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A small electric flash evaporator to dewater WVO.
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could it possibly be unremnoved contanination that is causing the plugging at high heats?

have you done any tests with known pure clean oil?


mathematical elegance -- desired result achieved with minimal complication
 
Location: Manchester UK | Registered: June 03, 2003Reply With QuoteReport This Post
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I have not run new oil through the FE but I was originally running the WVO through only after it has been warm-filtered at least 30 times through the bank of filters, smallest being 5 microns. Whatever it is that turns to a solid translusant plastic-like substance at the 300 deg high temps must be liquid at normal temps or is should not have made it through the filtering step. The new approach runs the oil with as little as one pass through the filters(when first starting the filter circulation process). Even though the oil may have only been filtered once (or more) the plugging problem, and the internal plumbing coating problem, so far have been eliminated with using the lower temps.

It may be "gums" that are naturally in plant oil, new oil has a lot of this and has to be processed especially to remove most of it (high steam heat plus a bit of acid process from what I read, makes the gums gell (polimerize ?) and become sticky so they clump together and become large enough that they can be filtered or centrifuged out of the oil). As with all natural material the gums come in a range of slightly different substances, some will react at lower temps than others, I suspect I am finding the higher temp component of these.

Whatever is causing the plasticized bits is a maintanance neusance that has been eliminated by reducing the average processing temp (or the extreme heating element upper temps) . The heater element is turning on about 30% of the time now as the filtered oil is already at about 100 deg f and the FE orifice input temp is now down to around 160 deg f. The FE heater element turns on for about 20 seconds and is off for about 40 seconds so I suspect it's surface temp is not getting nearly as hot at the end of this 20 seconds on/40 sec off cycle as it was when the element was running "on" around 90% of the time.
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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My SUNTEC pump (B2VA-8216) is acting peculiarly. I did Tim's modification. I added a long new thread ("SUNTEC"), but the gist is that the pressure set screw is working backwards. Screwing in should make pressure go up, but when it went to as low as 20 psi I turned it out and it went up to a max of 35 psi. Like I say, there's a more complete thread, but has anyone seen this? No other changes to process.


Mike Goodman
High Point, NC

83 MB 300SD (2 tank) - Greasel
98 Dodge 2500 (2 tank) - Golden Fuels
82 Rabbit Truck (2 tank) - my design) - SOLD
Diesel Craft CF process in enclosed shed
BD first batch 9/23/12, still going ..
6-4x10 solar hot water panels and 500 gallon wood-burning water stove
2.8 kW PV grid-tie w/batt b/u commissioned March 2011
 
Location: High Point, NC | Registered: September 30, 2005Reply With QuoteReport This Post
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I received this e-mail from Dale Hunsberger (Suntec). He suggests not using the B2VA-8216 (2-stage) pump. but instead using the A1VA-7112 single-stage pump. Mr. Hunsberge describes an adjustment to the 2-stage pump if yours is experiencing the loss of pressure that mine has suffered. Hope this helps.
_ _ _ _ _ _ _ _

Mike

Per our phone discussion I recommend you try an A1VA-7112 which is set for 1725 rpm operation and will give you roughly double the flow. There is no problem if you wish to run at a higher speed.

For your B2VA-8216 I recommend:
a. turning the cone valve screw (in the angled boss oposite the bleeder....need to remove plastic plug first) full in CW. This will be much better for 1725 rpm.
b. aligning the gearset by slightly loosening the 3 screws, bias the plate next to the body gently from 5 to 11 o'clock, then gradually tighten the 3 screws.

Dale


Mike Goodman
High Point, NC

83 MB 300SD (2 tank) - Greasel
98 Dodge 2500 (2 tank) - Golden Fuels
82 Rabbit Truck (2 tank) - my design) - SOLD
Diesel Craft CF process in enclosed shed
BD first batch 9/23/12, still going ..
6-4x10 solar hot water panels and 500 gallon wood-burning water stove
2.8 kW PV grid-tie w/batt b/u commissioned March 2011
 
Location: High Point, NC | Registered: September 30, 2005Reply With QuoteReport This Post
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Tim,
I love the idea and it sounds extremly intresting.
I just joined so sorry for all the late replys. I read the entire thread and have a few questions and ideas.

You have said many times once the process is up and running you don't see much if any steam. Steam is a almost invisable gas. You do not see steam you see water condensation in the air that has not percepitated. Think about a factory steam stack. You see a gap out of the top then the head of vapor. That is why you're not seeing the actual steam as the unit gets up to heat.

In your cool temp unit you are not seeing steam, it is just water vapor that is being released. Because there is no steam is why it takes multiple passes to remove everything.

Can you give me more detail on cold flow of oil before FE, after high temp FE, verses low temp FE?The polemerzation might be a good thing by lowering the cold flow point.

I think a critical part of removing water will be to get the steam out of the spray chamber before it condenses. The best way to do that is get the chamber hotter or reduce the pressure.

