[Gasification] Fw: Biomass heated ethanol plants

[Mark Ludlow]

The issue is that, plus, depending on the heat transmitivity of the
insulation, at some point the losses from convection and radiation can
actually be increased. A pipe insulated with poor insulation has increased
area from which to radiate energy. As the diameter is increased with
insulation, the Grashof Number increases (to D^3; D is a characteristic
diameter) and convective heat transfer also increases.

A poor insulation with a low resistance to conduction will actually increase
heat loss because it has a larger characteristic diameter and more surface
from which to radiate energy. Past the critical thickness this is not an
issue; economics is, however.

Mark 

-----Original Message-----
From: gasification-bounces at listserv.repp.org
[mailto:gasification-bounces at listserv.repp.org] On Behalf Of Ken Basterfield
Sent: Sunday, August 13, 2006 1:52 PM
To: 'Peter Singfield'; gasification at listserv.repp.org
Subject: Re: [Gasification] Fw: Biomass heated ethanol plants


Hello Mike & Peter,
Ok,
is it simply that the cost of extra layers of insulation can never be
recovered at such lowering  heat losses?
ken