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Rocket Stove & Oven Design  RSS feed

 
James Fleming
Posts: 15
Location: Baltimore
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I am considering building my first rocket stove/oven (I have built a pizza oven in the past) and am looking to use this primarily for cooking and baking. I saw this design:
multi source oven which I liked because there were multiple heat sources, so I assume that the chef could regulate the temperature. I also saw that people had done an oven to capture secondary heat for baking.

I created a very basic diagram but am wondering if anyone had done something similar. I've seen people build "white ovens" there the heat is channeled in indirectly. I'm just not sure if the oven would get hot enough without a heat source directly underneath the oven for pizza. My hope might be that if I run the one burner at the far end, the oven might be hot enough for baking, but if I run both burners, the oven would get hot enough for pizza.
oven.JPG
[Thumbnail for oven.JPG]
 
allen lumley
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Posts: 4154
Location: Northern New York Zone4-5 the OUTER 'RONDACs percip 36''
58
books fungi hugelkultur solar wofati woodworking
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James Fleming : So I tried to backtrack from your link which took me to here :
https://www.pinterest.com/pin/306596687111427394/


And then I got back to a fork, one branch went to :
http://www.inspirationgreen.com/masonry-wood-cookstoves.html


And another branch leading back to an old post here at Permies.com :
http://www.permies.com/t/22550/rocket-stoves/find-polished-rocket-stove


It looks as though inspirationgreen.com may have copied the picture from a search engine that Originally found it at Permies.com

You did not give a location, or whether you wished to build this inside your kitchen or outdoors - With very little modification and a baffle to direct
the flow of your hot exhaust gases to the left or to the right and using two short vertical chimneys the right-hand rocket stove should be able to
adequately heat both sides, one at a time !

Running this indoors would make using two chimneys an Expensive build ! I strongly suspect that running two rocket stoves will create issues with
proper chimney size and may require a damper to close off the unused rocket when trying to use just one at a time. Warning, a closed damper is
the best way I know of to fill a house with smoke !

A couple of things- I can only second guess why the designer went with a horizontally fed Firebox, I expect that he had not yet worked with a
Vertically fed rocket stove yet* - A major problem with the horizontally fed rocket stove is the tendency to try to push in more wood and end up
choking the fire with unburned Charcoal ! This occurs because the horizontally fed wood primarily burns just at its tips! This is the sweet spot that
is just above The Grate and Ash Pit **you have included in your drawing ! In the sketch in the last link you can see that the primary air is supplied
the fire from below, this is needed to help percent smoke drifting back and into the kitchen space.

My personal idea would be to Use the Vertically Fed rocket stove that still burns just the tips of the fuel allowing the wood to self feed, settling down
into the burn tunnel as it burns up

Very important to the Rockets ability to Burn at freaky high temperatures 1,000ºƒ, And burn cleanly is a Tall enough Heat Riser, with the Rockets
horizontally fed Combustion chamber and short Heat Riser I doubt that those temperatures were reached, I doubt it was able to burn cleanly enough!

The original inspiration for Your sketch has some heat storage ability embodied within its Mass, your design is much more bare bones and I expect
that your model will radiate most of its heat away - being a beast to work next to and exhausting the rest up the chimney, without mass as soon as
the fire goes out your design as is will (I Think ) Cool down rapidly { Except for the cob oven}


I have saved a sketch of the ratio of The Feed Tube to the Heat Risers Height This and the original picture you used to design a sketch from so that
you can see for yourself the original Masonry Rocket Cook stove has very short Heat Risers !

http://www.theresilientfamily.com/wp-content/uploads/2012/04/Rocket-Stove.jpg

If i can suggest you could try building just the righthand rocket and use that as a testbed before moving on to a '' Full Kitchen'' especially until you are
used to the heat output of a single Rocket

For theGood of the Crafts ! Big AL

* A third kind of Wood feed for a Rocket stove is The Batch loaded Rocket stove. I strongly suggest that everyone try the vertically fed rocket before
moving on to the much harder to build Bach Fed Rocket

** Because the rocket burns at such Freaky high temperatures all ash is reduced to fly ash , there is little need for an ash pit and no need for a big one
 
James Fleming
Posts: 15
Location: Baltimore
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All good points!
I'm located in Baltimore, but I'm currently looking at property in Western Maryland, VA, TN.

