Author Topic: Help with Corliss Engine  (Read 7897 times)

Offline sssfox

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Help with Corliss Engine
« on: March 10, 2016, 01:20:34 AM »
I've been collecting material to build a twin cylinder version based on the MEM Corliss.  I have most of what I need now and I have shifted to the research phase.  Over the past couple of weeks, I've been looking for a prototype to help me with the details, but haven't been able to find one.

Has anyone EVER seen a twin cylinder Corliss that wasn't a compound engine, i.e. with a high pressure cylinder on one side that fed the exhaust into the low pressure cylinder on the other side?

I've found a couple of models, but no full scale.  I haven't had any difficulty finding twin cylinder slide valve engines, although, they aren't common.  Most of the ones I have seen were illustrations, not photographs.  Maybe for marketing purposes?

That got me thinking, I've always liked twin cylinder engines because they can start from virtually any position of the flywheel.  When steam engines were in widespread use, were there any other reasons, other than VERY large engines, to install a two cylinder mill type engine instead of a larger one cylinder engine?  I can't recall ever seeing one in person. 

As an aside, my dad worked for a railroad and he took me there several times in the late 1950s and early 1960s just to show me steam engines before they went to scrap.  Among the things he showed me on the last trip were two steam powered air compressors.  One was still working, but the other was in the process of being cut up by a guy with a torch.  They had 5ft or 6ft flywheels and supplied compressed air for the entire yard.  They were being replaced by a 20hp electric compressor on an 80 gallon tank.  I asked why there were two of them and he told me it was because they needed an uninterrupted supply of air and had to be able to shut one down for maintenance or repair.  That made sense to me and I figured that was why they didn't have just one with two cylinders.

At every location where I have seen a working steam engine still hooked to equipment, none had two engines with one used as a spare. I have never been able to figure out if it was because they hardly ever broke or factories didn't run 24hrs a day, so they did maintenance and repairs at night.

Anybody got any answers?

Offline Maryak

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Re: Help with Corliss Engine
« Reply #1 on: March 10, 2016, 01:38:49 AM »
Your question is to me similar to how long is a piece of string?

As far back as one can go in the industrial age, services deemed essential had/have some form of backup system. The backup in many cases did not replicate the main system, rather it was smaller and backed up what was/is truly essential.

The  choice between simple and compounded engines is usually one of ease of operation/maintenance versus economy.

Bob
Если вы у Тетушки были яйца, она была бы Дядюшкой

Offline sssfox

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Re: Help with Corliss Engine
« Reply #2 on: March 10, 2016, 01:49:17 AM »
Sorry to have taken up your time.
I'll try to ask better questions next time.

Steve Fox

Offline crueby

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Re: Help with Corliss Engine
« Reply #3 on: March 10, 2016, 02:33:59 AM »
Don't give up too easy.

One example was the 1876 exhibition engine,twin beam with corliss valve gear.

It may be most were compound since they were more efficient, efficiency being the main draw of a corliss valve setup.

Offline sssfox

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Re: Help with Corliss Engine
« Reply #4 on: March 10, 2016, 12:54:36 PM »
Maryak,
I apologize for my last post, it was unwarranted.
Steve Fox

Offline pgp001

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Re: Help with Corliss Engine
« Reply #5 on: March 10, 2016, 01:10:13 PM »
Efficiency was everything at the time Corliss engines were being built and used, I have personally not come across a double high pressure twin (I am not saying there never were any)
You will also find that a lot of these engines were fitted with condensers as well in a further bid to improve efficiency.

The fact that a twin would self start was not too important because they were only ever stopped very infrequently, maybe once a day at a shift change. These engines normally have a barring engine which is used to position the crank into a starting position ready for steam to be applied.

Out of interest, I am building a 1/16 scale Corliss tandem compound which has the features I describe above.

Phil

Offline Jasonb

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Re: Help with Corliss Engine
« Reply #6 on: March 10, 2016, 01:24:15 PM »
I suppose you could always build it as a double high but make one cylinder larger externally so it looks like a low pressure one and add a dummy link pipe. That way you will not have to worry about too many mechanical alterations to the design and will have a larger choice of original engines. Also unless you are going to be running it on reasonably high steam pressures it won't compound anyway, certainly not if air run.

As the others have said why would an engine maker go to the trouble of building an efficient corliss engine to then only use half the energy of the costly steam?

Offline sssfox

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Re: Help with Corliss Engine
« Reply #7 on: March 10, 2016, 03:47:11 PM »

It may be most were compound since they were more efficient, efficiency being the main draw of a corliss valve setup.

crueby, You must be correct.  I was afraid of that and the more I read, the more it becomes apparent that was the case.  I just went through three more books from the late 1800s and found nothing to the contrary.  In fact, from what I have read, the larger the cylinder, the more efficient it is at retaining heat, which leads to higher efficiency, so there is no reason to build a twin cylinder engine that isn't compound unless the desired output is larger than the capacity of a single cylinder, which appears to be somewhere north of 800hp.

Corliss had deals with most, if not all, of the companies where he installed engines.  He charged a fixed cost or a percentage of fuel savings.  According to the records, most companies took the percentage of fuel savings, which turned out to be much more expensive than the fixed cost would've been.

