Mill Engine Question

[Shopgeezer]

The Ag museum in Austin MB has this amazing mill engine that they run during their annual Thresherman’s Reunion. Didn’t happen this year due to Covid so we went and camped there on our own. I got to spend a few days in their huge collections without the usual crowds. This mill engine was taken out of a local flour mill and restored. It would make a great modelling project. It is an expansion engine with one cylinder larger than the other. But as far as I could figure out the steam enters the larger cylinder first, crosses to the smaller cylinder, and exits from there. This is opposite to what I understand for an expansion engine. Complex valve arrangement. Any ideas on how this engine works?

 

[HMEL]

The Weelock system uses a rotary valve. Each of these cylinders have the rotary valves located beneath them. Each of these cylinders are equipped with its own governor and this would indicate you have two separate engines connected to the flywheel pulley system. I cannot see if the valves are synchronized to allow it to operate as an expansion engine. My guess is No. This is all I can tell from the picture. Interesting set up to say the least.

 

[Shopgeezer]

Interesting. Thanks for the info. If they are separate engines they seem to be sharing steam from the steam chest of the bigger engine to the smaller one. The big cylinder has a steam supply entering the bottom front and the smaller cylinder has a steam exit pipe at the bottom rear. You would think that there would have to be some coordination between the cylinders so that one doesn’t fight the other on the common crankshaft.

Not much info on the valve mechanism from a quick web search other than it is complicated. The governors seem to control valve duration. This makes me even more curious about how they run. I will have to try and track down a museum volunteer who knows the engines.

 

[JCSteam]

Forgive my ignorance here, but this does rather resemble the Corliss engine in its valve arrangement. I don't think it's an expansion engine.

Very interesting engine none the less, would love to see it running.
Jon

 

[Richard Hed]

The Ag museum in Austin MB has this amazing mill engine that they run during their annual Thresherman’s Reunion. Didn’t happen this year due to Covid so we went and camped there on our own. I got to spend a few days in their huge collections without the usual crowds. This mill engine was taken out of a local flour mill and restored. It would make a great modelling project. It is an expansion engine with one cylinder larger than the other. But as far as I could figure out the steam enters the larger cylinder first, crosses to the smaller cylinder, and exits from there. This is opposite to what I understand for an expansion engine. Complex valve arrangement. Any ideas on how this engine works?
View attachment 118182View attachment 118183View attachment 118184

Maybe someone, not familiar with steam engines, hookt the steam inlets wrongly. Does you have more photos?

 

[Shopgeezer]

QUOTE="Richard Hed, post: 344773, member: 39773"]
Maybe someone, not familiar with steam engines, hookt the steam inlets wrongly. Does you have more photos?
[/QUOTE]

The museum staff are very expert at running steam engines so I doubt they are hooked up wrong. This engine runs regularly over the summer at events. I assumed it was an expansion engine because of the different cylinder sizes but I see now that this is not likely. The question then becomes why the cylinder sizes are different. Something to do with sharing steam from one to the other?

 

[Richard Hed]

QUOTE="Richard Hed, post: 344773, member: 39773"]
Maybe someone, not familiar with steam engines, hookt the steam inlets wrongly. Does you have more photos?

The museum staff are very expert at running steam engines so I doubt they are hooked up wrong. This engine runs regularly over the summer at events. I assumed it was an expansion engine because of the different cylinder sizes but I see now that this is not likely. The question then becomes why the cylinder sizes are different. Something to do with sharing steam from one to the other?
[/QUOTE]
Curious. Very curious.

 

[peterl95124]

yes these appear to be Corliss valves, but with compression springs to close the valves rather than weights in dashpots, I wonder what the tripping mechanism is for early cut-off ?

 

[jumps4]

I found this by typing in Jerome Wheelock Steam valve patent.
Does that photo help?
Steve

here are 3 videos on Youtube of the engine running:

 

[peterl95124]

great videos, but show the engine running slow and with the governor set high, so the early cut-off mechanism never kicks in. when it kicks in I would expect the valve to disengage from the eccentric rod and the compression spring to close the valve, and if I had to take a wild-ass-guess it would be that the scimitar like part of the eccentric driven mechanism gets pushed up by a cam on the valve stem and that disengages the eccentric driven mechanic from the valve. but the problem with that theory is that the valve bell crank end would move towards the eccentric mechanism and there doesn't appear to be room for that to happen. so I'm still puzzled.

 

[J Harp]

This cut shows that the steam enters the middle of the cylinder and exhausts at the ends.

http://vintagemachinery.org/MfgIndex/Images/2790-B.jpg

The picture in the OP shows the vertical pipe connecting to a much smaller pipe with a stop valve in it, that wouldn't work very well for an exhaust pipe. The exhaust from the HP cylinder is most likely connected to the inlet of the LP cylinder with underfloor piping.

 

[peterl95124]

Over on smokstack.com someone found these additional references, showing that my intuition was totally wrong
Pete.

Colin, as Joe said, there is some reference material in Google Books; pages 58-61 inclusive in the link below might be of use.

Corliss-engines and Allied Steam Motors.... by Wilhem Uhland, on Google Books:

http://books.google.ca/books?id=FTM...gU#v=onepage&q=jerome wheelock valves&f=false

Here's a short video clip of another preserved Goldie-McCulloch Wheelock valve engine:

Good luck in your quest!

Al