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A small electric flash evaporator to dewater WVO.
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I also am concerned about the possibility of igniting the oil, that is why I am trying to stay away from any type of actual "spray" nozzle. A streight pinhole produces mostly a stream of oil without the fog of a spray nozzle. If a ball valve allows dewatering I think a stream should also work. The flash evap chamber will be mostly sealed to the outside world, oil will be expelled through a gooseneck type oil trap that is several inches under the surface of the oil and will be under a bit of pressure from inside the chamber. The other output will be steam/oil vapor from the top of the flash chamber, this could be a problem as the steam can react the same as air, only again, this steam is contained inside a conduit and the steam will be routed into another sealed chamber and exit below the surface of water that has condensed from the steam.

carborator jets -- Probably would work just fine, unfortunatly the external mounting threads are not standard, this limits the selection to what ever is available for one perticular carberator. These are usualy only available as a "kit" of jets, these are also costly and not readily available from many sources.

Fuel injection pump -- Problem here is these are designed for thin gasoline not thicker oil, They also are not designed to produce 150 pounds pressure, about the highest pressure seen in a gas fuel injection system is 60-65 pounds, they also aint cheap.

gate valve to regulate pressure -- This system needs to be automatic, don't want to have to manualy adjust anything.


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92 dodge cummins with over 260,000 miles. Running an unheated 50% diesel/50% WVO blend for about the last 75,000 miles when temps above 50 deg f, no modifications or heating except the addition of a throw-away in-line fuel filter (removed during cold weather).
As of 8-01-05 I have been testing a 75% WVO/15% gasahol (90% RUG/10% ethanol)/10% diesel blend. Works fine down to about 65 f then starts rough. Runs ok once engine warms up. Back to a 50/50 diesel blend sence 9-15-05, just to cool now. -- 11-01-05 Modified stock fuel tank internal fuel pickup to have I.D. of 3/8 inch, this eliminated cold start slow idle and bogg on acceleration. Now adding 1 ounce each of acetone and pure gum spirits of turpentine to each 5 gallons of any blend, seems to help keep the fats in solution to a lower temperature --Heated 2nd tank fuel system installed january 2010, now running on a heated blend of 90% veg/5% diesel/5% RUG (no acetone or turpentine, heat replaced these).
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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Did a little testing concerning the flow rate of verious orifices, Well, one anyway, sorta got cut short when I closed a valve before turning off the pump, Blew a bubble and then a BIG hole in the side of the VGA tubing on the high pressure side of the pump. I will spend a bit of time tomorrow replumbing the filter setup using 3/8 ID 175 pound test duel-layer plastic air hose instead of the 75 pound test eva tubing.

Did get one test done. I decided to get some baseline info before actualy using hot oil, The ambient temp of the oil today was 103 deg f. I used a veriac to control the AC volts into the pump battery charger, adjusted the pump voltage to get for a steady 140 (pegged guage) pounds pressure with whatever flowrate was going through the orifice.
I have several of the smaller LP gas orifices to test. I started with the smallest one. The orifice hole is 23/1000 in diameter(snug fit with a tiny drillbit, then measure the bit). Unfortunatly this orifice is not marked but 23/1000 falls between LP gas orifice numbers 73 and 74.

Flow rate -- 23/1000 orifice, 103 deg f oil, 140 pounds pressure = 82 seconds to fill a quart measuring cup.

This equates to just a tad under 11 gallon per hour with cool oil, a lot more with 300 degree oil. -SO- I need to find a smaller orifice !!

If the diameter is cut in half the flow will be reduced by 4 -- A 11.5/1000 hole should flow 2.75 G/H of 100 degree oil, probably still to large a flow rate with hot oil ? I will try to find a 10/1000 orifice to test (10/1000 is a #87 wire drill and LP orifice number) ??


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92 dodge cummins with over 260,000 miles. Running an unheated 50% diesel/50% WVO blend for about the last 75,000 miles when temps above 50 deg f, no modifications or heating except the addition of a throw-away in-line fuel filter (removed during cold weather).
As of 8-01-05 I have been testing a 75% WVO/15% gasahol (90% RUG/10% ethanol)/10% diesel blend. Works fine down to about 65 f then starts rough. Runs ok once engine warms up. Back to a 50/50 diesel blend sence 9-15-05, just to cool now. -- 11-01-05 Modified stock fuel tank internal fuel pickup to have I.D. of 3/8 inch, this eliminated cold start slow idle and bogg on acceleration. Now adding 1 ounce each of acetone and pure gum spirits of turpentine to each 5 gallons of any blend, seems to help keep the fats in solution to a lower temperature --Heated 2nd tank fuel system installed january 2010, now running on a heated blend of 90% veg/5% diesel/5% RUG (no acetone or turpentine, heat replaced these).
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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Found a couple of LP pilot orifices on ebay, the hole is 10/1000 inch, shipping costs twice as much as the parts. Probably be a week before I can try this again.


