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homemade centrifuge plans
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i'm not really absolutly positive why the first one i built worked poorly but i think it was because the oil would sort of stick to the outer vessel and the cf and just stay there. would build up and not drain off well and would cause friction between the cf and outer bowl. it was 1/2 an inch of clearance. i installed these downward aluminum spiral fins that helped push the oil down but still couldn't put very much oil to it. my new one is 12"x12" square with the cf measuring axrox 8" on the outside diamiter and works great.as far as clerance from the bottom i was woried that not drained oil would slow the cf down if it were close enough to contact it via friction of the oil so i just made sure that it was high enough to clear any oil that would be leftover from draining. anyway these numbers are just based on my own guesses and not fact, but the new one does work really well so far.
wish i could give you more absolute advise but thats about all i know. good luck buddy.
 
Registered: October 01, 2009Reply With QuoteReport This Post
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I measured the CF bowl opening - width of the lip from the inside of the outer bowl that holds the oil as it spins out is 1"; the lip where the CF'd oil slips over is 1 3/4" wide. I never measured the volume of oil in the bowl, but with the above measurements, the volume is quite small. If the concern is to get the FATs out of the WVo, then run the oil Cold. Heat will melt the fats. Take two samples ( qt glass jars) of a cold oil run and another with heated oil. Place both samples in the fridg over night. The oil will separate into two layers - fats on the bottom (yellow) and the good oil on top - golden or honey color.
 
Registered: October 30, 2005Reply With QuoteReport This Post
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Thanks guys,
Filtering cold is the option I am going for as fat is my main concern, intermittently shorting out the spark electrodes on my burner. I cant see any reason why the outer collection bowl needs to be close to the spinning bowl.
Thanks again for posting.
 
Location: ireland | Registered: December 02, 2012Reply With QuoteReport This Post
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i mean the cf that didn't work properly had small gap of 1/2 " between the cf and outer bowl,my new one has about 3 inches but i still don't know if that was the whole reason i couldn't put the amount of oil in the old one as the new square one. doubt you need to go as big as this either i just didn't want to build an other flop.
i'll try the fridge test to see how my oil is, thanks for the tip.
 
Registered: October 01, 2009Reply With QuoteReport This Post
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dragonfly , what about water, have you ever noticed water in the oil you drain off when you clean the cf? or even vapor? just wondering if their was a way to judge when you should be done cleaning.
 
Registered: October 01, 2009Reply With QuoteReport This Post
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The oil that is picked up from three restaurants doesn't see the light of day as I pick it up from inside their back prep room. I have noticed some water in the dregs" as it drains off. I have my CF'd oil tested by the Sandy Brea Water testing device. The Lexan cover fits rather tight but does allow some space for any moisture. I don't get the preverable "splash" with the oil hitting the sides of the aluminum pot.
 
Registered: October 30, 2005Reply With QuoteReport This Post



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Hi Guys,
Taking on board all your comments. Will get back when I spin at 5500 rpm and let you know what happens. Worst case scenario is 'Discovery Channel' have new material for their UFO program. Friz be from hell.
 
Location: ireland | Registered: December 02, 2012Reply With QuoteReport This Post
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quote:
Originally posted by hs5424:
Thanks guys,
Filtering cold is the option I am going for as fat is my main concern, intermittently shorting out the spark electrodes on my burner. I cant see any reason why the outer collection bowl needs to be close to the spinning bowl.
Thanks again for posting.

not sure if i no how to quote but hs5424 when the electrodes are shorting out on your burner is it because the fat has "gummed them up"? been frigin with my conventional burner with some heated 50/50 blend d2 and veg and i noticed some hard resin on them. i just cleaned them up with a jack knife,but maybe i should get a spare pare. any input would be apreciated
 
Registered: October 01, 2009Reply With QuoteReport This Post
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Hi J rip,
My burner originally was fitted with a Delevan 30609-11 venturi type nozzle. After checking the specs I decided to try another one with a more acute spray angle so I fitted type 30609-9. My reasoning behind this was with the wider spray angle some slight 'over spray' was occurring which was causing some oil to hit the swirl plate and the spark electrodes. Changing the nozzle greatly improved the interval between electrode cleaning. If I reduce the % of fat in the oil when I get my centrifuge up and running should yield improvements also.
 
