[Stoves] Three (?) Stoves from Rockworks

[Ron]

Crispin. With ccs. (think you wanted the list)

Thanks.

You ask some good questions below.  Dean Still can perhaps answer.

I am amazed at the 20% char value below.  Hmm.

Ron



On Feb 19, 2013, at 6:26 PM, "Crispin Pemberton-Pigott" <crispinpigott at gmail.com> wrote:

> Dear Ron
> 
> [RWL:  I'd like to hear your set of differences.   I wonder where this fits in the range described by Nordica at last ETHOS meeting in terms of dimension ratios.]
> 
> I have found the exact description of a Rocket Stove somewhat elusive. In this case we see a company called Rocket Works making a stove that is a side-fed stick burner, but that is hardly a rare or novel description. It does not follow Larry's description of 'how to design a stove' so where does it fit? 
> 
> It has very restricted primary air and charcoal sits on a grate with a pretty fine aperture. It has no 'shelf' in the Rocket sense. It hoves closer to the original with the flat metal shelf, nowadays dropped in favour of a 'ladder' which allows in far more excess air which was already a problem. 
> 
> The Rocket Works stove has preheated secondary air with tangential injection and might still benefit from more control over it - hard to tell at this stage. The thermal efficiency is pretty high at high power and lower at low power which is what you would expect from an 'in-the-bottom-out-the-top' layout. 
> 
> [RWL:  This is first time I have heard this about charcoal and Rockets.  Can some users describe the maximum amount they have ever retrieved?]
> 
> Any layout where there is no grate to support the charcoal will see the dropped fuel roasted (pyrolysed) but the char will not burn well (lack of under-air). The numbers from boiling tests will show the typical char from say, a kg of wood. 
> 
> Because historically the charcoal remaining has been subtracted from the 'fuel consumed' figure (because it was energy not consumed) you would not see the actual fuel and actual car number unless you saw the calculation sheet. That may explain why you didn't hear about it before. 
> 
> Putting in a grate (like the StoveTec stoves) raises the char and allows it to burn. In some cases this may be a disadvantage. It depends on the local cooking cycles. 
> 
> So the question remains, is a Rocket Stove anything from Aprovecho? It is a particular layout? It is a set of dimensional relationships? Is it a rocket stove if sticks are fed into the side?  In short, is it a brand name or a type of stove. I remain confused on the answer. Rocket Works doesn't make Rocket stoves in the classic sense. Does this matter?  There are lots of stoves with side-fed sticks going back millennia. Some have grates, some don't. 
> 
> On the question of additional data that should come from the company.  I don't know the price but do know they said they could make 500 a day if I recall correctly. It is not very heavy. 
> 
> Regards 
> Crispin
> 
> PS The highest char production of char I have seen from a side-fed stove is the Namibian Tsotso which has a (slightly) perforated sheet metal grate instead of a fuel shelf. It made something like 20% char - about the same as a TLUD.