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92 dodge cummins with over 260,000 miles. Running an unheated 50% diesel/50% WVO blend for about the last 75,000 miles when temps above 50 deg f, no modifications or heating except the addition of a throw-away in-line fuel filter (removed during cold weather).
As of 8-01-05 I have been testing a 75% WVO/15% gasahol (90% RUG/10% ethanol)/10% diesel blend. Works fine down to about 65 f then starts rough. Runs ok once engine warms up. Back to a 50/50 diesel blend sence 9-15-05, just to cool now. -- 11-01-05 Modified stock fuel tank internal fuel pickup to have I.D. of 3/8 inch, this eliminated cold start slow idle and bogg on acceleration. Now adding 1 ounce each of acetone and pure gum spirits of turpentine to each 5 gallons of any blend, seems to help keep the fats in solution to a lower temperature --Heated 2nd tank fuel system installed january 2010, now running on a heated blend of 90% veg/5% diesel/5% RUG (no acetone or turpentine, heat replaced these).
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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I'm thinking the orifice approach might not be the way to go & would like to hear comments about a possible alternative variation. My concerns with the orifice:
1) the spray of oil & steam seems bound to create some nasty greasy-frying-kitchen-style messes in short order, with condensed oil becoming more like a semi-dry resin than a fluid
2) pressurized hot oil/steam are certain eventually to injure someone
3) flammability concern, as already discussed

So rather than heat-dewatering as a "batch" process, as Tim is describing (in the flash process, oil/water reside for a time in pressurized cavity, and are intermittently ejected, thus flashing water to steam) couldn't the same objective be accomplished through a safer and simpler steady-flow process? I'm thinking:
1) a small stream of oil, regulated by (say) a needle-valve at gravity-feed from tank (or at positive-displacement pump outlet)...
2) ...passes through a t'stat-regulated, resistance-heated segment of pipe/fittings (whatever hardware works)...
3) ...and is allowed to exit as a small hot stream of WVO, via an open-pipe spillway to an open-topped collection tank, thus allowing any steam to rise freely from this trickle of hot oil as it falls.

User would set up process by monitoring the exit-oil stream temp, and regulate inlet volume and/or t'stat to produce an exit stream of something as high as possible between 212-F and "too-smoky" degrees F. (A wildly-high t'stat setting could of course be a fire-starter, though.)

This method would be carried out entirely at atmospheric pressure except upstream of the needle-valve or other inlet regulator.

I believe the *flash*-evap concept is based in part on creating a spray from an exit orifice (though Tim seems to be stepping away from this by seeking orifices that will NOT spray anyway, per the direction taken in the last page or so of this thread). By definition, the flash process *must* expose the hot exit-spray to cold air in order to condense the steam, thereby to me seeming inherently messy, as it requires an air-exchange and can't be carried out in a closed container without reintroducing condensed water back in the product we're trying to dewater. I'm not convinced that the spray is really needed here...yet AM convinced that the spray will result in high maintenance, and that the pressure adds to the potential for injury.

Anyone see any reason why the "trickle" steady-flow process might not work, even if less dramatic than flashing off steam?

Maybe it's time for me to get back to my workshop and try it...

--ds
 
Location: Honolulu | Registered: April 15, 2005Reply With QuoteReport This Post
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DS -- This flash evaporator is not a "batch" process (unless you consider 50 gallons to be a "batch"), the oil is pumped continuously under 150 pounds pressure into one end of the heater pipe and the water flashes to steam as the hot oil/water exits the other end, for as long as you want to run it. The idea is still in the early development and open-air prototype stage but The hot oil/steam will eventualy be flashed off inside of a small sealed steel tank (1-2 quart), the hot oil is collected in this tank and exits by a closed tube, no mess here. The steam is transfered out the top of this tank, through another closed tube into a second closed tank, here the steam is introduced below the water line and the water is used to condense the steam (magnito already successfully does this with his BIG flash evaporator), this tank will also seperate and collect any oil vapor that was carried in the steam, both the condensed steam (water) and the seperated oil will exit this tank from 2 seperate closed tubes, no mess here either.

