Cuiseur micro gazéificateur/en-gb : Différence entre versions

(Page créée avec « * A drill and 2 drill bits:11mm and 7mm respectively * A hammer and a large nail (or a metal punch) * A wooden block, a part of which can be inserted inside the tin can. »)
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{{ {{tntn|Tuto Details}}
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{{Tuto Details
|SourceLanguage=fr
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|Main_Picture=Cuiseur_micro_gazéificateur_DSC_0024 (sans logo).jpg
|Language=en-gb
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|Licences=Attribution-ShareAlike (CC BY-SA)
|IsTranslation=1
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|Description=How to make an inexpensive portable wood cooking system.
 +
|Area=Food, Energy
 
|Type=Tutorial
 
|Type=Tutorial
|Area=Food, Energy
 
|Description=How to make an inexpensive portable wood cooking system.
 
 
|Difficulty=Very easy
 
|Difficulty=Very easy
 +
|Duration=1
 +
|Duration-type=hour(s)
 
|Cost=0
 
|Cost=0
 
|Currency=EUR (€)
 
|Currency=EUR (€)
|Duration=1
 
|Duration-type=hour(s)
 
|Licences=Attribution-ShareAlike (CC BY-SA)
 
|Main_Picture=Cuiseur_micro_gazéificateur_DSC_0024 (sans logo).jpg
 
 
|SourceLanguage=fr
 
|SourceLanguage=fr
 
|Language=en-gb
 
|Language=en-gb
 
|IsTranslation=1
 
|IsTranslation=1
 
}}
 
}}
{{ {{tntn|Introduction}}
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{{Introduction
 
|Introduction=Factors relating to cooking remains one of the biggest challenges in the areas of health and energy. In many developing countries, the classic three-stone cooking fire is the technology that is most commonly used.This is extremely inefficient (with a thermal yield of 10 to 15%  if sheltered from the wind and 5% if exposed) and releases toxic smoke into dwellings.There are two concerns with this:
 
|Introduction=Factors relating to cooking remains one of the biggest challenges in the areas of health and energy. In many developing countries, the classic three-stone cooking fire is the technology that is most commonly used.This is extremely inefficient (with a thermal yield of 10 to 15%  if sheltered from the wind and 5% if exposed) and releases toxic smoke into dwellings.There are two concerns with this:
*  Energy output is so poor that a huge amount of wood is needed to cook one meal.
+
*  Energy output is so poor that a large amount of wood is needed to cook one meal.
 
This leads to extensive deforestation in certain parts of the world.
 
This leads to extensive deforestation in certain parts of the world.
 
*  Evidently, this creates certain problems with regards to health: smoke given off causes respiratory problems for people in the community and the reduces their quality of life. A technology that uses the same biomass but has a higher output
 
*  Evidently, this creates certain problems with regards to health: smoke given off causes respiratory problems for people in the community and the reduces their quality of life. A technology that uses the same biomass but has a higher output
Ligne 26 : Ligne 23 :
 
The micro gasifier which is a low-tech and very economical way of cooking and, if well-made, has an output higher than a three stone stove (thermal output of approximately 35%). Output is even higher with the enhanced industrial version (which has a thermal output in the order of 45%)
 
The micro gasifier which is a low-tech and very economical way of cooking and, if well-made, has an output higher than a three stone stove (thermal output of approximately 35%). Output is even higher with the enhanced industrial version (which has a thermal output in the order of 45%)
  
It is possible to make a very basic model out of tin cans, but this will have a limited number of features. However, this can be very useful for instance for heating water, cooking small quantities of food and for doing demonstrations/teaching purposes.
+
It is possible to make a very basic model out of tin cans, but this will have a limited number of features. However, this can be very useful, for instance, for heating water, cooking small quantities of food and for doing demonstrations/teaching purposes.
  
 
More complex models do exist which, although more costly, tend to last longer and allow control over the power you can get from the flame.
 
More complex models do exist which, although more costly, tend to last longer and allow control over the power you can get from the flame.
 
