Here is a project I've been working on, my goal is 50/50. Thank's to my new friends over at http://groups.yahoo.com/group/altfuelfurnace/ I found out that the basics to a conversion are:
Heat oil 180'F+ at nozzle (hotter the better)
increase pressure at pump 150psi
smaller nozzle(maybe, Plus: finer mist better starts, Neg: easier to clog)
adjust air intake
I'm up to about 35% WVO, here is what I have
done so far. Starting at the tank, mix tank that is, it's a 10
gallon galvanized steel trash can. I had to solder all the seams
first to keep it from leaking (lable said it was leak-proof, RIGHT), last year I picked up a nice
labratory grade submersable heater (at a flea market for $2.00) that peaks out a 100'C, (can't run this at full power as the fumes are overwellming) running at about 1/2 power, this is placed in the can (fits perfect). The can is insulated and has a 3/8 fitting soldered into the side 1.5" from the bottom. The fitting is attached to a insulated 3/8 line that runs to a fuel filter and then continues to
the pump(only about 3 feet long total). Just before the pump I have a short piece of copper line
with a heat sink made of copper flashing soldered to it that holds a ceramic resistor 110 ohm 30 watt, this preheats the oil to the pump. The next thing I did
was get a longer line from the pump to the nozzle feed tube to this
I also soldered a heat sink and placed a 48ohm 30 watt resistor. The
curcuit is wired in series with a switch to turn on and off. Feeding 120 AC
was out of the question so I placed a diode in line to rectify the
voltage to half wave giving me about 60 volts , a near perfect
match. Both resistors get good and hot, however don't seem to overheat,
can't measure the temp but the lines get hot enough that I can't
hold my finger on them without fair discomfort(redneck thermometer).
In addition I have boosted the fuel pressure to 150 psi. The nozzle
is the original at 1.00 80' hollow though I'm going to try an .85
to see if I can clean up the startup just a little. Furnace fires
pretty good on cold start and burns like a dream. Also I am going to try
and figure out a way to get a wire into the burner and mount a
resistor directly to the feed tube just before the nozzle. Hopefully this will enable the final goal of 50/50 maybe a little less. Very pleased with results so far, cost to date of conversion under 25 bucks ( some stuff laying around). System has been running now for 5 days with little attendence, just filling tank with mix, periodic checks of temps(right index finger temp probe)etc.
The system is still kind of cobbed together, but once I get things 'prettied up' solder all connections include fuse protection, and finish fine tuning I'll post all info and some pics in my diary.
Any suggestions on heating curcuit to keep the pre-nozzle oil temp at about 200F would be appreciated. Maybe another resistor that I can push a little but is thermally regulated(can't be to cumbersom as feed tube/nozzle assembly has to be easily removed for cleaning) every few months.
Wildbill
