Vacuuming your WMO

[subway]

well i had a thought the other day, i have been heating my oil to try to get the water out and i cant get it much past 160-170 range with the current heater i have in it now. it gets a lot of moisture out but i would be more happy if i could heat the oil to 220 to make sure its all out. i had a thought wondering if we could use vacuum to get the water out. this is done with ac systems, if you pull and hold a vacuum on the the system for a while the water will boil out at room temperature. no need to run a heater on it anymore.....

has anyone tried this? i have a truck vacuum pump but not a true dedicated one for ac work.

 

[chvycmnslvr68]

that would help probably ... but what kind of vac tank would you use ... maybe a propane tank ... i think they would hold vaccum pretty good ... would be interesting to see how it works out for you ... centrifuge looks like the way to go from what i have been reading on here though

 

[subway]

i have a centrifuge but i still try to boil or heat of the water ahead of time. was just thinking it could have the potential to get the water out with less energy and it would be safer that heating the oil. i would probably use a old water heater since they are easy to get. an old propane tank should work just fine to if you could get a hold of one.

 

[Blind Driver2]

The Chinese are using a vacuum on their wmo cleaners.

Or you could try something like this http://utahbiodieselsupply.com/dryingtank.php

 

[gearhead]

if you put a vacuum on water it will boil then freeze so it wouldn't really get rid of it all.if you were to heat the liquid enough to keep the water from freezing then it would all boil out.

 

[Blind Driver2]

if you put a vacuum on water it will boil then freeze so it wouldn't really get rid of it all.if you were to heat the liquid enough to keep the water from freezing then it would all boil out.

how is the water going to freeze?

 

[subway]

i dont "think" freezing should be to much of a problem, even some ice can be tranferred back into a gas at vacuum, according to this chart with 29 inches of vacuum water will boil out at 76 deg F not much trouble to get oil that warm.
http://www.accontrols.com/documents/WaterBoilingPointsatVariousPressures.pdf

might have to break out my thermodynamics book

i am thinking i could incorperate this stage with my super sucker

 

[Brad S.]

Thats a good idea and reminds me of something we did in high school for experiments.
We said we could "boil" water at room temp and drink it. Using a old fashion bell jar vacuum, small beaker of water. When we would put the water under a vacuum all the "air" would bubble out of the water leaving water with little air in it.
Now in regards to water in wmo, not sure how much water would "boil" out, it should take some.

What about using ethanol either in gas (10%) or little bottles of Heet, since your gonna thin it out any way???
Do your normal process of removing water, then use the ethanol as the last step???

 

[chvycmnslvr68]

Thats a good idea and reminds me of something we did in high school for experiments.
We said we could "boil" water at room temp and drink it. Using a old fashion bell jar vacuum, small beaker of water. When we would put the water under a vacuum all the "air" would bubble out of the water leaving water with little air in it.
Now in regards to water in wmo, not sure how much water would "boil" out, it should take some.

What about using ethanol either in gas (10%) or little bottles of Heet, since your gonna thin it out any way???
Do your normal process of removing water, then use the ethanol as the last step???

that would work just keep in mind that water is very corrosive to your injection pump ... It causes micro cavitation in the piston pumps of the injection pump ...

 

[Brad S.]

that would work just keep in mind that water is very corrosive to your injection pump ... It causes micro cavitation in the piston pumps of the injection pump ...

Right, thats kinda why I was thought it(ethanol/gas) would work the best after he'd do everything else to take out the water. Thinking the ethanol would bond or absorb the water and make it "burn" easier. (Like 10% ethanol does for gas engines)
Not being to **** about things, but doesnt normal diesel fuel have certain maxiums for water, etc.
I know underground tanks have water sensors to guard against this kind of problem.

 

[gearhead]

water freezes in a vacuum while its boiling because the heat to make it "boil" is coming directly from the water itself.

the triple point is the point where a substance can be all three phases at once solid,liquid,gas.

the triple point of water is .006 atm(.17 inches of mercury) at .001*C.

to to make all the water evaporate out and not freeze. it would have to be below .17 inches of mercury and remain at a temp higher than .001*c.

the heat of sublimation, the amount of heat a substance looses as it sublimates, of water is 46.7 kj per 18g of water.If the water takes one second to boil(sublime) in a vacuum the power required to keep it from freezing will be 46.7 Kw.

however, you could always pull a vacuum on the oil until all the water froze solid then you could pump the oil out.leaving the ice in bottom.That could get rid of 95% of the water.

 

[crazytwo]

You can use a water heater as a vacuum chamber. When I helped a friend make biodiesel, we pulled a vacuum on the water heater after the process to recover as much methanol as possible.