i've read some of this post over time, but maybe i missed something? it was straight wvo? heated? was ps ever used? or any other type? it is a two tank system? thanks for the info
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Remember, we aren't eating this stuff, we're turning it into diesel fuel. Your truck only cares about viscosity, acidity, and BTUs. Nothing else. -unknown?
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NC State law defines biodiesel as ''any fuel or mixture of fuels derived in whole or in part from agricultural products or animal fats or wastes from these products or fats.''
WE have found that contaminants in wvo acidic or corrosive enough to cause any etching are carried by water..since they tend to be water soluble. This coupled with the fact that unless the engine is running this potentialy corrosive contaminant is not in contact with the parts showing the etching. Testing of components such as the injectors inquestions will show that even when exposed to heat and the acidic wvo in question these components will show etching similar to this at exposures of 2,3,or even 10 times as long. Clearly acids are not the culprit...cavitation is.
A microscopic examination of the pits themselves will also reveal that the damage is cavitation casue. Acids tend to create pits with edges which are even or depressed from the surrounding material since they "eat" material away . Cavitaion "craters" have edges which appear raised from the surrounding material since they are litterally "blasted" into the material. A fairly powerful microscope is neede to see this..but is a definative signature of cavitation etching.
Is there some reason you feel that enough pressure differential is not available in this area? Remember that pressure waves can be transmitted through solid metal and manifest themselves as cavitation bubbles at the metal liquid interface if any water is present in fuel. This would tend to explain how cavitation can occurr at places where the expected pressure differential would appear to be too small to cause cavitation on its own.
Please let me know if I can be of further assistance in this. I have found the cavitation phemomenon to be fascinating and have begun to develop a "feel" for how it works and how to prevent it over the past year. At first it appeared to manifest in places it "did not belong" but as I learned more and spoke to researchers in the field I began to understand that ambient pressure might not be as important as the pressure waves often generated by combustion pulses themselves in cavitation instances in fuel components in close proximity to the combustion chamber.
Please let me know if I can be of further assistance.
Thanks you for notifying me of your latest post.
Dana
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1988 F250 SC converted to run dual fuel(Diesel/filtered used fryer vegetable oil) Smells like a Bar-B-Que driving down the road. Chicken one day..pork the next.
Interesting Dana. Helped me to see this possibility a bit clearer. Wish I had one of them to put under a microscope.
The fact that the owners sample separated into layers certainly indicates disimilar materials, with water being a high probability. Plus odds are any water used to clean a fryer probably had caustics or other chemicals in it for cleaning. And if it was caustics it would not likely have reacted with the oil to make soap if disolved in the water. Thus explaining the discoloring of other tested metal as well as the presence of cavitation damage. I'd imagine there is probably enough of a pulse transmitted thru the cap walls from the high pressure pulse internally to create a bubble formation and collapse on the outside. That would certainly explain why the cap is erroded but the cup it is installed in was not.
Makes me want to pull my injectors and get a good look under magnification. I don't have serious free water in my oil, but enough to show some bubbles if I try hard enough...
There are two types of water common in wvo: Free water (large droplets) and suspended water (microscopic droplets).
Free water tends to drop to the bottom of any liquid oil.
Suspended micro droplets of water tend to remain suspended in unfiltered wvo indefinitely. Removing suspended water from wvo REQUIRES filtration to at least 10 microns before attempting to get it to settle out. In several cases suspended water has settled out in fuel tanks resulting in free water showing up in the water separators or filter drains...and owners scratching their heads and saying "Where did that come from?" A few have only discovered they had a puddle of free water in the bottom of their tank when they toasted their IPs. [img]/ubbthreads/images/graemlins/eek.gif[/img]
As more and more are discovering suspended water will also toast their IPs or injectors. But it is a slow process and they usually only discover it when performance drops or their engines fail to start as easily as they "used to" in cold weather.
