[Stoves] Commercial purposes in homes was Re: Biomass Fired Appliance Characteristics, Features, Qualities, Attributes and or Considerations

[Cecil Cook]

Dear Paul et al,

Pardon me for  not replying sooner to your request.  I was in the air
and/or in recovery mode after my two day return journey from Indonesia to
South Africa.  Now I am gathering my wits and beginning to function again.

There is mountainous ridge running down the spire of the entire length of
the Island of Java.  More than 60% of the population of Indonesia resides
in Java.  In the mountains, when the environment is right, households tap
the sugar palm trees that grow on their land.  It can be as few as 5 or 6
trees up to as many of 30 threes.  Depending on the season, the palm trees
give about a liter of nectar from the flower per day which is then boiled
until it crystallizes and becomes solid.  It is then poured into coconut
shell bowls to cool and after cooling is put into a plastic bag and sold to
a nearby buy trader for about $1 a kg.  It takes about 10 trees to produce
enough sap -really nectar from the bud which is trimmed two times a day.
 The nectar is collected by climbing up 6 to 10 meter palm trees, with no
safety belts, and only small hand and foot holds chopped in to the trunk.
 It must be difficult on rainy days to climb to the top.  The collector
carries a 250 mm long tube of bamboo which he clips onto his belt.  He
removes the tube with nectar and replaces it with the empty tube.

The nectar from one or two collectionis placed in a large 15 to 20 liter
capacity wok about 400 mm in diameter and 150 mm in depth.  If there is too
much nectar it goes into a second pot or wok.

The wok and the pot are boiled at full power for between 2 to 3 hours,
depending on the power of the fire and the amount of nectar that needs to
be dehydrated.  There are a number of different kinds of stoves used to
dehydrate the nectar down to sugar. The stove can be a three stone fire, a
two pot hole traditional stove with no chimney inside the traditional
Javanese kitchen which is high roofed and covered with clay tiles and the
woven bamboo and palm leaf walls which do not interfere with the exhaust of
the smoke created by the fire.

There is also an improved stove with a chimney with 2 or 3 pot holes - the
Jolentho - which the World Bank's partners in Yogyakarta evolved over a
number of years through trial and error that has now been standardized and
is being demonstrated, tested and optimized in a few villages to the west
of Mt Merapi, a hyperactive volcano for which Yogyakarta Province is
becoming famous.

A typical work load of nectar cooking would be +/- 15 liters per day.  I
 observed the following daily sequence of cooking tasks performed by rural
households to dehydrate  nectar into palm sugar. The following different
types of stove work are typically performed on the 2 and 3 pot hole stove
in farming households.


   - First  one or two kettles full of water (5 to 8 liters) are brought to
   a boil and poured into big thermos for use during the day to make tea and
   coffee or to take the chill off bath water in the early AM.
   - Next the rice for the day is boiled and then steamed into a two piece
   steamer (called '*soblok*').  The amount of rice cooked is a function of
   family size and income.  That takes up to 1 hour to complete cooking the
   rice properly.
   - Then other types of foods for the day are cooked using woks, oil,
   water and vigorous stirring or pots to cook a range of different types of
   soup for another 30 minutes.

The second pot hole is used to warm up the nectar whenever it is free.  The
third pot hole is either simply closed with a pot lid or used to keep a
kettle of water hot. Additional hot water is used to wash up the bamboo
tubes, woks, and cooking tools used to cook the nectar which becomes
quickly acidic and ferments.

When the household cooking tasks are completed, the stove operator
concentrates on the task of dehydrating the palm nectar.  We do not have an
accurate method for estimating the K watts of the wood fire. It can range
between 4 K watts to 6 K watts.  One variable factor is whether long sticks
are pushed deep into the multi-pot hole stove so that the fire is burning
under both the first and second holes.

While examining the use of traditional biomass stoves in Central Java to
dehydrate palm sugar, it is necessary to also look at all the other tasks
that stoves are expected to perform in a  rural Javanese home:

(1.) dry firewood which is piled on top of the stove after it is
extinguished (also drying clothes during the long rainy season);

(2.) the source of heat needed to dry corn and peanuts and other crops
piled on a platform about 1.5 meters above the stove;

(3.), also the smoke helps to protect these crops from destructive pests
and weevils;

(4.) warming the kitchen space and family members on cold mornings and
evening which is normally the social center of the family;

(5.) cooking large wok-fulls of mean and vegetables on ceremonial occasions
such as funerals or weddings which express ones solidarity with a larger
community of relatives.

We do not know what percentage of rural households produce palm sugar in
Central Java and Yogyakarta.  In some areas and communities it is more than
50% of the households.

It must be remembered that in all the households that are working 2 to 3
hours a day cooking palm sugar, there is not shortage of free biomass.
 However, there may be a shortage of labour in particular households to
gather and dry the required quantities of high quality fuelwood needed to
boil down 10 to 20 litres of palm nectar every day.

Maybe this gives you a sense of full spectrum of different kinds of stove
work that is going on in typical villages in Central Java.

In service,

Cecil Cook



On Mon, Apr 8, 2013 at 3:20 AM, Paul Anderson <psanders at ilstu.edu> wrote:

> Dear Cecil,
>
> Please describe the commercial purposes referred to by Crispin:
>
>> Cecil found that in some areas of Java 90% of rural homes use the cooking
>> stove for commercial purposes and that more fuel is burned for home
>> industry than for cooking meals.
>>
> The sizes (heat output) of the fires is important, as is the physical
> structure of the heat-capture device (pot, griddle, oven etc)
>
> Paul
>
> Paul S. Anderson, PhD  aka "Dr TLUD"
> Email:  psanders at ilstu.edu   Skype: paultlud  Phone: +1-309-452-7072
> Website:  www.drtlud.com
>
> On 4/7/2013 8:53 AM, Crispin Pemberton-Pigott wrote:
>
>> That is a good idea.
>>
>> Consider this: Cecil found that in some areas of Java 90% of rural homes
>> use the cooking stove for commercial purposes and that more fuel is burned
>> for home industry than for cooking meals.
>>
>> Is that an industrial stove?
>>
>> In towns the %is not much lower though varies a lot with the
>> neighbourhood.
>>
>> If we want to promote better stoves to the general population we have to
>> consider what they do with them, carefully.
>>
>> Lanny: it occurs to me that the definition of a chimney stove (or not) is
>> whether there is something after the pot that increases draft. Draft
>> inducers below/prior to the pot are not included in the chimney group.
>>
>> What'cha think?
>>
>> Regards
>> Crispin
>> -----Original Message-----
>> From: "Paal Wendelbo" <paaw at online.no>
>> Sender: "Stoves" <stoves-bounces at lists.**bioenergylists.org<stoves-bounces at lists.bioenergylists.org>
>> >
>> Date: Sun, 7 Apr 2013 15:43:36
>> To: Discussion of biomass cooking stoves<stoves at lists.**
>> bioenergylists.org <stoves at lists.bioenergylists.org>>
>> Reply-To: Discussion of biomass cooking stoves
>>         <stoves at lists.bioenergylists.**org<stoves at lists.bioenergylists.org>
>> >
>> Subject: Re: [Stoves] Biomass Fired Appliance Characteristics, Features,
>>         Qualities, Attributes and or Considerations
>>
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