[Gasification] heat exchanger

[Energies Naturals]

Toby,
all I´ve learned about xchangers says that turbulance enhances xchange very 
much. Thus the criss-cross patterns in flat plate designs.
Rolf
----- Original Message ----- 
From: "Toby Seiler" <seilertechco at yahoo.com>
To: <jimmason at whatiamupto.com>
Cc: <gasification at listserv.repp.org>
Sent: Tuesday, September 18, 2007 1:06 PM
Subject: [Gasification] heat exchanger


> Jim,
>
>  A comment on heat exchangers that stuck with me is about turbulence. 
> Turbulent flow is not the proper flow to maximize heat exchange, laminar 
> is.  The hot surface should be wiped clean of it's heat and moved on. 
> Turbulent flow regions in a given pipe should be avoided.
>
>  A boiler is a big heat exchanger.  Fire tube boilers are often used for 
> wood burning because of the larger passage size that does not clog as fast 
> as the smaller spaces of the typical water tube.  But a water tube can 
> have more surface area for collection.  Be it radiant or conductive, 
> square feet matter.
>
>  Also the bending of the water tube can be shaped to collect from a given 
> fire box. Water tubes over an iridescent catalyst unit fed from a gasifier 
> would work, since most ash and solids would have been significantly 
> reduced, compared to a direct wood fired boiler.
>
>  Regards,  Toby Seiler
>
>
>
>
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