Sunday, June 5, 2011

Multi-fuel jet burner and carburetor

In this post I would like to mention my trusty burner system. I've only ever needed one burner to get up to temperature even for the large kiln at the top of the page .It can run on sump oil obtained free from a mechanic, or canola oil from the local fish and chippy, but are designed for diesel. Sometimes I mix all three together and cut it with a little petrol. I am always experimenting with various fuel mixes, researching flash points on the net, and am in the process of developing a filtration system for cleaning up waste oils. Maybe I'll purchase an old diesel car and beat skyrocketing fuel prices!        

It's pretty full-on firing a kiln with diesel -  the roar of the burner easily drowns out the old electrolux vacuum cleaner I use for a blower. There can be a lot of smoke, but it will burn clean if oxidation is desired. It's a lot more dramatic and hands-on than a gas kiln and is not for the 'clean freak' or the faint hearted.                                                                              
Diagram from New Zealand Potter mag No. 1, 1991 showing cross section and details of burner. On my burner I don't have the water pressure gauge but might try it on my next one when this one wears out

Detial showing jet orifice and primary air hole.Secoundry air is sucked in around burner.

More details of the jet burner tip

Attached to the burner I use a precision tap for turning the fuel up or down

Plastic fuel line attached to copper pipe going to the tap then into burner, then exploding under the floor before entering the main kiln chamber
My original design for the carburetor to mix the air with the fuel . Simple but effective. I also use an old cistern elbow between the carburetor and the burner.

Carburetor with two sliders and hose coming from vacuum.

Fueling up a old LPG tank converted to diesel found at a scrap metal yard for five dollars. I also have another tap here so I can remove the fuel-line when not in use.
 Using diesel can be more dangerous than firing with wood especially when extremely high temperatures are involved. Fire bricks can easily glow red hot, and caution must be used when removing spy-hole bricks around the fuel line.   I've been doing this for a number of years and I was trained at art school under expert supervision. I've gained confidence through necessity,  having to do repairs in the middle of firing and so on. There is some mechanical aptitude required, and I urge caution at all times.  If in doubt get assistance and advice before even starting to build and fire kilns.                                                                        

1 comment:

Peter said...

Great advice there, and really helpful pictures. Huge thank you!! Funny thing was that I was just chatting about burners with a friend a couple of hours ago, so it was nice firing up the computer just now and reading your info on the subject.

Hope you are feeling much better now, and are back to strength again after the flu.

Best Wishes, Peter