Simple Centrifuge
Clean waste vegetable oil (WVO), bio diesel, lube oils, and even hydraulic oil in your garage
Lab Centrifuge
Last updated 2008-10-01
Newest questions at the bottom

How does it work? A centrifuge works by rotational force in order to increase gravitational force on the product being separated. In the case of our machine it generates 1200 times the force of gravity. Please see this video how_it_works.wmv
How much does it cost to run? The machine is modestly sized. Large enough to clean hundreds of gallons per week yet small enough that it is inexpensive to run, just pennies per day.
How much product can I run per hour? This depends on your product. We've found that heated oils can be processed at a rate of over 20 gallons per hour. The slower you go the finer the particulate it will capture.
What kinds of products can I run through the machine? We have successfully run WVO, lube oils and hydraulic oil. I believe that any liquid can be processed.
What kind of power requirements does the machine need? Single phase 110v or 220v power. Please specify your preference and we can pre-wire your motor for either.
Can I set this machine up in my garage? You bet. The machine is small enough and quiet enough to put anyplace near for feed stock.
How well does it clean the product? Easily down to 1 micron. Unlike filters it can capture smaller particulate based on its weight, not size, so not only does it capture small carbons but it can capture water.
How do I clean it? We generally stop our machine every 24 hours for cleaning. We suck out any liquid using a syringe and then wipe the crude or cake from the bowl walls. Once wiped down it's ready to go again.
What is the maintenance? The machine should be wiped down between usages.
Motor type? The motor is single phase. We recommend you purchase a motor from us when you order the bowl. This ensures a good match. The motor is run in a vertical position so your typical pool pump motors will wear out very quickly due to the thrust. Our motors are Baldor brand and are designed for this out of position application.
Replacement motors? Sure. We have them in stock.
How was this machine born? Please read our history page.
Can I use this machine to clean and re-use my motor oil in my engine? Conventional oils tend to break down so I wouldn't recommend it. Synthetic oils on the other hand can hold up for tens of thousands of miles. We haven't done it. I'd send a sample to the lab and see what it looked like. Our focus is on fuels. We'd be interested in your results.
Do I need to heat my oils before running them through the centrifuge? Yes. We have had great results running heated oil. Heated oils release the captured dirt quicker than cold oils. In the summer your oils may be light enough to skip the heat. Vegetable oils may load up the machine with shortening if unheated.
Why wouldn't I simply bag filter it? Bag filtering is good but it cannot capture water. Often heavier than oil particles can still slip thru the filter.
I have an old cream separator, can I use that? We tried it. Oils are simply too heavy for it. It plugged solid within minutes.
Can I convert a washing machine to a centrifuge? No. A washing machine isn't nearly sturdy enough and only generates about 100 times gravity.
How many g forces does it generate? We state 1200 but if you want the actual number it's 1269.76 g at 3450 rpm.
What is the waste holding capacity of the bowl? About 750ml while running.
If I belt drive the unit can I generate more g force? We have a machine using this bowl that generates 5000 g at 6900 rpm. We have 8 months of nearly 24x7 use on this machine doing lube oils. Remember you have two factors at play, centrifugal force and centrifugation time. A machine with less rpm is less maintenance, noise and worry but a lot slower due to it's lower g force. If I use 50 gallons a week (which is a lot) what do I care if it takes a while, it works 24x7.
Can you make me a larger bowl, say 12"? A direct drive machine has it's limits. In order to reach 5000 g with a direct drive you would need at least a 16" bowl. We've built some crazy machines but that would be nuts, not to mention un-safe. A centrifuge is like a flywheel, it can carry A LOT of potential energy, even at low rpm.
How does your machine compare to a DieselCraft? On paper the Dieselcraft generates more g-force, 2000 vs 1200 but don't get caught by the lust for g-force. Been there. The main differences are: 1) The Dieselcraft requires oil flow to generate the g-force. There is really no way to guarantee it is actually going that fast. It's rotor speed can vary greatly depending on the viscosity of the material you're pushing through it. In contrast with a driven rotor that always generates the same g-force. 2) If you are cleaning oil un-attended like we do, a hose break could pump a lot of oil unto the ground. By contrast with a gravity system the chance of rupture is much less. This was important for us. 3) You have to disassemble the DieselCraft to clean it. This is time consuming and messy. With our machine, you simply shut it off, it drains, you scoop out the crud and re-start the machine. 5 minutes every 24 hours or when needed. 4) The DieselCraft requires a pump to generate the required flow rate, if your input oil isn't pre-filtered sufficiently this pump may be over worked and/or clog. By contrast we are pump less. We've used pumps. They fail and are expensive to maintain and replace.
Can I use your centrifuge in my car? Our machine is designed for stationary use. A DieselCraft would be a great addition to any car provided you can maintain the oil flow.
