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Description
Wood feeds slowly from an overhead container into a small size very hot fire box masoned from bricks and clay. Mass of heat buffering stones therefore can be smaller.


Please visit also the research pages. (D15)
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BrickStove with container
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Ready for testing in practice Twentyfold cost reduction Applicable in modern as well as in poor economies Comfort Environment Rural as well as urban.


Why
Stoves built to be build at lowest cost. Taking far less time and care for handling than present wood stoves. To be acceptable in a dense neighbourhood, the stove must not stink or smoke. A chimney of a The stove should be applicable in multi level appartment houses.

How
The brick stove is masoned with mortar of clay and sand. Wood fuel lowers gradual from the container into the small but very hot fire box from an overhead container. An emply container can be replaced by a full one. The small stone lined fire box heats up quickly and burns clean. When the fuel runs out the air circulation stops by itself.

Additional information

The brick stove is masoned with mortar of clay and sand. Wood fuel lowers gradual from the container into the small but very hot fire box from an overhead container. An emply container can be replaced by a full one. The small stone lined fire box heats up quickly and burns clean. When the fuel runs out the air circulation stops by itself.

  • The stove will have a table like model, thus also functional when not burning. It rests on a metal frame 30 cm above the ground and is about 1 meter high.
  • The stove is constructed out of concrete paving stones (60x40x6cm) for bottom and top.
  • In between bottom and top two walls are masoned from ordinary bricks with mortar. This mortar is a mix 1 to 1,5 from clay and sand.
  • The channels in the stove fit inside the two brick walls. Soft baked bricks and thin gauge RVS-sheet metal are used. All parts are stacked loose next to- or on top of each other. A clay-sand mix is only used as fill when parts do not have the proper size. These channels get very hot. At the hottest parts bricks can be protected with thin RVS sheet metal. Cracked or eroded brick can also be replaced, as they are only loosely stacked and well accessable.
  • The lower channel is horizontally split by thin RVS sheet metal, that gets very hot when the stove is burning. Air that streams in under this sheet metal heats up before it enters the fire box, thus contributing to a cleaner combustion.
  • The firebox is wide at the top and narrow at the bottom. This is done by placing bricks slanted against the outside walls. The space behind the slanted tiles functions as the channel to guide preheated air to the opposite side, where this air can enter between the grates of the fire box.
  • As grates of the fire box function short bits of rebar.
  • Hot gas is guided from the fire box horizontal through a channel above the inlet duct, then goes up to a channel on top of the first.
  • From there is can escape sideways into the metal ducts shaped out of a flattened oil drum. From there smoke flows out to the chimney.
  • In our first experiment we used forced draft, using an electric vent of which the speed could be regulated.
  • In coming experiments we will pump the exhaust gasses through a basin with water. The warmed-up water assists in heating the house. Further it filters the smoke, for which some chemicals can be added. The water itself is filtered in a plant bed.

    This wood burning stove is expected to function as follows:

  • A tube like container, open only at one side and filled with wood is placed in thte circular opening in the top of the stove.
  • After the wood in the container is lit, fuel wood slides down from the container to the top of the grates, that is the top edge of the tiles. Burning parts falling off, slide down while burning to a smaller size. Small parts falling through, burn to ashes on a plate positioned under the fire box.
    Air is pre-heated before ist reaches the fire. Preaheated air flows in from both open sides of the tile grades.
    To attain a very high burning temperature the actual fire place is small. It is expected the fuel will be consumed at a slow pace. This is in contrast with a nomal stone wood burningstove, that burn their fuel fast.
  • Hot gas from the fire box moves horizontal through a channel. This channel will be the hottest part of the stove. Gassified wood will burn at this spot. If necessary extra air will be let in.
  • From the first channel it can rise to a second on top of the first, to transmit its heat to the walls.
  • From there it can escape sideways into the sheet metal outside ducts. This metal sheet will get warm soon after the stove is lit. When the fire is down, the hot inside stone mass will radiate its energy through this enclosure.
  • From the wide metal duct the smoke flows out to a chimney with a minimal cross section, only large enough for the reduced airflow through the stove.

    Top picture shows scheme of position of fuel container.
    Middle picture shows ventilator in exhoust duct.
    Bottom picture shows first brick stove with messy fueling.

