Steam & Excursion > Elesco vs Worthington

Could someone please compare the pros and cons between the Elseco and Worthington feedwater heaters? Thanks!

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Open heat exchanger vs closed heat exchanger....

Typical Elecso systems used a singe pump ( but with two parallel cylinders). the pump drew in water from the tender, pressurized it to above boiler pressure ( in order to open the chackvalves ---- both the pump's discharge check and the boiler check.

Thus, all the piping, the heat exchanger and the piping between the heater and the boiler check was under pressure, greater tha boiler pressure.

The heat exchangers were tubes, under pressure from the feed pump, surrounded by hot exhaust steam contained in the heater housing. The hot exhaust steam surrounded the myriad of tubes in the bundle, thus transferring heat to the pressurized water.

There were two types of heat exchangers marketed by ELESCO, but the familiar cylindrical bundle is the most common.
The other style was sometimes referred to S the "coil type".  The coil type enclosed about 6 copper coils, resembling coil springs.
However, the coils contained an inner and an outer winding, so that the open ends were at to bottom of the coil assembly.
The coil ends were a 'ground joint' meaning that they were metal-to-metal, gasket-less, open tube connections.  
Large through-bolts  extended above the coils and a large retainer plate, held by a suitable nut, lock washer, etc.  
Ground joints also did not use any threaded fittings of the tubing, or on the manifold.

The ground joint typically uses a spherical section machined on the end and polished ( ground)  and the manifold was reamed with a mating seat, tha was true conical in shape, typically a seat ground to a 45-degree angel.  The coil,was clamped to the manifold and the 'ball-cone' ends became a self-aligning, steam-tight joint.

The ELESCO 'bundle' type of heat exchanger was typically mounted at the front of the smokebox --- and eitherartially concealed, or hung out in front of the smokebox....giving a serious look to,the werare of the 'brow'.

The bundle heater, was divided into 4 quadrants of tubes, and the pressurized water made 4 circuits inside the heater, all surrounded ny hot exhaust steam.  The hot and cold supply pipes were typically mounted next to each other, and could be either vertically oriented, or horizontally oriented. 

The cold water was pumped, first through the primary quadrant, the split end cap ( the cap had a divider, so that the flowas driected  back through the next pass of tubes,  a matching split end cap, was mounted 90-degrees differten, so that the second pass was above the first, pass...thus the third pass was adjacent to the second, and the fourth pass was below pass number three.
Thus the inlet pipe and the outlet pipe were adjacent.

The exhaust steam, partially condensed on the outside of the enclosed copper tube bundle, and the resulting condensate water was returned to the tender, and was collected in a separating drum in the tender's cistern.  This separating chamber allowed the valve oil whic was carried over from the cylinders, to float to the surface and was syphoned-off, down to the ground.

Retaining valve oil in the feed water, and not expelling it, results in sever foaming other water in the boiler, being fed oil-polluted  feedwater.  ELESCO also ( commonly) fitted the exhaust steam pipes that ran from the exhaust cavity in the cylinder saddle to the steam inlet to the heat exchanger, with 'mechanical' separators that contained centrifugal vanes to spin the steam and whirl out the oil droplets, that were sent to the ground under the smokebox.

The closed type heaters suffered from two problems: one was dissolved minerals ( in the feedwater) that became separated under the heat of the process. The minerals, typically a calcium compound, built up, over time, on the inside of the heater tubes.
This calcium build-up was a very effective insulator.....effectively preventing any heat transfer into,the cold feedwater.
Elesco tried lining the tubes with vanes to give a spin to the flowing water....of limited useful benefit.

The second challenge was related: the steam from the cylinders aiways carried with it the valve oil droplets from the cylinders.
When the hot steam met the cold copper tubes, the oil droplets cling to the external surfaces of the copper tubes.
This oil build-up on the surfaces of the tubes also builds-up an insulating, non-conductive, layer of goop that prevents virtually any heat transfer.

Elesco fitted the external feedwater piping, with special wash-out fittings.  An ELESCO-supplied flushing, circulation & acid wash machine that, when both ends were connected to the washout fittings, recirculated acid water through the coil interiors to dissolve the calcium layers that built up, over time.   Typically, this procedure was performed at monthly boiler washouts....

I'm running out of room using this message system...so I'll do the Worthington System later, or i'll yield the floor to others to explain how that system works...
Please...

W.

 



Edited 4 time(s). Last edit at 10/11/16 18:27 by wcamp1472.

