[Stoves] Agglomeration vs densification.....?

Tue Feb 26 08:54:01 CST 2008

Dear Richard:

I feel your pain.  However, as oil prices escalate the first casualties 
will be the US Department of (no) Energy, and the Environmenal (jobs) 
Protection Agency.

------------------------------------------------------------------------
I am putting together a cement mixer to make "fire balls", agglomerated 
(not briquetted) charcoal or other particuate matter held together by a 
minimal amount of binder (usually starch).  I learned of these from 
Jouhn Tatom in GA, 30 years ago and still have a few.  They survive a 6' 
drop to a hard floor.

Charcoal is one of the best fuels, easily made, stored and used, but so 
very light.  It needs briquetting/agglomeration. 

Do you have any experience along this line?

Your pal,

TOM REED        BEF/BEC

Richard Stanley wrote:
> Stovers, esp. those in/familiar with  the US part of the Americas and  
> more specifically  the Oregon part of all that.
>
> We have remained pretty much silent participants as our interest is  
> pretty much focused on just "low tech"  biomass briquetting. --until  
> now...
>
> Increasingly arising, are requests for the tech and training here in  
> the USA  --for application in the USA to the household cooking and  
> heating stove.
>
> As cylinders ranging between 8 to 15 cm in diameter by  X 7 to 10 cm  
> height, the briquettes we promote  are mot really adaptable to pellet  
> stoves. Although they will do nicely in a open hearth or barbecue, we  
> are at a bit of a loss to find a really modern affordable wood stove  
> that would fit the bill.
> We have been fortunate to have worked with Jon Davies, Kobus Venter,  
> Paul Anderson, Sanu Kaji, Lanny Hansen  and others on this list on  
> briquette  use in stoves, designed for the third world (or the third   
> world parts of the first world) but not on a functional and   
> affordable stove for our own nation.
>
> HAving heated our house and cooked largely off a small wood stove  
> this past 4 months ( we're doing a near total --far more than  
> anticipated at least-- house remodel) I can tell you that finding a  
> good looking stove oven burner wood and kindling storage which looks  
> like something halfway modern, is functional and affordable --- for  
> use with biomass briquettes of the above sizes, is almost non existent.
>
> For the functional oven cooker heater stove, I see lots of 20's retro  
> and lots of scandanavian designs for 8+ grand USD, but nothing  
> simple, well design and practical for wood or biomass.
> Heating stoves yes: Stoves which heat and incorporate an oven and  
> stovetop cooking and wood kindling and wood or briquette fuel  
> storage,  no...
>
> So we designed one... Its really not rocket science (no pun  
> intended,  Approvecho). Doors open out like and oven door, for ---the  
> oven---, and also for the combustion chamber to keep ashes headed  
> inward, (a side tray handles the ashes away from the food and oven),  
> and flat top for cooking / grilling surfaces.  Add on a CO meter/ 
> alarm, a timer, and temperature gages for the combustion chamber, the  
> oven and the cooktop  mounted well above and behind the cooking  
> surface, add glass doors for oven and combustion chamber and a  
> perforated 12 ga steel  door for the kindling fuel supply at the base  
> ---with primary and secondary feed and appropriate insulation at  
> optimal locations.
>
> Aside from the glass, the instrumentation, this, thus far is all  
> within the realm of a local blacksmith shop, frankly.
>
> But then the bureaucracy of  well intended  regulation hit us in the  
> face: The figure I have is 84,000 USD for the magic certification by  
> the EPA.
>
> Yikes: Why and how could simple testing procedure for safety,  
> efficiency , CO /CO2 and particulates emissions cost so much?
>
> As with our long standing mechanisee press development, I am  
> perfectly happy to share the design with anyone who wants to develop  
> it and share the returns after costs are all in... but first what am  
> I missing on this immense stumblng block of EPA testing..?
>