}}
 
}}
{{ {{tntn|Materials}}
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{{Materials
|Material=*  A large tin can (in terms of height and width)  (1): for the external chamber;  
+
|Material=*  A large tin can (in terms of both height and width)  (1): for the external chamber;  
 
*  A tin can which is slightly shorter and thinner (2): for the combustion chamber;
 
*  A tin can which is slightly shorter and thinner (2): for the combustion chamber;
*  A tin can of the same diameter to the combustion chamber (3): for the stand on which the pan sits.
+
*  A tin can with the same diameter as the combustion chamber (3): for the stand on which the pan sits.
 
|Tools=* Marker
 
|Tools=* Marker
* Wire cutter
+
* Tin snips
  
For drilling, there are 2 options:  
+
For drilling, there are 2 options:
  
 
*  A drill and 2 drill bits:11mm and 7mm respectively
 
*  A drill and 2 drill bits:11mm and 7mm respectively
 
*  A hammer and a large nail (or a metal punch)
 
*  A hammer and a large nail (or a metal punch)
 
*  A wooden block, a part of which can be inserted inside the tin can.
 
*  A wooden block, a part of which can be inserted inside the tin can.
 +
|Tuto_Attachments={{Tuto Attachments
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|Attachment=Cuiseur_micro_gaz_ificateur_Affiche_RechaudPyrolyse_FR.pdf
 +
}}
 
}}
 
}}
{{ {{tntn|Separator}}}}
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{{Tuto Step
{{ {{tntn|Tuto Step}}
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|Step_Title=How it Works
|Step_Picture_00=Cuiseur_micro_gazéificateur_Schéma fonctionnement.jpg
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|Step_Content=This is based on the concept of gasification: Wood is heated in an environment containing very little oxygen, giving off combustible gases known as “Syngas” which are then burnt in the upper part of the stove.
|Step_Picture_01=Thermal efficiency.png
 
|Step_Title=Fonctionnement
 
|Step_Content=Il repose sur le principe de la gazéification : Le bois est chauffé dans une atmosphère peu oxygéné, ce qui va permettre le dégagement de gaz inflammables dits « Syngas», qui vont ensuite être brûlés en partie haute du réchaud.  
 
  
Le Micro-gazéificateur s'allume par le haut.
+
The micro-gasifier is lit from the top.
L’air primaire introduit en partie basse traverse la masse du combustible et permet d’entretenir un lit de pyrolyse qui descend à mesure que les gaz combustibles se dégagent. L’air secondaire est injecté en partie haute pour fournir de l’oxygène nécessaire à la combustion des gaz qui se dégagent vers le haut.
+
Primary air, flowing into the lower part, passes through the mass of combustible fuel, maintaining a pyrolysis layer which then drops as the combustible gases are released. Secondary air is forced into the top of the stove, supplying the oxygen that is needed for combustion of gases emitting in an upward direction.
  
De meilleurs résultats sont obtenus en convection forcée avec l’usage d’un ventilateur intégré sous la grille support du combustible, mais cela induit un approvisionnement fiable en électricité.
+
Better results are obtained with forced convection, using an integrated fan under the grid which supports the fuel.  However you will need a reliable supply of electricity for this.
  
La température de combustion se situe autour de 800°C, et les rendements thermiques vont de 30 à 45%, selon la qualité de fabrication du système et de son isolation.
+
The temperature at which combustion takes place is around  800°C and thermal yields are between 30 to 45% depending on how well it is made and the quality of the insulation.
  
Il est léger, compact, fiable, utilise peu de combustible et génère, dans le meilleur des cas, du charbon réutilisable pour d’autres applications. C’est donc un système très low-tech et très performant par rapport aux systèmes classiques utilisés dans le monde.
+
It is light, compact, reliable, uses little fuel and, in the right circumstances, produces reusable charcoal which can be used in other applications. This system is therefore extremely low-tech and very efficient compared to conventional systems used throughout the world.
  
