On Fri, 24 Aug 2012 05:54:22 -0500, "RogerN"
wrote:

"PrecisionmachinisT" wrote in message
...

"Tim Wescott" wrote in message
...
On Thu, 23 Aug 2012 21:04:08 -0500, RogerN wrote:
snip
So I think you're doomed to have some sort of a batch process. Putting
in the next batch of fermented stuff as you draw out the spent batch
would help with the energy efficiency, particularly if you make up some
sort of a heat transfer gizmo.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

The amount of heat that ends up in the alcohol itself isn't a whole lot,
with most of the heat used in distilling simply being spent in raising the
entire wash temperature to the point at which the alcohol(s) boil off...

--if you want to drink it, first you raise (and hold) the temp till all of
the methanol boils off, discarding that because it's poison...after this,
you again raise the temperature till the ethanol boils off, holding it
there and collecting....now what you finally will have left is mostly hot
water and dead yeast, easy enough to recover the heat from that concoction
by using a counterflow chiller but unless you have another batch that's all
ready to go or you have some other use for hot water then there's really
not much sense..

I never thought of it but I guess the overflow of hot water could be used to
pre-heat the alcohol/water going into the still, no need to waste all the
heat.

RogerN

Roger, just another idea for you. I've often thought using vacuum
would be the way to go for small scale fuel production. You'd need a
serious tank that wouldn't colapse, using an old refrigeration
compressor would pull off the alcohol at room or very slightly
elevated temperature.

it would work to have pretty small batches for this step and leave it
run all the time.

Just an idea, worth what you paid for it.

Karl