If you run your preheat the through the oil in that chamber it will lower the temp and any wet oil that falls in will absorb the water. Try to put your preheat in the dry hot oil coming out of the spray chamber.

I also think the blower is introducing pressure(less then 1" water colum) and cool air. You should move the blower to pull a suction on the vapor condensation tank. Then block the inlet you had it on. That will cause a vacuum of 3-4" Water colum. it will keep the air in the spray chamber hotter and as the water turns to steam volume at 1200-1600 times it's wet volume it will be sucked through the system and not condense. I would put water in the bottom of the condensation tank and make the vapor tube travel below that level. as the vapor passes through it will recondense. That water can be your oil preheat then into your hot dry oil to get even more energy recovery. That will also keep that water from boiling off or evaporating as it builds heat.

To make your oil and or water drain in this setup. I would use a small pipe and raise the tank high enough(less than 1 foot) that the oil weight and weight will overcome the vacuum and allow it to drain. A small needle valve will adjust flow rate so you don't drain the oil too fast and suck air. You could use a manometer on the closed system to see total vacuum and calculate to see the exact height. Or you can use oil in it to avoid calculating the heigth needed. You might try to get a spring loaded cap that can be adjusted. As the fluid heigth raises it builds pressure and the cap opens releasing fluid it would need to be a very light spring but would make it completely self substaning. The bigger diameter your drain pipe is would apply more pressure and allow this function to be much more accurate and easier to setup.

I have no experiance with polmerization. Do you know someone who could do a biodiesel titration for you. It might be Free Fatty Acids that are solidfying and pluging your filter. Or the heat and pressure could be releasing glycerine. A before and after would be real nice if you could manage that. G. Mark maby you could help?

Maby heating a tank of oil(3-5 gallons)is a better solution to the element on off problem. The emement can be run at a lower steady temp and the amount of heat transfer coil or the flowrate of the oil could change, but it would buffer the dramatic heat changes in the oil outlet from element on to element off. It would also make your cycling switch last much longer. You could use a Volume tank and use FE oil to fill it then give some air pressure(50psi) and a gauge. You know if there is a leak becasue you loose air pressure and the pressure would buffer any volumic changes of the oil. It would also allow for some residual water to steam without a dramatic change. If there is still polemerzation then you might have to find another fluid that won't polomerize at that temp.

I'm not crisitising, but personally think one thing stated is just wrong in this discussion so please don't take this the wrong way. Vegetable oil has a specific heat of approxiamtely 0.46. I use 0.5 just to be safe. To my understanding that Means it takes .46 BTU to heat 1LB of Vegetable oil 1 degree Fahrenheit.
When the oil is moving through the FE it takes half the energy to get to temp as the same volume of water would take. As it passes the heating element the whole mass heats up and by the time it reaches the temp probe the temp should have equalized. The water then has all the heat it needs to fully turn to steam if it is over 212 degrees F. Idealy higher because of the boiling point changeing in a mixture and the cooling as it goes through the system. If it did not have the energy to turn to steam it would not need the pressure to keep it liquid. When it leaves the orifice it esentialy goes through explosive decompression(for lack of better terms). When this happens the drop in pressure causes rapid cooling. It is the same bases of a Air condetioning system. Most people here should be able to relate it to a Oxy Acetelyne cutting, after 15 min of cutting the regulators are cold and have condensation dripping off.

The reason for the tempeture drop is not the water removing heat so it can form steam, It is the rapid pressure drop that causes the temp to lower.

Lastely I know it's probably stupid of me to ask, but when shutting down have you tried turning off the Heating Element and letting the oil flow until the outlet temp is the same as the inlet.

Logan Vilas
 
Registered: January 01, 2007Reply With QuoteReport This Post
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Logan -- welcome --

Steam --

quote:
You have said many times once the process is up and running you don't see much if any steam. Steam is a almost invisable gas. You do not see steam you see water condensation in the air that has not percepitated. Think about a factory steam stack. You see a gap out of the top then the head of vapor. That is why you're not seeing the actual steam as the unit gets up to heat.

In your cool temp unit you are not seeing steam, it is just water vapor that is being released. Because there is no steam is why it takes multiple passes to remove everything.


This seems reasonable as the oil does end up being dry (or drier) even when there is no visable steam. The fact that a cool mirror will condense water droplets even when there is no other visable indication of water vapor would seem to support this.
------------

Cold flow --

quote:
Can you give me more detail on cold flow of oil before FE, after high temp FE, verses low temp FE?The polemerzation might be a good thing by lowering the cold flow point.


The oil that has been through the FE will stay liquid to a much colder temp than the same oil that has not been through the unit, no exact numbers as this is simply an observation from moving around 5 gallon jerry cans of oil. Oil that has NOT been through the unit will turn translucent beigh in color and become thicker at 40-50 deg f and pasty thick around freezing, the upper 2/3 of a can of oil that has been through the FE will stay dark liquid and slosh in the can down to as low as 15 deg f, The bottom 1/3 will be translucent beigh, I atribute this to being a mix of hydrogenated oil and/or animal fat. The upper liquid oil thickens as the temp falls but It usually still pours to even lower temps.
I have attributed this to eliminating the water that can turn into ice crystals and make the oil into a "slushy", no actual proof of this but it sounded good.

