Making a ceramic burner,

[rholebrook]

I'm nor familiar with ceramic burners and I wondered if you could put me right on a couple of points. The jet appears to be mounted externally on the end of the brass tube but I am unable to see any holes or perforations in the tube within the burner. Is it just I can't see any holes or does the flame pass right through the tube and reflect back from the end of the container. I would be interested in one or two dimensions ie: the tube diameter internal/external and the amount that it stands off from the end.

 

[Ripper]

I too would be grateful for the details that rholebrook has requested.

 

[bobs7-62steamair]

Hi,

I decided to make a ceramic burner to replace the Sterno tray used to heat the boiler of my recently built oscillating steam engine. The Sterno worked OK but wasn't easily controlled, OK outdoors but really a bit too much heat for indoors, I could have made a smaller tray.

Hopefully the photographs will explain its construction. The brass sheet used is really a little thick but it was all I had. It is all silver soldered.

First the control valve from a gas torch was modified to take a pipe.



Pipe connector.



The brass sheet used.



Cut into strips.



Edges machined.



First strips bent.



Ready for first soldering.



Soldered and ready for second soldering.



Second soldering finished and pipe fitted but not soldered with the ceramic element to be used.



Cutting the ceramic.





Air holes drilled and tube soldered in.



Ready for a test.



Test using a No. 5 jet.



General set up.



As the burner worked OK the ceramic will be held in to it using a silicon sealant and some solid pipe work fitted.

Regards Tony.

 

[bobs7-62steamair]

Hi Tony: Where did you acquire the ceramic burner materials? Also some guidance or a sketch of the supply tube under the ceramic would be appreciated.
Regards.
Bob E.

 

[Mechanicboy]

I created the ceramic burner to the vertical boiler and learned out a lot of try and fail. The size of gas orifice must be tried to find the flame is blue above the ceramic surface with a nice glowing ceramic. Yellow flame: Too little gas velocity or too little air. Gas velocity into the burner must be high enough to take with air into the camber to prevent the backfire (burning inside instead above the ceramic surface).

 

[grg12]

Is the ceramic soldering board suited (for example https://www.amazon.com/dp/B000OVK3XO/?tag=skimlinks_replacement-20 ) or something special is needed?

 

[Mechanicboy]

Is the ceramic soldering board suited (for example https://www.amazon.com/dp/B000OVK3XO/?tag=skimlinks_replacement-20 ) or something special is needed?

I am not sure the ceramic soldering board is suitable. The ceramic board for burner is white and porous, easy to form with sandpaper.

http://www.induceramic.com/industri...pment/infrared-honeycomb-ceramic-burner-plate

 

[Tony Bird]

Hi Bob,

Where did you acquire the ceramic burner materials? Also some guidance or a sketch of the supply tube under the ceramic would be appreciated.

I get my ceramic panel here in the UK from a model engineering supplier Polly Engineeering www.pollymodelengineering.co.uk the last panel I bought from them cost about £20; not cheap, but it does make a lot of burners. The panels are used in portable gas heaters, there appears to be two types of panel; one made out of a hard ceramic, the other out of a very soft ceramic which is the one that is used. There are several different patterns of matrix in the soft material I have used several types they all seem to work OK if you want extra heat extra holes can be drilled in some of them.

On this particular burner the tube used was 1/4" K&S brass tube bought from a model shop which I use because it has a very thin wall and I have a theory that the thinner the wall the less the air is disrupted when entering the tube. The tube in the burner tray has no holes drilled in it. It extends almost the length of the tray stopping its diameter from the end of the tray, the gas/air mix hits the end of the tray and is defused over the whole length of the burner. There are other ways of doing this but this system works well for me. The ceramic is held about 1 mm above the burner tube to allow the gas air mix through. In the burner tube there are 2 pairs of air holes at 90 degrees to each other. Regarding the jet I have a number of jets of different sizes in holders which can be presented to the burner tube and I start with the smallest and work my way up and see which works the best the air holes are gradually increased in size until the flame looses any yellow colour it might have.

Regarding a sketch at the moment I am in Madeira and have no access to scanning so if you need one remind me in about a weeks time. I hope this helps a bit

Regards Tony.

 

[Tony Bird]

Hello Again,

I wrote another thread on ceramic burners at:

https://www.homemodelenginemachinist.com/threads/making-a-simple-ceramic-burner.24235/

Which might be found informative.

Regards Tony.

 

[grg12]

I am not sure the ceramic soldering board is suitable. The ceramic board for burner is white and porous, easy to form

Material in my soldering board is quite soft, "chalky" in touch - board can be brought to white heat without damage (doesn't like flux though). But i doubt it has catalytic properties like the one you linked

Regards
Gregor

 

[chris]

Tony , very nice project. Not being familiar with gas lines and valving,where is the jet positioned in the line?

