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[1967Brutus]

Hi Guys,

I happen to have a Microcosm M29 installation, and although the burner functions well, a minor downside is that minimum fire still is enough to pop the safety valve at the minimum sustainable fire.
It is a burner of the type with a fuel nozzle, mixing tube, and a cup-shaped burner with a perforated plate in it.
Now I was told the other day, that ceramic burners can regulate down much lower, and that it would be enough to get me a disk of this cheramic material and fit it on the fireside of the perforated plate.

Is this true?

If so, which glue/kit do I need to fix his material in place?

If not, which exact brand/type would fit?

Not at home right now, so I do not have a diameter of the furnace at hand.

TIA and best regards,

Bert.

[Mege66]

Hi Bert
I assume that you have to use a fire resistant cement from a stove /chimney builder. But I have no experience with such stuff.
Why don‘t you simply use a ceramic burner from the BIX range or from Martin Baylis? If the fire tube should be larger than 28 mm outside, then you may have to add a turned brass adapter piece.

[1967Brutus]

Hi Bert
I assume that you have to use a fire resistant cement from a stove /chimney builder. But I have no experience with such stuff.
Why don‘t you simply use a ceramic burner from the BIX range or from Martin Baylis? If the fire tube should be larger than 28 mm outside, then you may have to add a turned brass adapter piece.

That is an option too, but I an hesitant in that it most likely will have different thread sizes for the fuel line connections, and I really dislike "non-standard"...
As it is, I am allready combining Regner thread standards with those of Microcosm, prefer not to add another size, and I suspect Martin Bayliss to use imperial thread sizes.

Besides, it would be fun if I could do this myself.

The question left unanswered is: am I correctly informed that ceramic burners can handle much lower fire settings? And is it indeed as simple as fitting a piece of ceramic material? Or is the tech behind it (nozzle and mixing tube) different?

[Mege66]

Well, I have both types of burners in use and always in combination with a gas attenuator valve.


And both burner types can be throttled down by the attenuator valves to a level where the boiler safety valve doesn't blow off anymore. I couldn't tell a difference.


But I assume that the ceramic burner with its red glowing ceramic insert is more tolerant to loose the flame. But saying so, I never had any issue with any of the two types of burner at all.


My best answer is this: it doesn't really make a notable difference.

[Mege66]

And yes, Martin Baylis - and almost any other UK supplier - uses ME threads on the gas connectors.
1/4“ x 32 (or 40) tpi to be more precise.

[pipercub1772]

If i understand correctly the burner produces to much heat at the lowest you can turn down the gas valve could you not simply fit a smaller gas jet

[1967Brutus]

Well, I have both types of burners in use and always in combination with a gas attenuator valve.


And both burner types can be throttled down by the attenuator valves to a level where the boiler safety valve doesn't blow off anymore. I couldn't tell a difference.


But I assume that the ceramic burner with its red glowing ceramic insert is more tolerant to loose the flame. But saying so, I never had any issue with any of the two types of burner at all.


My best answer is this: it doesn't really make a notable difference.

Well, my burner does not allow itself to be throttled down far enough to not pop the safety with stopped engine (otherwise I wouldn't be asking )


FWIW (and I don't know if this makes any difference), I am using a Regner RC gas throttle valve, controlled via telemetry boiler pressure feedback.
The valve can go all the way down to "flame out" so I don't think that is the problem.

[1967Brutus]

If i understand correctly the burner produces to much heat at the lowest you can turn down the gas valve could you not simply fit a smaller gas jet

I don't know... Maybe. I do not know if flame stability at low fire is depending on nozzle size or on flame plate type.
But a smaller nozzle COULD cause lower top-end capacity.
I do not have any nozzles to experiment with, AFAIK, Microcosm does not sell different nozzle sizes.

[Mege66]

Hi Bert
Looking up your initial question, they should all be answered now. Lacking Microcosm experience, it is difficult to tell what might be the problem. If the burner with the lowest stable flame puts more energy into the boiler than it looses, then pressure will inevitably rise and the safety valve occasionally lift.
You can now either reduce energy introduction further or increase energy dissipation to a level there is a balance between both. I seem to remember that you have packed your boiler well with insulation material. So you may really have to use a smaller nozzle. But if you can‘t change it, then this will be difficult and you end up with your initial suggestion. Go and try it. Maybe it works, maybe not. You will loose a few Euros and some time, and all other Microcosm users will benefit from your findings. Anyone else will go the usual nozzle way or do not have this problem.

[1967Brutus]

Hi Bert
Looking up your initial question, they should all be answered now. Lacking Microcosm experience, it is difficult to tell what might be the problem. If the burner with the lowest stable flame puts more energy into the boiler than it looses, then pressure will inevitably rise and the safety valve occasionally lift.
You can now either reduce energy introduction further or increase energy dissipation to a level there is a balance between both. I seem to remember that you have packed your boiler well with insulation material. So you may really have to use a smaller nozzle. But if you can‘t change it, then this will be difficult and you end up with your initial suggestion. Go and try it. Maybe it works, maybe not. You will loose a few Euros and some time, and all other Microcosm users will benefit from your findings. Anyone else will go the usual nozzle way or do not have this problem.

The boiler lagging is still "original", with bare front and back and only a thin layer of wood around the shell.


Another question: Who sells this ceramic material?

[Mege66]

Google gave me these quick hits:


https://www.peninsula-live-steam-engines-tools-and-supplies.com/ourshop/cat_1754587-PENINSULA-STEAM-CERAMIC-BURNERS.html


https://www.ts-modelldampfmaschinen.de/gasbrenner-keramikbrenner/keramikplatte.html?language=de


https://www.modellbau-niggel.de/Keramikplatte-135x96x13mm-800-100-i394.html?sid=jbhenssoh549kgrnsjfaj8biuh

[1967Brutus]

Thanks, man!