Some questions to tease out a better intuition about the form and function of flash boilers.
kladue in particular:
Why go tall and skinny instead of short and chubby on your second generation flash boiler? It seems like you'll transfer more heat that way, but is it really that much more? Just considering options in terms of portability (short and chubby seems more portable).
What about eight coils instead of four? Perhaps three forming a sort of triangle in the middle, with five surrounding the inner three?
What about baffles? Would installing baffles on the coil help to disrupt the chimney effect and provide better heat transfer? Perhaps an idiotic question!
Also, how did you arrive upon your particular design. I've seen a few other designs now, from different industries. Here are a couple:
Boiler Basics: Waste Oil Generator System, Ken Rieli, Phoenix Turbine Builders Club, Tesla boundary layer disk turbines
Clayton Thermal Products UK - Steam Generators Principle of Operation
(Forget about the pressurized component; not interested in dying at the moment.)
For example, why did you go vertical (i.e. chimney) instead of horizontal (like a real BBQ)? (Perhaps that would require more extensive insulation? Thicker chimney material?)
Why coils instead of parallel tubing? (see phoenixnavigation link above)
I think that's it for my questions for now!
Can't wait to build one!