jscarmozza wrote: ↑Tue Jun 16, 2020 11:44 am
Pat, it seems like you have a good handle on the process, you may want to think about trying different oil additives to your diesel fuel.
I thought about oil firing one of my locomotives, so I made a trial nozzle and experimented with it on compressed air and kerosene. I was near the end of the trial when I added about an ounce of non detergent motor oil to the remaining half cup of kerosene left in the fuel tank, what a difference in the flame! Without changing the air pressure the flame moved from about 2" away from the nozzle to within a half inch of it and the flame color went from light yellow to dark orange. The heat output was unbelievable, it melted a hole in the cookie sheet that I was doing the experiment on and turned the fire bricks that the flame was hitting white hot. This is easy to do and may give you more heat output.
Good luck, John
Thanks John.
It took a long time to figure out how to make consistent iron castings that are easily machinable, and I got input from several art-iron folks who do a lot of iron casting work, along with help from a few people online who also do a lot of successful iron work.
I experimented with many types of burners, and there are several types of burners that will melt iron well, including the siphon/pressure nozzle designs, the Ursutz, drip-style, and propane/LPG burners.
All these burners require two critical items, which are:
1. Sufficient combustion air added to the furnace via some type of blower.
2. The correct mixture of fuel and air to produce complete or near complete combustion of the fuel.
As far as fuel, I have not seen a difference between people using waste oil, kerosene, diesel, veggie oil, or propane/NG.
All of these fuels have similar flame temperatures.
Here is some data I found online:
Common Flame Temperatures
Acetylene with Air 4532 F
Acetelene with pure Oxygen 6296 F
Natural Gas with Air 3562 F
Propane with Air 3596 - 3623 F
Propane with pure Oxygen 4579 - 5110 F
Wood 3596 F
Kerosene 3810 F
Light Fuel Oil 3820 F
Medium Fuel Oil 3815 F
Heavy Fuel Oil 3817 F
Coal 3950 F approx.
Heat Value of Materials
#2 Diesel 138,500 BTU/gal
Kerosene 135,000 BTU/gal
Natural Gas 100,000 BTU/therm
Propane 92,5000 BTU/gal
Sawdust (green) 10,000,000 BTU/ton
Sawdust (dry) 18,000,000 BTU/ton
Electric 1.0 kWh = 3,412.14 Btu
Oil burners act entirely differently outside of a furnace than they do when operated with a furnace.
The trick to melting iron is to use the right fuel flow (about 3 gal/hr for diesel), and the right amount of combustion air (generally slight flames coming out the furnace lid opening).
Using more or less than 3 gal/hr of diesel seems to make the furnace run cooler, and that indicates that there is a sweet spot for how much fuel a given furnace size can completely combust.
I use diesel because it is clean, readily available at most gas stations, doesn't contain heavy metals, and it works consistently.
Most people use what is readily available, and what is easy to use.
Some folks who use waste oil end up using diesel due to all the problems you can have with waste oil, such as sludge, water contamination, and the mess of trying to store/handle/filter it.
Some of the change you notice between the different fuels may be because of viscosity.
Changing to a higher viscosity fuel will increase the fuel flow, so that will affect how hot it appears that the burner is running.
Kerosene seems to be thinner than diesel, and diesel is thinner than motor oil.
The furnace interior gets extremely hot when it comes up to maximum temperature, and so it will vaporize and combust almost any fuel you put in it, as long as your air/fuel mixture is correct.
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