[Gasification] Gasification Digest, Vol 41, Issue 21

[Guy Thompson]

Doug

We have been working recently with wood micro-chips - i.e. chips that pass
a 12mm screen, de-dusted and very low bark/ash - and the case for field
chipping (leaving the bark in the woods) and then truck drying becomes
compelling. Direct use of the exhaust is a no-no, as you say, but a simple
on-board CHP system with, as Thomas Koch says, some air movement does mean
that much drying can be done at no marginal cost (money or energy) out on
the open road.

It works very well for micro-chips with their increased surface area/kg.
Not sure about standard G30 or G50 ŠŠ

Guy Thompson

-----Original Message-----
From: <gasification-request at lists.bioenergylists.org>
Reply-To: <gasification at lists.bioenergylists.org>
Date: Sunday, 26 January 2014 19:00
To: <gasification at lists.bioenergylists.org>
Subject: Gasification Digest, Vol 41, Issue 21

>Hi Tom and Colleagues,
>
>Having spent the first 9 years of my "trade "life in transport
>engineering, your idea is sound but difficult to put into practice. Chip
>trucks are tippers, so the exhaust would have to enter the box via a
>flexible hinge at the rear of the body. Not impossible, but difficult to
>organise as most exhausts exit vertically up the back of the cab. You
>would then need a body floor that is probably perforated, or for trials
>fitted with a piping system on top of the floor.
>
>Having used exhausts a lot over the years into drum driers, but not
>closely controlled to 300C, but around 300C just the same, given enough
>time, the chip on the bottom starts to cook, and you see this at a point
>when steam and blue smoke comes out the top. This is much the same
>problem for any static pile, so introduces the need for chip movement.
>Rotational drying is a known technology, but in the circumstances that we
>might dry chips for gasification and whatever, I have often thought that
>our primary sources of heat is slightly different in it's acquisition to
>those of most commercially available dryers.
>
>While we continue to seek easy solutions and simplicity of design, the
>answers to these questions remain complex for those charged with
>resolving the problems. The calculations may show what might be possible,
>but it doesn't tell you how it's achieved(:-)
>
>Doug Williams,
>Fluidyne.