Air/Steam Engine Conversion

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Air/Steam Engine Conversion

Post by WA3ETD » Fri Feb 25, 2011 5:27 am

All -
I've received multiple e-mails regarding my article in the March issue and I don't even have my snail-mail issue yet! Some notes:

The solenoid valves from STC I specified are rated for air only - they would not be happy under steam! For steam operation bronze / stainless valves are needed, at considerably more $$ that the $18 valves I used! It was my "ASSumption" that most readers interested in the project would use air. Live steam at 25 psig is 266 degrees F hot!

Feel free to contact me directly regarding steam operation, boilers in general, and safety considerations...


Dean Huster
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Re: Air/Steam Engine Conversion

Post by Dean Huster » Fri Mar 11, 2011 9:21 pm

After viewing "the real things" at gas and steam engine shows (and especially the UP "Big Boy" steam engine where there's one on display at the railroad museum in Green Bay WI), it's just hard to not rather have all the mechanical valves and linkages. Thing is, an EMP will render the modern µP version worthless while the 1932 version will keep plugging along.
Dean Huster, Electronics Curmudgeon
Contributing Editor emeritus, "Q & A", of the former "Poptronics" magazine (formerly "Popular Electronics" and "Electronics Now" magazines).


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Re: Air/Steam Engine Conversion

Post by CeaSaR » Fri Mar 11, 2011 10:29 pm

Mr. Molnar,

(Funny thing, I work with a guy who has the same last name. :) ) I enjoyed your article, but
I just don't understand the "green" aspect of it. Work has to be done somewhere in order for
this "engine" to run.

So the compressed air runs it as shown in the article. What compresses the air? Usually an
electric motor spinning a compressor. If the electric is removed, the air will only last a short
time, rendering the unit useless. Besides, how is the electric generated? Most involve burning
something. It is just a shift in the energy used.

Steam requires a heat source (ususally burning something) to boil the water to a useable point.
This requires a warm-up period and when heat is removed, the boiling subsides quickly, rendering
the unit useless. Again, it is a shift in the energy used.

The original configuration burns the fuel directly, not needing a conversion from one form to
another. As with the other methods, once the fuel is removed, the unit will cease to operate.
The thing is, this method retains the portability the engine was designed for, not needing to be
tethered to the much larger power support units you suggested.

Ultimately, I would like to see an efficiency comparison between all 3, gasoline, air and steam.
You would also need to factor in the "carbon footprint" of the systems as well. Then we could
see which one is actually the greenest.

Hey, what do I know?

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Re: Air/Steam Engine Conversion

Post by kheston » Sat Mar 12, 2011 7:29 pm


I've been thinking about the heat/solenoid valve problem and am wondering whether a suitable replacement could be fabbed instead of purchased (almost $100/per, I think). I like the idea of an MCU-controlled steam engine, but the cost of steam-rated solenoid valves looks pretty restrictive. Perhaps modifying one of the many cam-actuated valve DIY steam engine designs out there for use with a cheap solenoid is worth looking into.

Googling now...
Kurt - SF Bay

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