Interesting that four pass exchangers are still very common in hyraulic applications where water use (cooling media)
is an issue. We use the same sort of end casting to direct flow and most manufacturers install some form of "turbulator"
in the tubes to reduce the issues of laminar (insulated by layers) flow ie induce turbulence to increase heat exchange.
Some old things still work today as well as they did years ago.

Out

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Out...

Thanks, I hadn't realized the connection to modern hydraulics, fluid dynamics .

Very applicable comparison.  

​W.

Ready for Worthington locomotive feedwater heating systems?

Here goes....

There are major 2 styles of Worthington feedwater heaters that were marketed, along with some one-off variants.
The two types I will describe are the BL type and the SA type.

They were offered in various capacities, in gallons per hour of water fed to boilers.

The major identifying characteristic of the BL is that it is a large, one-piece heater and pump,assembly, typically mounted on the
fireman's side of the loco.

The BL heaters combined a low pressure pump ( takes water from the tender, and a high pressure pump that takes heated water from the open mixing chamber, and forces the hot water ipast the boiler checks and into the boiler.

There is one pump shaft to the reciprocating water pump.  There are two separate pumping cylinders, and one steam cylinder, at the top of the pump stack.   Cold water is pumped into the heating chamber, and passes through a spray head, under modest pressure.

The sudden decrease in water pressure, as the water exits the spray head effectively releases dissolved air and related gasses, like opening a shaken carbonated soda can.  Dissolved gasses, if released in the boiler,  produce rapid oxidation effects on the interior boiler steels.  The most deleterious dissolved gas is the oxygen component of air.
The releasing of virtually all ov the dissolved gasses is a higher benefint to the Worthington pumping systems.

A portion of the steam exhausted from the cylinders is fed to the mixing chamber of the combined heater and its pumps....
The cold water spray condenses the exhausted steam, and sprayed the water is heated by the copious amount of steam that is available while running.

The level in the mixing chamber typically sits at the height of a straight pipe that acts as a skimmer, and flushes the congealed valve oil tha floats on the heated water, down the skimmer pipe.  The released air gases are vented out the top of the heater chamber to a pipe, typically, at the top, front of the smoke stack.

In the BL, the two different temperature water chamber pistons, are operated together, in tandem. So that as water is drawn from the hat water chamber and forced into the boiler, the cold water piston draws water from the tender, and feeds it to the heating chamber.

The SA type system separated the two pumps and the heating chamber.  The heating chamber typically sits in the top of the smokebox, in front of the loco stack.  Typically a centrifugal cold water pump, is mounted on the loco, at a level below the bottom of the tender'S cistern.  This pump is operated from the same steam line that feeds the high pressure pump at the front of the loco.

Again, these are TYPICAL locations for mounting theses components, and many RRs had other favorite locations, so there many variants. To the 'typical' application.  

The SA systems were offered in various sizes, like from 5SA, to 7SA, and higher....Again according to boilers size and steaming capacity.

The same advantages of the heated tank on the BL system, were available on the SA-type.  A major advantage of the SA system
was the smaller size of the individual components over the all-in-one massive casting of the BL model.

​W.

Thanks, Wes, for the detailed descriptions of the two feedwater heater systems.   Appreciated by this student of steam.

One area we have trouble accessing, on a historical basis,  is the marketing of the systems, their comparative costs, and the sales
'incentives' offered to RRs  and the purchasing officers, to influence the builders' product selections.

The superior system, in my humble opinion, was the Worthington SA system, mostly because of its simplicity, the easy way the dissolved air/gasses were eliminated,  and the easy separation of the exhausted oil that floats as scum on the surface inside the heater box, this scum is continuously skimmed off the surface while in operation.

So, feedwater heating was a very successful necessity, and the various schemes are interesting to study...including the (late in the cycle) popularity of the exhaust steam injectors.....they worked well when new, but most were confusing to operate, unreliable and many were replaced by the simple, live-steam injectors.

Oh, and yes, I prefer lifting injectors to non-lifting injectors because of the better water delivery regulation at reduced flow rates.
By feathering the water flow, you can slow down the water going into the boiler and reduce the cycling of the injector on & off.
The 'cycling' of the non-lifting injectors occurs because so much water floods the boiler, compared to the actual steam consumption while cruising down the rails.  So the operator was continually turning-on the injector and turning it off.....

