I have a Fire Maple kettle with a recessed heat exchanger that unfortunately also raises the bottom of the kettle about 2 cm. above the burner (when on the pot stands of my Hipolito roarer). I suspect it counteracts any efficiency of the heat exchanger. I thought I 'd share my method of making adjustable pot rests to bring the burner closer to the recess.
Unfortunately, I wasn't scientific in my thinking, Tony. It's only a small Hipolito and I didn't time it before modifying the stands. (Should theoretically be slightly quicker.)
Tony, I know you have a Fire Maple. Hipolito No. 0.('half-pinter'?)- flame ring now just below heat exchanger base flange. Room temp water. 1300 ml.( just under spout level)- 6 min. 45 sec. "bubbles on floor, steam wisping from spout" 7 min. 25 sec. "full steam, violent boil, spilling from spout" Jaime.
For those who may still be interested I thought I'd show how close the burner is to the bottom of the kettle. The trivet is modified to enable 3 pot 'heights' via slots that engage the now lowered pot rests. The adjustable/rotatable tab at the front of the trivet engages the top of the door when closed as a safety feature to prevent tipping forward between the rests.
Just a question: didn’t some stovies and stove companies show that lowering the distance from pan to burner increase the carbon monoxide level?
In my experiments, I found that you actually need to raise the pot to prevent flame quench, when it has a heat exchanger. Not lower as you would logically think.
These points may be related. There is still about 2 cm between the pot base and the flame ring.( I haven't read anything about CO or quenching. ) I think the distance between the flame ring and the pot base may change the shape of the air passage, possibly flaring out the flame slightly more than usual. I also have different flame rings. Some throw the flame more vertically, others more sideways. I think that provided there is sufficient air to complete combustion there shouldn't be a problem. I suspect however that if you did have a pot substantially close i.e. effectively resting on the flame ring you might create an incomplete combustion.
