Annular burner design

[Mark Smith 3Participant @marksmith3]

<p style=”text-align: left;”>Does anyone know how to construct an annular burner for stirling engines. I believe Andy Ross had a design in the August 21 1981.</p>
 

 

[JasonBModerator @jasonb]

Not sure if the annular burner directs the flames inwards or along the hot end but a similar method can be used .

Turn what is in effcet a U section ring and solder in either a short tube or “washer” to close it off. Drill your ring of holes in the tube or washer and have a gas connection into teh U shaped section. Just don’t let Robeert catch You.

This one sends the flam along but if the inner face were the open part of the U shape you could drill the small ring of holes in the short tube that would close it off and have the flames at right angles. Though thinking about ease of construction it may be easier to form the U with a parting tool, drill the holes and the n close the U off with an external tube

If my descriptions are not clear, ask and I’ll sketch it but conform the direction of the annular flame.

What you can’t see in my hand is a Sievert 8842 burner which provides the gas/air mixing via a small 0.07mm jet.

[Mark Smith 3Participant @marksmith3]

Thank you, it looks interesting, but not quite what I was hoping for. I have made two burners but instead of nice blue flames coming from the row of hole a big yellow flame comes out of the open end.

[Andrew CrowParticipant @andrewcrow91475]

Nice design Jason, always useful to see as this is an area often poorly described in construction articles on Sterling engines.

Mark, if you are only getting a yellow flame, that usually means there is not enough air getting the mix prior to combustion.

Andy

[JasonBModerator @jasonb]

As Andrew says oramge/yellow flames are usually a sign of no or little air getting in before the gas burns. If you can remember back to school bunsen burners then when the hole at the bottom was closed you got a big orange flame, twist the cover to open up the holes at the bottom and you get the blue pencil flame.

A few more photos, if you look between the hex nuts and the straight section you can see the air holes where the air is drawn in just ahead of the jet.

I actually found the flame was a bit strong so made a stainless sleeve with smaller holes to bring it down to what I wanted

You can see a similar arrangement of the patent for this stirling fan that is on my todo list, there is a mixer before the gas enters the ring. N is the jet and n the air passages

Apart from doing what I did and making use of a small blowtorch burner I will have a look to see if I have any small boiler burner designs that could be adapted.

[Michael GilliganParticipant @michaelgilligan61133]

[ NEWSFLASH ]

I have just caught Google’s AI telling fibs !

.

.

Don’t worry … I found the actual patent for Jason’s crop

🙂

MichaelG.

[Michael Gilligan]

On Michael Gilligan Said:

[ NEWSFLASH ]

I have just caught Google’s AI telling fibs !

.

.

Don’t worry … I found the actual patent for Jason’s crop

🙂

MichaelG.

But have you found the mysterious Charles P. Hollister and his “Driven Fan”, and why has his patent been re-assigned to a telephone switchboard system?

The public need to know.

[Michael GilliganParticipant @michaelgilligan61133]

I have indeed found US605670, Andy … but no connection whatsoever with Hollister

Whatever is fuelling the Google brain must psychedelic !

MichaelG.

[JasonBModerator @jasonb]

This shows the jet and mixer for a 3″ dia ceramic burner by SandyC. You need something along these lines to mix the air before it enters the actual annular part of the burner. Not sure how easy it is to get gas jets down in NZ but the likes of Forrest Classics sell them here.That’s a No8 jet that I have just cropped off.

 

The other alternative if you are using small “camping” type gas canisters is to butcher one of th echeap Aliexpress camping stoves which will give you the jet and mixer. I have used these to run several hot air engines where I just want heat to the bottom of the hot cap.

[Engine BuilderParticipant @enginebuilder]

Jason, I built that fan 15 years ago. Interesting desing.

https://youtu.be/-Usiqpow_s0?si=MAW8GYESnhaeKUh0

 

 

[Michael GilliganParticipant @michaelgilligan61133]

Good to see that video … Thanks

What makes it so noisy when driving the fan ?

MichaelG.

[JasonBModerator @jasonb]

I had seen the video of your one before, there are also a couple in the US as it was featured in one of the Lindsay publications on hot air engines.

[Michael Gilligan]

On Michael Gilligan Said:

Good to see that video … Thanks

What makes it so noisy when driving the fan ?

MichaelG.

The friction drive to the fan pushes the pulley away.

[Michael GilliganParticipant @michaelgilligan61133]

Thanks … I shall ponder that one

MichaelG.

[Mark Smith 3Participant @marksmith3]

Thank you Jason and Andrew for your suggestions, I will try them. Thank you to others who contributed.

[Mark Smith 3Participant @marksmith3]

I have tried your suggestion of more air to the burner and it is a great improvement. I milled another slot on the opposite side and I feel like I need to put a third slot in. I have made the mixer tube adjustable so no fear of going too far.

I was originally going by the description in Andy Ross’s book re the size of orifices in which he seemed to indicate a smaller orifice but I might have been reading it wrong. Thanks again.

[Author]

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