    More pictures at 'See it', page Brick Stove


    • Planned progress

    Internal links

    Forced ventilation of wood stoves

    Questions asked to a list of chimney profeesionals. What can be expected if you apply the method of venting high-efficenty central heating stoves to the venting of wood burning stoves?

    History of the development of the BrickStove
    News items on the BrickStove in historical perspective

    This is a kind of diary of the development of the BrickStove. It contains copies of news items that relate to the BrickStove. Special ideas that came up but were not realized should get some attention in this diary.

    Russian Hybrid

    To make a warm place for a Demotech intern and for keep

    The Brick Stove, how it is build, how it functions, why we think this is a good idea

    Experiments with the brickstove gave extensive information, that ask for a separate publication. The three experimental prototypes build one after the other, ask first of all for complete realization of the total target of efficient heating without with a clean exhaust.
    This publication is to be developed into a description of the targets, the experiments and the development of the ideas behind this heating concept.

    External Links

    Links to masoned stoves and domestic heating

    • Instruction how to make insulating and heat resisting bricks
      http://www.repp.org/discussiongroups/resources/stoves/Still/VC%20Stov...
    • Extensive report on the issue of building stoves with an insulating fire box, small for one-pot cooking and large for bread baking can be found in this PDF-file
      http://www.repp.org/discussiongroups/resources/stoves/Scott/Uganda%20...
    • General use of stoves that burn wood in an inefficient way leads to pollution of the atmosphere. This PDF-file is about quantifying this effect. Demotech relates to this discussion as our design has the property to clean the smoke from any unwanted content.
      http://216.239.59.104/search?q=cache:4v0yo4KQIl0J:ehscenter.berkeley....
    • Clear explanation of the benefits of radiant heating. The following aspect (and more!) are highlighted: The Benefits of Radiant Heating, why do we heat, air temperature less important, environmental benefits, a sustainable technology, helping to reduce global warming, minimizing emissions from wood burning and more splendidly explained.
      http://mha-net.org/msb/html/guide2.htm
    • *This web site is about the construction of brick stoves according to a principle to maximize efficiency, based on natural gasflow. The design description highlights the controlled process of first the pirolysis, then the burning of the gasses., then the cooling of the hot gasses before they are allowed to escape. For sure this is very inspiring research.
      http://www.stove.ru

    Links to info on the Stirling energy cycle, as of potential use for venting the BrickStove

    • Use of the Free Piston Stirling principle for cooling
      A Free Piston Stirling Cooler (FPSC) is a single phase cooling device that moves heat from a cool source to a warm sink with the help of external heat exchangers.
      Extremely long life is reached through the use of non-contact running surfaces. Gas bearings allow the two moving parts to ?ride on a cushion of air? keeping the running surfaces from making contact while the machine is operating.
      http://www.globalcooling.com/technologyoverview.html

    Links to info on the wood burning stoves for cooking only

    • Similar to a downdraft stove that is being manufactured in China, a new "inverted downdraft gasifier" stove shown is described. It operates using only natural convection. The rate of gas production and heating is controlled by the primary air supply to the gasifier. As an option, the gasifier can make charcoal with a 20-25% yield. The wood-gas stove consists of an "inverted downdraft gasifier" plus a burner to mix air and gas and burn cleanly.
      http://www.crest.org/discussiongroups/resources/stoves/Reed/T1.htm
    • Ebook pdf about the Rocket stove for (rural African)use for cooking one pot only. Excellent description of what matters and why it matters while builing such a stove.
      http://ebookbrowse.com/lesotho-refresher-oct-05-ppt-d143969398
  • Send us an email form about any relevant link, that should be added here

    • What other people say...