 

[Tony Bird]

Hi Chris,

Not being familiar with gas lines and valving,where is the jet positioned in the line?

The jet fits on the end of the gas supply pipe and is a slide it in the end of the burner tube. On this particular project it screws into a right angle union on the end of the gas supply pipe.

Regards Tony.

 

[Donrecardo]

Is it important how far the end of the jet is from the air holes and if so how do you
work out the right position?

 

[Mechanicboy]

Is it important how far the end of the jet is from the air holes and if so how do you
work out the right position?

Air hole is positioned right after the end of jet. To suck the air into the pipe is affected by velocity from gas. See picture to understand better..

 

[Donrecardo]

Air hole is positioned right after the end of jet. To suck the air into the pipe is affected by velocity from gas. See picture to understand better..View attachment 105433

Thank you , that makes it clear

 

[Tony Bird]

Hi,

Is it important how far the end of the jet is from the air holes and if so how do you
work out the right position?

In my opinion Jen's drawing is correct with the jet lining up with the rear of the hole. I am sure there is a Health and Safety issue in the next couple of sentences. First you do not need air holes in the in the tube; it is just a convenient way of holding and lining up the jet. When making a new design burner I leave a burner tube with no air holes a slide fit in the burner body; I have different size jets mounted in a piece of angle that are supplied with gas using flexible tubes. On a flat surface the jet held in place by a weight it is pointed at the hole in the burner tube end and the burner lit. By adjusting the position of the burner tube to the jet and how far the tube is in or out of the burner the optimum position and size of jet can be found. This I usually do in the garage where there is plenty of space. I often if there isn't much space available make a boiler with its flue flush with the back head of the boiler and the jet held outside on some angle or the like. I have found that if the burner cannot be adjusted to work well with this system unless something is changed i.e tube diameter altered etc the burner will not work when holes in the tube are used.

Regards Tony.

 

[Ripper]

Thought I was following OK till you wrote that Tony

 

[Mechanicboy]

Hi,

Is it important how far the end of the jet is from the air holes and if so how do you
work out the right position?

I am sure there is a Health and Safety issue in the next couple of sentences. First you do not need air holes in the in the tube; it is just a convenient way of holding and lining up the jet. When making a new design burner I leave a burner tube with no air holes a slide fit in the burner body; I have different size jets mounted in a piece of angle that are supplied with gas using flexible tubes. On a flat surface the jet held in place by a weight it is pointed at the hole in the burner tube end and the burner lit. By adjusting the position of the burner tube to the jet and how far the tube is in or out of the burner the optimum position and size of jet can be found. This I usually do in the garage where there is plenty of space. I often if there isn't much space available make a boiler with its flue flush with the back head of the boiler and the jet held outside on some angle or the like. I have found that if the burner cannot be adjusted to work well with this system unless something is changed i.e tube diameter altered etc the burner will not work when holes in the tube are used.

Regards Tony.

Tony..

This is your assertion: "I am sure there is a Health and Safety issue in the next couple of sentences." Effective burning with air mixed in gas will not give air pollution. Do not forget: You did not die of gas stove in the kitchen by air pollution while cooking dinner.

Google "ceramic burner for steam boiler" and how many ceramic burners can you find without airhole, access to air to mixed into the gas in the pipe before entering the ceramic burner? Probably not. Gas and air in the right mixture provide good combustion and make ceramic burner glowing. With only gas, there is no efficient combustion and there is a yellow flame as there is no air mixed in the flame to burn efficiently. The nozzle size and air amount are determined by relative to the size of ceramic burner.

I created my own ceramic burner + gas attenuator and shut of gas valve by loss of water in boiler as you can see in my youtube.. There is hole for access of air in pipe for ceramic burner.

 

[Tony Bird]

Hi,

Thought I was following OK till you wrote that Tony.

What specifically would you like me to try and explain?

Regards Tony.

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Hi Jens,

This is your assertion: "I am sure there is a Health and Safety issue in the next couple of sentences." Effective burning with air mixed in gas will not give air pollution. Do not forget: You did not die of gas stove in the kitchen by air pollution while cooking dinner.

Quite right! I was referring to the possibility of something catching fire given the loose equipment being played with. I like your cut-off valve have you written a thread on it?


Regards Tony.

 

[Mechanicboy]

Hi,

Hi Jens, I like your cut-off valve have you written a thread on it?

Regards Tony.

I did not wrote a thread in HMEM.. I created the cut-off in my tool room in april 2017. The plan of cut-off valve not drawned.