>   Surely for example, the energy and accredited knowledge base  
> accumilated here can provide or at the minimum recomend such a  
> testing process/ resource which would satisfy the good EPA at a  
> reasonable price and time frame...?
>
> thoughts / advise ?
>
> Richard Stanley,
> Legacy Foundation
> www.legacyfound.org
> State of Jefferson
>
>
>
> On Feb 18, 2008, at 8:09 PM, Paul S. Anderson wrote:
>
>   
>> Dear Stovers,
>>
>> Some very illuminating comments have been made.
>>
>> Dean wrote:  (much snipped)
>>     
>>> The pot lid helps very, very much when simmering especially if the  
>>> cook does
>>> reduce power to keep the water just below rapid boiling which  
>>> cooks food as
>>> quickly (96C-93C).
>>>       
>> Yes, and we should be advocating this whenever possible.  And that  
>> means using
>> lids in the test measurements that are being consulted to judge  
>> which stoves
>> are best and get the funding.
>>
>>     
>>> So, in the Water Boiling Test we need to use a pot that is as  
>>> representative
>>> as possible of pots used in the world.
>>>       
>> That is good for being able to compare the lab tests, but quite bad
>> considering
>> that the test results are used to help make decisions as if all the  
>> target
>> populations use the same size pots.
>>
>>     
>>> Rob Bailis and Aprovecho did a
>>> survey, asking NGOs what they recommended. The range is enormous.  
>>> In Central
>>> America folks use huge pots. In India folks use tiny pots. Etc.
>>>
>>> A 7 liter straight sided pot holding 5 liters of water was thought  
>>> to be a
>>> middle ground.
>>>       
>>      (snipped)
>>     
>>> Now, the Water Boiling Test also used a standard pot holding 2.5  
>>> liters of
>>> water which is used in the stove cannot bring to boil the larger  
>>> amount of
>>> water.
>>>       
>> But the quantitative test results from 2.5 liter and 5.0 liter  
>> tests are not
>> comparible, and very limited data or test runs are available for  
>> either size.
>>
>>     
>>> The big problem with using a lid on the 7 liter straight sided pot  
>>> is that
>>> it affects the turn down ratio.
>>>       
>>   (snip)
>>     
>>> If a lid is used to simmer at just below the rolling boil state  
>>> (between
>>> 96C-93C) it is probably not possible to keep the fire lit using  
>>> normal sized
>>> wood.
>>>       
>> THAT statement should say something about the stove in use.   
>> Instead, the
>> ability to keep the fire going has been turned into an issue of  
>> fuel size and
>> having a lid on the pot.
>>
>>  From what I have seen in many countries, there is no "normal sized  
>> wood" until
>> the actual cookstove is also specified.  Lots of twig-sized wood is  
>> used in
>> many areas of India.
>>
>>     
>>> If I remember correctly, less than 1/6th the energy of high power is
>>> required for simmering with a lid even on a 7 liter pot. So for me  
>>> to do a
>>> Water Boiling Test with a lid, I normally need to split up the  
>>> wood into
>>> smaller diameters.
>>>       
>> That all depends on what size fuel you start with and the
>> characteristics of the
>> stove.
>>     
>>> When a lid is not used, then the Turn Down ratio is around 3-4 and  
>>> the
>>> larger fire used can be kept going without splitting wood.
>>>       
>> In my nearly seven years of serious stove work, I had never heard that
>> justification before.  Essentially:  The official water boiling test
>> has no lid
>> on the pot so that the stove in use (Rocket stove) could keep the  
>> simmer going
>> but not overly boiling too vigorously while maintaining a preferred  
>> size of
>> stick wood as fuel.
>>
>>     
>>> Again, it is
>>> possible to conduct a Water boiling Test either way. The question  
>>> was: which
>>> is more indicative of normal use? Thinking that people would not  
>>> split wood
>>> up very fine and faced with a lot of experimenters being bemused  
>>> that their
>>> simmering fires went out, we went with an uncovered pot for  
>>> simmering. It is
>>> another judgment call...
>>>
>>>       
>> And I think that it was not the correct judgment call.  It was correct
>> for users