    If you like you can add your own comment

    by Mail-correspondence Bram & Reinder - Fri Nov 01 (2002)
    Alternative for Low Efficiency Sterling Engine
    Van: Demotech
    Datum: Sun, 8 Jun 2003 16:01:00 Europe/Amsterdam
    Aan: Bram de Vries
    Onderwerp: Antw.: warmte pomp
    ... met de huidige ventilator kan er verder ge?xperimenteerd worden. Maar uitzicht op een ultieme oplossing inspireert meer.
    Wat betreft je bi-stabiele klep, dat lijkt me een eitje. Ik zie een beeld van een membraan van dunne plaat met een kleine slag, bv. 10 % van de diameter. Het vlieggewicht in het midden bevat de klep en de aanslag. De as van de klep, in de bewegingsrichting van het membraan, is aan beide zijden van het membraan opgehangen in een drietal licht gebogen korte stukjes metaal draad. die stukjes draad zijn aan beide einden gepositioneerd in een kommetje.
    Bij doorklikken bij de aanslag aan het einde van de werkslag, buigen de stukjes draad dus even iets verder door. In principe hetzelfde als jouw trekveertjes, maar zorgend voor geleiding EN bi-stabiel doorklikken.
    Zo'n membraan zou met een behoorlijk hoge frequentie moeten kunnen werken. het wordt dan een klein ding. Zoveel lucht is er bij een klein continue vuur niet nodig. Het wordt tijd dat we wat beter weten hoeveel lucht er werkelijk nodig is. Die gegevens moeten makkelijk zijn te vinden in kachelliteratuur. Hoeveelheid warmte versus hoeveelheid hout stond in je attachment, niet de benodigde lucht.
    Wat betreft Mathijs Vertooren, zijn aanvullende inspiratie is welkom. Houtvergassen levert houtskool op waarop het goed koken is. Mooie warmte, goed te regelen en geen rook en stank. Maar ik denk dat het niet te verenigen is met het kardinale uitgangspunt van het huidige kachelontwerp, namelijk de splitsing in een industrieel te maken klein slim mechaniekje, dat goedkoop in bulk te produceren is aan de ene kant en aan de andere kant de kachel zelf, die ruw uit gratis materiaal is op te bouwen, terwijl de combinatie een high-tech resultaat oplevert. Misschien vind Mathijs het leuk om mee te denken ...
    De temperatuur in de kachel hangt af van de afkoeling van de diverse delen. Hoe heter de binnenkomende lucht (denk aan een hoogoven) en dan in precies de goede hoeveelheid, hoe minder warmte-afvoer, hoe heter het vuur,
    Daarna moet je nog zorgen dat er geen grotere wervels zijn, waarin koelere lucht toch nog minder verbrand gas mee voert. Dat kan met een soort gloeiblok.

    Maar zou jij je kunnen concentreren op het idee laag rendement Sterling pomp? Ik ben benieuwd naar de uitkomst van je volgende experiment.
    Intussen, veel succes met alles en tot ziens of mails,
    Reinder van Tijen


    Bram de Vries heeft op Tuesday, 3 Jun 2003 om 10:16 (Europe/Amsterdam) het volgende geschreven:

    Beste Reinder,
    Na wat kleine experimenten heb ik inmiddels ontdekt dat er een behoorlijke druk te halen is door lucht op te warmen, maar de snelheid is vaak wat laag.
    Voor de werking van de pomp heb ik onderhand de bistabiele klep nodig. Hier heb ik veel over na gedacht en ga wat proberen met wat restjes binnenband.
    Verder heb ik een vriend die bij Ecofys werkt, Matthijs Vertooren is zijn naam. Hij weet veel over verbrandingen en wil graag de kachel zelf nog eens bekijken. Ik weet niet of je het principe van houtvergassing kent?
    Voor zover ik begreep komt het er op neer dat je hout verbrandt, maar dat vuur laat je stikken. Hier komt veel rook bij vrij. Die rook is weer brandbaar. Je verbrandt dus in twee stappen.
    Resultaat is meer warmte (hoewel dit niet uit de attachment blijkt) en (in principe) een schoner verbrandingsproduct. Het schijnt vrij eenvoudig uit te voeren zijn, maar je hebt dan wel een goed afgesloten verbrandingsomgeving nodig en een geregelde lucht toevoer is ook fijn (komt dat even goed uit dat er een warmte pomp in de lucht aanvoer komt te zitten).

    Ik ben ook op zoek geweest naar de hoeveelheid lucht die nodig is per kilo hout, maar dat is nog niet zo makkelijk te zeggen. Wel heb ik de verbrandingsenergie van hout gevonden die is ongeveer 16 MJ per kilo. Ik heb niet echt een idee wat ik met dit getal kan. Je wilt de temperatuur in de kachel weten, die is afhankelijk van de energie minus de warmte die je aan de omgeving verliest lijkt me.
    Kortom de ontwikkelingen gaan door, zij het niet zo snel. Bijgevoegd nog een paar scans uit het polytechnisch zakboekje mbt verbranding.
    Groetjes Bram

    by Ned Towle USA - Tue Dec 02 (2003)
    Re: Alternative for Low Efficiency Sterling Engine
    >Hello; I have a special home built wood burning boiler. Gasification style and heated my home with great sucess. I am interested in the low cost sterling engine? Can I build one? can you sketch it so I would get the concept? I would greatly appreciate it, and if so in English. Thank you Ned Van: Demotech