Feedwater pumps allow slow and steady pumping of the boiler was the ideal way of maintaining an uniform boiler temperature, as well as can be expected.  So most modern engines had feedwater pumping systems, which you could regulate down to a trickle, while running across the typical rail profile.  These were supplemented by non-lifting injectors, as the back-up water supplying system.

Large injectors, like the Nathan 4000 ( various capacities), were applied because, if over-heated, the non-lifting 'guns' cooled down really easily when the water valve was opened,
And these guns could really put out a torrent of water when needed.  
So, most modern engines ran using a slow cycling feed water pump, supplemented by a 'fire hose' of an injector.

​W.

 

Very many thanks for your explanations of Feedwater types. I am slowly learning more about steam locomotives and this was very timely, as questions do arise like why is one type/style/method preferred over another? Also helpful was your explanation on injectors. Bring on some more techno-explanations please!
 

The lifting injector had it's feed rate somewhat throttled by the requirement of a level of vacuum to lift the water. The
non-lifting had a flooded suction and instant prime. Look at the curves of any centrifugal pump, flooded suction vs some
feet/inches of lift, there's a sizeable difference in outflow.

Out

RE: dbinterlock....

Your interest in steam locos is heartening.
Please keep your curiosity at a peak state.

I had, and still have, a burning curiosity in understanding why and how these machines are so fascinating.
I have faced the same puzzles that that stump So,many of us....and it is the search to fill-in the gaps in our own knowledge.

So, this quest you're on is one that consists of taking things you HAVE figured-out and understand, and then expanding those related solved problems to give you insights into the 'new' concepts.

I encourage you to continue to make progress by linking what you already know, add the fundamental questions and expand your knowledge into the new areas.

It is also important to keep your B.S. Detector at the ready.....there are many folks who will try to concoct totally false stories about how these things work.

It is my fondest hope that many people will be encouraged to become involved in many restorations that are waiting your unique efforts to bring them back to life.

Welcome to The Journey..  The journey where you discover who you are, and what you have to contribute.
Many, many years ago, the dream of a restored SP 4449, burned brightly in my imagination.... but, it was a small band of friendly mechanics that all started where you are ----- and these folks have all had to learn the basic laws and the rules.
Never give up on your own powerful dreams.
Keep your curiosity burning brightly.....

My current dream is that new folks will pick up the hammers and tongs, and keep steam alive, in the decades to come.
Also, may you be lucky enough to find as good a leader and a mentor, as Ross Rowland was to me.... 

Thanks for becoming involved,  keep your curiosity burning brightly, learn, enjoy, share and accomplish.
You will surely be rewarded.

​W..
 

Thank you so much for your words of encouragement. It will be quite a journey, and it will have to wait for after retirement, but the flame of curiousity burns bright and will not be quenched.
It all started with my favorite Fallen Flag railroad NYC that had those impressive Niagara's which set my mind to the look of modern steam, and then I got wondering about the Hudsons so I bought the NYCHS book, talking with a friend who is deep into streamlined Pennsy, followed by an ebay purchase of a used Kalmbach's Steam Locomotive Encyclopedia, couldn't resist a Broadway Limited Model, going on a few walk arounds of 844 and 4449 and getting a private tour of ATSF 3751 at the Redondo Roundhouse, and....
The long and winding road awaits, and is so much fun!

The various earlier classes of NYC Hudsons used ELESCO bundle type heaters, ----- some were nearly hidden in the top of the smokebox, and still others used the Coffin feedwater system.  The major distinction with the Coffin system was a single large centrifugal pump ( mounted down in front of the trailer truck, on the fireman's side...),  and a rectangular heat exchanger wrapped to fit the curve of the smokebox.

Some Coffin heater applications, on other 'roads, hung the Coffin neater out in front of the smokebox, others like the NYC moved the smokebox front forward, ahead of the Coffin heat exchanger.

Glad to have you aboard The Journey....

W.
 

dbinterlock, your story sounds similar to mine.  I guess you know from my "handle" what my favorite fallen flag is, and I'm old enough to remember steam running through my old home town on the Central.   Which NYC book did you buy concerning the Hudsons?  Al Staufer's or the new one by Tom Gerbracht?  Like you, I got a renewed interest in steam and for the last 25 years have supported as much as I could all the operating steam in the USA.  Rode behind 3751's initial outing after restoration, New River behind (2)765, actually ran the 1225 back in their "Engineer for an Hour" days, rode with the 261 and crew, two Sacramento railfairs, Steamtown grand opening and after moving to Oregon have participated in as many of 4449 and 700 outings as I could.  There have also been many visits to the steam tourist lines and quite a few of Martin Hansen's photographers steam specials.  Nothing like a breathing, live steam locomotive.   It has been a great hobby.
Photo of NYCS J-1 5292, Elesco feedwater heater, from the collection of Harold K. Vollrath.
 

