Something hotter than Sterno

Discussion on Stirling or "hot air" engines (all types)
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Sched44
Posts: 12
Joined: Wed Jul 15, 2009 7:36 pm

Something hotter than Sterno

Post by Sched44 »

I built the Walking beam engine as per the plans online. It runs well and to add some running time, I added a pump and a cooling loop made from quarter inch OD soft copper. It drags the engine down because of the added pumping load and if I add a bit of butane heat to the Sterno it runs along just fine.

Is there something a bit hotter than the Sterno that I could use to fire the engine?

Thanks for any help in advance.

Sched44
Sched44
Posts: 12
Joined: Wed Jul 15, 2009 7:36 pm

Re: Something hotter than Sterno

Post by Sched44 »

The engine ran ok; I just wanted to give it a bit more energy to perform the work of the water pump. I bought an inexpensive camp stove at Wal-mart, cut it to the desired length containing one burner, made it adjustable up and down and use the side where the propane tank attaches. I remotely mounted the cylinder away from the heat of the stove. I also leak tested everything with soap prior to use.

I noticed immediately that I had to be careful not to turn it up too much. I installed a detent on the control knob and paint filled a line on the knob with a pointer installed that points to the line. This is the ideal running speed with the pump linked.

I am happy with the results. I ran it for three hours straight today and did not have to do anything with the coolant. There is a coolant loop. This is the function of the pump, to circulate coolant through the loop. I had plans to make a small evaporative cooler like a small cooling tower but ended up making the cooling loop instead. I may still make the tower.

Darryl’s plans were good but I did a lot of other research and being a First Class Millwright enabled me to make the engine to tighter tolerances. I understood the looseness required but having built precision machine tools for a living and having a machine shop at my disposal gave me the ability to build a precision machine. My hat is off to those folks who build these things in a home workshop or at the kitchen table. Those engines will require more “looseness.”

I belong to an old time power association and will set up a display at the annual show. I have looked around for an old hot air engine to restore but have not had any luck.

Thank you for your reply.
Sched44
Posts: 12
Joined: Wed Jul 15, 2009 7:36 pm

Re: Something hotter than Sterno

Post by Sched44 »

How would I post an image on this forum? Please tell me how and I will include pics of a new vertical I just completed.

Regards,

Sched44
Sched44
Posts: 12
Joined: Wed Jul 15, 2009 7:36 pm

Re: Something hotter than Sterno

Post by Sched44 »

Please see next two posts.

Sched44
Last edited by Sched44 on Sun Sep 27, 2009 7:39 pm, edited 1 time in total.
Sched44
Posts: 12
Joined: Wed Jul 15, 2009 7:36 pm

Re: Something hotter than Sterno

Post by Sched44 »

Let me try this. The last post was a goof!

Image

Got it!

Larger image at:

http://www.uploadgeek.com/share-02B7_4ABFF179.html

Sched44
Last edited by Sched44 on Sun Sep 27, 2009 7:37 pm, edited 2 times in total.
Sched44
Posts: 12
Joined: Wed Jul 15, 2009 7:36 pm

Re: Something hotter than Sterno

Post by Sched44 »

Some details:

First two images of the Walking beam horizontal Engine:

-Made as per Mr. Boyd's plans online.
-Base measures 18" x 24"
-18” high at top of beam support
-Stroke is 2 1/4"
-I converted the engine to propane from Sterno. (Warning: someone experienced in propane installations should only do this.)
-The piston is machined and measures 1 1/16" in diameter.
-The power cylinder is bored EMT.
-All joints are silver brazed
-I built a water pump as per plans on the same web page as Mr. Boyd's plans.
-I incorporated a cooling loop to waste off some of the heat before the water is returned to the cold end of the engine. It works pretty well.
-Running RPMs: 180 - 200

It will run for 5 hours straight on a bottle of propane in 95 degree Fahrenheit weather without cooling issues. Care must be exercised not to turn the propane burner up too high as you can get things too hot! The amount of peak propane flow is limited on this engine.

The last two images are of the Vertical Stirling Hot Air Engine:

-Base measures 14" X 14"
-Engine stands 24" high
-This engine runs off of Chafing Fuel.
-All joints are silver brazed
-There is a regenerator in this engine.
-The crank eccentric has a hole in it to accept a drive shaft and will have a small fan blade fitted to it.
-The piston is machined and measures 1 1/16" in diameter.
-Stroke is 2 3/8"
-Displacement cylinder is a Lysol can.
-Air-cooling provided by aluminum mat slats secured by hose clamps. Cooling capacity far exceeds needs.
-Running RPMs: 140 - 160

This engine will run for approx. 3 hours from one chafing fuel container.

Both engines are lubed with sewing machine oil.

Regard’s

Sched44
Sched44
Posts: 12
Joined: Wed Jul 15, 2009 7:36 pm

Re: Something hotter than Sterno

Post by Sched44 »

Thank you for the compliment.

Regards,

Sched44
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