    > Datum: Sun, 8 Jun 2003 16:01:00 Europe/Amsterdam

    > Aan: Bram de Vries

    > Onderwerp: Antw.: warmte pomp

    >
    > ... met de huidige ventilator kan er verder ge?xperimenteerd worden
    Maar
    > uitzicht op een ultieme oplossing inspireert meer.

    > Wat betreft je bi-stabiele klep, dat lijkt me een eitje. Ik zie een beeld
    > van een membraan van dunne plaat met een kleine slag, bv. 10 % van de
    > diameter. Het vlieggewicht in het midden bevat de klep en de aanslag. De as
    > van de klep, in de bewegingsrichting van het membraan, is aan beide zijden
    > van het membraan opgehangen in een drietal licht gebogen korte stukjes
    > metaal draad. die stukjes draad zijn aan beide einden gepositioneerd in een
    > kommetje.

    > Bij doorklikken bij de aanslag aan het einde van de werkslag,
    > buigen de stukjes draad dus even iets verder door. In principe hetzelfde
    > als jouw trekveertjes, maar zorgend voor geleiding EN bi-stabiel
    > doorklikken.

    > Zo'n membraan zou met een behoorlijk hoge frequentie moeten kunnen werken.
    > het wordt dan een klein ding. Zoveel lucht is er bij een klein continue
    > vuur niet nodig. Het wordt tijd dat we wat beter weten hoeveel lucht er
    > werkelijk nodig is. Die gegevens moeten makkelijk zijn te vinden in
    > kachelliteratuur. Hoeveelheid warmte versus hoeveelheid hout stond in je
    > attachment, niet de benodigde lucht.

    > Wat betreft Mathijs Vertooren, zijn aanvullende inspiratie is welkom.
    > Houtvergassen levert houtskool op waarop het goed koken is. Mooie warmte,
    > goed te regelen en geen rook en stank. Maar ik denk dat het niet te
    > verenigen is met het kardinale uitgangspunt van het huidige kachelontwerp,
    > namelijk de splitsing in een industrieel te maken klein slim mechaniekje,
    > dat goedkoop in bulk te produceren is aan de ene kant en aan de andere kant
    > de kachel zelf, die ruw uit gratis materiaal is op te bouwen, terwijl de
    > combinatie een high-tech resultaat oplevert. Misschien vind Mathijs het
    > leuk om mee te denken ...

    > De temperatuur in de kachel hangt af van de afkoeling van de diverse delen.
    > Hoe heter de binnenkomende lucht (denk aan een hoogoven) en dan in precies
    > de goede hoeveelheid, hoe minder warmte-afvoer, hoe heter het vuur,

    > Daarna
    > moet je nog zorgen dat er geen grotere wervels zijn, waarin koelere lucht
    > toch nog minder verbrand gas mee voert. Dat kan met een soort gloeiblok.
    >


    > Maar zou jij je kunnen concentreren op het idee laag rendement Sterling
    > pomp? Ik ben benieuwd naar de uitkomst van je volgende experiment.

    > Intussen, veel succes met alles en tot ziens of mails,

    > Reinder van Tijen

    >
    >
    >


    > Bram de Vries heeft op Tuesday, 3 Jun 2003 om 10:16 (Europe/Amsterdam) het
    > volgende geschreven:


    >
    > Beste Reinder,

    > Na wat kleine experimenten heb ik inmiddels ontdekt dat er een
    > behoorlijke
    > druk te halen is door lucht op te warmen, maar de snelheid is vaak wat
    > laag.

    > Voor de werking van de pomp heb ik onderhand de bistabiele klep nodig.
    > Hier
    > heb ik veel over na gedacht en ga wat proberen met wat restjes
    > binnenband.