The first flash tank will be insulated to contain the heat for use in preheating the incoming oil (internal coiled tube type heat exchanger) and the temperature in this tank should always be well above the boiling point of water so water will not be able to condense into the finished oil. The second steam condensor tank will NOT be insulated to allow as much heat as possible to excape from the external surface of the tank to cool the internal water to aid in condensing the steam, there will also be an internal heat exchanger tube to also use to preheat incoming oil.

I just spent an hour wandering around my local salvage yard, found several pilot orifices from propane water heaters. Only one is stamped for size, it says .013, the other should be similar -- will test these shortly.

The method described above by DS is basicly exactly what is being done in the 'electric skillet' setups other are using. (johno's method is discussed here, 5th post down)

Heating a very small stream of oil to allow evaporation does work but it will not insure that the oil that is exiting the unit is absolutely dry so you are back to the same old thing of circulating oil around and around, running tests for dryness, around and around some more etc - no thanks.


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92 dodge cummins with over 260,000 miles. Running an unheated 50% diesel/50% WVO blend for about the last 75,000 miles when temps above 50 deg f, no modifications or heating except the addition of a throw-away in-line fuel filter (removed during cold weather).
As of 8-01-05 I have been testing a 75% WVO/15% gasahol (90% RUG/10% ethanol)/10% diesel blend. Works fine down to about 65 f then starts rough. Runs ok once engine warms up. Back to a 50/50 diesel blend sence 9-15-05, just to cool now. -- 11-01-05 Modified stock fuel tank internal fuel pickup to have I.D. of 3/8 inch, this eliminated cold start slow idle and bogg on acceleration. Now adding 1 ounce each of acetone and pure gum spirits of turpentine to each 5 gallons of any blend, seems to help keep the fats in solution to a lower temperature --Heated 2nd tank fuel system installed january 2010, now running on a heated blend of 90% veg/5% diesel/5% RUG (no acetone or turpentine, heat replaced these).
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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I had some visions of injecting hot air (>212 F) into the flash tank - both to help keep the flash tank warm, and to enhance mass transfer out of the flash tank into the condensor tank.
 
Location: Saginaw, MI, USA | Registered: January 30, 2002Reply With QuoteReport This Post



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I don't think there will be any problem with condensation in the flash tank, at least not once the unit is up to temperature,may want to cycle the first gallon of start-up oil back through just to be sure. The lower half of the flash tank will be filled with hot oil, The amount of this hot outgoing oil will be several times the amount of cold incoming oil in the submerged heat exchanger so the temp should not be dropped by more than just a few degrees by the transfer of heat to the incoming oil.

The oil coming out of the heater is at 300 degrees f, way above the 212 deg boiling point. The oil/water is exiting the heater under pressure and the water changing into steam increases its volume Many times, this also creates pressure. The oil outlet will be submerged well below the surface of the oil so the steam can not excape by that route, the path of least resistance will be out the top and over into the condensing tank. Magnito did not indicate any problem with water condensing in his flash tank or with the steam not flowing into his condensor tank. My unit is basically just an electrified miniature version of his oil fired 5 G/M system. Will have to test it to know for shure.


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92 dodge cummins with over 260,000 miles. Running an unheated 50% diesel/50% WVO blend for about the last 75,000 miles when temps above 50 deg f, no modifications or heating except the addition of a throw-away in-line fuel filter (removed during cold weather).
As of 8-01-05 I have been testing a 75% WVO/15% gasahol (90% RUG/10% ethanol)/10% diesel blend. Works fine down to about 65 f then starts rough. Runs ok once engine warms up. Back to a 50/50 diesel blend sence 9-15-05, just to cool now. -- 11-01-05 Modified stock fuel tank internal fuel pickup to have I.D. of 3/8 inch, this eliminated cold start slow idle and bogg on acceleration. Now adding 1 ounce each of acetone and pure gum spirits of turpentine to each 5 gallons of any blend, seems to help keep the fats in solution to a lower temperature --Heated 2nd tank fuel system installed january 2010, now running on a heated blend of 90% veg/5% diesel/5% RUG (no acetone or turpentine, heat replaced these).
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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I just ran another nozzle flow-rate test on one of the salvage water heater pilot light nozzles, It is imprinted with "L-10", I assume this to mean "LP gas and 10/1000 orifice" as this seems to be the standard orifice size for LP pilot lights (or close to this anyway, I have 2 other nozzles stamped 013 ?). I will repeat this test using the NEW pilot nozzles I just ordered, they are known to have 10/1000 orifices.