I also read that the low pressure cylinder was one to seven times the volume of the high pressure cylinder.  I have no idea how that works out in the modelling world using compressed air and/or steam.  If I'm going to proceed with this, I guess I need to research some of the model compound engines to find out what ratio and valve timing they use for the second cylinder.

I watched the "Starting the Big Red Corliss Steam Engine" video here:
<a href="https://www.youtube.com/watch?v=PIza2qnOgQY" target="_blank">http://www.youtube.com/watch?v=PIza2qnOgQY</a>

At 4:44, It says "the LP cylinder is working with expanded steam therefore is no need for Corliss gear although it has got one for reasons of balance.

It strikes me as odd that they would go to the trouble of installing all of that extra equipment just for reasons of balance. I really like that flywheel.

I'm sure there are other factors involved in these designs, but some knowledge is assumed to be so well known and apparent at the time that it isn't written down.  What was obvious to people at the time, isn't so obvious to us now.  Since all of the people who designed and installed these incredible examples of technology are long gone, I guess I'll never know.

Offline kvom

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Re: Help with Corliss Engine
« Reply #8 on: March 10, 2016, 05:15:31 PM »
Since there is only one regulator controlling cutoff, I assume that the LP cylinder gets the same cutoff.  Although the steam in the LP cylinder is expanded, it still has energy available from further expansion.  That's why there were 3 and 4 cylinder compounds possible.

One of the benefits of the Corliss design was keeping boiler pressure constant.  I wonder if the valve on the LP cylinder results in the exhaust valve pressure remaining constant as well, and whether that also has efficiency benefits.


Offline Alyn Foundry

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Re: Help with Corliss Engine
« Reply #9 on: March 10, 2016, 05:38:32 PM »
Hello sssfox.

I have been here on many occasions with my models in the past. These engines are majestic.

<a href="https://www.youtube.com/watch?v=sIb5_qDimho" target="_blank">http://www.youtube.com/watch?v=sIb5_qDimho</a>

If memory serves each stroke delivered 4 tons of water to the reservoir situated some miles away !!

Kind regards, Graham.

Offline sssfox

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Re: Help with Corliss Engine
« Reply #10 on: March 10, 2016, 06:50:25 PM »
We have completely lost the ability to build that technology.  Why? Because cheap, fast, small and disposable is better than big and slow that lasts forever.

What is missing at 2:37?  It looks like a piston rod with nothing connected to the end and not enough room to put anything if it was connected.

Offline Jo

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Re: Help with Corliss Engine
« Reply #11 on: March 10, 2016, 07:02:08 PM »
The tail rods used to drive a double acting force pump but over the years the bed fractured and the well pumps were removed to lighten the load.



Jo
« Last Edit: March 10, 2016, 07:05:59 PM by Jo »
Enjoyment is more important than achievement.

Offline steam guy willy

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Re: Help with Corliss Engine
« Reply #12 on: March 11, 2016, 03:36:26 PM »
You could look at the Forncett Steam Musem site .They have quite a few old engines there.....just down the road from me. I go there occasionally and if you would like could take a load of photos for you. Willy, Norwich
« Last Edit: March 11, 2016, 03:42:19 PM by steam guy willy »

Offline sssfox

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Re: Help with Corliss Engine
« Reply #13 on: March 11, 2016, 07:33:17 PM »
Willy,
I would like that.  I appreciate any info I can get.

I looked at their site and with theirs, as well as most others I have found, the online documentation is severely lacking.  I'm sure most, if not all of the websites are run by volunteers with higher priorities.  That makes it difficult to even find existing engines from my chair, much less examples that have been scrapped.  I did find a book that showed there were seven major types of Corliss engines over the years.  I don't know if it had to do with increased efficiency or patent issues or both.  The last one had the valves on the ends of the cylinder, not the top and bottom as earlier ones.  I have never seen an engine configured that way.

From what I did see, the Forncett Steam Museum has two particularly interesting engines, the 150hp Vickers Armstrong cross compound and the Hick Hargreaves 50 HP horizontal single mill engine with Inglis and Spencer's Corliss valve gear.  The Robey 200 HP tandem compound mill engine may be worth a look, but there isn't enough shown in the picture to tell.

Those cross compound engines are of particular interest, but I don't believe there is enough time left in my life to build one.

Offline steam guy willy

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Re: Help with Corliss Engine
« Reply #14 on: March 12, 2016, 04:28:12 PM »

I would like that.  I appreciate any info I can get.



From what I did see, the Forncett Steam Museum has two particularly interesting engines, the 150hp Vickers Armstrong cross compound and the Hick Hargreaves 50 HP horizontal single mill engine with Inglis and Spencer's Corliss valve gear.
Hi. sssfox, The museum has produced a video called  Dr Frances i presume        I have a copy i could send to you if you would like. The Mus has a steam up once a month and is open other sundays. They also have a Tuesday work gang day and a Model engineers day in October. I am on good terms with the management especially with Bill Starling. so it is possible to get basic measurements and photos and Videos as well. You can contact me on email at         steamguywilly@icloud.com  or on 07796926784   
regards
Willy .....

 

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