Burning Liquid Fuels

[fredrosse]

Some use No 2 oil (Diessel Oil), Kerosene, or possibly Gasoline fired boilers. What is the good, the bad, and the ugly with these setups? The experiences of steamboaters here is requested.

Using a manufactured pressure atomizing oil burner, available in 12 volt service, is simple enough, but expensive (anout $600 for a new burner I think) and current draw is fairly heavy, limiting steaming time unless a few large deep cycle batteries are carried, or a generator is fitted to the boat, another couple of hundred dollars there, and more complication.

A well established alternative is a steam atomized oil burner, in use for at least 100 years. Simple enough, although a kinundrum of sorts as steam is needed to operate the burner, and without a burner, no steam! So an alternate method of getting up steam on startup is needed.

Finally the vaporizing burner setups, almost universal on the early steam automobiles, generally for Kerosene or Gasoline.

What can anyone tell us about their experiences running with these firing setups? Has anyone used a propane atomized oil burner?

[barts]

Otter originally had a vaporizing kerosene burner in her original boiler; when I built the 'new' boiler nearly 20 years ago I used a steam atomizing burner. I start it by using high pressure propane instead of steam in the burner. You can definitely use a propane-powered burner, but it does require attention and care - not difficult when just getting steam up, but more problematic over the long haul. A 12 amp 12V air compressor will also work, but the propane is easier and quieter.

- Bart

[cyberbadger]

A well established alternative is a steam atomized oil burner, in use for at least 100 years. Simple enough, although a kinundrum of sorts as steam is needed to operate the burner, and without a burner, no steam! So an alternate method of getting up steam on startup is needed.

You just need another boat near by to lend you some steam via a steam hose until you get up to steam. There is a youtube video of some steam locomotives doing just that. I think the other option can be to use compressed air - but that would probably require a large reserve or a portable ICky powered compressor. Neither option is particularly practical for a steam launch. For locomotives - it probably wasn't a big deal - there was usually another locomotive in the engine house that had steam up and could lend a hand. I'd image for larger steam ships they would have had an auxiliary boiler that ran on wood/coal - you'd get the auxiliary going, and it would help the main boiler(s) getting going.
-CB

[Lopez Mike]

I think Bart's solution is the best I've seen so far.

For now, I'm staying with wood but if I find that I want to explore beyond the range of my wood hauling capacity, I will probably go to stinky oil.

When attending steamups and the the like, waiting for enough pressure to get an atomizer going would be a pain. When I'm out for longer trips, just building a solid fuel fire and waiting might not be that big if a deal.

Stephanie, on Uno, uses a repurposed paint sprayer element with good results. I think she is burning either kerosine or truck fuel. I'm not sure. She builds a small wood fire to get startup pressure.

Bart, your burner involves more than just a simple burner as I remember. Perhaps explain how you use the air amplifier and all that.

[barts]

Bart, your burner involves more than just a simple burner as I remember. Perhaps explain how you use the air amplifier and all that.

One of the things I've noticed with oil burners is that commercial pressure atomizing burners use a fair amount of power running a blower to provide forced air for combustion and large scale atomizing burners (like the ones in a Liberty ship) use forced draft fans. It is possible to use enough extra steam to provide combustion air, but this is quite inefficient if you use the burner nozzle. A friend gave me an 'Air Amplifier' which uses a venturi to expand a relatively small amount of air (or steam) to a large blast.

I use this on the outside of my boiler to force extra air into the boiler through the burner intake. Up to about 1 gph fire, this is not needed = but if I want to go faster, I admit some steam into the air amplifier. On full blast, this will really produce steam, but my engine doesn't really like running that hard.

As I mentioned earlier, I start the boiler using propane instead of steam in the burner; I don't use the air amplifier during starting . When stopping for lunch, I put a small sauce pan lid into the top of Otter's titanium stack (courtesy of Boeing Surplus many years ago); this will easily retain enough heat to start the boiler w/o resorting to propane again as long as lunch doesn't take more than a couple of hours or so.

This past year I made a new firebox for Otter out of Mizzou castable refractory - it works really well. This is strong (and heavy) stuff; keeping the section size to a reasonable size is important.

- Bart

[Lopez Mike]

Any idea what the pressure rise is between the outside and the firebox when the air amplifier is in use? Measurable? Do you need to have a good fit around the various penetrations?

[barts]

Any idea what the pressure rise is between the outside and the firebox when the air amplifier is in use? Measurable? Do you need to have a good fit around the various penetrations?

No idea... but note that the pressure drop across the burner due to stack draft isn't much, and I
perhaps double fuel consumption w the air amplifier in use, so mass flow rate of air doubles as
well - so pressure drop goes up prob. by four or so. I'd guess that a little fiberfrax would prevent
any air leaks of significance.

- Bart

[fredrosse]

Bart, what is the approximate size/dimensions of the oil flame: something conical or flat, long and thin or short/wide? I am asking this to address the common problem of flame impingement onto relatively cool surfaces, the boiler metal is only 300 - 400F. Would you have a drawing of your burner head? Can you burn No 2 oil, and/or Kerosene?

Thanks in advance for answers.

[barts]

For some reason I cannot post pdfs here, so here are links to an article I wrote for Steamboating on my burner and firebox.

http://smaalders.net/barts/firebox.pdf
http://smaalders.net/barts/nozzle.pdf
http://smaalders.net/barts/steam-pressure-regulator.pdf
http://smaalders.net/barts/oil-burning.pdf

As you can see in the firebox doc, the flame is tangentially introduced into the box; it wraps around completely when steaming hard.
The inner insulation is now Mizzou castable refractory; the stainless gave up the ghost after 15 years or so. There is a top on the refractory that makes a 1.5" lip all the way around; this retains the fire in the firebox. The fire never touches the pressure vessel; it finishes burning before heading up the center hole.


The burner will burn any light oil; e.g. #2 fuel oil, kerosene, used hydraulic oil, ATF, etc.

The steam pressure regulator is required, otherwise you get positive feedback - the more steam you get, the harder the burner runs.
I use a small electric fuel pump to provide 3 psi or so to the burner; this works well.

- Bart

[Oilking]

Dave Bell"s captain Bell uses propane and furnace fuel for startup with a Binks paint spray nozzle. He describes the setup on his website http://www.captainbell.com/capbeltechnical.html which can alsobe found on the NWSS member list at the top of the page. With his setup the switch from propane to steam is automatic once the steram pressure exceeds the propane pressure.

Dave