The Principle behind Cleaning Used Motor Oil with a Centrifuge
When a mixture of different substances is rotated at very high speeds inside a closed path (in our case a closed container), substances of higher mass tend to move to the outermost path and lighter particles find themselves closest to rotating axis. The same principle is used in centrifuge oil cleaning.
Used motor oil that has impurities and dirt is fed into a centrifuge. The centrifuge has a rotor that spins a very high RPM (revolutions per minute) and it pushes the impurities to the wall of the container that houses the rotor. This works because the mass of the impurities is greater than the mass of the oil particles. Appropriate extraction methods are used so that impurities and the clean motor oil are properly separated, and the oil is ready to be re-used. These filtering systems are also appropriate for use with small-scale biofuel setups to remove any impurities.
Image Credit: Diesel Craft
Cleaning Used Motor Oil with a Centrifuge
Cleaning used motor oil with a centrifuge can be done using various systems. You can either build your own centrifuge system or buy one commercially available in the market. There are two videos posted below in the "References" section that will help you obtain a better understanding about how various centrifuge systems work. The principle used to purify the used motor oil is the same as for any biofuel and is employed in all centrifuge filtering systems. What differs is the extraction process in which the oil is separated from the impurities.
Step by Step Process
- Used motor oil is fed into a centrifuge using an inlet pipe that is present either near the bottom of the container or near the top of the container.
- The rotor is started and it spins at very high RPM.
- After a few seconds, the impurities move towards the wall of the container that houses the rotor. The rotor is set to rotate for a little longer so that the impurities of the scale 1 micron and less are also removed and a better quality motor oil is obtained.
- A few centrifuge oil cleaning systems have an outlet near the bottom of the centrifuge container that allows the impurities to be drained out. However many systems will need to be opened and cleaned manually of all the sludge and other impurities.
- The clean oil is always present near the center of the rotating axis. An outlet in the middle of the container is used from which clean re-usable motor oil is drawn from and stored for use in the future.
Cleaning used motor oil using a centrifuge system is that easy. The system and the mechanism are very simple and can be used by anyone to recycle used motor oil or as one of the final steps in the home production of biofuel.
Maintaining a Centrifuge Oil Cleaning System
Once you are done cleaning the motor oil using the centrifuge system, it is necessary to clean the centrifuge by removing the dirt, sludge, and other impurities that collected on the walls of the centrifuge system. To clean the centrifuge oil cleaning system:
- Open the centrifuge system so that the dirt and sludge is easily accessible. If you are using a centrifuge oil cleaning system that you bought, please read the instructions manual on how to open the centrifuge for cleaning purposes.
- Once the system is opened, wear hand gloves (not necessary, but saves you from washing the sludge off your hands) and use paper or cardboard to remove the sludge. Do NOT use water to wash the sludge off, as it will not wash off easily.
- Use some mild detergent to wash the last traces of sludge off and leave the system in the sun to dry or wipe it clean. In general, make sure that there are no water droplets in the centrifuge system when you store it away.
- Dispose of the sludge in plastic bags. Make sure you pack them well; double-bagging helps in avoiding messy spills.
1) How to clean waste vegetable oil using a motor oil centrifuge available in the market
2) How a simple centrifuge oil cleaning mechanism works