quote author=mobile_bob link=topic=5619.msg66767#msg66767 date=1296504805]
to the group:
mark my business partner burns waste motor oil to heat both the shop and his house
his house is quite large by most standards at ~6000sq/ft, the shop ~3000sq/ft
the house uses an omni waste oil boiler and the shop a lenaire waste oil air/air heater.
the omni is cleaned out every month and produces about 2 gallons of ash and carbon, after burning anywhere between 4 and 15 gallons per day
the lenaire burns a butt load of oil all winter and is cleaned out once a year, it produces approx 1/2 gallon of ash/carbon
so why the disparity? and what can we learn from it?
one possible and probable explanation might be, the boiler sidewalls are ~120 degree's F while it is likely that the sidewalls of the air/flue gas exchanger of the lenaire is probably well over 200 degree's F
the cooler side walls of the boiler will allow a much higher deposition of carbon
and some ash, the deposits of carbon would then be further heated by the continuous flames converting more and more of the carbon to ash.
the hotter side walls of the lenaire would impede the deposition of carbon and ash, and the force of the blower/gun assy would simply expel a significantly higher amount of carbon out the stack before further flame and heat could convert that carbon to ash, therefore explaining the much lower ash deposits in the furnace at cleanout.
now if we go back and look at spencer's rig and how he uses it
he reports using it to provide power for his modest home, and from the video it would appear he uses a 55gallon drum in thermal siphon.
it is my bet that the majority of run time the engines is lightly loaded, perhaps under
1kw electrical, with this size of cooling capacity it is likely that the engine is running too cool, perhaps no more than the omni reference earlier. if this is the case, as i am fairly certain of, any carbon will deposit more so in the cylinder/piston, and head
and be subjected to further heating and convert to more ash,, light loading also causes
an engine to load up a bit, added oily patially burned goop combined with this ash
and collected in the rings and ring lands would work together to wear the dog snot out
of his engine.
this might also explain how something like a changfa 195 does so much better on waster oil as related by the fellow David from africa, the cooling system of a changfa is such that even without a load the engine will attain much higher temperatures than a lister can achieve. due to a much smaller cooling capacity
of approx 2 gallons as opposed to 30 or more in the 55 gallon drum.
the lister uses the surface of the drum to release the heat from the coolant water, while the changfa uses the phase change to cool with so much less coolant and far less surface area.
i also strongly suspect that the fellow with the ashwemegh 12/2 in georgia
had his setup either thermstatically controlled, under heavier average loading, or had
a cooling system sized appropriately for the load he presented to the engine.
there are lots of pieces to this puzzle, and a clearer picture is emerging.
it seems obvious to me that burning waste motor oil produces ash, how much ash,
where it gets generated and deposited as well as how an engine is able to tolerate
it will all work together to establish how long the engine is likely to last.
it seem reasonable to conclude that running an engine at a light average load, running with an oversized cooling system for that average load, made from parts of lower quality than what might be needed for this type of fuel, will all work together to dramatically limit the longevity of the engine,,, as has been reported by spencer.
bob g
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That post is full of theory and misinformation
I own a Omni boiler and also a Thermobile jet type burner workshop heater and both produce lots of ash
The Omni boiler produces more to clean out because of the reduce air flow through the heat tubes where the slower the gasses pass through the more heat is transferred to the water, at no point any where in the combustion chamber of this Omni waste oil fired boiler is there any carbon just white dry ash.
All so the Thermobile blown air heater has no carbon just white ash.
The Thermobile heater being a blown air heater has a faster air speed through the combustion chamber as heat is dispersed over a longer heat exchanger and this has the result in more ash being blown out the chimney stack.
At no point will get black clumps of carbon when WMO is completely combusted.
The fact still remains that this ash from fully combusted WMO in any fairly large amounts will wear the moving pasts of an engine out
All fact as I own all three types of commercially produce waste oil heater and have done for many years.
Go to this site
http://groups.yahoo.com/group/altfuelfurnace/At no point will black carbon exit the chimney unless there's a problem or you have just lit a vaporise pan heater which is not up to temperature.
At no point was my engine under loaded or running cold, FACT
Some one here keeps forgetting that fully combusted WMO makes white ash and black lumps of carbon are not fully combusted WMO