I dought this has to do with polimerization as I define it (drying like paint) as the amount of thickened drying oil that I see associated with the FE unit is miniscule compared to the amount of oil being dried, several thousand gallons of oil has gone through the unit and the thickened oil coating the inside of the hoses, filter, and valves etc would maybe total a quart.
-----------------------

Vapor removal --

quote:
I think a critical part of removing water will be to get the steam out of the spray chamber before it condenses. The best way to do that is get the chamber hotter or reduce the pressure.

If you run your preheat the through the oil in that chamber it will lower the temp and any wet oil that falls in will absorb the water. Try to put your preheat in the dry hot oil coming out of the spray chamber.


I don't have any problem with water condensing in the flash chamber once the unit is up to temp, at startup I open the bottom drain from this tank and run the unit til approx 1/2 gallon of oil has exited the tank before closing the drain valve, this insures that the dryed oil, as well as the flash tank, are hot enough so as not to cause condensation.

The flash tank holds approx 1/2 gallon of oil directly below the flash orifice so the oil in this tank is above the boiling point of water when running the unit at 300 deg. The dry oil outlet from this tank is not simply a hole in the side of the tank, there is a dip tube that runs down inside of the tank to within 3 inches of the bottom, for the oil to exit the tank it has to travel down to the entrance of this tube and then up the tube to the outlet, for any oil to exit this outlet the top of the oil level in the tank must be at the same height as the outlet opening, this insures only oil, rather than steam (or water vaper), will exit the dry oil outlet. Even when running the unit at the lower temps I don't find any condensation in the flash tank as long as I pre-heat it.
--------------

Input oil preheater --

quote:
If you run your preheat the through the oil in that chamber it will lower the temp and any wet oil that falls in will absorb the water. Try to put your preheat in the dry hot oil coming out of the spray chamber.


Sounds reasonable, haven't gotten around to adding the preheater yet. I would not expect this to be a problem running in the high-temp mode as the oil will not be wet, the water vapor should have all been removed through the orifice and swept from the chamber. It could be a problem when running at the lower temps, future testing here.
------------------

Removing vapor from flash tank --

quote:
I also think the blower is introducing pressure(less then 1" water colum) and cool air. You should move the blower to pull a suction on the vapor condensation tank. Then block the inlet you had it on. That will cause a vacuum of 3-4" Water colum. it will keep the air in the spray chamber hotter and as the water turns to steam volume at 1200-1600 times it's wet volume it will be sucked through the system and not condense. I would put water in the bottom of the condensation tank and make the vapor tube travel below that level. as the vapor passes through it will recondense. That water can be your oil preheat then into your hot dry oil to get even more energy recovery. That will also keep that water from boiling off or evaporating as it builds heat.


Sounds good - but I have found trying to remove vapor from tanks using vacuum just does not work all that well, it takes a high vacuum to draw the molacules from all sections of the tank and it takes time for these molacules to actually move to the tank outlet, may work better here as there is a constant new influx of water vapor being injected into the tank, don't know.

The cross-flow air concept seems to be working OK for now, I had intended to draw the crossflow air from around the heater pipe to preheat the air before injecting it into the flash tank but never got to it, it seems to be working ok with just ambiant air, at least in the high-temp mode. Running in the low temp mode requires several passes anyway so I don't think all the extra problems with getting the dry oil out of a chamber under vacuum is worth the trouble just now, may be a future refinement (dought it though - centrifuge filtering/dewatering looks like an easier approach to all this).

Water in bottom of flash chamber -- I think this defeats the purpose, don't want to add water to already dry oil ?
--------------

Polimerization --

quote:
I have no experiance with polmerization. Do you know someone who could do a biodiesel titration for you. It might be Free Fatty Acids that are solidfying and pluging your filter. Or the heat and pressure could be releasing glycerine. A before and after would be real nice if you could manage that. G. Mark maby you could help?


I have done the titration tests, mine are not sensitive enough to show any differance between the "goes in" oil and the "comes out" oil.

Glycerin --

Don't think the problem is glycerin as I suspect hot glycerin should re-melt and go through the filter ? could be wrong here.

I realy suspect that it IS polimerization plugging the high-temp filter as this filter is located directly AFTER the heater element, I know the heater element throws off small pinpoint-to-pinhead sized chunks of something plastic-like, calling it "polimerized" may be wrong, it may actually be "vulcanized" ?
---------

Heater element --

quote:
May be that heating a tank of oil (3-5 gallons) is a better solution to the element on/off problem. The emement can be run at a lower steady temp and the amount of heat transfer coil or the flowrate of the oil could change, but it would buffer the dramatic heat changes in the oil outlet from element on to element off. It would also make your cycling switch last much longer. You could use a Volume tank and use FE oil to fill it then give some air pressure(50psi) and a gauge. You know if there is a leak becasue you loose air pressure and the pressure would buffer any volumic changes of the oil. It would also allow for some residual water to steam without a dramatic change. If there is still polemerzation then you might have to find another fluid that won't polomerize at that temp.


