[Stoves] briquettes: more about presses or more about processing

Thu Sep 5 19:15:51 CDT 2013

Kobus Paul et al., 

There are so many different presses by now ( I recon there are  some 25 generically different types out on line and in use in actual projects) Clearly another  press design is not going to shake the earth for the small scale project setting. 

The development of a variety of useful practical methods for processing the residues is however a different story:
It's  an element of the small scale entrepreneur based production process that --done with a mortar and pestle- can consume up to 70% of  total production labor in this 90% + labor intensive activity. It's the deal breaker of the process. MAny fail to appreciate this and wind up desperately using paper as a quick fix (but poorly combusting) binder.  

There are  Mortars and pestles, grinding stones, flexing hacksaw blades cutting through meshed with wire brushes and nail-studded drums , cement mixers-- alone or with rocks or rods,  and others have emerged and these and other designs continue to evolve, globally. One should target an output of 150 kgs (dried to ambient) of  ag. residues, a day, with two workers, to realise economically viable  briquette production in the rural to peri urban setting in most of the developing nations. Reduce the figure to 60% of  that mass,  if you are adding the balance of granular combustible infiller material ( sawdust or paper or charcoal fines rice husks etc) or any combination of the latter. 

The technical problem is that for a good quality ag- residue blend briquette (beyond just paper based blends) , one needs to see more than just chopped material. They  need to see  the necessary plethora of floppy ganglia from a process of scruffing, scraping, flailing leaves and grasses  , which are so essential in binding agro residues together. Where this cannot be achieved by machinery, it is necessary to partially  decompose materials. That  is an added and protracted management challenge for most small producers. 

Processing material efficiently remains th greatest challenge and requires the most skill for  attaining viable production at the manual production level

In short Paul and others who may be  curious about presses, Please look into the material processing issue first, at least if you are not using paper as the binder.

Plugging ourselves (and our counterpart organisation in Guatemala)  
We will be completing or manual on a 'molino ya mano', a portable hand grinder designed expressly for processing ag residues after our next visit with or counterparts in Guatemala this fall where user-based field testing has been going on for the past 8 months.  Its one solution but again by no means the only  or even the best one for your own conditions. 
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Molio ya mano on tial in Cunen, Quiche Guatemala JAn/Feb.,  2013. 

Likewise, the use of a garbage disposal I  posteda few days ago, as efficient as it is, is more likley to work in an urban production or test lab situation: Its not really not really for the rural setting.

Aluta continua and pressing on?

Richard  

========

On Sep 5, 2013, at 12:16 PM, Kobus Venter wrote:

Hey Richard,

Here's a pic of some of my winter supply briquettes:
http://vuthisa-techblog.com/wp-content/uploads/2013/07/BP3ZhfJCEAA10jX.jpg

And this is how I made them:
http://vuthisa-techblog.com/wp-content/uploads/2013/06/Steps.png

One cold and rainy night I used 30 briquettes in one go.  I have taught my gardener to make around 20 briquettes per week with the "test briquette maker" you encouraged me to make back in 2003 or there abouts - and the metal press stand is still going strong - just needed another lick of paint and I changed out the wooden block.  The Rhodesian Teak piston is still around but I've switched to a PVC piston now.  Working on a new design to produce some square shaped briquettes for easier storage pressed down inside a square section of gutter downpipe.

Regards

Kobus
>> Dear fello briquetters with ready access to, of all things, a used garbage disposal and household sink.
>> 
>>> Planning for the winter supply of hollow core ag and household residue based  briquettes, means a lot of material processing.  Thats the not so
>>> much fun part of the process. I have long thought about the possibility of
>>> using a garbage disposal for pulping materials so I got ahold of a scrapped
>>> double basin sink and bolted a scrap disposal on a few days ago, just to see if it was worth pursuing.
>>> Turns out a that its pretty efficient but you really have to clean out any
>>> rocks.  I got rid of those, by filling the non disposal side of the sink The larger basin, half full of
>>> water and soaking and sloshing the leaves /grasses ferns and wigs around a
>>> bit, to settle out the rocks, stones, metal stuff.  Next, I  skimmed off  the
>>> floating material into the second smaller basin-- the one onto which I had attached  the disposal.
>>> I then plowed screed the material over the entrance hole with right hand then stuff it in with
>>> a running garden hose spray nozzle in my left hand left hand .  It does  a good job  of chopping  and
>>> pulping the fibrous  mass into a really well mixed slurry-without destroying the fibers entirely- good enough in fact, that that with just a day of soaking to soften everything a bit,  I can compact it directly in the press,  no paper or other binder,--and more critically, no decomposition needed.
>>> (it's amazing too, just how much gritty sediment accrues, in
>>> the larger soaking basin as well). Clearly wet processing of the feedstock seems to be a good way to go..Will have to test it out over the coming month before I am assured of its real viability but it' be far better if several of us do the same thing -and share back the findings to speed up and deepen the learning curve for the rest of us, eh !
>>> 
>> Richard Stanley
>> Legacyfound.org
>> 

-- 
Please vote for VermiChar: http://bit.ly/FNBVermiChar

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