Repeatable flow rate using 100 degree f oil was - 5 min 10 seconds for 1 quart of oil, or 2.9 G/H.-- I think this is a good place to start testing with hot oil. I will add the thermostat and a couple inches of fiberglass insulation to the heater pipe tomorrow and dewater some oil, need fuel anyway.

This LP pilot light nozzle has a very nice thin stainless steel orifice plate inserted in the end, the oil exits in one solid thin stream. Will be interesting to see how well this flashes water to steam ?


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92 dodge cummins with over 260,000 miles. Running an unheated 50% diesel/50% WVO blend for about the last 75,000 miles when temps above 50 deg f, no modifications or heating except the addition of a throw-away in-line fuel filter (removed during cold weather).
As of 8-01-05 I have been testing a 75% WVO/15% gasahol (90% RUG/10% ethanol)/10% diesel blend. Works fine down to about 65 f then starts rough. Runs ok once engine warms up. Back to a 50/50 diesel blend sence 9-15-05, just to cool now. -- 11-01-05 Modified stock fuel tank internal fuel pickup to have I.D. of 3/8 inch, this eliminated cold start slow idle and bogg on acceleration. Now adding 1 ounce each of acetone and pure gum spirits of turpentine to each 5 gallons of any blend, seems to help keep the fats in solution to a lower temperature --Heated 2nd tank fuel system installed january 2010, now running on a heated blend of 90% veg/5% diesel/5% RUG (no acetone or turpentine, heat replaced these).
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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Sounds like it's about perfect to me.
 
Location: Saginaw, MI, USA | Registered: January 30, 2002Reply With QuoteReport This Post
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I installed the thermostat and insulated the heater pipe today. The evaporator ran automatically for a measured 3 hours, The flow rate was 2.625 G/H. (the pressure dropped down to around 120 pounds somewhere along the line, this reduced the flow a bit)

Surpisingly the flow rate with hot oil is so close to the same as with 100 deg f oil that I did not see any differance. I had expected it to be more due to hotter oil being thinner, guess it was not that much thinner ?

By using a veriac to control the AC volts going to the battery charger that is powering the shurflo pump I was able to run the pump motor slower but continiously rather than have it cycle on/off, this kept the pressure within 10 pounds rather than the 40-50 pounds that results from using the pressure cutoff switch that results in on/off cycling. This test also indicates that the electronic pressure control idea should work just fine for this pump.

I did the "frypan bubble test" at the end of each hour and was suprised when the second test showed just a few bubbles. Put a thermometer in the hot oil output stream and found that by the end of the "OFF" time of the thermostat the oil temp was dropping down to 210 deg f, during the "ON" time it was only reaching 240 deg f even though the thermostat knob was set to 300 degree. Turned the thermostat to the 350 setting and got 260 degree "ON" time oil and 220 degree "OFF" time oil. This seems to indicate that the 300 degree temp is not actualy nescicary, as long as you keep the oil above the 212 boiling point of water it seems to dewater ok. More testing here.

Oil stream from nozzle -- Interestingly I found that at pressures below about 90 pounds you do get a nice single stream of oil from the 10/000 orifice but above that pressure the stream starts to break into a narrow spray. The spray was actualy boiling off some water even before I turned the heater on (hot day, oil was at 113 degrees f in the barrel).

With the heater on and 130-140 pounds pressure there was a spray directly from the orifice, I suspect it is caused by the water flashing to steam and breaking up the oil stream. This is a narrow spray, 6 inches from the orifice it was only about 1 inch around.

Heater duty cycle -- With the insulation installed and 110+ degree ambiant oil the heater only ran half the time, 2 min on, 2 min off, but this was before I found that it was not heating the oil to 300 degrees. I will run this test again in a few days but make sure the oil is being heated to 275-300 degrees.

This duty cycle does indicate that if the heater was on all the time the unit could dewater twice the flow rate or about around 5 G/H. I will try using the 13/1000 inch orifice, I think it should flow just about this rate of oil ?

For this test the cost for electricity was about 1 cent/gallon of dewatered oil, and this is without the heat exchangers to preheat the incoming oil. Based on this it looks like the cost may actualy end up being closer to 1/2 cent per gallon once the incoming oil heat exchangers and adaquate insulation are installed.


