[Gasification] heat transfer - critical radius etc - was: Re: Fw: Biomass heated ethanol plants

[Daniel Chisholm]

On Wed, 2006-16-08 at 01:47 -0400, Jeff Davis wrote:
> I wonder what would happen if we replaced the poor insulation (critical radius 
> and below) with some shinny tin foil?

That would depend on the magnitude of the decrease in radiation losses
from adding the shiny tin foil (i.e. low emissivity), vs. the increase
in conduction/convection losses you would experience because you are
below the critical radius.  And that would depend (very strongly!) on
the hot-side and cold-side temperatures involved (since radiative heat
transfer depends on the difference of the fourth powers of the
temperatures, and conduction/convection is linear with temperature).


-- 
- Daniel
Fredericton, NB  Canada