Glenn Brooks wrote: ↑Wed Oct 02, 2019 12:09 am
Russ, did you have a separate oil flow valve- to allow more oil flow? Of just increase steam to atomize more fuel??
Glenn
Definitely a separate oil flow valve. Internal valve passage is diamond shaped for good control.
Then you could control fuel volume, atomization, air mixture, and stack blower to change draft.
RussN
More on oil firing full-sized locomotives.
The logging locos I've run were all originally using Bunker C oil, which is so thick that in winter you can walk across it! I've done that.
So the tender tanks and oil delivery lines were all equipped with steam heaters.
The tender tank had two heaters:
One was closed loop running steam through coils in the oil and exhausting out the top of the tank.
The other heater simply blew steam into the bottom of the oil tank, helping stir up the oil.
This caused water to condense into the oil, so periodic draining the tank of water was normal operation.
The oil delivery lines to the locomotive had steam heating jackets around the pipe delivering the oil from the fireman's oil control valve to the burner at the front of the firebox. So the fireman was also tasked with using these heaters to keep the oil at the best consistency.
With gravity feed and thick oil, heating the oil was required.
In my steaming experience, we used waste oil for firing, and seldom used any heaters due to its light consistency. Although we often "stirred up" the oil in the tender tank using the "mixing heater" during fire up of the loco. And then had to drain the resulting water out of the tank.
So anyone firing their miniature steam locomotive with light oil can appreciate the simplicity of that operation, compared to full-sized firing with Bunker C oil.
I'm just completing a restoration of a steam launch with a Blackstaffe-designed boiler, burning diesel oil. The first test firing might happen soon. I had to design and build a new oil burner because the original excellent cast bronze burner got tossed in the trash by some "helpful" person before I got the boat!!! Along with all the plumbing and other steam devices! It has taken me 4 months of work to re-plumb the boiler and engine, and get ready for testing.
Anyway, I'll soon be learning how to fire this setup, and expect it to be similar to firing a small locomotive boiler.
RussN
I want to thank everyone for their input. Mike, you sir have given me what I needed to know in order to purchase the correct adjustable regulator. Now I know I want a gauge as well.
Thank you
If you are burning oil i.e. Kerosene or Diesel fuel, it is not necessary to pressurize the tank. Just make sure the oil control valve is not too small to allow fuel to flow when the head pressure drops as the tank empties. Based on my experience, this applies to 1 inch scale - 1.5 in scale.
References talking to Dave and Bruce Saylor about oil firing.
Yes a Clippard regulator is used on the atomizer line. Nelson/Dave mention 8 psi for the atomizer. Nelson also mentions putting one on the blower line.
His website is an amazing amount of information in one place for someone building a steam locomotive and is a delightful way to spend some time when building or running aren't possible.
And yes, you need an oil control valve to the burner, a steam atomizer valve to the atomizer at the burner, and a steam blower valve for the blower at the exhaust stack.
Glenn
This is what I did for my 14” gauge Wagner American that previous was a coal burner. I made the fuel tank bottom 6” above the burner. I made a 6” diameter access hole in the top of the tank for annual tank bottom cleaning. All fuel and atomizer lines were 1/8” npt. I had a fuel shut off value at the bottom of the tank next a glass sediment bowl with a brass screen. On the left tender floor was a fuel control value ( needle stem - water bypass value from a steam car something like 20 tpi ). I scaled up a RRSC burner to 3” scale and drilled the oil hole 2 number sizes smaller then scaled. The atomizer value was a regular 1/8” npt steam globe value. I wanted to keep the plumbing as simple and clean as possible. This combination worked very well for me.
Thanks Craig, good description - simple and effective. Looks like the key is coming up with the proper nozzle.
One question: Just to confirm, I assume you mix the fuel and the steam in the nozzle. Or inject steam into the fuel line behind the nozzle, Does it matter...?
Glenn
Moderator - Grand Scale Forum
Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge
Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....
My oil burner (from Eccentric Engineer) uses the same method as the 1964 burner design by Cliff Blackstaffe in my steam launch boiler, rated > than 2 h.p.
I designed an assembly using the E.E. nozzle, because the original oil burner was missing when I acquired the steam launch project. I measured an identical old burner for measurements and dimension, so I am confident the new burner output is equivalent to the original design.
Oil enters the central chamber with an outlet hole just 0.059" diameter.
Steam enters a surrounding chamber and exits an annular ring around the oil nozzle.
This produces a vacuum in the oil outlet which sucks the oil out and mixes it with the steam.
That resulting oil/steam fog is combustible.
Varying the oil flow and the atomizer pressure determines the Btu output of the burner.
I performed some burner experiments on a test stand and indeed the oil will get sucked from the top of a container six inches above the burner!
I did not test how high it would work. The atomizer was propane from a small 1 lb tank.
A gravity flow system should work quite well, due to the vacuum produced by the atomizer.
RussN
My experience oil-firing was with the BJWCRR #2, 18" gauge. Gravity feed, no regulators, separate valves for oil, blower and atomizer, although the blower and atomizer valves were on the same branch from the turret. The atomizer used an insignificant amount of steam. I liked having no regulators, because then as the pressure rose and you increased the oil, the atomization increased in correspondence. Unless you had to go to a spot fire, once you set the atomizer at the start of the day it was pretty much good to go the rest of the day. The burner was a plate burner, the oil ran from a tube on top of the plate to the lip, and the atomizing steam was coming from a tube on the bottom side of the burner blowing along the bottom to the same lip, where it picked up the oil. It worked well, and had been working well since 1905.