Either heat the oil in a seperate tank, to 45 celcius or above (we use a large metal drum with a band heater)
5. Pump oil into the centrifuge, remember that during the start-up and shut down period, the centrifuge will only pass waste oil. Ensure the oil going in is free of air bubbles, and the centrifuge can drain freely from the bottom, maintain 100PSI pressure throughout the operation, leave centrifuge to circulate the oil for as long as it takes to gain the purity you desire