Location: ireland | Registered: December 02, 2012Reply With QuoteReport This Post
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thanks i just started messing with the burner, and it's not a waste oil burner like yours. i'v been doing some research and started gathering some parts and will try to build one this summer. all i'm doing right now is pumping the oil through the un converted burner i have in my house right now and noticed some build up of crust around the tip of the gun etc. just trying to burn as much oil as i can for now,until i have time to make a proper burner. good luck with cf, it's a good tool for sure. o also i metered the oil going through mine and it's about 2 litres per minute and is working fine at that rate.
 
Registered: October 01, 2009Reply With QuoteReport This Post
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Hi j rip,
Take a look at this. http://www.youtube.com/watch?v=ZEBc0_cSoh4
This is the way my burner works. You can see the Delevan nozzle and the tube it screws into. I think Delevan will supply this part also.They are a US company so you should have no problem getting your hands on the parts. These two parts are the only special ones needed. All other bits are off the shelve such as, thermostat, heating element. One word of caution. Pre-heating of veggie to 120C is recommended by the burner manufacturers, however I have no problems with ignition at 100C. Waste engine oil I pre-heat to about 85-90C. I added two thermostats in series as failure of one caused my oil to reach very high temp (flash point of veggie 300C region). I noticed that the manufacturers now have a high limit stat included as a modification, so I was not the first person to have a stat stick closed.
I reckon that building your own will save you 1000 euro as I paid 1400 euro plus tax and shipping for mine.
Good luck and let me know if you need any advise. I am now into year 3 running mine summer and winter.
 
Location: ireland | Registered: December 02, 2012Reply With QuoteReport This Post
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do you only have to pre heat the oil in the syphon resivoir? i saw one kit on ebay that had an aluminum block that was machined to except the nozzle ,the syphon line and an electric heating elament that would heat up in the tube. i figured you had to pre heat the res and here for good ignition. thanks for the tip on the 2 thermostats is series i can use that other places as well, might help me sleep lol.
 
Registered: October 01, 2009Reply With QuoteReport This Post



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quote:
Originally posted by j rip:
do you only have to pre heat the oil in the syphon resivoir? i saw one kit on ebay that had an aluminum block that was machined to except the nozzle ,the syphon line and an electric heating elament that would heat up in the tube. i figured you had to pre heat the res and here for good ignition. thanks for the tip on the 2 thermostats is series i can use that other places as well, might help me sleep lol.


My burner heats the oil using a 1Kw element in a small tank which I guess holds about 1.5/2 pints of oil. The flow to this is controlled with a float or ball cock arrangement. The float kicks a switch which opens a valve to allow oil top up the per-heat chamber. There is also a second switch installed as safety should the first switch fail and flood your boiler house with oil. This second switch shuts the burner down completely making the red light come on in the control module. One thing I noticed when burning waste engine oil is if I had the pre-heat set to high the oil would 'boil up' or expand in the tank causing the float to rise high enough and activate the second switch which will cause the burner to shut off. To avoid this happening I now set the pre-heat temp to a point where I can see the oil just starting to simmer. This is normally around 80-85C even though the label on the burner states to set engine oil at 100C. I only check this if I get a new supply of oil as some oils seem to foam or expand more than others. I do not have this problem with veggie. When you start to build your burner I will post some picks as I may help to clarify what I have just posted.
 
Location: ireland | Registered: December 02, 2012Reply With QuoteReport This Post
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yea that be cool, i got a real problem with starting things before i finish the last thing i started and i just bought a truck that i'm going to make a two tank system out of so i want to do that first. i'm hoping to learn some stuff this winter then build this summer.
i kinda under stand what you mean though just because i'v looked at alot of pics of burners already,and i think i got alot to go on, but sometimes the practacle version dosn't work like it did in my head so i want to make sure i have some free time on hand when i start. i'm sure i'l be talkin with you though. thanks
 
Registered: October 01, 2009Reply With QuoteReport This Post
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Hi Guy's,
My first run of my homemade centrifuge has yielded similar results as was previously mentioned in this forum. When I applied some water during my test the entire unit started to vibrate and move across the floor. I made mine using a 1hp motor running at 2800rpm which drives a shaft using pullies and a drive belt. This shaft is mounted to my setup using 2 X 'pillow blocks' with bearings which can handle 7000rpm and couples directly to the CF bowl and is ratio-ed to deliver a speed of about 5000rpm approximately to the bowl. I am wondering if I need to keep the length of the shaft and the height that the cf bowl is above the top bearing to a minimum.
 
