Steam & Excursion > Layden vs. Kylchap Exhaust Systems

Information on the Layden exhaust system seems very hard to find. Can anybody comment on the relative merits of these two exhaust systems, relative to each other? Thanks!

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Don't know about the better system of the two you've cited;
but, simply what you want to research....

The idea with exhaust-induced fire drafting schemes is about getting the greatest
'impingement areas' to entrain the greatest volume of smokebox gasses up the
stack. The more draft volume you entrain, the better the draft; the stronger the draft, 
the hotter the fire...

The more volume of gasses up the stack, the greater the oxygen moved through the
combustion zone of the firebox, to more rapidly burn the fuel.  

In later years, steam-assisted, 'over fire  jets' were used to add oxygen into the smoke over
the firebed.  They were mostly applied in response to smoke abatement measures in cities
that had engine terminals in their jurisdictions.  Often, with many engines sitting idle, and adding
clouds of smoke.

 I have seen positive improvements using over-fire jets on coal burners 
while running over the rails.   Just a light cross-draft adding the oxygen into the flames
will cause the safties to lift!   They can save fuel, if used consistently--- probably adding
2 or 3 eqivalent tons to the tender capacity..

Locomotive Starting exhaust blasts have been the strongest....later, at higher speeds,
as the engineer shortens the valvel admission timing, the less volume of steam up
the stack, at the exhaust periods of the piston cycles.

So, the problem is to get a system that yields  greater effectiveness at speed, than
the conventional common, single-Venturi arrangement. Higher speeds consume greater
amounts of steam, in shorter time periods.

Systems like KlyChap, set up multiple, smaller Venturi jets that resulted in greater total
surface-impingement areas, than the single jet type.   Their systems also had increased
the total exhaust passage areas ( cast into the cylinder saddle, under the stacks)---
resulting in lower back-pressures acting against the pistons.  

This was especially important at starting.....when you want more even
exhaust-steam flow, and not so much the heavy blasts ( which can result in 'crowding' 
pressures between the exhaust nozzle & the valve bushing ports, above the pistons)

During starting, there are fewer exhaust cycles in a time period, and lower total steam consumption,
thus, you don't need the heavy blasting through the grates to draft a good fire.  At higher speeds,
you need a very bright fire to generate the greater amounts of steam that you need at the higher speeds...

Remember, it takes 8-times the numbers of BTUs to get steam from the water, as it took
to get the water to that boiling temperature ... thus, if it takes a million BTUs to get the water 
temp up to boiling, it takes 8-million BTUs to generate the steam --- at the same temperature
as the water you're boiling.  That's why improved  drafting is SO IMPORTANT.

The multiple jet exhaust schemes, have greater effectiveness on increasing the draft volume,
while reducing the exhaust restrictions.   Greater draft effectiveness results in hotter fires,
while yeilding lower steam consumption rates...

Alco and UP developed a very effective arrangement used on the later 800s,
Challengers & Big Boys.  They used two primary Venturi stacks, fed by 4 smaller,
Venturi jets under each of the two primary exhaust stacks.  It was their plan to 
increase the total impingement-area, compared to a single exhaust column.

The four small columns each generated two major columns up the stack ---- all producing
greater exhaust effectiveness, while increasing the available exhaust volume &passages
and lowering back-pressures, at the pistons, at starting..

This arrangement worked very effectively when designing the conversion to burning oil
in the formerly coal-fed fireboxes.  Unmodified Oil burning systems are effectively
wide-open through the firebox account there are NO coal grates and no thick coal bed
of ashes on the grates.

The challenge with oil burners is configuring and regulating the combustion air flow to support
the ideal 16:1 ratio of oxygen gas to carbon gas, by weight.  Thus, steel fire-pans, covered with
refractory  bricks , are fitted with variable damper systems to control & regulate the air into
the combustion space.

The existing multiple exhaust streams in the above locos' smoke boxes worked very well,
in both coal grate systems and with properly designed dampers used with oil burner, pan,
arrangements..

I hope this allows you to evaluate the research you're doing on improved multiple 
exhaust jet schemes. for steam locomotives.

​W.
 



Edited 8 time(s). Last edit at 06/21/21 11:51 by wcamp1472.

Another masterful description of steam locomotive details and operation that I for one would probably never have thought much about, if at all. Wes, you have educated us all so articulately and insightfully on so many details of steam locomotive design and operation that I have long ago lost count. Continued thanks and much appreciation for having done so. I look forward to very one of your posts.

MC

Across the western 'roads, there were many Master Mechanics and mechanical tinkerers
that each added to the total knowledge-base of what makes a successful oil burner combination
in loco fireboxes.

The design challenge was trying to solve the combustion mysteries when trying for
high-firing rates and burning high volumes of oil.   That prediction/calculation conundrum 
was very hard to solve.  It was trial-and-error, over several decades before designing success
was achieved.....

I'm always impressed at the ingenuity of our grandfathers' to pursue the many paths 
to failure , yet pushing ahead to come to achieve forward progress.  

Very little "predictive engineering" on the draft boards was ever contributory to that struggle;
It was very much a process of experimenting and community knowledge-sharing of experiences
its what had worked and what was faulty --- in their trials & experiments.

It is all a Monument to their hard work,  that lsuccessful oil burning locomotives exist today, at all.. 
Discovery of success is continuing today, as conversions are applied to existing coal burners..
it's fascinating watching the "learning process"..... as our processors had struggled, years ago.

Sadly their experiences were shared verbally, with very little written about the experiences and
final paths to success.  There is so much, now lost to the mists of the past....

​W.



Edited 1 time(s). Last edit at 06/21/21 10:19 by wcamp1472.

 The book The Fire Burns Much Better …200 years of steam locomotive exhaust research by J.J. G. Koopman should be of interest to you.   The 1946 proccedings of the Railway Fuel and Traveling Engineers Association of 1946 discusses Multi-Blast Pipe as Tested on Frisco Locomotives. The 1937 has a paper on Front Ends, Grates and Ashpans by E. C. Schmidt.

Dreeamer
 

The Fire Burns Much Better …200 years
> of steam locomotive exhaust research by J.J. G.
> Koopman

What is a current source for the book?

Sounds interesting..I'd like to get it...
I'm continually learning fresh discoveries, and i apppreciate information
and explanations from actual sources that composed the research.

Wes



Edited 1 time(s). Last edit at 06/23/21 08:17 by wcamp1472.

wcamp1472 Wrote:
-------------------------------------------------------
> The Fire Burns Much Better …200 years
> > of steam locomotive exhaust research by J.J. G.
> > Koopman
>
> What is a current source for the book?
>
> Sounds interesting..I'd like to get it...
> I'm continually learning fresh discoveries, and i
> apppreciate information
> and explanations from actual
> sources that composed the research.
>
> Wes

Camden Miniature Steam Services in the UK has it in stock for around 25 Pounds, and shipping isn't too expensive, either.