Bulk buffering heating tank --

A buffering bulk heating tank would likely work, girl Mark indicated she was going to try this approach, havent read any conclusions on how that went.

Running the heater at a lower steady temp is the way to go but you need to select the physical size and surface vollume of the heater to match your flow rate to get an efficient transfer, not practical if trying to use off-the-shelf water heater elements.

Cycling switch - Not a problem wnen using a solid state electronic temp sensor and power switch.

air pressurized tank -- This can be done but I feed the FE directly from my open-toped filter tank setup, this eliminates the extra step of transfering the oil to a pressure tank and everything runs continuously without needing my physical presance.

Find another fluid -- Don't understand this statement, sort of stuck with the working fluids of vegoil and water.
----------------

vegoil heat transfer --

quote:
I'm not crisitising, but personally think one thing stated is just wrong in this discussion so please don't take this the wrong way. Vegetable oil has a specific heat of approxiamtely 0.46. I use 0.5 just to be safe. To my understanding that Means it takes .46 BTU to heat 1LB of Vegetable oil 1 degree Fahrenheit.
When the oil is moving through the FE it takes half the energy to get to temp as the same volume of water would take.


From what I have read it actually takes TWICE the heat for oil as it does water rather than half the heat, I think this has more to do with how FAST the oil will ABSORBE heat rather than the AMOUNT of heat. "time" and "amount" are sort of "inverses" of the same thing here.

Heat VS pressure --

quote:
The water then has all the heat it needs to fully turn to steam if it is over 212 degrees F. Idealy higher because of the boiling point changeing in a mixture and the cooling as it goes through the system. If it did not have the energy to turn to steam it would not need the pressure to keep it liquid. When it leaves the orifice it esentialy goes through explosive decompression(for lack of better terms). When this happens the drop in pressure causes rapid cooling. It is the same bases of a Air condetioning system. Most people here should be able to relate it to a Oxy Acetelyne cutting, after 15 min of cutting the regulators are cold and have condensation dripping off.

The reason for the tempeture drop is not the water removing heat so it can form steam, It is the rapid pressure drop that causes the temp to lower.


I think this is sorta true but not the complete story. This is based on changing a fluid into a vapor, it takes heat to do this, don't think pressure comes into it. Not sure really, I have asked sort of the same question here when posting about low-temp dewatering, can pressure do it alone, so far heat and pressure works better than heat -OR- pressure ??

"mushmoo" gave a convincing explination about "latent heat of vaporization" in the middle of the second page of this discussion, convinced me.
------------

Shut down procedure --

quote:
Lastely I know it's probably stupid of me to ask, but when shutting down have you tried turning off the Heating Element and letting the oil flow until the outlet temp is the same as the inlet.


This is my general method of shutdown, I don't actually measure the temp, I just run everything for an additional 1/2 hr or so before pulling the plug.
--------------

Thanks for taking the time to read the entire discussion and ponder the concept, build something to test and add your findings.


Cold temps have sort of slowed any oil processing, mostly just collecting and storing now. I haven't yet got the heated fuel system completed so I am back to straight diesel in the truck til warm weather. All my filtered oil is being burnt for house heat, I have not been dewatering this oil and it seems to be working just fine making fire without it. More testing next spring..
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post



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Tim

Removing vapor from flash tank --

quote:
The cross-flow air concept seems to be working OK for now, I had intended to draw the crossflow air from around the heater pipe to preheat the air before injecting it into the flash tank but never got to it, it seems to be working ok with just ambiant air, at least in the high-temp mode. Running in the low temp mode requires several passes anyway so I don't think all the extra problems with getting the dry oil out of a chamber under vacuum is worth the trouble just now, may be a future refinement (dought it though - centrifuge filtering/dewatering looks like an easier approach to all this).

Water in bottom of flash chamber -- I think this defeats the purpose, don't want to add water to already dry oil ?



I understand the vacuum problems, but just personally think pulling the air through the outlet will work beter. I'll try it and let you know. Blowing into the chamber will cause the air to become turbulant and move all around. A suction would cause the air to move from inlet to outlet right across the splash plate and would probably move the vapor better.

---------

Bulk buffering heating tank --

quote:
air pressurized tank -- This can be done but I feed the FE directly from my open-toped filter tank setup, this eliminates the extra step of transfering the oil to a pressure tank and everything runs continuously without needing my physical presance.

Find another fluid -- Don't understand this statement, sort of stuck with the working fluids of vegoil and water.


I meant adding air pressure to the bulk buffering tank. Just in case your oil wasen't completely dry.