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92 dodge cummins with over 260,000 miles. Running an unheated 50% diesel/50% WVO blend for about the last 75,000 miles when temps above 50 deg f, no modifications or heating except the addition of a throw-away in-line fuel filter (removed during cold weather).
As of 8-01-05 I have been testing a 75% WVO/15% gasahol (90% RUG/10% ethanol)/10% diesel blend. Works fine down to about 65 f then starts rough. Runs ok once engine warms up. Back to a 50/50 diesel blend sence 9-15-05, just to cool now. -- 11-01-05 Modified stock fuel tank internal fuel pickup to have I.D. of 3/8 inch, this eliminated cold start slow idle and bogg on acceleration. Now adding 1 ounce each of acetone and pure gum spirits of turpentine to each 5 gallons of any blend, seems to help keep the fats in solution to a lower temperature --Heated 2nd tank fuel system installed january 2010, now running on a heated blend of 90% veg/5% diesel/5% RUG (no acetone or turpentine, heat replaced these).
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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quote:
Originally posted by Tim c cook:

From testing I find that for around 1000 watts of heat you can dewater around 2 gallon of oil/hour with no insulation and no heat recovery to preheat the incoming oil. If heat exchanger tubing is installed into the flash tank and the steam condensing tank to route the incoming oil through to preheat it, I think that at least 1/2 the heat can be recovered. this should allow the same 2 gallon/hour of oil to be dewatered using 500 watts of heat instead of 1000 watts (once the unit is up to temp). This also reduces the outgoing dry oil temp down from the 300 degrees to something around 200 or a bit more, have to build it to be sure just what this temp ends up being.


I wasn't sure exactly what you meant by heat exchanger here, but what about using engine coolant to preheat the oil before the electric takes it that final 80 degrees or so?

Maybe you need to put a diesel WVO powered generator in the bed of your truck that just runs to generate 110v AC to power the heater core, then you can just plugin at grandma's house and process while you're sleeping, or fire up the gnereator while you're on the road. Smile
 
Registered: July 25, 2005Reply With QuoteReport This Post
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Great research, Tim. Thanks for all the hard work.

Todd


2002 F-250, 7.3l on WVO since '04
'82 VW Rabbit diesel 1.6l na
'83 GMC 6.2l Class C RV
'85 F-350, 6.9l flat bed
'85 E-350, 6.9l cube van
2 Mercedes 300SD's
3 Chinese Changfa-style diesel generators- 12kw, 8kw & 7.5kw
Mitsubishi 3 cyl diesel generator/light tower
Kubota 2 cyl. diesel, water cooled air compressor
Onan 12.5kw air-cooled diesel genset
I run my company entirely on renewable energy including electricity from generators running on biofuels.

 
Location: El Dorado, Ark | Registered: July 04, 2004Reply With QuoteReport This Post



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Tim: I'll add my opinion that a heat exchanger will reduce your electric load by about 50%. My Birdwaterer did just that. Once the heat exchanger gets big and efficient enough, the primary power requirement becomes that necessary to boil the water (because that energy isn't easily recoverable), rather than heating the oil.
I have a germ of a thought for a pressure control orifice - look at the way a pressure cooker pressure control works - it's a weight sitting on top of a fairly large orifice, so the steam escapes by squirting through the gap around the edges of the orifice, so the control area is the annulus (the gap in shape of a ring), not the diameter (which is much bigger). Not much to go wrong with it, and it can't easily plug up. Better than springs or fixed orifices.
 
Location: Moses Lake, WA, USA | Registered: August 15, 2001Reply With QuoteReport This Post
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quote:
Originally posted by Tim c cook:
{Snip}

I did the "frypan bubble test" at the end of each hour and was suprised when the second test showed just a few bubbles. Put a thermometer in the hot oil output stream and found that by the end of the "OFF" time of the thermostat the oil temp was dropping down to 210 deg f, during the "ON" time it was only reaching 240 deg f even though the thermostat knob was set to 300 degree. Turned the thermostat to the 350 setting and got 260 degree "ON" time oil and 220 degree "OFF" time oil. This seems to indicate that the 300 degree temp is not actualy nescicary, as long as you keep the oil above the 212 boiling point of water it seems to dewater ok. More testing here.
{Snip}


The oil temp after the nozzle will be lower than before.

Whatever water there is has to get heat to boil; latent heat of vaporization. In this case, it's coming from the heat stored int eh oil.

