[Gasification] filtration options and their varying discontents

[jim mason]

On Mon, Dec 10, 2012 at 12:41 PM, David G. LeVine <dlevine at speakeasy.net>wrote:

>  On 12/09/2012 10:34 PM, jim mason wrote:
>
> other than the explosive risk
>
>
> There is an interesting question here:
>
> Is there an explosion risk if the gasses have not been diluted by the
> atmosphere?
>


well, in principle, the gas should not be diluted with air during typical
operation, and thus no explosion problem.  you are correct.

the problem is typical operation is variable.  during start up you always
go through a stoich point as you move air out of the system and
progressively make gas.  even if you leave the system full of gas on shut
down, start up in the reactor can pass lots of air until things get up to
temp again.  this can easily result in a combustible mixture in the system.

we've found this to be a fairly significant operational reality that needs
to be addressed for regular users.  similar for the impact of backfires
from the engine igniting the intake stream.  while things are "usually" ok,
the marginal events can be quite, umm, compelling . . .   we've started
adding more pressure relief points where typically not needed to cover
these outliers.  we're also looking to add a flame arrestor right  at the
manifold to prevent backfires propagating.

again, you never use these during typical operation.  somewhat like an ESP
shouldn't cause any problems during regular operation.  it is the outliers
that are of concern.  when you start running these systems regularly, you
tend to find all the outliers.  and the ones you don't find in house, those
out in the fields certainly will.

j











> Let's start with gasoline, if we evacuate a bell jar and inject enough
> gasoline so there is a layer of liquid gasoline on the floor or in a pan,
> and we generate a hot arc 1/2" above the gasoline, will there be an
> explosion?  The correct answer is "only if there is an air leak."
>
> Without an air leak, there will be no oxidizer, fire (or explosions)
> require three things:  Fuel, Oxidizer and Ignition.  Fuel is gasoline (in
> this case), Ignition is the spark, but where is the oxidizer?
>
> If woodgas has excess oxidizer as it exits the reaction zone, it simply
> burns off the extra gas.  So, unless there is an air leak, the reaction can
> not occur.  However, if there is an air leak in _any_ fuel system, there
> will be severe problems.
>
> Dave  8{)
> --
>
> *"The first method for estimating the intelligence of a ruler is to look
> at the men he has around him."*
> Niccolo Machiavelli
>
> * NOTE TO ALL:
> When forwarding emails, please use only "Blind Carbon Copy" or "Bcc" for
> all recipients. Please "delete" or "highlight & cut" any forwarding history
> which includes my email address! It is a courtesy to me and others who may
> not wish to have their email addresses sent all over the world! Erasing the
> history helps prevent Spammers from mining addresses and viruses from being
> propagated. *
>
> THANK YOU!
>
> _______________________________________________
> Gasification mailing list
>
> to Send a Message to the list, use the email address
> Gasification at bioenergylists.org
>
> to UNSUBSCRIBE or Change your List Settings use the web page
>
> http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org
>
> for more Gasifiers,  News and Information see our web site:
> http://gasifiers.bioenergylists.org/
>
>


-- 



Jim Mason
Website: http://www.whatiamupto.com
Current Projects:
   - Gasifier Experimenters Kit (the GEK): http://www.gekgasifier.com
   - Escape from Berkeley alt fuels vehicle race: www.escapefromberkeley.com
   - ALL Power Labs on Twitter: http://twitter.com/allpowerlabs
   - Shipyard Announce list:
http://lists.spaceship.com/listinfo.cgi/icp-spaceship.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/gasification_lists.bioenergylists.org/attachments/20121210/6ef25279/attachment.html>