Pour comparaison, le graphique ci-contre montre les performances énergétiques de différents systèmes. Le micro gazéificateur est ici nommé « wood gas stove ».
+
As a comparison, the diagram opposite shows the energy performances of various systems. The micro-gasifier here is called  “wood gas stove”.
 +
|Step_Picture_00=Cuiseur_micro_gazéificateur_Schéma fonctionnement.jpg
 +
|Step_Picture_01=Thermal efficiency.png
 
}}
 
}}
{{ {{tntn|Tuto Step}}
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{{Tuto Step
|Step_Picture_00=Fabrication Chambre externe.jpg
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|Step_Title=External Chamber
|Step_Title=Chambre externe
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|Step_Content=- Mark the positions of a approximately 10 holes, spread out evenly all around the upper part of tin can (1).
|Step_Content=1 - En partie haute de la grande boite de conserve (1), marquez l'emplacement d'une dizaine de trou, répartis équitablement tout autour de la boite.  
 
  
2 - Percez ensuite aux emplacements marqués à l'aide d'une mèche de 12mm (ou avec le marteau et le clou).
+
- then drill where marked using a 12mm drill bit (or with a hammer and nail)
(Pour un rendu plus propre il est recommandé de pré-percer avec la mèche de 7 mm avant d'attaquer avec la mèche de 12 mm).
+
(For a cleaner finish, we recommend that you make pilot holes with a 7mm drill bit before tackling it with a 12mm drill bit).
  
'''Remarque''': Pour plus de facilité et de propreté, il est possible de serrer la cale de bois sur un étau et de l'utiliser comme appui pour faire les trous dans la boite.
+
'''Note''':To make things cleaner and easier, you can clamp the wooden block onto a vice and use it as a support when making the holes in the tin can.
  
3 - Découpez le fond de la grande boite de conserve (1). Le trou doit avoir un diamètre légèrement inférieur à celui de la petite boite de conserve (de façon à pouvoir l'encastrer dedans).
+
- Cut the bottom out of the large tin can (1). The opening must be of a slightly smaller diameter to that of the small tin can (so that it can sit inside it)
 +
|Step_Picture_00=Fabrication Chambre externe.jpg
 
}}
 
}}
{{ {{tntn|Tuto Step}}
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{{Tuto Step
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|Step_Title=Combustion Chamber
 +
|Step_Content=- Mark the position of approximately 15 holes spread out over the whole surface of the bottom of the tin can (2).
 +
-  Mark the positions of a approximately 10 holes, spread out evenly all around the upper part of tin can (2).
 +
 
 +
- then drill where marked using a 7mm drill bit (or with a hammer and nail)
 
|Step_Picture_00=Fabrication Chambre interne.jpg
 
|Step_Picture_00=Fabrication Chambre interne.jpg
|Step_Title=Chambre de combustion
 
|Step_Content=1 - Sur le fond de la boite (2), marquez l'emplacement d'une quinzaine de trous répartis sur toute la surface.
 
En partie haute de la boite (2), marquez l'emplacement d'une dizaine de trous, répartis équitablement tout autour de la boite.
 
 
2 - Percez ensuite aux emplacements marqués avec une mèche de 7 mm (ou avec le marteau et le clou).
 
 
}}
 
}}
{{ {{tntn|Tuto Step}}
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{{Tuto Step
|Step_Picture_00=Support du plat.jpg
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|Step_Title=Pan Support
|Step_Title=Support du plat
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|Step_Content=- Mark the positions of approximately 10 holes spread out evenly all the way around the small tin can (3).
|Step_Content=1 - Marquez l'emplacement d'une dizaine de trous répartis équitablement tout autour de la petite boite de conserve (3).  
 
  
2 - Percez ensuite aux emplacements marqués à l'aide d'une mèche de 12mm (ou avec le marteau et le clou).
+
- then drill where marked using a 12mm drill bit (or a hammer and nail)
  
3 - Découpez le fond de la boite.
+
- Cut out the bottom of the can.
  