As the water boils off, it will cool the oil.

The temp needed before the nozzle will vary with water content. If you've got really wet oil, you will need to get things hotter before the nozzle.

you can do some algebra to figure out what the temperature has to be, but it doesn't take much water at all to drive the temp up fast - Heat of vaporization for water is 970.3 BTU per pound. Specific heat for water is 1 btu per pound deg F, and about 0.4 for various oils.

We'll assume we're doing a batch of a pound of mix coming in. Continuous flow should give the same numbers - because flow rates will balance on each side.

CAll X the water fraction (1 percent water = 0.01) and T the start temperature. We'll assume everything lands at 212 - which doesn't allow any safety factor, but you can adjust this as you see fit.

heat content to boil the water has to equal the heat change in the liquids.

(1-x)*1 pound*(T-212)*0.4 + x*1 pound*(T-212)*1.0 = x*1 pound*970.3

The weight drops out - which proves this is independent of flow rate.

It boils down to a sloppy quadratic that my algebra is too rusty to calculate. If somebody remembers how to run these things, have at it.

If you know one number, you can plug and chug to get the others.

I'll cheat and use "goal seek" in an excel like program.

X T

0.0000 212.0000
0.0010 214.4221
0.0020 216.8370
0.0100 235.8990
0.0150 247.5853
0.0200 259.1030
0.0250 270.4510
0.0500 324.8250
0.0750 375.5348
0.1000 422.9348

It isn't quite linear because the water contributes more of the proportion of heat at the percentage goes up.

If you call it 24 degrees drop per percent of water it looks like you'll be safe...
 
Location: Saginaw, MI, USA | Registered: January 30, 2002Reply With QuoteReport This Post
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Very interesting work Tim. Solid and substantial research and experimentation.

A very usefull device.

I agree on the problems with other methods.

I use circulate and spray hot oil and although this gets it 'dry enough' even at 120 or 130 degC there is still some steam coming off. The bulk seems to be removed while the temp rise stalls at 100degC.

Even so this seems much better.

I may try to convert a diesel pressure washer I have into a high capacity flash dryer such as the one that inspired you.

Set me back another 6 months lol.


mathematical elegance -- desired result achieved with minimal complication
 
Location: Manchester UK | Registered: June 03, 2003Reply With QuoteReport This Post
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quote:
Originally posted by mtushmoo:
...It isn't quite linear because the water contributes more of the proportion of heat at the percentage goes up.

If you call it 24 degrees drop per percent of water it looks like you'll be safe...


Now you have to figure out how to determine your water content percentage of your oil or these calcuations won't help. Also you have to have the water mixed in real well. For example if it is settled some you will have a higher water content percentage toward the bottom of the vessel than you will the top.


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If you believe you can't YOUR RIGHT;

But equally so.... if you believe you can, YOUR RIGHT as well.
 
Location: North Tx | Registered: November 23, 2002Reply With QuoteReport This Post
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Mr.CPU -- I think the Idea of using engine coolent to preheat the incomming oil has merit for the on-board mobile dewatering version of this unit, will definatly reduce the amount of electric heat nescicary. Mobile home and bus use probably would already have an on-board 110 volt AC generator so might as well use them for the electric heat.

johno -- Still thinking about the "pressure cooker" orifice idea. So far the 10/1000 orifice has not plugged up feeding it with 5 micron oil directly from the filter tank although when I first installed it I did have to remove and clean it about a half dozen times before I got all the plumbing cleaned out, after that it ran for 3 hours straight without plugging. Next test will be with a 13/1000 orifice, only a bit bigger but it should clog even less and flow about 4 G/H.

mtushmoo -- Outstanding -- thanks. Once you pointed it out it is obvious that more water will need more energy to flash off, should have seen this but had not even considered it.

I will have to accept your math - mine is nill. 24 deg/percent of water is workable. I don't know at what percentage you would most likely begin to percipitate water into free water but I suspect if you DO NOT see free water droplets the percentage of microdroplets/dissolved water has to be small. By using 150 pound oil pressure it allows a bit over 300 degrees before the pressurised water boils so with the temp differance of about 100 deg f (312 - 212) and with 24 deg/percent this allows for about 4 percent water to be flashed off.