I have been involved in testing of VO conversion technology for over a decade. My main business is converting fleets of diesel delivery trucks and this has provided a new and larger source of funding for more advanced testing. VO conversion technology is advancing at an ever faster rate. Much of the info that is over 2 years old is outdated as a result...as are most of the conversion kits available.
It must still be considered experimental though.
But I digress.
WVO tends to separate into layers mainly due to lighter oils rising to the top. While these lighter oils (some of the more outdated conversion refer to them as "good oils") do not tend to hold as much water as the more fat laden and hydrogenated oils they hold enough suspended water to significantly decrease the life of fuel injection systems.
Any wvo used for fuel in a diesel needs to be not only filtered to remove particulate contamination it must also be dewatered to remove several other contaminants like salts, sugars, and water soluble acids. Luckily all of these tend to be dissolved in any water present so settling out the free and suspended water removes these as well.
The basic process to settle out suspended water is to prefilter and heat to reduce viscosity but since heating can easily create strong convection currents that will continually remix the settling micro droplets of water some fairly sophisticated equipment must be used to do so. My fleet clients use continuous flow centrifuges for the huge amounts of wvo fuel they use each day. These cost in excess of $10,000. A much simpler unit can be fabricated in a weekend for less than $200 but only prefilters and dewaters around 120Gal per week.
There are folks using Salt or Baking Soda in attempts to remove suspended water. Having tested these methods I know they work poorly for this purpose. They do speed remodel of free water..but this can be accomplished with simple settling as well.
I have also designed and tested vacuum evaporators, "flash" evaporators and other devices that use evaporative techniques to remove suspended water quickly. These methods work to remove water..and are much less expensive than continuous flow centrifuges..but unfortunately leave the salts, sugars, and acids behind in the fuel. And these cause other problems. The biggest being that they are highly hygroscopic and so tend to draw moisture from the air. This can quickly create suspended water in wvo fuel that was dewatered only a few days before.
If you are interested in more info please let me know.
Dana
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1988 F250 SC converted to run dual fuel(Diesel/filtered used fryer vegetable oil) Smells like a Bar-B-Que driving down the road. Chicken one day..pork the next.
Gear_head, the owner of the destroyed injectors, did say that the grease 'smelled a little funny'. In my experience , that almost always means that it's degraded enough to have significant water. ( if the grease doesnt' smell like food, suspect water and both free fatty acids and water-soluble acids).
wow, well out goes my idea to dewater using salt and a home water filter! [img]/ubbthreads/images/graemlins/frown.gif[/img] has anyone tried those silca beads that come in electronic stuff? the stuff that said do not eat? it dries the air so if you put this in with a filter and then flow the oil through it will this help?
but this only matters with running with wvo right not bio? [img]/ubbthreads/images/graemlins/confused.gif[/img]
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Quote:
Remember, we aren't eating this stuff, we're turning it into diesel fuel. Your truck only cares about viscosity, acidity, and BTUs. Nothing else. -unknown?
Quote:
NC State law defines biodiesel as ''any fuel or mixture of fuels derived in whole or in part from agricultural products or animal fats or wastes from these products or fats.''
I may be revealing my ignorance here, but by heating the WVO (after prefiltering), won't we evaporate the water, regardless of convection currents? I'm talking about heating to 150F for several hours.
I have a set of injectors that have stopped working on one of my trucks running WVO. It has run about 500 gallons of a RUG mix first then about 1000 gallons of heated WVO before systematic failure of the injectors. I beleive it is the injectors that failed as the engine lost one cylinder at a time and I could feel each cylinder "drop off" as I drove along looking for an exit to the highway. In the end I had 1.5 injectors working.Using a diagnostic tool I showed no errors. I have good fuel pressure to the engine prior to the final steel lines into the heads. I also have good HPOP oil pressure as read by the diagnostic computer. I sprayed brake cleaner into the turbo intake and cranked the engine over by the starter relay and the engine proceded to run evenly and on all cylinders- I did this for about 1 minute to confirm compression and the engines mechanical operation was not to fault. I have now pulled one bank of injectors and they appear to be somewhat dirty and gummed up some but I am not versed in these injectors at all to read them. What I was wondering was if there is anyone that has experience with the injectors and WVO and have them help diagnose the cause of the failure. Are these injectors able to be taken apart easily? I could not find a D-I-Y on the procedure if there is one. I have bought a used set of take out injectors to replace these with until I can find a cause of the failure so time is not pushing at me terribly to find out the cause. I will not be running on the WVO till I find out the cause for these failures- especially how so many could fail so fast.