4 - NB : Pour plus de facilité à l'utilisation, vous pouvez découper un trou large sur le côté de la petite boite (3) : il permettra de facilement ravitailler le feu en bois !
+
- NB: For ease of use, you can cut out a large hole on the side of the small can (3): this makes it easier for the fire to catch the wood
 +
|Step_Picture_00=Support du plat.jpg
 
}}
 
}}
{{ {{tntn|Tuto Step}}
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{{Tuto Step
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|Step_Title= Final Assembly
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|Step_Content=- Put tin can (2) into the large tin can (1) as shown in the diagram.
 +
 
 +
- Place tin can (3) on top of the two other tin cans which have been nested one inside the other.
 +
 
 +
- The pyrolytic stove is now ready for you to use !
 
|Step_Picture_00=Montage.jpg
 
|Step_Picture_00=Montage.jpg
|Step_Title=Montage final
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}}
|Step_Content=1 - Encastrez la boite (2) dans la grande (1) comme indiqué sur le schéma.
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{{Tuto Step
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|Step_Title=Directions for Use
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|Step_Content=Despite this type of cooker being more environmentally friendly than the “three stoned” ones, it still gives off smoke. For this reason, it needs to be used in a well-ventilated area.
  
2 - Déposez la boite (3) sur les deux autres boites encastrées.
+
<div class="mw-translate-fuzzy">
 +
To light the stove, fill up and light it in the upper part.
 +
</div>
  
Votre réchaud à pyrolyse est prêt !
+
To ‘turn off’ the stove, simply wait until all the wood has burnt down and the casing has cooled down,
}}
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{{ {{tntn|Tuto Step}}
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THE TEMPERATURE OF WOOD AND GASES WHEN BURNT CAN REACH UP TO ALMOST 1200°C. HANDLE THE STOVE WITH EXTREME CARE : DO NOT MOVE THE STOVE WHEN LIT.
|Step_Picture_00=Cuiseur_micro_gazéificateur_Utilisation.jpg
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|Step_Title=Utilisation
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'''Problèmes techniques :'''
|Step_Content=Même si ce type de cuiseur est plus propre que les cuiseurs "trois pierres", il dégage tout de même de fumées. C'est pourquoi il doit être utilisé dans un milieu très ventilé.
+
 
 +
- ''La flamme monte très haut'' '''ou''' ''la flamme s'éteint parfois malgré libération massive de gaz''
 +
 
 +
<u>Problème probable</u> : l'arrivée d'air secondaire est trop faible par rapport à l'arrivée d'air primaire, les gaz produits massivement ne sont pas brûlés immédiatement car il y a un faible apport d'oxygène. La flamme se développe donc en hauteur, dans l'air, pour terminer sa combustion ([https://wiki.lowtechlab.org/w/Http%3A//www.drtlud.com/epost/upright-split-log-burning-and-stealth-fires-and-tlud-camping-fires-was-re-stoves-how-to-make-smokeless-coal/ source]). Aussi, la production trop massive de gaz relativement à l'air secondaire peut "souffler" les flammes et les éteindre (ce qui déclenche une libération massive de gaz (fumée)).
 +
 
 +
<u>Solution</u> : Si dans un même temps le combustible brûle trop rapidement ou la flamme est trop intense, chercher à réduire l'arrivée d'air primaire. Changer la conserve concernée, boucher quelques trous avec de l'aluminium, ou déplier les bavures des trous pour les refermer.
 +
 
 +
Sinon, augmenter l'arrivée d'air secondaire. Agrandir ou refaire quelques trous.
  
Le réchaud fonctionne avec des granulés de bois ou des copeaux de biomasses.
+
- ''la flamme est trop forte et le combustible brule trop rapidement''.
Pour allumer le réchaud, remplir le réchaud et allumez dans la partie haute.  
 
  
Pour éteindre le réchaud, attendez simplement que tout le bois soit consumé et que l'enceinte aie refroidie.
+
<u>Problème</u> : le dispositif est trop ventilé. S'il n'y a pas de problème de combustion des gaz ou une flamme qui se développe haut dans l'air, alors l'arrivée d'air secondaire est au bon ratio avec l'air primaire. En revanche, l'arrivée d'air totale est trop importante.
  