If polomerization became present in the bulk buffering tank because of Heating element surface heat you might be able to find another fluid to solve that problem. Even if you used water under 175-200 psi it might solve that problem. WATER COULD BE VERY DANGERIOUS THOUGH.
----------------

vegoil heat transfer --

quote:
From what I have read it actually takes TWICE the heat for oil as it does water rather than half the heat, I think this has more to do with how FAST the oil will ABSORBE heat rather than the AMOUNT of heat. "time" and "amount" are sort of "inverses" of the same thing here.


I called a chemist at Oil Center Reaserch www.oilcenter.com about this one.
Specific Heat works like Specific Gravity. The Specific gravity of gold is 19.1 the specific gravity of biodiesel is about .86, glycerine 1.26. When you have volume of water and equal volume of the other material the water weight multiplied by the specific gravity is the weight of the other material.
Specific heat is based on the AMOUNT of energy it takes to heat the water. If you are heating 5 gallons of oil at 7.6 pounds per a gallon it will take 17.48(38x.46) btu to heat it one degree. That equates to 5.14(17.48/3.4) watts for 1 degree. If you are getting 1100 watts from your heating element over the course of 1 hour for 5 gallons you will get an average of 214.01(1100/5.14) degree temp rise. Obviousely you have water also which will lower that number and a little heat loss overall.
I have no clue about the thermal transfer rate of the oil. I do know a very little about thermal transfer rate of metals though.

Heat VS pressure --

quote:
I think this is sorta true but not the complete story. This is based on changing a fluid into a vapor, it takes heat to do this, don't think pressure comes into it. Not sure really, I have asked sort of the same question here when posting about low-temp dewatering, can pressure do it alone, so far heat and pressure works better than heat -OR- pressure ??


I am not sure on this one either. I just think it is getting the energy to turn into vapor from the heating element. That is the reason you apply pressure to keep it from vaporizing. I could be extremely wrong though.
----------

Sorry to hear you have to loose out becasue of the cold. I'm in louisiana so it's cold to me if it gets below 60F.

Logan
 
Registered: January 01, 2007Reply With QuoteReport This Post
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I have two Shurflo pumps: 2088-422-444 that could work well as a portable FE. One is new in box and the other is new with the exception that I've defeated the pressure cut-off switch. I mounted it for use in a Flash Evap, but never hooked it up.

http://www.shurflo.com/pages/RV/rv_categories/potable_w...tableWaterPumps.html

PERKHOUSE has run his pump at 80-100 psi on a single orifice FE, if I recall, for extended periods by cutting out the pressure switch, with no problem. I've simply decided to stay 110V.

Label says $59, but these go for $63 at http://www.bigdiscountrv.com/waterpumps_shurflo.htm

I will sell one or both at $55 (each) plus shipping, say $10 for one and $13 for two, (cheapest USPS). Payment by cash or money order.


Mike Goodman
High Point, NC

83 MB 300SD (2 tank) - Greasel
98 Dodge 2500 (2 tank) - Golden Fuels
82 Rabbit Truck (2 tank) - my design) - SOLD
Diesel Craft CF process in enclosed shed
BD first batch 9/23/12, still going ..
6-4x10 solar hot water panels and 500 gallon wood-burning water stove
2.8 kW PV grid-tie w/batt b/u commissioned March 2011
 
Location: High Point, NC | Registered: September 30, 2005Reply With QuoteReport This Post
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Tim,

I have played around with aluminium sand casting a bit, do you think a Heating element cast into an aluminium rod would lower the heat density of the entire rod for working with the flash evaporator? What is the maxium temp that heting elements can take? it takes about 1200-1600F to get the aluminium to flow thouroughly and fill every crevice. If the heat transfer rate was not high enough then I could use copper or brass, but the pooring temps on them is much higher. more in the range of 2600f.

Loan Vilas
 
Registered: January 01, 2007Reply With QuoteReport This Post
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I am soooo disappointed. It seems mcmaster no longer has the $12 nozzle heaters. They start at $39 now. I guess I missed my chance at this. Frown
 
Registered: December 04, 2006Reply With QuoteReport This Post
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Tim,
I've been operating my FE at about 225F and 175 psi since last fall with good results. I've also insulated my evaporation tank to reduce the risk of condensation.

But the main thing I've noticed is that I haven't had any polymerization and my nozzle hasn't clogged once since lowering the temp and raising the pressure.

Rkpatt,
I know it's been almost a full year since your request, but I'll try to get some pics posted soon.


