[Stoves] Wattle cuttings - c6rr4ct56ns

[Dave Lello]

Hi Paul and others

No harm done

My discussion was about this… Depending on the density of the fuel, the diameter of the burn chamber on a TLUD determines the area of fuel being burned.

In the case in point the wood pellets are more dense, but have less his space between them.  Based on the density, I worked out that 150mm diameter of cut wattle wood of about 300mm in diameter (10 sticks) would fill a 150mm diameter chamber, and produce the same heat as wood pellets in a 100mm chamber.

As dried wood has a slightly lower MJ value per kg, we have to take this into account. Dried wood has a higher moisture value, thus when we weigh it we are weighing the water as well.

The depth of the TLUD determines how long the fuel will burn. Based on the burn rate we can determine how much heat will be generated from one burn, and how long this will burn for. We do this by dividing the kW heat into the kWh of fuel being burned. i.e. 7,5 kWh of wood burning at a rate of 5kW will burn for 90 minutes.

Why do this?

Well if we start with the fuel and work out its density, burn rate and weight, we can design a burn chamber that will provide the heat we need for the time we need it. We can work out what diameter the chamber needs to be and what depth we need it.

i.e. If we need 2 kW for 90 minutes, this will be 3 kWh. As stated by Ron, 1kg pellets = 18MJ = 5kWh. And the volatiles are about 70%, giving 3,5 kWh of effective heating. In the case of the FAABulous with 100mm chamber, we burn 600 grams in 1 hour as described below.

I would have saved a lot of time if there was some kind of a TLUD calculator published for the different fuel types. Hope this helps.

As Paul always tells me “START WITH THE FUEL”.

Dave
dave at ekasi.energy <mailto:dave at ekasi.energy>
Mobile: +27 82 891 8335

PS Please note that all of these discussions are based on a FA TLUD where the air is “pushed/forced”. I have found that even with a FA TLUD, there is an optimum fuel burn rate and that the fan needs to calibrated to the fuel (air flow rate) and not the other way around.


> On 07 May 2017, at 20:51, Paul Anderson <psanders at ilstu.edu> wrote:
> 
> Andrew, Ron and all,
> 
> 1.  The mentioned Elsa stove is not by Dave Lello, but is by David Young
> dyoung at pobox.com <mailto:dyoung at pobox.com> Urbana, IL (217) 721-9981   
> 2,  Dave Lello's stove is named FAABulous.   FAAB stands for Fan Assisted Appliance Base.   It is not yet on the market, but is in limited peoduction in South Africa for trials and testing etc.   Dave Lelo's company name is Ekasi Power.  I am an advisor to Dave, esecially aboutTLUD design and about getting the FAABulous Stove into areas ourside of Southern Africa.  He is subscribed to the Stoves Listerv, is certainly seeing the messages, and he will send comments whenever appropriate.
> 3.  Andrew is correct, the message that Ron received was not intended to be forwarded to the Stoves Lisrserv.   My opinion is "no serious harm done, but premature disclosures should be avoided."   So do not expect answers right away to all of Ron's questions.
> 4.  Anyone interested in communicaring with Dave should NOT do so via the public Stove Listserv.   His address is not a secret, but I am not at liberty to give it to you here.   If you write privately to me at      psanders at ilstu.edu <mailto:psanders at ilstu.edu>     I will forward everything to Dave.  
> 5.  Opinion:   If you are interested in investing some serious amounts of money into a primier woodgas / TLUD project anywhere in the world, please let me know and I will put you in touch with Dave.  Yes, much is possible very soon, so now is the time for contact.
> Paul
> Doc  /  Dr TLUD  /  Prof. Paul S. Anderson, PhD
> Email:  psanders at ilstu.edu <mailto:psanders at ilstu.edu>
> Skype:   paultlud    Phone: +1-309-452-7072
> Website:  www.drtlud.com <http://www.drtlud.com/>

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