'''ATTENTION : LA TEMPERATURE DE COMBUSTION DU BOIS ET DES GAZ AVOISINE LES 1200°C. LE RECHAUD EST A UTILISER AVEC BEAUCOUP DE PRECAUTION : N'ESSAYEZ PAS DE DEPLACER LE RECHAUD LORSQU'IL EST ALLUME'''
+
<u>Solution</u> : envisager de réduire l'apport d'air général, par exemple en refermant partiellement des trous basaux de la boite support extérieur.
 +
|Step_Picture_00=Cuiseur_micro_gazéificateur_Utilisation.jpg
 
}}
 
}}
{{ {{tntn|Tuto Step}}
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{{Tuto Step
|Step_Title=Remarques
+
|Step_Title=Comments
|Step_Content=Le système présenté ici est très simplifié et ne permet donc pas de gérer par exemple la taille de la flamme.  
+
|Step_Content=This is a very simple system and does not, for example, allow control over the size of the flame.
  
De part les matériaux utilisés, la durée de vie du réchaud est assez limitée.
+
Due to the materials used, the stove has a very limited service life.
  
Des versions améliorés de ce système sont en phase de test/validation dans différents contextes urbains, ceci du aux efforts de Paul Anderson, spécialiste des micro gazéificateur.  
+
Improved versions of this system are currently being tested/validated in various urban settings thanks to initiatives taken by Paul Anderson, an expert in micro-gasifiers.
  
Des essais d'implantation ont eu lieu en Inde sans grande réussite: Il est en réalité compliqué de trouver des granulés ou de la biomasse en copeaux dans ces contextes, le prix du micro-gazéificateur optimisé se rapproche du coût de la cuisson au gaz, sans en avoir tous les avantages.
+
Trials have been carried out in India but have not been hugely successful as the reality is that it is quite a complicated operation finding pellets or biomass chips in this area and the price of the enhanced micro-gasifier is approaching that of the cost of cooking with gas but without all the advantages that comes with it.
 
}}
 
}}
{{ {{tntn|Tuto Step}}
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{{Tuto Step
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|Step_Title=How to make a bigger stove
 +
|Step_Content=To  adapt any container or tin you may have available to use as the outside casing, it is possible to make the combustion chamber from sheet metal, ideally stainless steel. It must be of a thickness of 1mm maximum so that you are able to cut it with tin snips. It is important to cut out the tabs and drill the holes whilst the sheet metal is still flat before rolling up and fastening the ends together. Using stainless steel will make the stove last longer.
 +
The photos opposite show how to make the stove from a paint pot and a 1mm thick sheet of stainless steel. The metal sheet should be machined flat before being rolled and fastened (to fasten: fold back approx 5mm of both of the two edges of the sheet metal  in opposite directions and then fix the two together by hammering one flap inside the other). To avoid cuts to hands, wear gloves!
 
|Step_Picture_00=Cuiseur_micro_gaz_ificateur_IMG_6375.JPG
 
|Step_Picture_00=Cuiseur_micro_gaz_ificateur_IMG_6375.JPG
 
|Step_Picture_01=Cuiseur_micro_gaz_ificateur_IMG_6365.JPG
 
|Step_Picture_01=Cuiseur_micro_gaz_ificateur_IMG_6365.JPG
Ligne 129 : Ligne 148 :
 
|Step_Picture_03=Cuiseur_micro_gaz_ificateur_IMG_6368.JPG
 
|Step_Picture_03=Cuiseur_micro_gaz_ificateur_IMG_6368.JPG
 
|Step_Picture_04=Cuiseur_micro_gaz_ificateur_IMG_6376.JPG
 
|Step_Picture_04=Cuiseur_micro_gaz_ificateur_IMG_6376.JPG
|Step_Title=Fabrication d'un réchaud de plus grande taille
 
|Step_Content=Afin de pouvoir s'adapter à n'importe quel récipient ou conserve disponible utilisé en enceinte extérieure, il est possible de confectionner la chambre de combustion à partir d'une tôle, de préférence en acier inoxydable. Son épaisseur doit être de 1mm maximum pour une découpe à la cisaille à tôle. Il faudra découper des languettes et percer les trous dans la tôle à plat avant de la rouler et de la fermer par agraffe. L'utilisation d'acier inoxydable augmentera la durée de vie du réchaud.
 