Location: ireland | Registered: December 02, 2012Reply With QuoteReport This Post
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A description and dimensions of the "new" CF bowl would be helpful. The inner bowl should be as close the the CF bowl as possible. My inner bowl to the CF bowl wall is 1/4". The edge of the CF bowl lip where the good oil spills out is 1.125" to the outer bowl. What was the ppm of water after using the Sandy Brea test? Did you test with a RAW sample to get a base line? Also, suggest running the CF bowl DRY with no WVO in it to see if it vibrates. I'd be very careful with that CF bowl spinning at 5500 rpm and up.
 
Registered: October 30, 2005Reply With QuoteReport This Post
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Hi Dragonfly,
Thanks for getting back to me. The CF bowl I am using is the Raw Power Centrifuge make. It spins at 5000rpm (approx) with some vibration but when I started to do my first test using cold water with some tea leaves mixed in the entire unit got very loud and decided to vibrate severely and move across the workshop floor. If I did not use my boot to stop it I reckon the entire unit would be several miles away by now. I am doing some slight modifications now such as adding a stabilizer bar to the 'L' bracket which holds the shaft, pulley and two bearings. I think that there is a slight movement in this bracket. Do you know the height that the CF bowl needs to sit above the outer collection bowl. I have a feeling that fixing the CF bowl as low down as possible on the main shaft will help mask any slight imperfections in the shaft. I will also try to put some tension on the drive belt as I have it not very tight at the moment. Maybe when I applied the water the load started an oscillation and the whole thing went wild. I will post what changes (if any) my mods made. This is a learning experience.
P.S. I may as a last resort change the pulley ratio and slow the CF bowl down below 5000rpm.
 
Location: ireland | Registered: December 02, 2012Reply With QuoteReport This Post
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IMHO, running at 5000 RPM is not the key to clean VO. A standard 1/3 HP Baldor AC motor spinning at 3450 RPM is enough. The other part of cleaning WVO is heat. Don't need very hot temps - 140F. Any chance of a direct drive setup to see if it vibrates? I visited a mid sized CA Renderer that used a commercial CF. Upon questioning his operation, he said that heating the WVO is very important for extracting the junk. The feed "drum" held over 5K gals that fed a very tall CF about 12' x 6' dia, if I recall correctly. I use those principles to clean my WVO. Settle the RAW at ambient temp (70F), 3450 RPMs @ 125F is what I use to clean WVO.
 
Registered: October 30, 2005Reply With QuoteReport This Post



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quote:
Originally posted by Dragonfly:
IMHO, running at 5000 RPM is not the key to clean VO. A standard 1/3 HP Baldor AC motor spinning at 3450 RPM is enough. The other part of cleaning WVO is heat. Don't need very hot temps - 140F. Any chance of a direct drive setup to see if it vibrates? I visited a mid sized CA Renderer that used a commercial CF. Upon questioning his operation, he said that heating the WVO is very important for extracting the junk. The feed "drum" held over 5K gals that fed a very tall CF about 12' x 6' dia, if I recall correctly. I use those principles to clean my WVO. Settle the RAW at ambient temp (70F), 3450 RPMs @ 125F is what I use to clean WVO.

Thanks ,
If my few mods don't fix things I will either direct drive and spin at 2800rpm or slow down the present setup with the pulley ratio's.
Let you all know how it goes.
 
Location: ireland | Registered: December 02, 2012Reply With QuoteReport This Post
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If you direct drive at 2800 rpm and can run the same batch for two or three times, the amount of junk AFTER each run will give you a good idea of how much junk remains after each run. The warmer the oil as it drops into the CF bowl will allow more junk to move through to the oil. Hopefully, the oil inlet is as close (1/4") to the bottom of the CF bowl so it has to travel the longest distance up the side of the CF bowl before it is thrown out as clean oil. Try to keep the flow per minute less than 1/2 gal per minute as a bench mark. Adjust accordingly when evaluating the amount of junk in the bowl. I use a glass qt jar and stop watch in my testing. Keep us posted.
 
Registered: October 30, 2005Reply With QuoteReport This Post
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