This would only be simple if you had a large assortment of springs the proper sizes, and liked lots of greasy trial and errors.
Just thought of a potential concern. If you start the unit empty on really dirty oil, you run the risk of some chunks clogging the orifices. Heat settled oil shouldn't be a problem. Otherwise it might be wise to start the unit up on a little previously cleaned oil, then switch over to dirty once it spins up. I'll measure the orifice size when mine gets here. Probably only run settled oil through it normally, but do want to test it with nasty stuff to see how it does.
I think it may be more of an atomizing effect than steam evap. Kind of like when you spray cold water through a fine misting nozzle and it can all evaporate before it hits the ground (with our low humidity.) Only I am doing higher pressure and temperature than a mist nozzle. And I think the spinning has an effect on the atomizing, imagine how fast it must be coming out of the nozzle at 6000 rpms? I wouldn't be surprised if there is a strong vacuum created there.
The drop in pressure as a fluid increases its velocity is govern by Bernoulli's equation.
In incompressible flows, the pressure is inversely proportional to the square of the velocity. This means that a slight increase in velocity causes a significant drop in pressure. The OC-20 spits out WVO at fast speeds causing the pressure to drop significantly causing water to boil out of the WVO. (like in vacuum dewatering.)
Does any know what the velocity is of the exiting WVO for the OC-20. From there we can calculate the Pressure of the squirting fluid. Then Tim can consult his steam tables to determine the temps that this will flash the water. Although this calculation would be moot since we already know that it is getting flashed at 120*F.
Nice, pose it as engineering and I can't resist getting the calculator. The nozzles are at ~1.5" radius from the center = 9.42" circumference per rev. x 6000rpm /12= 4712 ft/min. or 53mph wow thats fast. OK you take it from there.
I think its flashing at even lower than that temp but I get that hot even on my first pass just to provide good filtering.
Not really moot. It could allow for calculating the best nozzle size for a given pressure, to get the lowest temp for flashing...
Edit: SunWizard, the velocity of the oil will be higher than the spin speed in order to overcome frictional losses. I'm sure there is a way to calculate it based on pressure and orifice size.
OK, I need another piece of info. What is the flow velocity just before it exits the nozzle.
We know that it is at 4712 ft/min squirting out. What is its velocity prior to squirting out?
Also need the fluid density of WVO.
Back to mobile use for a moment, the Mallory 5110fi pump I (and Vegistroke) use is rated 77gph at 60 psi. Wonder if it drops to 55gph by 90 psi??? Used to be a graph, will see if I can find it.
EDIT: HERE WE GO. 50 GPH at 90psi. It's rated at 70 psi continuous, but I've ran 170-190 degree WVO through a used one over 35,000 miles at 90-100 psi.
The 4712 ft/min is the speed of the nozzle, so it must be almost that speed before exiting. As JOAT says, I'm sure there is a way to calculate it based on pressure and orifice size.
I think there is more at work here than just Bernoulli, since the stream hits a plate and goes from 53 mph to 0 instantly which must do something too.
OK, here's the reduced formula after plugging in the known values.
PO = ((VI * VI) * D)/2 - 1598611968 * D + 90
PO = Pressure out in psi
D = WVO fluid density in Lbs/cubic inch
VI = Velocity inside just before it squirts out in inches/min
I assumed the pressure inside is 90 psi.
Plug in your assumptions of the value of VI and D and you have the pressure of the squirting fluid.
My physics is rusty so if someone could verify the above results, that would be great.
I appears that
Nice, looks like about the right size. How does it do on cold WVO? I bet those graphs were for diesel. Can it still keep up that flow rate on WVO?
No, no, you need the velocity relative to the nozzle. Not the velocity relative to the outside object. The velocity of the squirting fluid is 4712 ft/min relative to the nozzle, right? if not, then my formula is incorrect.
Crank those numbers --
Based on my past flowrate/orifice size testing I suspect each of the two nozzles in this unit will measure around 45/1000 diameter, possibly 50/1000 due to your lower-than-mine 90 pounds pressure.
Mallory gearotor pumps -- I thought these would work with veg, glad to hear someone confirm this, I think these will be my only choice for a factory made pump, too bad they are so expensive.
OK guys, here's the Bernoulli's equation without plugging in values:
(VI*VI)/2 + (PI/D) = (VO*VO)/2 + PO/D
PO = Pressure out, Pressure of Squirting fluid in psi.
PI = Pressure inside, known to be 90 psi
VI = Velocity of fluid inside the nozzle relative to the nozzle (inches/min)
VO = Velocity of squirting fluid relative to the nozzle. (inches/min)
D = Density of WVO in Lbs/cubic in
Plug in your assumed values and you can calculate the PO.
4712 is just how fast the nozzle is spinning, JOAT correctly pointed out that the fluid exiting must be faster than that, you would need pressure vs. orifice size calcs. and maybe friction in the centrifuge to figure that. Too complex, plus I think there is more to it than Bernoulli.
Like I have said in other threads that got into formula, the best data is in testing it.
Bashing the oil/water into a static plate definitely causes an visual increase in the amount of steam released. I was just reading back through the first few pages of my FE discussion and was reminded of this, I was getting dry oil without the bash plate but not the visable steam, still don't understand this exactly but a static bash plate definitely release more steam than peeing the stream into the liquid oil.
How does this occur in the spinner, does the oil hit the outer wall of the unit ?
Yes the bottom part is cast and it bashes into that and takes out all the energy before dripping out the bottom.
I'm pretty sure the flow rate decreases with viscosity, as with any load. At some point I'll run some tests with my spare. It pumps cold WVO decent, just makes more noise.
One concern that occured to me last night is the 5110's gerotor may not have enough clearance to handle dirty oil. May need to stick with vane pumps.
Got each of mine off Ebay for about $100. Only a couple a year go for that price tho.
pump- I have an oil pump lying around from a small block chevy... I was gonna use it to make a sucker/filter/filler-upper pump but I went with a hand pump instead.... Do you think this might work if hooked up to a 1/8 or 1/4 horse motor or so? Actually, now that I think of it, my hand powered pump (Tractor supply "stroke" not "crank" type) might just make enough pressure..... Hmmmmm... Don't really want to sit there that whole time but it sure would be cheap to light a wood fire under the 55gal drum and pump it through by hand.... I know the safety nuts on this forum are gonna have a field day with this one, but just remember, what I do on my land is my business, what you do on yours is yours
<1984 Mercedes-Benz 300TD>
Espar Hydronic D5
2 tank, returns to both tanks, backflushing capability
heated dirty tank
holy grail onboard centrifuge