    >
    > Verder heb ik een vriend die bij Ecofys werkt, Matthijs Vertooren is zijn
    > naam. Hij weet veel over verbrandingen en wil graag de kachel zelf nog
    > eens
    > bekijken. Ik weet niet of je het principe van houtvergassing kent

    Voor
    > zover ik begreep komt het er op neer dat je hout verbrandt, maar dat vuur
    > laat je stikken. Hier komt veel rook bij vrij. Die rook is weer
    > brandbaar.
    > Je verbrandt dus in twee stappen.
    Resultaat is meer warmte (hoewel dit
    > niet
    > uit de attachment blijkt) en (in principe) een schoner
    > verbrandingsproduct.
    > Het schijnt vrij eenvoudig uit te voeren zijn, maar je hebt dan wel een
    > goed
    > afgesloten verbrandingsomgeving nodig en een geregelde lucht toevoer is
    > ook
    > fijn (komt dat even goed uit dat er een warmte pomp in de lucht aanvoer
    > komt
    > te zitten).


    >
    > Ik ben ook op zoek geweest naar de hoeveelheid lucht die nodig is per
    > kilo
    > hout, maar dat is nog niet zo makkelijk te zeggen. Wel heb ik de
    > verbrandingsenergie van hout gevonden die is ongeveer 16 MJ per kilo
    Ik
    > heb
    > niet echt een idee wat ik met dit getal kan. Je wilt de temperatuur in de
    > kachel weten, die is afhankelijk van de energie minus de warmte die je
    > aan
    > de omgeving verliest lijkt me.

    >
    > Kortom de ontwikkelingen gaan door, zij het niet zo snel.
    > Bijgevoegd nog een paar scans uit het polytechnisch zakboekje mbt
    > verbranding.

    >
    > Groetjes Bram
    >
    >

    by Reinder / Demotech - Wed Dec 03 (2003)
    Re: Alternative for Low Efficiency Sterling Engine

    Ned Towle/ USA wrote on Sun, 8 Jun 2003 16:01:00 Europe/Amsterdam
    Hello; I have a special home built wood burning boiler. Gasification style and heated my home with great success. I am interested in the low cost sterling engine...

    Ned, sorry, Demotech's idea of using a Stirling engine is not even in a prototype phase. I can't help you with a manual. But you could help Demotech with your results with this wood stove. Demotech is specially interested in the gasification process you mention. The understanding and control of this process is basic for the quantity of air that has to be pumped per unit of time. From experiments by others we understand only little energy (10 to 100 Watt?) is needed for ventilating the stove.
    Could you please send us a sketch and data of what you made? Kind regards, Reinder

    by abakyayita@umu.ac.ug - Sat Nov 02 (2002)
    need some advice.
    hullo, i tried to research on how i can detail drawings of a suspended slab that is supporting a fire place. i failed to accomplish this. i need some advice on what type of cement i should really use leave allone the general title "fire resisting cement". its for this reason that i write to you requesting for technical advice. i will be great for whatever support you provide. sincerely, alex.

    by Reinder/Demotech - Sat Nov 02 (2002)
    Insolating bricks at hot spots
    Dear Agakyita, Demotech has no general expertise on stoves, only some on our special design. According to our experience the floor of a fireplace does not get that hot, compared to walls and especially ceiling. When burning wood, the floor of a fireplace is soon insulated from the fire by ashes. When you look for locally to be made firebricks, then go to www.repp.org/discussiongroups/resources/stoves/Still/VC%20Stove/vcstove.html Also see a very informative report made in your own country: www.repp.org/discussiongroups/resources/stoves/Scott/Uganda%20report.htm Further consider to insulate bricks at hotspots with a shield from thin stainless steel sheet metal (0,5 mm or less). Possibly you can find it as scrap from the housing of a washing machine. Regards, Reinder

    by Mark Surnoskie - Mon Dec 01 (2003)
    brick stoves
    There is a site called the Masonary Heater Association www.mha-net.org/

    by Dirk Bauwens, Belgi - Wed Dec 03 (2003)
    stoves and... steam ?
    Hi, Recently, I happened to stumble into the idea of steam power. I am already more than convinced that masonry stoves offer most marvelous perspectives. A second, obvious step was then, to provide means to store this obtained energy into water and to become able to transport this energy. But then, a third, less obvious step forced itself upon me. Would I dare to cross the 100 degree Celcius border into low pressure vapour that is capable to drive most powerful machines ? To me, the use of steam looks very promising. First of all, we are now able to burn biomass very efficiently. Secondly, even if a steam engine runs with "low efficiency" (10 till 20 percent), we live in very different times than a hundred years ago and those heat "losses" could be used much more efficiently than then... Any thoughts ??? Sincerely, Dirk