Les photos ci-contre montrent la fabrication d'un réchaud à partir d'un pot de peinture et d'une tôle en acier inoxydable de 1mm d'épaisseur. La tôle est usinée à plat avant d'être roulée et agraffée (l'agraffage consiste à replier sur environ 5 mm les deux bords d'une la tôle dans des sens contraires, avant des les marteler l'un dans l'autre pour vérouiller l'ensemble). Porter des gants pour éviter les coupures !
 
 
}}
 
}}
{{ {{tntn|Notes}}
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{{Tuto Step
|Notes=Télécharger le tutoriel [http://lowtechlab.org/wp-content/uploads/2016/09/LE-LAB-Micro-Gazeificateur.pdf ici]
+
|Step_Title=Contenu pédagogique à télécharger
 +
|Step_Content=Vous pouvez télécharger une fiche pédagogique créée par le Low-tech Lab  dans la partie "Fichiers" du tutoriel (onglet au niveau de la section "Outils-Matériaux")
 +
|Step_Picture_00=Cuiseur_micro_gaz_ificateur_pyrolyse.JPG
 +
}}
 +
{{Notes
 +
|Notes=<div class="mw-translate-fuzzy">
 +
To see report by Planète Bois (in French) comparing different types of stoves: http://www.planetebois.org/glossaire/cuiseur-domestique-econome-cde/
 +
</div>
 +
 
 +
Ce réchaud est deux fois plus grand, il contient plus de combustible pour une cuisson plus longue, mais il est moins stable, moins portable et un peu plus long à fabriquer.
  
 
Rapport comparatif des différents types de cuiseurs par Planète Bois (en français): http://www.planetebois.org/glossaire/cuiseur-domestique-econome-cde/
 
Rapport comparatif des différents types de cuiseurs par Planète Bois (en français): http://www.planetebois.org/glossaire/cuiseur-domestique-econome-cde/
  
Site internet du Docteur Paul Anderson, spécialiste des micro-gasifiers (en anglais): http://www.drtlud.com/
+
The Mirco-gasifier expert, Dr Paul Anderson’s website (in English) : http://www.drtlud.com/
  
N'hésitez pas à commenter, partager, et agrémenter le tutoriel d'informations utiles à son amélioration.
+
Please share the tutorial and give feedback, or add any comments that may be helpful for making any improvements.
  
L’équipe du Low-Tech Lab vous invite également à consulter sa Biblilowtech.
+
<div class="mw-translate-fuzzy">
 +
Low-Tech Lab team also recommend you consult their Biblilowtech.
 +
 
 +
This English translation has been possible thanks to the PerMondo project: Free translation of website and documents for non-profit organisations. A project managed by Mondo Agit. Translator: Gill Barringer. (Whilst great efforts have been made to ensure the quality of this translation, the translator makes no guarantees and will accept no liability for any claims made against her in the event of any misinterpretation, errors or omissions thereof)
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</div>
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{{Tuto Status
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|Complete=Published
 
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Version actuelle datée du 31 décembre 2022 à 00:46

Tutorial de avatarLow-tech Lab | Catégories : Alimentation, Énergie

How to make an inexpensive portable wood cooking system.

Licence : Attribution-ShareAlike (CC BY-SA)

Introduction

Factors relating to cooking remains one of the biggest challenges in the areas of health and energy. In many developing countries, the classic three-stone cooking fire is the technology that is most commonly used.This is extremely inefficient (with a thermal yield of 10 to 15% if sheltered from the wind and 5% if exposed) and releases toxic smoke into dwellings.There are two concerns with this:

  • Energy output is so poor that a large amount of wood is needed to cook one meal.

This leads to extensive deforestation in certain parts of the world.

