[Stoves] air for gazification

[Tom Miles]

Frank,

Go to the Biomass Cooking Stoves Website

Select Design->Fan
http://www.bioenergylists.org/en/taxonomy/term/193

You'll find a report by Mark Witt with fan calculations and computer fan
data.

Several other stoves have been built with fans, especially by CSU Students
and others at the Aprovecho camp last year. There are some pictures in the
reports of those stoves but no useful fan data. 

You can also enter "fan" or "computer fan" in the discussion archives Search
which will get you the messages about computer fans from both the stoves and
gasification lists.

Tom Miles
    

-----Original Message-----
From: stoves-bounces at listserv.repp.org
[mailto:stoves-bounces at listserv.repp.org] On Behalf Of frank at compostlab.com
Sent: Saturday, June 09, 2007 8:32 PM
To: Discussion of biomass cooking stoves; 'Kevin Chisholm'
Subject: Re: [Stoves] air for gazification

Dear Martin and stovers,

<snip>
> My assume:
> -I expect for a normal 10cm diameter can to play with a power of 
> about 1kw
> (That is roughly: 1kw / 80square-centimetres) -To begin with 1/2 the 
> amount of the total burning air (I think or even hope, it will be 
> less for merely smoke making) In cifers: 1/2 of the total amount is: 
> 20 cubic feet of air per hour, that are 566.339 litres per hour, or 
> 9.439 litres per minute, or 157 millilitres per second.
> 
> - 10 litres per minute are in the upper range of a normal oxygen-rotameter
> in anaesthesia-equipment. Such a rotameter would fit.
> 
> - Transformed to the square-measure-unit 1 square-centimetre: 0.125 litres
> per minute.
 
So, if my calculations are correct, our goal is an air flow of ~2cm/sec that
will produce 0.22 BTU/cm2/sec at the surface where the primary burn takes
place. This is the estimated ideal air flow be it forced air from a fan or
heat convection? 

Can anyone give me the pressure produced from a computer fan? I have
compressed air but would like to simulate a computer fan blasting up the raw
fuel chamber to the primary. 

Thanks
Frank  






> 
> Let us have fun!
> 
> Best wishes!
> 
> Martin
> 
> > -----Ursprüngliche Nachricht-----
> > Von: Kevin Chisholm [mailto:kchisholm at ca.inter.net]
> > Gesendet: Samstag, 9. Juni 2007 01:59
> > An: boll.bn at t-online.de
> > Betreff: Re: [Stoves] air for gazification
> > 
> > PERSONAL TOP SECRET INSIDER INFORMATION!!! :-)
> > 
> > Dear Martin
> > 
> > One cubic foot of air, under stoichiometric conditions will support
> > combustion that releases 100 BTU
> > 
> > If you want 1 kw in 1 hour, ie, 1 kwh, you have to liberate 3412 BTU
> > 
> > Therefore, you need, in theory, 34.12 cubic feet of air.
> > 
> > Be\cause of poor mixing, etc, you will probably need about 15% top 25%
> > excess. Say 20% excess, or say a total of roughly 40 cubic feet of air
> > per hour.
> > 
> > Now, roughly 1/2 should be blown in below the grate, as primary air, to
> > make gas, and the other half should be blown in above teh fuel, as
> > secondary air, to burn the gas to completion.
> > 
> > That will be our little secret!! :-)
> > 
> > Best wishes,
> > 
> > Kevin
> > 
> > Boll, Martin Dr. wrote:
> > > Dear all,
> > >
> > >
> > >
> > > where can I find a rough and ready-number, of the needed air (oxygen)
> > amount
> > > for e.g. the release of 1kw heat-making wood-gas-amount in a
T-LUD-type
> > > burner?
> > >
> > > - I am aware that moisture will make differences.
> > >
> > > - How many litres air per minute?
> > >
> > >
> > >
> > > Regards
> > >
> > >
> > >
> > > Martin
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > _______________________________________________
> > > Stoves mailing list
> > > Stoves at listserv.repp.org
> > > http://listserv.repp.org/mailman/listinfo/stoves_listserv.repp.org
> > > http://stoves.bioenergylists.org
> > > http://info.bioenergylists.org
> > >
> 
> _______________________________________________
> Stoves mailing list
> Stoves at listserv.repp.org
> http://listserv.repp.org/mailman/listinfo/stoves_listserv.repp.org
> http://stoves.bioenergylists.org
> http://info.bioenergylists.org


--
Frank Shields
Soil Control Lab
42 Hangar Way
Watsonville, CA  95076
(831) 724-5422tel
(831) 724-3188fax
www.compostlab.com
www.greenrooflab.com


_______________________________________________
Stoves mailing list
Stoves at listserv.repp.org
http://listserv.repp.org/mailman/listinfo/stoves_listserv.repp.org
http://stoves.bioenergylists.org
http://info.bioenergylists.org