    by Sasha - Sat Dec 06 (2003)
    Re: stoves and... steam ?
    I think the idea is good,but there is a real danger in working with high pressure steam,the danger of explosion.
    Sasha

    by Dirk Bauwens, Belgium - Sat Dec 06 (2003)
    Re: stoves and... steam ?
    Sasha,
    I saw a steam engine, designed for just one third of a bar, but able to deliver 20 horsepower!
    Low pressure steam just requires bigger diameter pistons. A steam engine and especially one for low pressure, can be considered as a very useful kind of pressure regulator, an interface that instantly reduces low pressure steam back to very hot water.
    It could, eventually, be developed into a cheap, "poor man's" solution and provide some very much needed mechanical and/or electrical energy.
    Photovoltaic, thermoelectric and stirling engine based systems are just way too expensive!
    Greetings, Dirk

    by Reinder / Demotech - Sat Dec 06 (2003)
    Re: stoves and... steam ?
    Energy only for venting the stove, that's what Demotech is searching for. More energy for other job's is an interesting topic though. Have a look at Demotech's WindDrive and the Hydraulic Ram pump

    > Photovoltaic, thermoelectric and stirling engine based systems are just ....
    Thermo electric could be usefull, Papanek's radio worked on it, with a candle as an energy source. It became popular in Indonesia as he wrote in his book 'Design for the Real World'.
    Do you have data on the price and capacity? 10 Watt energy is what is needed to drive a little electric van to get the BrickStove properly working, a little more would be welcome.

    by Dirk Bauwens, Belgium - Sat Dec 06 (2003)
    Re: stoves and thermo-electricity...
    > Energy only for venting the stove, that's what Demotech is searching for ...
    This page has prices: www.hi-z.com/websit40.htm
    I'm sure better prices can be found. The rest of the site is very interesting, thought-provoking and helpful.
    It could be worthwile to experiment with the "Peltier" modules of those cheap small car refigerators. In reverse mode, when heated up on one side and kept cool on the other, they should deliver electrical energy (Seebeck-effect). All I know for now is that they are not electric-energy-efficient when used for cooling. Maybe they perform better when producing electricity ?

    by Dirk Bauwens, Belgium - Sat Dec 06 (2003)
    Re: venting the stove.
    > Energy only for venting the stove, that's what Demotech is searching for ...
    I have very much respect for the demotech stove design, but I think it is kind of a weak point that it needs artificial draft. It should be not too difficult to use the energy of the rising power of the warm exhaust gases. Of course, then the chimney has to go vertical, somewhere!
    I have been thinking of two concentric pipes, the outside one for the flue, the inside one for the fresh air (so that it is preheated by cooling the exhaust gas: a heat exchanger)
    Extra pressure could be obtained by natural air pressure differences, by making a rotatable chimney top (on a simple central pin) that changes with the direction of the wind. When the exhaust flue ends with a curve that faces away from the wind direction, it will cause a underpressure in the exhaust line (venturi-effect). At the same time, the smaller air inlet on top of the chimney, should face the wind direction. This would cause an overpressure in the fresh air line.
    But I agree: variable artificial draft is nice, because it gives the possibility to experiment with air/fuel ratio's and optimize combustion under most circumstances.

    by HBaarslag - Sat Dec 06 (2003)
    the use of steampressure
    Having a fire goiing of wood or biomass also means you can not turn it out when neeeded. But metal tubes or other exposed to the fire wil burn through if not cooled sufficiently. Anyway they become very weak when hot.The use of steam can be very threatening. That is why a lot of regulations and laws are made for using steam power.
    Ofcourse one does not have to use the first type of using steam power. That was very inefficient.But using steam of low pressure and temperature automatically means inefficiency because the heatlos of condensing the steam to water. Eg steam of 12 bar and 250 C contains 700 kcal/kg. Condensing steam to water at atmospheric pressure uses 540 kcal/kg. Meaning an thermic efficiency of 160:700=23%. If the engine itself has 50% the overall eff. is 11.5%

    by Dirk Bauwens - Sat Dec 06 (2003)
    Steam
    Steam pipes could be put in a separate, closeable, downdraft channels of a masonry stove. If they contain water, they can never overheat.
    The production of steam can be a very energy efficient process in itself. At 1 bar, 5 times more energy has to be put into water of 100 degrees to evaporate it into steam, than to bring it from 0 to 100 degrees!
    So, at 1 bar, 1 kg steam of 100 degrees contains 6 times more energy than
  • kg water of 100 degrees!
    I think, it's very interesting to think of the steam engine as a kind of pressure regulator and as a condensor!
    Of course, I would only consider the use of low pressure steam power in combination with necessary and/or useful heat production.
    A low pressure, slowly moving steam engine could be made, basically maintenance free when using modern materials. Even, some of those old fashioned, primitive steam engines were in non-stop use for more than 150 years!