Can I use it in my RV? If your an RV owner the centrifuge can be setup at night to clean the next day's fuel, but not while traveling. In the early days we cleaned oil straight from the totes, that's the advantage of this machine, you can clean 5 gallons a week or several hundred gallons per week.
How many gallon of oil have you processed? I pulled the hours on Mike's two Clean Burn (CB-500) furnaces this after noon. One has 926 hours and the other 1186 hours. At 3 gallons per hour we estimate we have we have burned over 6300 gallons of oil this winter for a net savings
of over 15,000 dollars. We've eliminated water and nozzle problems since adding the centrifuge. Now, with the self draining design, the daily clean out of the centrifuge only takes minutes.
What is the typical power consumption of your centrifuge with the motor you provide?
Nameplate use is 690 watts per hour. Measured usage is about 575 watts. Here in the Northwest we pay about 6 cents per kW·h which is reasonable. Cost works out to about 3.5 cents per hour or 83 cents per day.
What is the most oil you have run per hour or per day? We are currently running about 500 gallons of lube oil per day thru a single centrifuge. This works out to just about 21 gallons per hour. Heated vegetable oils typically are run at 3 to 10 gallons per hour.
When can I order a complete machine? The turnkey machine started shipping in July. You can order on the ordering page.
Will a bowl be offered without the drain holes? The bowl ships with holes. We have found the self-draining design to be a wonderful time saver. If you need a bowl without holes please contact us. Alternatively, the holes can be filled with silicone if you need to plug them.
How is the captured debris kept from contaminating the clean oil output? The debris remain captured in the centrifuge bowl and are held in place by gravitational force. Also, there is an inner wall that prevents contamination upon draining. Please see this video how_it_works.wmv
Can I run cold oil through the machine? We started out running cold oils. Typically, cold oils can be run at about one gallon per hour, maybe two. The biggest problem we had was cleaning, about every 5 gallons, due to the bowl filling with shortening. You can actually remove the "creamy" from creamy shortening and recover liquid oil... it's actually very cool but time consuming.
What temperature do you recommend running the oil at? We run our oil at about 120 degrees.
How many gallons per hour can you do? We typically run heated vegetable oil at 3 to 10 gallons per hour. We can run faster, it's largely dependent on the oil we're running. With un-heated vegetable oils we typically run at about 1 to 2 gallons per hour. We typically run lube oils at about 20 gallons per hour. We publish the rates that we actually use and are comfortable running our oils at. We do not publish the flow rate or flood rate of the machine as our gallons per hour.
Your machine is too slow! Can I go faster? Maybe. Centrifugal separation is based on two factors, force (g force) and time. The material being cleaned plays a huge part on the time factor. Thicker oils take longer than thinner oils and cold oils take longer than hot oils. The more time your oil spends in the machine, the finer material it will remove. A higher g machine will cut the time required. It doesn't improve the effectiveness. For example, oil running at a rate of 5 gallons per hour through a 1200 g centrifuge, like simple centrifuge, would be the same as 8.3 gallons per hour through a 2000 g machine. Even at a conservative 5 gallons per hour, our machine could handle over 43,000 gallons annually.
Do I need to make more than one pass through the machine? No. We run our oils slow enough that we get the results we want in a single pass.
Have you noticed any corrosion when used with WVO? No. WVO isn't an issue. The 6061 Aluminum hard oxidizes and has good chemical and corrosion resistance. We have one bowl that has two years on it. No corrosion.
Won't the lye in biodiesel corrode the aluminum bowl? Lye will eat aluminum at an alarming rate. You should never attempt to run un-washed biodiesel through any aluminum parts, including your vehicle. You should always drain off your excess glycerin, wash your biodiesel to obtain a neutral pH and then run though the centrifuge to finish.
Have you attempted spinning biodiesel to remove glycerin and/or contaminants? The machine isn't a separator. We use it to de-water and remove any trace particles from the biodiesel after washing. The biodiesel in this state isn't (or shouldn't be) anymore caustic then when you put it in the tank. It simple saves you the week or two of settling.
What are the dimensions of the machine? The machine is about 18" in diameter and 20" tall. The machine weighs about 60 lbs. This is a current picture:
Can I use this centrifuge to remove yeast from beer? We haven't tried it, it should work. According to the foundry the alloys used in the machine it are food safe. If your thinking of using one of our machines for food please contact us prior to ordering so we can ship a non powder coated version.
How well does your centrifuge handle WVO that is rancid and has a lot of emulsified water according to the hot pan test? Much of the WVO we process contains a lot of water by volume. Due to wash water and rain contamination many of our pickups average 10% water by volume. We typically are able to settle a large percentage of this free water prior to the centrifuge. The centrifuge removes the rest. We may need to adjust our feed rate to separate heavily contaminated oil.
Can I use the Simple Centrifuge to recover green algae? Yes, it works very well. The algae forms a cake that can then be further processed. These pictures in the gallery show our experiments:

Numeric Control, LLC
PO Box 916
Morton, WA 9846