Brian

2000 Jetta TDI
1982 Mercedes 300D Turbo
1986 Isuzu P'up (NA)
1985 Mercedes 300D Turbo
75/25 WVO/D2 for warm weather
50/50 WVO/D2 for cold weather
Uniqueness is a treasure not to be buried. - Laurence Martel
 
Location: High Point, NC | Registered: May 04, 2006Reply With QuoteReport This Post
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Perkhouse -- That is great to hear, I also have been running at a lower temp of around 225 deg f but at the same 150 pounds pressure, and having much less problems with orifice plugging, still plug the orifice once out of 4-5 cold startups even though I let the unit run while the heater cools down? I recently had my temp controller malfunction and turn the heater full-on over night, did a number on the FE and also left about an inch of toasty crispies in the bottom of the filter barrel and the condensing chamber, also scorched all the paint off the outer steel insulated heater housing, and crudded up the inside of all the plumbing, still have not got it back in operation.

I needed to de-water a couple barrels of oil that had been mixed with a few percent diesel and gasoline, I didn't think it wise to run this through the FE so I made up a version of Johno's "bird waterer" dryer using an electric shillet, burnt up the thermostat the first night so wired the 110 volt 1250 watt heater direct so it is on continuous, and adjusted the flow to keep from overheating the oil. ran this continuously for 3 days while circulating the oil through the filters, a portion of the oil was passed over the skillet dryer. LOTS of bubbles for the first day but no bubbles by the last day, worked better than I was expecting, also a LOT easier to clean the teflon skillet than the FE. I placed some 3/8 square steel keystock pieces in the bottom of the skillet so the oil had to take a zig-zag path, in total, the oil travels 22 inches back and forth across the skillet.

I had been running the 225 deg FE for several days continuous also, to insure complete de-watering, so the electricity used is about the same. Sort of hate to admit it but the electric skillet is a LOT less hassle and way easier to clean, sort of makes me wonder if it is worth the hassle going back to the much more complicated FE, since, because of the reduced temps, I had to also run it continuously for days to insure all the water was removed from the oil. The skillet won't allow as much oil to be heated in each pass as the FE but it has been getting the job done over the 3 days that I normaly circulate the barrel of oil through the filters, so no time is lost.

What size output oriface are you using on your unit, do you pass the oil through it more than once?

I have been testing Suntec pumps for use as vehicle lift pumps and vegoil home heater fuel pumps, I find that a somewhat modified 3450 RPM rated suntec pump will move about 11 G/H of hot oil when turning the pump at 1600 RPM using a 24 volt DC sidewalk scooter motor on 12 volts. this will allow me to double the flow through my FE from 5 G/H to 10 G/H when I get it put back together. This higher flow rate should allow the 1125 watt (220 volt heater powered by 110 volts) to be wired to run continuously and not overheat, this will allow me to remove the temp controls completely and eliminate the possibility of another failure of it. hopefully the 50% larger diameter of the orifice will also reduce, or eliminate, the orifice plugging problem.

By running the oil through a continuously-on heater the oil in the insulated 50 gallon filter barrel slowly increases in temp but not to the point of being a problem, even in 90 degree ambient outdoor temps. The oil going into the frypan dewaterer was about 165 - 175 deg f, oil going out of the frypan was 240 - 250 deg f, it then runs back into the top of the barrel and gets recirculated. The 175 degree oil has not caused any problems passing through the Shurflo 12 volt diaphragm pump or the Omnifilter whole-house water filters.

Looking seriously at the Dieselcraft centrifuge setup to replace my current entire filter/dewater unit, it appears to be able to clean and dewater a 50 gallon barrel of oil in about 4 hours as compared to my current 72 hour process. A 3 G/H shurflo pump should be able to power the pressure-powered centrifuge directly and since I already have electric heaters in the barrel I can simply turn the thermostat up to 150 deg f rather than the current 90 deg f. The 4 hour time period will reduce the electricity needed to clean and de-water the 50 gallons by a HUGE amount. Running a 1200 watt heater continuously for 72 hours is now costing me 7-8 dollars to de-water the 50 gallons, 4 hours through the centrifuge would cost less than a dollar. I will still do my current water/baking soda washing of the oil, followed by at least a week of warm settling to allow the BS time to do it's thing, and for the bulk of the particulates to get heavier by absorbing water and drop to the bottom, then the almost clean settled oil, from above the soap and water layer, will get moved into a seperate barrel to circulate through the centrifuge.
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post



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quote:
Originally posted by Tony from West Oz (The Wizard of Oz):


With vegoil which is suspected of being wet, get some biodiesel byproduct (glycerol) and mix in around 10% of byproduct into the vegoil. This should absorb the water and settle to the bottom of the vessel.
The dry vegoil should be able to be decanted from the top of the glycerol. This seems to remove many solid contaminants as well.
Be sure to check before and after this process, to see how well it works for you. I have been told that it also causes the high MP oils to be retained with the byproduct.

have a few ques
if the glycerol being mixed in wwo to be dried is effective then why in the biodesel making steps do they dry it at the end with drying nozzles
i just ordered some from utah biodesel when using them to dry i guess they say around 40 psi i plan on using two tank method let settle then pump from 1/4 way up of a 250 gal bung plastic thing with metal cage ! then pump into another one with top cut off with another one attached to the top with the bottom cut out to help contain every thing

what my main question is in all this is how or where does the water go does it mist out into the air or does all these process cause the oil not to emulsify and make it go to the bottom of the tank or evap out into the air ! if it goes and separates out into the air what keeps it from acquiring back onto the sides, or is this the point then it settles to the bottom if so seems to be back where you started

hope my question make sense just trying to understand and learn what and how these ideas work of water removal !

i am building a smudge pot design 55 gal drum and experimenting with spraying oil into that to see if i can heat and water remove at same time with no elect !


