Steam & Excursion > Oil-fired steam.

When under heavy acceleration, steam engines all belch a lot of smoke...coal burners do, but there doesn't seem much that could be done about that short of granulating coal...costly.  But oil burners...  The smoke is really unburned fuel plus impurities.  Is there no way the atomizer in the firebox, not so different from the one in your oil-fired heating plant at home could be "programmed" or adjusted to avoid that blast of unburned fuel?  It looks neat, but it seems to be money up the stack...

Depends mostly on the fuel being burned, and how well the Fireman was prepared.

HotWater Wrote:
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> Depends mostly on the fuel being burned, and how
> well the Fireman was prepared.

You mean like Diesel? 😏

bankshotone Wrote:
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> HotWater Wrote:
> --------------------------------------------------
> -----
> > Depends mostly on the fuel being burned, and
> how
> > well the Fireman was prepared.
>
> You mean like Diesel? 😏

No, as the Engineer has absolutely no control over the combustion process, unlike an oil fired steam locomotive where the Engineer and Fireman are in total control.

I disagree with the statement that under heavy acceleration steam engines all belch smoke.
On an oil burner if the engineer and fireman are in sync it will belch a lot of steam with a light tint of gray from the combustion. If you are belching black smoke, your fire is orange instead of being nearly white. As you said, black smoke is unburned fuel and will only accomplish sooting up the flues/tubes. And back in steam days could get the fireman a "Smoke Letter".
Firing valve, atomizer and temperature of the #6 or Bunker C oil, engineer and fireman working together and "knowing" your railroad make for a good trip. Nothing like experience.

If you have your fire right, know the railroad and your engineer, , when he widens out on her, that haze might dissappear for a few seconds and then return, but no huge clouds of smoke.

Txhighballer Wrote:
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> If you have your fire right, know the railroad and
> your engineer, , when he widens out on her, that
> haze might dissappear for a few seconds and then
> return, but no huge clouds of smoke.

Right. 

Remember the original poster is an airline Pilot, and why he thinks the "atomizer" is the cure-all, is beyond me.

To add to what's been said, steam locomotives certainly do not automatically make smoke during heavy acceleration. In fact if you do nothing they will actually have a clearer stack because of the increased draft. But when you sometimes see smoke during hard acceleration, particularly on oil-burners, it is a function of the fireman crowding the fire and trying to maintain boiler pressure near the maximum. During an initial departure, when the engineer opens the throttle a significant amount, there is a tendency to lose steam pressure due to the firebrick not being warmed up, etc. In order to minimize this loss, the fireman will sometimes fire heavier than normal until the pressure comes back up to where you want it. On an oil engine you can sometimes increase atomizer to help clear up the smoke, but only to an extent. Some engines it won't really help at all. And the idea of making smoke to crowd the fire to keep steam up also only works to an extent, because the more smoke you make you'll end up sooting up your tubes and insulating them. Then you'll need to sand them out. Traditionally, on an oil engine, the first hard pull upon a departure is a good time to sand out, and this will make a significant amount of smoke for a few seconds. So that is another reason you will see smoke when accelerating.

Scott Gordon

HotWater Wrote:
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> Txhighballer Wrote:
> --------------------------------------------------
> -----

>
> Remember the original poster is an airline Pilot,
> and why he thinks the "atomizer" is the cure-all,
> is beyond me.

it should be slightly obvious I'm not completely immersed in railroad jargon, and getting the fuel to burn efficiently, I presume, requires some sort of delivery, which in most oil - burning boilers is referred to as an "atomizer", in this case a generic term, and I make no claim to its effectiveness...if that's not the correct terminology, or correct device, please forgive my lack of knowledge, which is precisely why I asked the question.  Thanks for all the good answers.



Edited 1 time(s). Last edit at 03/16/25 15:41 by a737flyer.

a737flyer Wrote:
-------------------------------------------------------
> HotWater Wrote:
> --------------------------------------------------
> -----
> > Txhighballer Wrote:
> >
> --------------------------------------------------
>
> > -----
>
> >
> > Remember the original poster is an airline
> Pilot,
> > and why he thinks the "atomizer" is the
> cure-all,
> > is beyond me.
>
> it should be slightly obvious I'm not completely
> immersed in railroad jargon, and getting the fuel
> to burn efficiently, I presume, requires some sort
> of delivery, which in most oil - burning boilers
> is referred to as an "atomizer", in this case a
> generic term, and I make no claim to its
> effectiveness...if that's not the correct
> terminology, or correct device, please forgive my
> lack of knowledge, which is precisely why I asked
> the question.  Thanks for all the good answers.