    • by Sasha - Sun Nov 02 (2003)
    Email corresppondence with Sasha, Serbia
    From: Sasha Date: Mon July 22, 2003 Hello, I work in the field of masonry stove building (trying to establish small ethical sustainable business open source kachelofen (a little bit hard to establish something like this especially in my part of the world).
    So I am little bit confused with your brick stove. What are you trying to achieve here? A downdraft wood gassifier stove? The pictures on the site doesn't explain anything. The best is the small drawing on the top of the page.
    I am trying currently to think out how to build kachelofen of compact concrete elements, anyone have experience with something simmilar? It would be excellent in colder part of the world like poor eastern european countries.

    Best, Sasha Mrkailo, Serbia
    my home page: http//:www.geocities.com/frogkailo
    From: Demotech Date: Thu Aug 21, 2003

    Sasha, hello!
    I would be glad if my info could be of help in getting you in business in the building of stone heaters. I have a lot of info for you, on which I would like to have your comment. I'll sort it our soon. For the time please visit the source of my inspiration, the befriended non-profit organization "The 12 Ambachten". They have similar objectives as Demotech, but luckily have more impact, work out their designs in a realistic way, that can be applied right away. See their Finn-oven, a downdraft kacheloven, build by clients themselves, from heat-resistant cement and tiles. Clients can make use of a workshop where they find all the molds needed for casting the slabs out of which the Finn-oven is build. I think they have a manual, hopefully in English. I just checked it at www.de12ambachten.nl
    They have the manual only in Dutch. As the heat resitant cement is very expensive the cost of these stoves is low compared to commercial kacheloven, but still cost a lot of money: They charge clients ? 2000,- for the cement, the use of their workshop and expert guidance. The outcome is very attractive. The Finn-oven has a great reputation. What I like is the approach of offering the workshop and guidance, and let people build their stove themselves. Maybe this concept is worth studying for you. Demotech approach on stoves is different from that of the 12 Ambachten. Starting point is that many people who have no money at all, still need to warm up their house. So Demotech started from what is available for free and then tested what could be done with it, still honoring some of the principles of the kacheloven. Some of those principles, not all of them. To tell you more about it, I'll look at the new-items I wrote in the past on construction of a no-cost stove of a new radical design, with forced draft. Many years I warmed my office with a kacheloven made entirely from concrete street bricks, masoned with a mix of clay and sand, the lining made from normal bricks. Now it needs some new bricks at the hottest parts of the stove, but I rather build a stove of the new concept.
    www.demotech.org/design/designB.php?sub=150
    www.demotech.org/design/designB.php?sub=99
    www.demotech.org/design/designB.php?sub=78
    www.demotech.org/design/designB.php?sub=76

    You still should get my response to your questions, but this is it for now!
    Regards, Reinder

    From: Sasha

    Hello Reinder,
    ( ....) I had just this moment a idea that would be excellent if it works.Maybe I could just take some regular ceramic tiles and glue them together with some kind of binder so they represent a kachel? I could evade all the hard work with processing clay and firing the kachel in the kiln and just take cheap finished mass produced tiles and glue them and build a kachelofen.These needs to be worked out.
    Back to your message,I find that the concept of 12 ambachten is interesting but dont know if tit is aplicable here because of cultural differiences.
    If you could tell more about your stove...
    Here the kachelofens are build from kachels and ordinary clay.
    But your principe is cheaper because no kachels are needed.
    I dont know would your forced draft stove gain anything ,because as far as I know the kachelofen is unsurpassbar if you measure energy efficiency, eco friendlines,local producable,extreme simple design solution ...