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Location: airzona | Registered: June 04, 2005Reply With QuoteReport This Post
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Other methods:
I thought about doing the centrifuge idea too, but didn't like the idea of multiple passes. My FE is still doing a single pass reliably. I don't like the frying pan idea because it's an open design. My system is (almost) totally enclosed. (It's not totally airtight though - the wet-oil tank and the storage/filter tank are both vented and the fan intake is filtered to keep bugs and dust out.) The whole setup is inside my garage so it's critical that the vapor is pushed outside.

Bash plate:
I never actually made a bash plate. I'm just using the side of my evaporation tank along with a 45 degree 1/4" npt adapter just before the orifice.

Orifices:
My orifices are 0.016" (McMaster #2712T578)

What size will your new orifice be? I was running 2 orifices at one time, but because I was having pressure regulation problems, I discontinued that. Unfortunately, the problem continued after I went back to a single orifice. It turned out that the problem was unrelated to the higher flow rate though, so I may put that 2nd orifice back in. The pressure problem was twofold: the cork gasket was leaking, so the pump was sucking air AND the pump couldn't lift the oil very far. I replaced the cork with Buna-N and lowered the relative height of the pump to the wet-oil tank. The problem is gone.

Lesson learned: Most pumps push a lot better than they pull!

Completed enhancements:
I also added hydraulic hoses with valved quick couplers. (Btw, I have some couplers for sale with/without valves.) Sure makes disassembly a breeze - and a lot less messy!

Future:
Install a pressure switch and a relay or two, so that if the pressure drops below 100 psi, the whole system will shut down.

After reading about your recent problem, I'm also going to install a thermal breaker from a water heater (has a red reset button) at the top of the heating chamber.


Brian

2000 Jetta TDI
1982 Mercedes 300D Turbo
1986 Isuzu P'up (NA)
1985 Mercedes 300D Turbo
75/25 WVO/D2 for warm weather
50/50 WVO/D2 for cold weather
Uniqueness is a treasure not to be buried. - Laurence Martel
 
Location: High Point, NC | Registered: May 04, 2006Reply With QuoteReport This Post
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Hi Perkhouse
I was interested in your fe design I am waiting for a drying nozzle from utah bio-diesel is that a good one to use !
Also what is a good cheap pump maybe with a cut off sw ?
Does your system pump in air and exhaust it to remove air ?
Does does drying with a flash evaporator require to be open to the air or will it work in a enclosed 250 gal bung
thanks phil


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Location: airzona | Registered: June 04, 2005Reply With QuoteReport This Post
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I can't take any credit. Everything I've done I learned on this thread and through much trial-and-error. I'll post pictures and a diagram soon.


Brian

2000 Jetta TDI
1982 Mercedes 300D Turbo
1986 Isuzu P'up (NA)
1985 Mercedes 300D Turbo
75/25 WVO/D2 for warm weather
50/50 WVO/D2 for cold weather
Uniqueness is a treasure not to be buried. - Laurence Martel
 
Location: High Point, NC | Registered: May 04, 2006Reply With QuoteReport This Post
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PerkHouse -- Single pass -- your oil must be drier than mine to start with, once I lowered the heat to 225 deg f at 150 pounds pressure my oil is not completely dry after only one pass,it takes several passes, I just let it run for the same amount of time as I run the filtering process, usually 3 days. I have the Suntec pump's pressure control set to max but can only get about 165 pounds pressure turning it at 1600 rpm, I will have to change to a faster turning motor to get the pressure higher.

I don't remember just what pump you are using, if it is a Shurflo, they don't suck oil well at all, the one on my filter setup, that I was originally using for the FE, is located several inches below the bottom of the barrel, works fine there as it stays flooded by gravity.

Bash plate - the side of the tank would work fine, just never thought of it.

Orifice diameter -- From memory, I have been using an .018 oriface, getting 5.25 G/H flow rate using 150-160 pounds pressure, I will move up to a .028 size as I have that on hand. Doubling the diameter of the oriface will increase the flow 4 times, increasing the diameter by 50% will double the flow, the .028 is a 50% increase so I shopuld get about 10.5 G/H flow from it.

I have been using a Suntec fuel oil pump for the FE for the last year, this is a cast iron based true gearotor style gear pump and handles the heat and pressure better than the plastic Shurflo. I have not had any of the aggrivating problems that I had with the Shurflo, no screw loosening, no pressure cutoff switch leaks etc.

