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- Joined: Tue May 22, 2012 7:50 pm
- Location: Oregon
jscarmozza wrote: ↑
Fri Oct 26, 2018 5:32 pm
How do you regulate steam production during operation? Most importantly, I don't hear a chorus singing the praises of oil firing, I'm not discounting it yet, but I'm less enthusiastic about it then I was yesterday. Very interested in hearing more!
You regulate steam by changing the size of the fire, adjusting the firing valve and atomizer and very rarely the damper to make a nice orangish-yellow flame. When standing you need to use the blower to pull the flames back to the tubes, but when running you normally shut the blower as the exhaust provides the draft. After you've set your fire size you then open and close the firing valve slightly ahead of your throttle adjustments, keeping a slight haze (about like a diesel truck exhaust) in the stack exhaust. You can usually hear when you need to open the firing valve as your fire sounds a little hollow or thin, and you can see when you need to close it as your exhaust is too dark.
I really like oil firing as you don't have to fire as far in front of your demand curve as you do with coal, and you don't have to mess around with gas cylinders like you do with propane. That said, I'm planning on using propane, Train Mountain restrictions, my increasing laziness as I get older, etc.
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- Joined: Fri Oct 28, 2011 10:42 pm
#60 holes sound big to me, but we had more pressure.
meaning, #56 outlet hole, #57 inlet hole/#60 steam Jet, 5 sets of orifices/2500 lb hour fuel flow... so at a #57 hole for fuel, and 50-250 psi fuel pressure, you get up to 500 lb/hr of fuel flow. At 50, it was around 100 lb/hr/hole, as one burner on the minimum stop would give about 500 lb/hr of fuel flow.
That's burning F76/#2 Diesel. If you turned off the atomizing steam, then the fuel flows would decrease, even when the fuel pressure was higher than the steam pressure. (some of my fellow "engineers" couldn't figure out why/how that was possible, when we used 70 lb/hr of steam per burner, I said it was about equal to 7 hp added in per burner...dolts... the oil pump was driven by a 15 hp electric motor, so not that big HP going into the oil system)
Steam was at a constant 150 PSI superheated for atomizing. It came off the desup line, but dropped from 600 PSI to 150, so was well superheated by that.
I'd be tempted to try a smaller set of nozzles in the burner, with more pressure. I get that fuel pressure is only the head pressure, but trying a smaller steam nozzle may result in a better ability to flame shape & turn down.
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- Joined: Tue Jul 31, 2012 1:59 pm
- Location: Germany, Duesseldorf
Maybe I can help a little bit - just my two cents.
A few years ago I had a conversation with James Keith where I answered his questions regarding dimensions of nozzles and such.
My life steam model of a DB class 44 (043) of 5" gauge got oil firing from the start back in 1977. It's still working fine.
Please see drawing of it's burner and some photos of burners built for 1 1/4 " scale locomotives some time later. They all were built of the same principle. No smoke or dripping and adjustable over a wide range
. Dimensions are [ mm ].
- Original (small) burner used for my DB class 44
- Somewhat bigger used for a 7.25 engine
- Conversation with James Keith
- Posts: 312
- Joined: Mon Mar 03, 2014 5:09 pm
Thank you all for the information and advice, along with what was posted here I found some information on line and in a few old live steam books a friend loaned me, the bottom line for me is that I don't know enough about the subject or the boiler on my new engine to be comfortable with oil. Again, thanks to all who took the time to respond. John