  • Evidently, this creates certain problems with regards to health: smoke given off causes respiratory problems for people in the community and the reduces their quality of life. A technology that uses the same biomass but has a higher output

is:

The micro gasifier which is a low-tech and very economical way of cooking and, if well-made, has an output higher than a three stone stove (thermal output of approximately 35%). Output is even higher with the enhanced industrial version (which has a thermal output in the order of 45%)

It is possible to make a very basic model out of tin cans, but this will have a limited number of features. However, this can be very useful, for instance, for heating water, cooking small quantities of food and for doing demonstrations/teaching purposes.

More complex models do exist which, although more costly, tend to last longer and allow control over the power you can get from the flame.

Matériaux

  • A large tin can (in terms of both height and width) (1): for the external chamber;
  • A tin can which is slightly shorter and thinner (2): for the combustion chamber;
  • A tin can with the same diameter as the combustion chamber (3): for the stand on which the pan sits.

Outils

  • Marker
  • Tin snips

For drilling, there are 2 options:

  • A drill and 2 drill bits:11mm and 7mm respectively
  • A hammer and a large nail (or a metal punch)
  • A wooden block, a part of which can be inserted inside the tin can.

Étape 1 - How it Works

This is based on the concept of gasification: Wood is heated in an environment containing very little oxygen, giving off combustible gases known as “Syngas” which are then burnt in the upper part of the stove.

The micro-gasifier is lit from the top. Primary air, flowing into the lower part, passes through the mass of combustible fuel, maintaining a pyrolysis layer which then drops as the combustible gases are released. Secondary air is forced into the top of the stove, supplying the oxygen that is needed for combustion of gases emitting in an upward direction.

Better results are obtained with forced convection, using an integrated fan under the grid which supports the fuel. However you will need a reliable supply of electricity for this.

The temperature at which combustion takes place is around 800°C and thermal yields are between 30 to 45% depending on how well it is made and the quality of the insulation.

It is light, compact, reliable, uses little fuel and, in the right circumstances, produces reusable charcoal which can be used in other applications. This system is therefore extremely low-tech and very efficient compared to conventional systems used throughout the world.

As a comparison, the diagram opposite shows the energy performances of various systems. The micro-gasifier here is called “wood gas stove”.



Étape 2 - External Chamber

- Mark the positions of a approximately 10 holes, spread out evenly all around the upper part of tin can (1).

- then drill where marked using a 12mm drill bit (or with a hammer and nail) (For a cleaner finish, we recommend that you make pilot holes with a 7mm drill bit before tackling it with a 12mm drill bit).

Note:To make things cleaner and easier, you can clamp the wooden block onto a vice and use it as a support when making the holes in the tin can.

- Cut the bottom out of the large tin can (1). The opening must be of a slightly smaller diameter to that of the small tin can (so that it can sit inside it)




Étape 3 - Combustion Chamber

- Mark the position of approximately 15 holes spread out over the whole surface of the bottom of the tin can (2). - Mark the positions of a approximately 10 holes, spread out evenly all around the upper part of tin can (2).

- then drill where marked using a 7mm drill bit (or with a hammer and nail)




Étape 4 - Pan Support

- Mark the positions of approximately 10 holes spread out evenly all the way around the small tin can (3).

- then drill where marked using a 12mm drill bit (or a hammer and nail)

- Cut out the bottom of the can.

- NB: For ease of use, you can cut out a large hole on the side of the small can (3): this makes it easier for the fire to catch the wood




Étape 5 - Final Assembly

- Put tin can (2) into the large tin can (1) as shown in the diagram.

- Place tin can (3) on top of the two other tin cans which have been nested one inside the other.

- The pyrolytic stove is now ready for you to use !




Étape 6 - Directions for Use

Despite this type of cooker being more environmentally friendly than the “three stoned” ones, it still gives off smoke. For this reason, it needs to be used in a well-ventilated area.

To light the stove, fill up and light it in the upper part.

To ‘turn off’ the stove, simply wait until all the wood has burnt down and the casing has cooled down,

THE TEMPERATURE OF WOOD AND GASES WHEN BURNT CAN REACH UP TO ALMOST 1200°C. HANDLE THE STOVE WITH EXTREME CARE : DO NOT MOVE THE STOVE WHEN LIT.

