Seattle Steam Plant Engine

[Neil K]

Anybody that's interested in stationary steam engines should visit the youtube video site and type in "Seattle Steam Plant Engine." The clip has some interesting features such as the start-up of the engine. What got me is the valve-side of the cylinder head showing the inside of the valve chest. I'm not sure I understand just what I'm seeing. Maybe others can help?

Neil

[Jan-Eric Nystrom]

Here's te direct link to the video, so you don't have to do a search:

http://www.youtube.com/watch?v=RMiu1SBqSxM

It appears the cover for the exhaust valve has been removed - maybe the engine is running on the high-pressure cylinder only? (One viewer calls it an "in-line compound"...)

[Neil K]

Thanks for posting the link, J-E. I forgot to include it in the original post.

I'm pretty sure its a compound, but if that's the exhaust valve, is the thing running on air? I don't see any vapor.

[Steamboy89]

I have never seen a steam chest like that before, whats the deal with it and why is it exposed?

[Jan-Eric Nystrom]

Maybe they're running the engine on the high-pressure cylinder only, and releasing the exhaust before it reaches the low-pressure valve chest?

[Neil K]

I'm really puzzled with the disks on the valve and am trying to understand their function. I'm supposing the exhaust steam goes out the disks into the valve outer chamber to then exhaust to atmosphere. The inlet steam must be ported internally somehow.

SB: The outer cover has been left off for some reason, maybe to show the valve disk action. I would presume, for permanent display, the cover would be replaced.

Maybe Glen can chime in here and help us out??

Neil

[Jan-Eric Nystrom]

Since there is no steam coming through the disks, but they still "flap", wouldn't that indicate that the large (i.e. low-pressure) cylinder is only "pumping" air, not steam? We see a lot of steam around the high-pressure cylinder...

[Neil K]

Agreed... without steam present, it must be pushing air. If that is the low-pressure cylinder, there must be a closed interstage block valve. I have never seen that kind of circular disk arrangement on the valve itself and wonder if that is unique to that engine or unique to that builder's design.

[Michael Heck]

Did anyone click on any of the links following the Seattle site? OOOH OOOH

[Chris W]

I did a little search and found a link to a ASME National Historic Mechanical Engineering Landmark document about the Georgetown Steam Plant in Seattle. In the document is a picture of the "engine" shown in the video with the following caption: "1907 vintage horizontal Tandem Weiss Crank and fly-wheel air pump produces 15 ft. of water vacuum in the barometric steam condenser for each vertical steam turbine."

I guess that explains the unusual valves and lack of steam from the LP chest.

journals2.iranscience.net:800/www.asme.org/history/brochures/h045.pdf

Looks like a cut and paste job, I couldn't get it to work the other way.

[Neil K]

Chris and Mike:

Thank you both for sleuthing out further information regarding the steam engine video. Understanding now that it's a steam-driven compressor, it makes a lot more sense. (grinning from embarrassment)

I'll definitely have to keep the Georgetown Steam Plant in mind for a visit the next time I'm out there. Looks like they have some interesting machinery.

Neil

[willy]

Being a compressor would explain why there was no dynamo on the power side of the crank.

Although it looks as if there may be a steam driven dynamo off to the side as per the drawing

[mdainsd]

Great video, and with only a nudge more technology, infernal ah sorry, internal combustion. The resemblance is striking.

http://www.youtube.com/watch?v=zLf0uXocpQE&feature=related

[Joel]

A year and a half late but I'm here.

The engine IS a simple and yes, the center cylinder is a compressor of sorts. It is an air pump and its purpose is to remove the non-condensable gases (mostly air) from the condenser to maintain the vacuum on the exhaust of the main turbo-generator.

The cover was removed some years back because we heard a thump in the valve chest. We discovered that there were two pieces of spring steel that held the slide valve against the face and that these springs had either worn or lost their tension over the years. We had two new springs made (although the spring company did a less than stellar job) and it just took several years to get the cover back in place.

You can see hundreds of pictures by doing a Google using the term Georgetown Steam Plant. You can see my YouTube videos by doing a search at YouTube using Furd2000.