Trevithick Gas Burner Problems
by John
Today I connected the gas burner to a propane bottle, and it would not light.
The jet, tubing, control knob, and connectors were removed from an old gas camping stove. The camping stove burner is in the picture above.
The only way that I could get the engine burner to light up was to block off about half of the outlets in the ceramic burner.
With half of the burner blocked, the other half produced a nice hot flame, but whenever I increased the open area the flamed spluttered, and died.
The more area exposed, the worse the flame.
..And eventually it died. Adjusting the gas settings made no difference. Blocking the other end of the ceramic burner resulted in being unable to light it at all.
It appears that that the gas air mixture is being blown to the distal end of the burner, where it will burn. But if too many holes in the burner are exposed, it just will not function.
So, I came home to ask for advice from my readers, and lo and behold, before I even opened up the blog I checked my emails, and there was a message from reader Huib who predicted the problems after looking at yesterday’s post, and told me how to overcome it.
Huibs letter,
Hi John,
I have read your blog about the gasburner, I suggest that you make a brass pipe with small holes in it to spread the gas all under the ceramic stone, otherwise I think the stone will only fire up at the beginning of the stone.
Or as I did, fill the space unther the stone with stainless steel wool, this material will also ensure a spread of the gas under the stone, but not as much as a brass pipe with holes.
I have the stone sealed in the holder with stove kit, this kit is heat resistant. I think that is available in your area.
Regards Huib
There are some aspects of this blogging business that I really like!! I will let you know how the suggestion works in a couple of days. Thanks Huib!!!
johnsmachines 
I liked my own post! But actually I am liking Huib’s helpful suggestion.
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It’s amazing, this morning at about 06.00 european time I reed the blog of John an I thought that’s gonne be not good. So at work I took a new paper an make a sketch that i thought would be an better way to fire up the burner. I mailed the sketch to John with the explanation of it an a few ours later it is on the blog. That’s the way modelers can help each other even on the other side of the World. I hope my suggestion will work to fire up the burner. It can be a lot of experiment to get a nice flame on the stone, enough air is even a impotant item the gas will only nice burn if there is enough air to, so the right mix gas/air is the solution.
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It is amazing Huib, that with good will, help is available almost instantly, from the other side of the world. John.
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Was going to say surface area, versus pressure, but Huib beat me.
The round burner from the camp stove is a point heater, think grill plate, whete you have the long multiple hole burner.
You may have to do two, or three pipes, before you get the pressure / length / number of holes balance right.
Don’t know off the top of my head a calculation for this. Maybe consult a gas fitter who does burner installations.
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thanks Ian. I was wondering whether the total surface area of the outlet holes was also relevant. Maybe need more total gas + air for the bigger hole surface area of the ceramic burner. (ie bigger jet?).
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Quite possibly John.
That’s why I’m suggesting a gas fitter, who may know the surface area ratio calculation.
As you’re going to be working off bottled gas, and even with mains gas, your pressure is finite, especially once you have the valve open the whole way.
Ian
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I tried the fix suggested by Huib Hoogendoorn and that seems to have worked very well on the original fittings and jet, despite the larger area of the ceramic burner! John
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