The reason for the horizontal fuel intake was to better control the temp by way of moderating the amount of fuel better (I was under the impression this would be best for cooking), but once I adjusted the scale of my design more accurately, you can see much has changed. Taking from your minimum of 40cm, I've got that covered (if you measure from 1/2 way up the fuel intake before the chimney hits the duct on the r/h side.
I'm thinking that the fuel port, chimney and duct would be 8" terracotta chimney liners, (perhaps maybe use a 10" liner for the chimney or 6"for the fuel intake) with the chimney being put inside a 12" liner (or sheetmetal) that is insulated with perlite. I would try to keep the thermal mass of the structure low where possible (perhaps build the outer frame w/ aluminum studs and concrete board) to allow for maximum insulation. The design is to vent the whole thing out a chimney at the back of the oven.

I've seen designs where the rocket stove has openings for multiple pots (typically counter set for better tranfer of heat). cooktop

Based on your comments, and how low the fuel port is now, I'm thinking of making an angled fuel port, or a J-channel. Any info on that Batch loaded Rocket stove?
oven.JPG
[Thumbnail for oven.JPG]
 
allen lumley
pollinator
Posts: 4154
Location: Northern New York Zone4-5 the OUTER 'RONDACs percip 36''
58
books fungi hugelkultur solar wofati woodworking
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James Fleming : Before we settle into a discussion on your plans I want to introduce a different type of Two-Chamber oven to you- Mostly because I may forget otherwise.

from the new page you will need to scroll down . Link below :

http://www.permies.com/wood-burning-stoves.html

The good people at Dragonheaters.com, *use terra cotta tile which they precut, dividing the tiles in half along their lengths, that and the Tiles vertical use (not horizontal) is
their way of dealing with the tiles shattering due to uneven heating ! Y.M.M.V.

Generally we want to have a constant Cross- sectional area throughout the build, this ensues a strong draft !

This is where I recommend going to Rocketstoves.com, to download a PDF copy of the brand-new 3rd Edition of rocket mass heaters,This will make sure that
we are using the same words to describe Measuring Cross-sectional Areas, burn chamber parts, lengths, Ratios, and Orientation of those parts to each other and the whole!

Eventually I will be dragged kicking and screaming into the 21st century, right now I have not advanced past the J-tube style rocket mass heater RMH because the j-bend

meets my needs! I do feel justified in pointing out that the horizontally loaded batch style RMH is a more difficult build. Here is another place where the real egg-heads hang
out and describe the which-ness of what! They are hard to follow if you are not already a Ninja type Rocketeer ! link below :


http://donkey32.proboards.com

I hope this is both helpful and timely, For the Good of the Crafts ! Big AL


*a series of Rocket Mass heaters 4'', 6'', and 8''
 
allen lumley
pollinator
Posts: 4154
Location: Northern New York Zone4-5 the OUTER 'RONDACs percip 36''
58
books fungi hugelkultur solar wofati woodworking
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James F. :I hope you appreciate my jumping out of bed at 2 A.M. Because I realized that if you had not been exposed to the works of Kiko Denser

you still have much to learn about Cooking /Baking Kilns ! link below :

http://www.handprintpress.com/authors/kiko-denzer


Just wanted to make sure you were not held back by the fact that I run to my neighbors to use their kiln and am still learning to turn out decent bread !

For the good of the craft ! Big AL

Late note ! This should have self directed you to his self published (he owns the publishing house) book on cob ovens "Fire - ovens " - Check out his

comments

-and do a little research on " Waterglass " _ O.K., i'll check my Mail and go back to bed ! Big AL
 
a wee bit from the empire
2017 Rocket Mass Heater Workshop Jamboree - 15 workshops in one event
https://permies.com/wiki/63312/permaculture-projects/Rocket-Mass-Heater-Workshop-Jamboree
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