[Stoves] Heat transfer and in-line water heater

[John T. Frimenko]

Crispin Pemberton-Pigott wrote:
> Reducing the gas speed through the mechanism of reducing the excess air
> usually sees an increase in heat transfer efficiency and an increase in the
> exit temperature _if_ the gas path is short and the system efficiency low (a
> single pot stove).  If the gas path length is long and the system efficiency
> high (a fish dryer), the same change will also usually see an increase in
> efficiency but a drop in the exit temperature. Interesting, eh?
>   
This is a topic beyond my technical comprehension, but consider the 
industrial application of turbulators. In a boiler heat exchanger, 
turbulators are used in the flue gases,  to passively break the laminar 
flow, encouraging the scrubbing of the hot gases against the tubing 
walls, and increase residence time. Resulting in an increase in heat 
transfer. There is reduction in draft vacuum(?), requiring an inducer fan.

This may not be directly applicable to small stoves, but I wonder if  a 
stainless scrubbing pad inserted into the annular gap, between the pot 
and stove would improve the heat transfer?

John in Pa.