I bought a 23 jet burner and was very disappointed in it's performance.
23 jet burner link
While it brought wort or water up to a boil quickly enough it had a few problem.
1) It was hard to light, 3 or 4 of the jets would light and then you had to fan the flame around to get the rest of them lit.
2) Unburned gas tended to "pool" under the skirt of the keg and then roll up the outside of the keg and sooted up the outside of the keg.
3) When you got to a boil, if you turn the propane pressure down it sooted up the bottom of the keg/kettle. What a pain to clean!
As I mentioned in my first post I had seen a single jet burner design for home forge use.
Just for grins I decided to build one and see if I could run it low enough to brew with.
It works Great!
I used the regulator and gas hose off an old turkey fryer (10psi low flow connector) and mounted it in the custom stand we'd built for the 23 jet burner. It runs from almost no gas pressure to full out without soot and full out will take a gallon of cold water to a boil in 3 minutes!
Better yet, because it only has one .045 jet rather than 23 .033 jets it uses less gas!
Single Jet link
It's a little touchy to light, if you more than crack the gas valve it tends to blow out the lighter but if you keep the gas pressure low to light it, no problem, once it's lit, crank it up!
It burns very clean, no unburnt gas smell at all,
it doesn't cause any flame crawl up the outside of the keg
and best of all, No soot!
I'm still playing with the design, I'd like to add an air intake adjustment for a better mix at low pressure and I've ordered a 20psi regulator with a high flow connector to see if I can get more out of the upper end (not that I need it).
We've only done one brew with it but I'm very excited with the results so far!