JMJ -- Eventualy I may actualy measure the temp of the oil just after the orifice and control the heater based on this, This would allow for any veriation of water percentage and save a bit of electric power over just forcing the wet oil temp to over 300 degrees to cover the possibility of very wet oil. I have been feeding the prototype evaporator from the bottom af my filter setup barrel, From 'frypan bubble" testing there is definatly more water in the bottom 1/3 of the barrel than in the top 2/3. By doing a rough "bubble" count I estimate the bottom has about twice the water of the upper 2/3.

I need to dry some more oil shortly so will run the unit for another 3 hour test using a 13/1000 orifice. this should flow about 4 G/H, will set the thermostat to 350-375 for this test to insure there is enough heat to eliminate all the water, will keep track of the heater duty cycle to deturmine the watts needed for the larger orifice flow rate.

I just picked up a 25 foot length of steel 3/16 brake line to make the heat recovery exchangers so will finaly have to build the small flash tank for testing this heat recovery exchanger idea...


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92 dodge cummins with over 260,000 miles. Running an unheated 50% diesel/50% WVO blend for about the last 75,000 miles when temps above 50 deg f, no modifications or heating except the addition of a throw-away in-line fuel filter (removed during cold weather).
As of 8-01-05 I have been testing a 75% WVO/15% gasahol (90% RUG/10% ethanol)/10% diesel blend. Works fine down to about 65 f then starts rough. Runs ok once engine warms up. Back to a 50/50 diesel blend sence 9-15-05, just to cool now. -- 11-01-05 Modified stock fuel tank internal fuel pickup to have I.D. of 3/8 inch, this eliminated cold start slow idle and bogg on acceleration. Now adding 1 ounce each of acetone and pure gum spirits of turpentine to each 5 gallons of any blend, seems to help keep the fats in solution to a lower temperature --Heated 2nd tank fuel system installed january 2010, now running on a heated blend of 90% veg/5% diesel/5% RUG (no acetone or turpentine, heat replaced these).
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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Hey Tim, great work. I was wondering what the minimum amount of filtering you thought could be done and still get the FE to run reliable. I plan to make biodiesel from the oil and don't filter it nearly as much as people running svo. Where did you get the brake line? Do you have any idea how much pressure a 1/4 inch copper line can take? I never really thought about it before but it should take 150 psi.
-Richard


2002 Excursion 4 x 4 with a 7.3 liter powerstroke and Several diesel trucks and equipment associated with the arborist field.
 
Location: Bonnieville, Kentucky | Registered: June 20, 2005Reply With QuoteReport This Post



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Filtering -- Sorta depends on the size of the FE orifice and the size of the orifice depends on how much heat you make. The last test of the FE was using a 10/1000 orifice, the next one will be using a 13/1000 orifice, these are with about 500-600 watts of heat using 110 volts. If I run 220 volts full time on this same heater it will put out 4500 watts so the flow of oil could be 6-8 times larger, this would take an orifice someplace around 25-30 thousandts ID, a 40 micron filter would catch everything larger than a couple of thousandts so it would definatly catch anything that might plug up this size orifice hole.

(EDIT-- Had the conversion from microns to inches wrong)

There are 25.4 microns in each 1/1000 of an inch so even with the tiny 10/1000 inch orifice filtering with any filter finer than a couple hundred micron should keep it from clogging. Finer is better and using a water wash/settling step seems to remove almost everything big enough to be a problem, I suspect one 40 micron filter between the water washing/settling step and the FE would last for hundreds of gallons before you needed to change it.

Steel brake line -- This is steel tubing only, no fittings -- I have gotten 25 foot coils from ebay but this last 25 foot length was from my local Napa auto parts store, they had it in stock and the price was about the same as ebay figuring the shipping.

1/4 inch copper line -- The thicker refrigeration tubing regularly sees pressures of 300 pounds and above, the normal tubing for water lines has to be specked for at least the same 125 pounds that all other water devices are designed to handle so it should handle 150 pounds ok. The problem with copper tubing in hot oil is that it turns green, my copper garden hose connections are green and also put off a bit of green slime ? The steel brake line is galvanized, From reading other posts this also is not the best so once I get this built into the tanks I will run a bit of diluted muriatic acid over and through it to remove the galvanize, once it gets oil coated it will not rust.