>> of Rocket stoves, and has reinforced their beliefs in the  
>> superiority of the
>> Rocket stoves.  But in my opinion it was not correct considering  
>> the vast
>> variety of other stoves then and now available.
>>
>> Is it realistic to say that in the standard WBT with a lid on the  
>> pot, the
>> Rocket stoves would have heavy boiling during the 45 minutes of  
>> simmering, and
>> therefore yielding significantly different results?  Of course the  
>> users could
>> opt to use smaller diameter stick-wood fuel which may __or may  
>> not___ allow
>> that stove to still produce the published results on quantity of  
>> fuel used and
>> the emissions during the simmer stage.   (data related to the bring- 
>> to-boil
>> stage does not change unless the physical stove is altered to  
>> accomodate the
>> simmer stage.)
>>
>> In another recent message, Dean wrote:
>>     
>>> However, a stove that is fast to boil was the number one concern of
>>> cooks in an extensive survey of Indian cooks.
>>>       
>> I agree with that statement.  But for the most part, Indians cook in
>> small pots
>> without much excess water.  In the Hyderabad area where I have worked
>> recently,
>> a family of 3 or 4 would make rice, dal (lentals) and chapati  
>> (tortilla-like)
>> for one main meal.  One burner was generally sufficient to use in a  
>> succession
>> of pots.  2 cups of water with one cup of rice (or 3 cups with 1.5  
>> cups of
>> rice) was brought to a boil quickly.  How long does it take to boil 2
>> or 3 CUPS
>> of water with rice in it?  6 to 9 minutes or average of 7 or 8  
>> minutes,
>> and let
>> it boil for another 4 or 5 minutes.  Then the rice (always with the  
>> lid
>> on) was
>> placed to the side to finish cooking with the heat within the small  
>> pot (and
>> often without even a cloth cover for retained heat cooking).  That  
>> is a bit
>> different from the WBT with 5 liters.
>>
>> Then the same high fire is used to boil the pre-soaked lentales, which
>> also was
>> with only 2 or 3 cups of water.  Disregarding that many families  
>> have pressure
>> cookers, allow another 10 to 15 minutes with high fire.
>>
>> Total time so far is 20 to 30 minutes.  But if the cook fires up two
>> burners (as
>> in LPG or a TLUD gasifier or a two-hole stick-wood stove), the clock
>> time is cut
>> in half.
>>
>> The chapatis are cooked one at a time on a tawa', essentially a  
>> slighly
>> concave
>> circular griddle or mini-"plancha".  Mostly at high fire.  Less  
>> than a minute
>> each, all are finished in another 10 to 15 minutes.
>>
>> No meaningful simmer where I was working in India. And no cooking  
>> without lids
>> except to stir in spices and then replace the lid.
>>
>> So, I am increasingly LESS impressed by the results of the WBT.  It  
>> is nice to
>> know that the TLUD emmissions are so low.
>> (Thank you Dale Andreatta for the one  set of data from under the
>> emissions hood
>> using the TLUD as it should be used. --- Yes, much better than my  
>> own two test
>> runs in 2005 when I was still learning how to use the TLUDs, and still
>> won by a
>> significant margin the Cat Pee Award for cleanest combustion.)
>>
>> Finally, Martin Boll wrote:
>>     
>>> Just want to draw your attention to the well known fact, that
>>> small fires (I think [of them] as well turned-down-fires) need
>>> small-calibrated fuel/wood, to be managed well.
>>>       
>> Hail to small wood!!!!   Hail to small fuel!!!!!     And that includes
>> the wood
>> chips and hammermill wood and broken twigs, etc. that are so good in
>> the TLUDs.
>> Although the low fire was not used much where I was working in India,
>> the TLUDs
>> have a very good turn down ratio.
>>
>> Paul
>> -- 
>> Paul S. Anderson, Ph.D., Geography professor - Emeritus
>> Telephone:  USA-309-452-7072 (residence and office)
>> Internet site:  www.ilstu.edu/~psanders
>> For my gasifier stoves info, go to:
>> http://bioenergylists.org/contributors#Paul_Anderson
>>
>>
>>
>> ----------------------------------------------------------------
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>>
>>
>>
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