I am testing these Suntec pumps to use as vehicle lift pumps, home/shop heater fuel metering pumps etc. I am about to do flow testing of stock 1725 and 3400 RPM pumps, then I will make several flow improvement modifications and re-test them, I will start a new thread about this once I have the data. There is some info about my preliminary testing starting on page 11-12 of this discussion, and more recent info (with pictures) in the "reliable electric lift pumps for svo" discussion (HERE).

The Suntec will suck fuel to at least a 6 ft height, I have the FE and the pump setting on the plywood cover over the filter barrel and draw the oil from an outlet at the bottom of the barrel, no problems.

Safty pressure cutoff switch -- I added this to my FE after having the local power go off, then back on, while I was not around. wanted the unit to stay off til I could properly restart it. I used a standard air compresser pressure switch as the sensing element. Unfortunatly, the contact closure on these is just the reverse of what is needed for a pressure safty switch. An air compressor pressure switch makes contact until you reach the preset pressure, then opens the contact, for a safty switch you need it to make contact once you reach the preset pressure. I used the pressure switch contacts to control a power FET transister to power the motor, and another tiny signal relay to shut down my temp controller on the heating element. This has saved a lot of possible problems by shutting everything down, a couple times due to power failures, a couple times due to the pump intake hose getting plugged, a couple other times for unknown reasons?

The picture below is an end view of the pump unit, the pressure switch is the green box on top, both the power transister and the small relay are mounted inside this box. The beigh box mounted on the side of the green box is just a standard modular telephone jack, this allows me to use a normal telephone coily-coard over to the heater control, this makes it easy to unplug the two units for disassembly. The momentary red button turns everything on so the motor runs and can make pressure, once the pressure switch clicks you can let go of the button, only takes a couple seconds for the pump to make pressure. The red indicator light just lets me know from a distance that the unit is running normally under pressure.

ImageFE_pump_with_poressure_switch_-_end_view_.JPG (81 Kb, 50 downloads)
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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This is a side view of the Suntec pump/motor combination.

ImageFE_pump_with_pressure_switch_-_side_view_.JPG (96 Kb, 52 downloads)
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post



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ConfusedI have a dumb question I guess ? In your evaporation tanks are they open to the air or enclosed if so how or where does the water go? How does the water disappear by this process trying to understand sorry! Been reading for some time now trying to get the concept here ! thanks for any ones input on my ques


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Location: airzona | Registered: June 04, 2005Reply With QuoteReport This Post
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Philman,
Mine is enclosed. Well, sorta... I have a fan forcing air through woven landscaping cloth down through some black corrugated drainage pipe (for landscaping) going into my evaporation chamber. Which by the way, is quite a bit larger than Tim's - his is a fire extinguisher body, mine's a 16 gallon Penzoil barrel - no particular reason except I got the barrels for free. Then out of the top of the barrel, I have a piece of flexible corrugated vacuum cleaner hose (not quite as big as shopvac hose, but close) going out through the side of my garage.

Tim,
Yeah, I made the switch over to a Suntec pump last year too. I got one of the 2-stage pumps, so that's probably why I can get such high pressures easily.

lift problem:
I think it was mainly due to the cork seal leaking so much suction, but the homemade Buna-N/Nitrile gasket has been working like a charm! (I just laid the cork gasket on top a sheet of 1/16" Buna-N and traced it with a Sharpee. Then went to work with a new Exacto blade.)

Orifice:
The only concern I would have about doubling the diameter of the orifice is that you'd also double the diameter of the stream and possibly risk trapping moisture in that stream. I'd be more inclined to use multiple orifices. But test away and let us know!

Compressor cutoff switch:
Yes I have one of those and I figured I could make it work by controlling a SPDT relay with the contacts.
closed sw contacts = energized relay -> open relay contacts
However, SurplusSales has a brake light switch with 1/8" npt for $3 that closes it's contacts at 100psi, so I might just order one of those and put it on a Tee at the top of my heating chamber with my pressure gauge.

Pictures:
Your setup looks a lot like mine, but my motor/pump bracket is a lot more flimsy and my motor is a 1/3hp. (It looks like yours is about 1/6hp?) I got the metal shop class at school to make it and the steel they used was too light weight so the motor causes the frame to distort its shape. That wouldn't be so bad if I had used the same high tech coupler you did. Wink But, I spent the $6 or so and got a spider coupler since the shafts are different diameters. So anyway, I have to use a chain and turnbuckle to adjust the amount of distortion in the frame. It's a hassle I hope to remedy eventually, but not high on the priority list right now.


Brian

2000 Jetta TDI
1982 Mercedes 300D Turbo
1986 Isuzu P'up (NA)
1985 Mercedes 300D Turbo
75/25 WVO/D2 for warm weather
50/50 WVO/D2 for cold weather
Uniqueness is a treasure not to be buried. - Laurence Martel
 
Location: High Point, NC | Registered: May 04, 2006Reply With QuoteReport This Post
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