The Home Machinist!

Hello all,

I have a friend who has a 7 1/2" gauge steam engine powered by diesel fuel. He is having a devil of a time getting it to make proper power. When he is firing on diesel fuel and you open the firebox door, the fire in the firebox is a definite yellow color.

Is this correct? I am not sure what I expected to see, but the flames are definitely yellow.

Any comments?

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Steamer Bill Smith
Cypress, Texas U.S.A.
Houston Area Live Steamers

Yep, that's what it should be....Bright Yellow.

Here is a picture you can see the fire thru the door.

Part of the problem with firing oil ( or for that matter any fuel ) is getting the right air mix.
You don't want too much primary air i.e. the air that comes in at the burner opening. The secondary air on the sides or the bottom of the fire pan is important and needs an adjustable louver. On my 15 in. ga. engine I also have a damper on the fire door for overfire air which is prototype practice.

BTW is the oil being atomized or is the burner a drip type?

John B

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http://www.ngshay.com/
Shay drawings and castings

The fuel is being atomized. The symptom is that only one of the two atomizers appear to be operating, which obviously prevents it from making full heat (for lack of a better term). The two atomizers are fed by a single fuel pipe. There is a fuel adjustment as well as an air adjustment which seems to work properly on the one atomizer that is operating.

When initially firing the engine external air compressor is used for air and then later the steam driven blower is used.

Thanks for the feedback by the way.

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Steamer Bill Smith
Cypress, Texas U.S.A.
Houston Area Live Steamers

Bill,
A couple of questions

You say the fire is yellow when you open the firebox door. Can you crack the door or maybe look under the firebox and see what color the flame is without letting all of that air in?
There may not be enough oxygen getting to the fire with the door closed.

You also said the oil line feeds two atomizers. Burners, right? What size is this line?
Might be starving the fire, but then that would be opposite of whether the fire is getting enough air with the door closed.

Depending on the size of the boiler one burner/atomizer should be sufficient. Chet Petersen had three in his Northern, but then that was one big Motha. Something like an Allen ten wheeler, Railroad Supply Mogul or something like that should run just fine with one burner if it is getting enough fuel and oxygen.

A couple of more. Is there an in-line fuel filter? Is it clean? Is there a separate adjustment for the second atomizer steam line? Could you be blowing steam into the firebox through both atomizers yet only putting oil into one?

A few things to look for.....

Brian

Bill

BTW don't worry about the color of the flame just make sure the exhaust coming out the stack is clear and not black.

John B.

_________________
http://www.ngshay.com/
Shay drawings and castings

No stack haze at all could mean too lean as well John, but he'd probably find that out as soon as he pulls the throttle!

Grins,
Brian

Hold on. What exactly does this mean? Are you making proper steam pressure, or is the engine failing to use the steam generated? There's an easy test for the engine itself when cold. Close the angle cocks, and put the engine Johnson bar in full forward. Push it gently backward a bit, and when you let go it should roll forward again. If you can't do that, it's not the fire..

tburzio,

Could you explain what that test is trying to prove?? I have a guess or two but I'm still learning things and would like to know.

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-ken cameron
Syracuse Model Railroad Club http://www.SyracuseModelRr.org/
CNY Modelers http://www.cnymod.com/
Finger Lakes Live Steamers http://www.fingerlakeslivesteamers.org/
Member JMRI Developer Team http://www.jmri.org/
mailto: kcameron@twcny.rr.com
In the Upstate New York US area of the world

Throttle closed, Johnson full foward, the cylinders become an air compressor when pushed in reverse, and charge the steam feed lines. This modified principle was used in mountain engines all over the world, to retard the trains without using the brakes escessively. It will tell you if your system is tight, although slide valves will have a tendancy to lift.

Engines were modified so as not to draw through the petticoat, and inhale cinders and smoke from an idling Downhill engine.

Several Utube rail vids show Indian engines running downhill, with a noticable hiss-hiss-hiss, as they go by. That is the engine venting air from the retarding throttle. More pressure built up, the slower the engine will roll down hill.

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Big Dave

Be Alert! The world needs more Lerts.

Good post on the wrong forum!

Not anymore!

Harold

Nto to throw fuel on the fire but there was an engine runnign in the Midwest that was 7.5 NG that was oil fired with 50/50 fuel oil, and drain oil Mix. I dont know the details, but it ran clean without smoke, and only the faintest of blue puffs as the throttle began to open, clearing up quite nicely even at low speed. Only the heavy starting chuffs, held any blue. Sorry, I dont remember the owners.

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Big Dave

Be Alert! The world needs more Lerts.

That is generally what I burn. The fellow next door changes his oil every 2000 miles so I have a great supply of barely used oil to mix with diesel at the local BP. It burns just fine.

John B.

_________________
http://www.ngshay.com/
Shay drawings and castings