What is the difference between the US Filtermax® 2400, 2750 and 3000G centrifuges?
All models use a common centrifuge body and rotor assembly. The rotor assembly spins faster in the higher G centrifuge models. In order to start and run the higher G force rotors, the motor and drive system are upgraded. The  2400 uses a .75 hp motor, the 2750 uses a 1 hp motor and the 3000 uses a 1.5 hp motor The 3000G centrifuge also has the option of a 1 1/4inch NPT output.
Should I use 120 or 240 volts?
All motors may be wired for 120 or 240 volts; however it is recommended that only the 2400 be used on 120 volts. Motors start better on high voltage and it is preferred. High G force centrifuges require a large starting torque which requires a high starting current. The starting current may be cut in half when using 240 volts. This allows the use of smaller wire and breakers. The motor starting and running currents are found in the user’s manual.
How fast can the centrifuge be fed with oil?
Feed rate is determined by the initial contamination of the oil or liquid, the viscosity of the liquid and the difference in density of the materials being separated. Typical feed rates, depending upon the centrifuge, contamination and viscosity are between 10 to 70 gallons per hour.
What is the Daily Processing Rate when using the automatic controller?
Depending upon the centrifuge model, you may expect between 600 and 1500 gallons per day. Biodiesel, being thin, may be processed at 900 to 2400 gallons per day.
What effect does viscosity have on the cleaning rate?
Lower viscosity liquids are much easier to clean. Contaminants must flow through the liquid to the rotor wall. Thick liquids slow down the separation. A rock will drop quickly to the bottom of a tank of water, which has a low viscosity while a rock will very slowly drop to the bottom of a tank of molasses which is very thick.
How do I reduce the viscosity of the oil?
Heating the oil to 120°F to 160°F or blending with a lower viscosity solvent will reduce the viscosity of the oil. Some oils may be heated higher, nearly to the gassing point.
Will it separate water or antifreeze from the oil?
Yes, centrifuges separate materials in order of density with the heavier materials going to the outside of the bowl. Dirt is heavier than water and will go to the outside followed by a layer of water with a layer of cleaned oil on top. This cleaned oil will spill over the top of the bowl and flow through the cleaned oil port.
Can it be used for Biodiesel?
Yes, the centrifuge provides excellent results when used for biodiesel. Typically the raw oil is spun to remove dirt, water and fat. Then the processed biodiesel is spun to remove water and glycerin.
Will it separate glycerin?
Yes, it provides excellent results when removing glycerin.
Does it remove sub-micron particles?
Yes. Many centrifuge ads claim to capture sub-micron particles, however this is only part of the problem. “What percentage of submicron particles is removed?” is a more accurate question. The time spent in the centrifuge has a considerable effect on the percentage of particles removed with long residence times being much more effective in removing a higher percentage of particles. Using the typical feed rates, the liquid may remain in the US Filtermax® rotor for 30 seconds to 2 minutes. Residence times for other centrifuges such as spinners may only be about 2 seconds. While others may advertise removal of sub micron particles, they do not report the percentage of particles removed. A typical user comment is that “the Filtermaxx oil was coming out much cleaner after 10 minutes than our spinner oil did after 3 days of running.”
Is the rotor machined and balanced?
Yes. The rotor is sand cast, machined and balanced to approximately 1/10 gram. A 1-gram imbalance at 3000g’s is equal to a 3000 gram imbalance. Therefore balance is critical in any centrifuge.
How does the centrifuge cycle?
As the centrifuge runs, the contaminants concentrate forming sludge with some of the hard particles depositing on the bowl. If centrifuge is stopped periodically, the concentrated sludge will drain out the sludge port. A typical cycle is run 1 hour on and 4 minutes off to drain. Depending upon the contamination, hard particles will collect on the rotor walls and may be removed by scraping the bowl with a wood paddle.
Is it difficult to clean the centrifuge rotor?
No, hard particles may be removed by scraping with a small wood paddle cut from ¼ inch plywood. The rotor may be removed in about 30 seconds by loosening the spindle lock and motor mount slightly then pulling straight up on the rotor.