    Maybe you are trying to achieve something like this but,there are some problems with this very interesting and promising design (health hazard for example)
    www.ikweb.com/enuff/public_html/Turbo/Turbo2.htm
    just to pass some links that I found very helpfull
    www.solaroofgarden.com/
     guy who also is trying to promote open source appropriate technology solaroof technology using soap bubles for thermal insulation and shading of greenhouses.
    journeytoforever.org/
     excellent site

    From: Demotech Date: Fri Oct 10, 2003

    Sasha, hello again!
    (....) Regarding the site of the builders of the Finn-oven: Their site is now partly translated, go again to www.de12ambachten.nl
    For heating a workshop of a friend of mine a remodeled the inside of this oven. It became a lot simpler to build. No more tiles, no more heat-resisting cement, but thin stainless steel to guide the hottest part of the air stream in the fire, while this sheet metal is cooled at the inside by incoming air. The clay, used as mortar is drying now. Next week I am again at that place and expect to find out if it works as expected. There may be an other cold factory place in Holland where I can have another opportunity to test the stove-setup. So this winter will offer a lot of practical experience. I'll report to you as soon there is news. Now regarding your suggestions. The 12 Ambachten uses ordinary tiles, not glazed, somehow soft, reddish. The heat-resistant concrete is cast on top of these tiles as they are positioned on the bottom of the casting mold. But this is just the outside. The real hotspot is a box constructed also from heat-resisting cement slabs, the fire inside this box gets real hot, being the reason the combustion is very complete and the smoke is relative clean.
    Please explain what is it you name : kachel, that has to be made from clay and fired in an oven?
    Regarding the chimney, I try to get rid of it for a number of reasons. It is a very expensive part of the construction of the house. It attracts cold air and moist (rain). It cools down the oven when the fire has burned out, but the warm chimney still produces a lot of draft. It is very hard to create the right draft in a chimney. Given wind or fog in the air, then to much or to little draft.
    Forced draft can be applied as little ventilators are cheap and reliable (compare computers) Also using a small fan creates the opportunity to use a very small fire that burn for a very long time. In this way the need for a large buffering capacity in stone can be reduced, which works out well regarding price, suitability in apartment houses and ease of building.
    I do not expect any danger of suffocation in case the ventilator would stop when the fire is burning. As it is only little material that is actually ablaze, this will soon stop burning as there is no new oxygen at all. Remember there is no natural draft in Demotech's system.
    Your link offers supportive information. And these people really know what they are talking about. Apart form that they have done so much demonstrating in poor countries. Yes this is a great source, that I'll study thoroughly. Only sorry, my theoretical knowledge on heat transfer is only little. Best would be to contact these people and ask their opinion.
    (...) Reinder

    by f_karaoglu1985@hotmail.com - Wed Dec 07 (2005)
    bricks only with one phase
    I search that the probability of brick making only with one phase.I have to find related topics.so that how can ı reach these? thank you

    by Reinder / Demotech - Wed Dec 07 (2005)
    Re: bricks only with one phase
    > I search that the probability of brick making only with one phase.I have to
    > find related topics.so that how can ? reach these?
    > thank you Sorry, we have no expertise regarding brick making. Regards, Reinder

    by Sasha - Thu Dec 08 (2005)
    Re: bricks only with one phase
    Hello there karaoglu, what kind of bricks you want to make with ?one phase? (you mean with electricity),monophase? regards,Sasha
    > > I search that the probability of brick making only with one phase.I have
    > to
    > > find related topics.so that how can ? reach these?
    > > thank you
    >
    > Sorry, we have no expertise regarding brick making.
    >
    > Regards, Reinder
    >

    by f_karaoglu1985@hotmail.com - Fri Dec 09 (2005)
    Re: bricks only with one phase
    hi sasha,? mean that electricity(how can ? make a new brick form with electricity)

    by Sasha - Fri Dec 09 (2005)
    bricks
    Hi Karaoglu You have to tell me more specifically what is that you are interested in.What kind of bricks? You need to have a pottery kiln to fire ceramics.If you want it,kiln can be fired with electricity,or it can be fired with wood,oil,natural gas etc. Kiln is basically a insulated shell which can endure frequently firing to
  • C without deteriating.Simplest kiln is a hole in the earth with clay bricks in it and wood over it.You need to fire clay slowly (temperature increasing) so to avoid cracking of bricks.If you want a electric kiln you need to have electric resistant heaters.You can build it yourself but you need canthal wire which you can wind in a coil.Wire it to elecricity suply and you have a kiln.

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