---

I don't know about all the relationships between railroad motive power departments, locomotive builders, and appliances salesmen.  I'm sure, however, that these interpersonal relationships di play a part in decision making as to what was applied to any particular railroads selection of such devices at initial purchase or rebuilds.

I've had a fair amount of experience handling two locomotives with advanced feedwater systems (as opposed to a straightforward injectors), and view this question from the operations (not purchasers) perspective.

All locomotives are required to have two separate systems of feeding water into the boiler, one of which must be a conventional lifting or non-lifting injector. Both systems must be fully functional at the start of each day.  If one fails, you may continue.  If both fail, The engine must be taken out of service.  RIGHT NOW!

On all railroads the engineer was responsible for ensuring that proper water level was maintained in the boiler.  On most railroads (exceptions were primarily on Eastern roads) the engine was set up so that the control for the requisite injector was under his direct control (i.e. was physically placed directly within his reach) and the secondary system was placed on the left side within easy reach of the fireman.  In the East, both were within reach of the engineer.

Therefore, in the East both systems were controlled from the right side of the cab, while from a practical standpoint, elsewhere the fireman working under the engineers supervision.

The two engines I've worked with with feedwater heaters are SOO 2719 (4-6-2) amd SOO 1003 (2-8-2).

The 2719 has a Worthington Model 3 1/2 SA.  It is mounted in a very unique position on the pilot beam, rather that at to top front of the smokebox per Wes' description.  To operate it, a single globe type of valve is turned to regulate steam supplied to drive the cold water pump.  It has the disadvantage that it only heats water when the engineer is working steam.  When the engine is not working steam it pumps cold water (somewhere between 40 and 60 degrees F) into the boiler, which is not a good thing.  Do this for a minute or so and you will start to hear the boiler make popping, clicking, ticking, or pounding noisess indicating sthe stgress this puts on the boiler.  When sitting at station stops, or other times when its undesirable to add cold water to the boiler, it is preferred to use the Ohio lifting injector on the engineers side, instead.  The best time to use the squirt hose to wet down the coal pile or flush dust off the cab interior and floor is, of course, during station stops.  The squirt hose takes its water from - you guessed it - the cold water delivery pipe to the feedwater heater.  Thus,  you have to run the feedwater heater supplying cold water to the boiler in order to wash down the cab, deck, or coal pile.  Not a good arrangement.

The 1003 does not have a true feedwater heater, but r froather it has an Elseco exhaust steam injector, knicknamed a poor mans feedwater heater.  When the enigne is not working steam, this device functions exactly as a non-lifting injector, but when working steam it automatically switches to function as a nonlifting injector but takes its steam supply from a pipe from the exhaust passages of the cylinder casting.  Slick!  It does not have any of the problems of delivering cold water that the Worthington does.

-John

LarryDoyle Wrote:
-------------------------------------------------------
> The 2719 has a Worthington Model 3 1/2 SA.  It is
> mounted in a very unique position on the pilot
> beam, rather that at to top front of the smokebox
> per Wes' description...  

Actually we had a thread on that feedwater heater about five years ago, which you contributed pictures to:

http://www.trainorders.com/discussion/read.php?10,2567977,2568696#msg-2568696

The 3 1/2 size is correct, but the heater actually is the elusive Type SC2A, 

Thank you wcamp1472, nycman, and LarryDoyle. More great steam tech stuff to mentally gnaw on. Also a nice shot of an NYC Hudson. Good lookin' engine there. I did just purchase "Know Thy Hudsons" by Thomas R. Gerbracht.
    Now why would a boy developing a powerful nascent interest in trains growing up in Santa Barbara, CA, Espee territory exclusively, form an interest in the Central? I was 5 years old when the merger with Pennsy was consumated. My dad did tell me stories of commuter trains in Yonkers, Poughkeesie, and NYC proper, but that wasn't it. It was my first book purchase, "Focus: The Railroad in Transition" by Robert S. Carper. Plenty of NYC pictures and this really modern system called "Flexivan." The future seemed so potentially bright and exciting. Those early impressions do have a lasting effect.
    Tonight I'll crack that Hudson book, and after a bunch more tomorrows, who knows what fun with steam I may get into?