Also to explain my system- I have a huge heated 10 micron filter prior to the aeromotive pump, with heated fuel pickup and H-o-H lines from the pickup bed to the engine. I was maintaining 140 degrees for the WVO PRIOR to any of the h-o-h lines and would guess the final WVO temp (at the minimum) is around 170 prior to entry into the stock steel fuel lines.
Any help would be appreciated.
Tony
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2000 CC SRW 6 spd silver, BB turbo, AFE filter cone, intank mod, 4" Magnaflow SS exhaust, DP tuner 6 position chip, Custom Bypass filtering, currently down awaiting newer injectors, Bridgestone Revo's, was running on WVO
1999 Early Lariat CC SRW Green/Brown with BB turbo and newer intake, auto with custom built trans and 5r110 TC, late model radiator and soon to be installed 6.0 trans cooler, AFE intake filter cone, 4" Aluminized exhaust, rotella ELC coolant,DP tuner 3 position chip,Bridgestone Revo's.
I have had good results drying (filtered) WVO in a the same set-up that I dry my finsished washed biodiesel...that is heated to 150-200 and pumped through either a pinched hose or modified lawn sprinkler (to increase surface area). I add a very small fan to move air in the vessel to increase the evaporation of the water. Works pretty well, but takes electricity. Same concept is outlined at www.biodieselcommunity.org
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2000 F-250 Super Cab Longbed
Bright red, they call me "Clifford"
tony--swamp has the offer to send injectors to him that used bio--calll him for details--
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94 f250 idi turbo sc e4od alum fac rims 149,289 --dana 60 frt with posi--10.25 rear w/posi--shouldnt get stuck!! ats turbo 3" parts on--what a diff from stock turbo!!!!!--- also 96 F250 with 305,000 is fixed!!-- 7.3 rattler-also 85 6.9-needs new engine!! tired!!
There could have possibly been some water, but a piece of an injector (not mine) was soaked in the oil that I sent to Swamps for a couple of days. When it went in, it was nice and shiny. When it came out, it was badly etched and discolored. It's possible that there was water in there, but I think there might have been something else.
About the seperation, after sitting on my bench for a few months now in a sealed container, there are 2 definate layers. A nice dark golden, translucent oil layer on top, and a dark, opaque layer on bottom. No free water is present. There might be some, but if so, it's very suspended.
Water soluble acids tend to concentrate in supended (microdroplets of) water in the wvo. Evaporating off some of this water just concentrates these acids even more. Vegoil is very unreactive..but the concentrated microdroplets of acid..are very reactive. Also..as the concentration of acid rises in these droplets they tend to be harder to evaporate.
Dewatering wvo by evaporative means may cause more harm than good. Water ..even microdroplets of water are a bad thing to have in your fuel...but highly acidc microdroplets are worse.
If you must use evaporative drying techniques with wvo fuel mist wash it first to reduce the amount of water soluble acids in it, then dry it. There are simpler less energy intensive ways. Discused on the infopop svo forum.
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1988 F250 SC converted to run dual fuel(Diesel/filtered used fryer vegetable oil) Smells like a Bar-B-Que driving down the road. Chicken one day..pork the next.
as o1 said--anything yet??????? inquiring minds want to know--
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94 f250 idi turbo sc e4od alum fac rims 149,289 --dana 60 frt with posi--10.25 rear w/posi--shouldnt get stuck!! ats turbo 3" parts on--what a diff from stock turbo!!!!!--- also 96 F250 with 305,000 is fixed!!-- 7.3 rattler-also 85 6.9-needs new engine!! tired!!
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