OK but, relating to '"stationary boilers" has NOTHING to do with oil fired steam locomotives and your comments related to smoke really had nothing to do with the "atomizer". You might want to research just how oil fired steam locomotives were designed/built.

I thought it was an interesting question, with intresting answers; and learned something myself.

Kirk Out 

HotWater Wrote:

> OK but, relating to '"stationary boilers" has
> NOTHING to do with oil fired steam locomotives and
> your comments related to smoke really had nothing
> to do with the "atomizer". You might want to
> research just how oil fired steam locomotives were
> designed/built.

Perhaps you could at least give the OP some direction for his/her research.  Nobody is born knowing this stuff. 

sf1010 Wrote:
-------------------------------------------------------
> HotWater Wrote:
>
> > OK but, relating to '"stationary boilers" has
> > NOTHING to do with oil fired steam locomotives
> and
> > your comments related to smoke really had
> nothing
> > to do with the "atomizer". You might want to
> > research just how oil fired steam locomotives
> were
> > designed/built.
>
> Perhaps you could at least give the OP some
> direction for his/her research.  Nobody is born
> knowing this stuff. 

Being a "737 Pilot" he/she seems to know it all, anyway.

It's. Simple:

An atomizer for locomotives is a long, tongue-like oil burner, designed for 
heavier weight fuel oils, like used to come from old-time refineries.
The  Navy first use the heavy 'resid'(ual) in big ships, rather than the 
continued use of coal.  Now, Resid is hard to find these days because 
refiners have found markets in plastics and other economic
cash flows.

On locomotives the burner ( atomizer) consists of two, wide, flat passageways,
making-up the burner: steam in the lower passage, oil o top.

The passageways made wide-flat 'fans' of the pre-heated  fuel.
the burner assembly and steam and oil lines are mounted 
Kon the longitudinal centerline of the boiler, and way up front,
down-low  & near the front of a trailer-truck, if equipped.

The preheated, thicker, fuel ran quicker and broke into droplets very rapidly,
wnen the drool was busted-up on top of the "steam fan", of the loco's burner.
There are two fuel heaters for handling the heavy resid: one to warm the 'resid'
oil in the tender.  At ambient temperatures, resid become a heavy solid,
and shrinking volume.

At loco fuel terminals, the resid is pumped slightly warmed, but, when adding fuel to the 
tender's tank,  you always needed to save expansion room in tenders' oil tanks ---
so you didn't run black, slippery goo all over the place!  The expansion rate of that oil 
is an unexpectedly big volume --- especially at 5000, or so , gallons.
An over-filled tender can expand by a several hundred gallons --- can make quite a mess!

In oil burner locos, the most important aspect of successful combustion is
ensuring that there is 16-times the WEIGHT of Oxygen for every droplet/ ounce
of oil molecules..  That amounts to immense quantities of air to burn a nice 
clean, hot fire.  Black smoke is the surest indicator of way-lower combustion.
Temperatures....adding more fuel simply tends to cool & extinguish the flames...

So, there is a fixed large air hole surrounding the burner, for initial
combustion air at the burner.  A seconday, manual damper, operated by the 
fireman, allows him to adjust the secondary air flow damper to match the throttle
setting and running style of the engineer.

The lower slot of the burner shapes the Atomizing steam-flow into "a flat,
moving table" of steam that carries the drooling fuel toward the fireman's firebox door,
and to it's rearward, second oxygen flow inlet of ( combustion air) at the firebox's
door-sheet, near  the fireman's right knee.

On SP 4449, there are, additional dampers to the original  2.,
with two long, longitudinal air dampers, along the bottom side sheets of the
firebox, one on each side.  They are counter weighted, opened under strong 
draft rates. & to close at low drarft rates, so that they automatically regulate
the incoming air-flow to match the strength of the draft, as determined by
the number of cars, & the track-route hills profile.

How hard the engine is worked is the greatest determinant of air flow to and
through the firebox.  The fireman regulates the airflow, but he has very little 
control over the air-flow ----- that's determined by the weight of the cars
being hauled.

The immense amount of cubic feet of air, is hard to grasp,
but, that mixture is common to all carbon-fuled engines.

​W.


 



Edited 7 time(s). Last edit at 03/30/25 21:01 by wcamp1472.