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92 dodge cummins with over 260,000 miles. Running an unheated 50% diesel/50% WVO blend for about the last 75,000 miles when temps above 50 deg f, no modifications or heating except the addition of a throw-away in-line fuel filter (removed during cold weather).
As of 8-01-05 I have been testing a 75% WVO/15% gasahol (90% RUG/10% ethanol)/10% diesel blend. Works fine down to about 65 f then starts rough. Runs ok once engine warms up. Back to a 50/50 diesel blend sence 9-15-05, just to cool now. -- 11-01-05 Modified stock fuel tank internal fuel pickup to have I.D. of 3/8 inch, this eliminated cold start slow idle and bogg on acceleration. Now adding 1 ounce each of acetone and pure gum spirits of turpentine to each 5 gallons of any blend, seems to help keep the fats in solution to a lower temperature --Heated 2nd tank fuel system installed january 2010, now running on a heated blend of 90% veg/5% diesel/5% RUG (no acetone or turpentine, heat replaced these).
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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Dewatered 12 gallon of oil today using the 13/1000 orifice. Using this orifice and an average of 135 pounds pressure it took almost exactly (plus/minus 1 sec) 4 minutes to fill a 1 quart measuring cup, equils 3 3/4 G/H flow rate.

This 13/1000 orifice acted differently than the 10/1000, may be some slight veriation in the actual hole shape ? (both these nozzles had the orifice hole placed in a very thin SS orifice plate insert in the tip of the nozzle). This 13/1000 orifice produced a nice thin continious solid stream that did not break up into a spray even when releasing steam. I could not actualy tell where the steam was coming from, didn't seem to be from the stream of oil or from the surface of the oil in the catch-pot either, just a lot of steam rising out of the pot.

Surpisingly the steam went away completely about 15 minutes into dewatering ? There was no obvious steam rising for the remainder of the 3 hours that I ran the unit. The area around the unit did definatly feel heavier in humidity but could not see actual steam. I ran "frypan bubble" tests of oil going in and oil coming out. The oil going in was definatly wet and showed bubbles over the entire bottom of the frypan, the oil coming out showed absolutely NO BUBBLES even when heated to a lot of smoke. Dewatering was definatly taking place, just no steam, no explination ?? - It still did the appropriate dewatering.
(this oil was being drawn from the very bottom of the filtering barrel so it is reasonable that any water that was present would be in the bottom of the barrel and drawn off first - just trying to rationalize the lack of steam ?)

I adjusted the thermostat up a bit to insure the oil would always stay above 212 deg f. The coolest the oil got when the heater was off was 240 deg f, the hottest was just before the heater turned off at 285 deg f.

With the larger flow from the 13/1000 orifice and the thermostat turned up a bit the thermostat still cycled on/off. ON-time averaged 210 seconds, OFF-time averaged 69 seconds. From these numbers the heater is on 3/4 of the time, it is a 1100 watt heater being powered by 110 volts so the average heat is 825 watts to dewater 3 3/4 G/H of this fairly dry (no obvious steam) oil. This should leave enough margin to dewater oil that is wetter than this batch.

This 3 3/4 gallon flow rate looks to be about the best compromise of orifice size for the amount of heat being supplied (max of 1100 watts) until I get the flash tank finished with the heat recovery tubes in it to preheat the incoming oil. This preheating should recover another 40-50% of the heat, this would allow the flowrate to be almost doubled (7-8 G/H) for this same amount of heat.

To double the flow rate the orifice should be increased by 1.5 times, this is 19.5/1000. The pilot light orifices for NATURAL GAS home appliances seems to be standerdised at 18/1000, this is close enough to the 19.5/1000 for testing purposes. If this all works it looks like 1100 watts will be enough heat to reliably dewater even very wet oil at a flow rate of around 7 G/H -- better than I ever invisioned when starting out ..


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92 dodge cummins with over 260,000 miles. Running an unheated 50% diesel/50% WVO blend for about the last 75,000 miles when temps above 50 deg f, no modifications or heating except the addition of a throw-away in-line fuel filter (removed during cold weather).
As of 8-01-05 I have been testing a 75% WVO/15% gasahol (90% RUG/10% ethanol)/10% diesel blend. Works fine down to about 65 f then starts rough. Runs ok once engine warms up. Back to a 50/50 diesel blend sence 9-15-05, just to cool now. -- 11-01-05 Modified stock fuel tank internal fuel pickup to have I.D. of 3/8 inch, this eliminated cold start slow idle and bogg on acceleration. Now adding 1 ounce each of acetone and pure gum spirits of turpentine to each 5 gallons of any blend, seems to help keep the fats in solution to a lower temperature --Heated 2nd tank fuel system installed january 2010, now running on a heated blend of 90% veg/5% diesel/5% RUG (no acetone or turpentine, heat replaced these).
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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