So you get the max BTUs and heat with a smaller blue flame than cranking it on high? I’m having trouble figuring out how to get the perfectly blue flame. Seems like you’re right, it’s at only 10 to 15% open, but then I thought the heat wouldn’t be enough to get a boil?
Balancing your burner is kind of like doing a balancing act using
Gas Pressure,
Gas Flow and
Air. I have an Edelmetall propane burner and the actual flame itself is only about 3/4” high at full flow and it’s 72,000 btu’s. While propane burns a bit hotter than natural gas, the balancing principles are the same.
Your Gas Pressure is determined by the regulator and I’ll assume it’s set for the typical 3-5” water column. Now you’re relying on the needle valve to regulate the quantity (flow) of gas entering the burner at the orifice AND the quantity of gas entering the burner through the burner orifice creates a venturi at the air intake. The burner orifice is the brass component the air intake rotates around. Adjusting the opening to the venturi finalizes the perfect balance. So, the more you open the needle valve, the more air enters through the venturi and too much of the gas & air mixture is what causes the flame to lift off the burner face.
My 72,000 btu Edelmetall takes about 30-40 minutes to bring 9 (+/-) gallons of 120* (+/-) wort to a full rolling boil in my 15 gallon boil kettle with the lid on. I’m not familiar with the Banjo Burner, or it’s BTU capacity. So I really can’t comment on the time it would take to boil wort.
I hope this answers your question. Good luck!