Problèmes techniques :

- La flamme monte très haut ou la flamme s'éteint parfois malgré libération massive de gaz

Problème probable : l'arrivée d'air secondaire est trop faible par rapport à l'arrivée d'air primaire, les gaz produits massivement ne sont pas brûlés immédiatement car il y a un faible apport d'oxygène. La flamme se développe donc en hauteur, dans l'air, pour terminer sa combustion (source). Aussi, la production trop massive de gaz relativement à l'air secondaire peut "souffler" les flammes et les éteindre (ce qui déclenche une libération massive de gaz (fumée)).

Solution : Si dans un même temps le combustible brûle trop rapidement ou la flamme est trop intense, chercher à réduire l'arrivée d'air primaire. Changer la conserve concernée, boucher quelques trous avec de l'aluminium, ou déplier les bavures des trous pour les refermer.

Sinon, augmenter l'arrivée d'air secondaire. Agrandir ou refaire quelques trous.

- la flamme est trop forte et le combustible brule trop rapidement.

Problème : le dispositif est trop ventilé. S'il n'y a pas de problème de combustion des gaz ou une flamme qui se développe haut dans l'air, alors l'arrivée d'air secondaire est au bon ratio avec l'air primaire. En revanche, l'arrivée d'air totale est trop importante.

Solution : envisager de réduire l'apport d'air général, par exemple en refermant partiellement des trous basaux de la boite support extérieur.




Étape 7 - Comments

This is a very simple system and does not, for example, allow control over the size of the flame.

Due to the materials used, the stove has a very limited service life.

Improved versions of this system are currently being tested/validated in various urban settings thanks to initiatives taken by Paul Anderson, an expert in micro-gasifiers.

Trials have been carried out in India but have not been hugely successful as the reality is that it is quite a complicated operation finding pellets or biomass chips in this area and the price of the enhanced micro-gasifier is approaching that of the cost of cooking with gas but without all the advantages that comes with it.

Étape 8 - How to make a bigger stove

To adapt any container or tin you may have available to use as the outside casing, it is possible to make the combustion chamber from sheet metal, ideally stainless steel. It must be of a thickness of 1mm maximum so that you are able to cut it with tin snips. It is important to cut out the tabs and drill the holes whilst the sheet metal is still flat before rolling up and fastening the ends together. Using stainless steel will make the stove last longer. The photos opposite show how to make the stove from a paint pot and a 1mm thick sheet of stainless steel. The metal sheet should be machined flat before being rolled and fastened (to fasten: fold back approx 5mm of both of the two edges of the sheet metal in opposite directions and then fix the two together by hammering one flap inside the other). To avoid cuts to hands, wear gloves!

Étape 9 - Contenu pédagogique à télécharger

Vous pouvez télécharger une fiche pédagogique créée par le Low-tech Lab dans la partie "Fichiers" du tutoriel (onglet au niveau de la section "Outils-Matériaux")




Notes et références

To see report by Planète Bois (in French) comparing different types of stoves: http://www.planetebois.org/glossaire/cuiseur-domestique-econome-cde/

Ce réchaud est deux fois plus grand, il contient plus de combustible pour une cuisson plus longue, mais il est moins stable, moins portable et un peu plus long à fabriquer.

Rapport comparatif des différents types de cuiseurs par Planète Bois (en français): http://www.planetebois.org/glossaire/cuiseur-domestique-econome-cde/

The Mirco-gasifier expert, Dr Paul Anderson’s website (in English) : http://www.drtlud.com/

Please share the tutorial and give feedback, or add any comments that may be helpful for making any improvements.

Low-Tech Lab team also recommend you consult their Biblilowtech.

This English translation has been possible thanks to the PerMondo project: Free translation of website and documents for non-profit organisations. A project managed by Mondo Agit. Translator: Gill Barringer. (Whilst great efforts have been made to ensure the quality of this translation, the translator makes no guarantees and will accept no liability for any claims made against her in the event of any misinterpretation, errors or omissions thereof)

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