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Rocket Stove for heating water  RSS feed

 
                                        
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Does anyone have experience in using a rocket stove for heating water

Looking for a way to heat or boil about 10 gallons of water.  Would there be enough heat over the 55 gallon drum on the rocket stove?
 
                        
Posts: 278
Location: Iowa, border of regions 5 and 6
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circumspice wrote:
Does anyone have experience in using a rocket stove for heating water? 

Looking for a way to heat or boil about 10 gallons of water.  Would there be enough heat over the 55 gallon drum on the rocket stove?


Seeing as how every single picture I've seen of a rocket mass heater (RMH) has a teakettle on top of the 55-gal drum, I'd say yes.

If you don't care about building an RMH, you just want to heat the water, the answer is still yes.  There are some videos on the web about building rocket stoves for use in schools and other "industrial strength" cooking applications.  If I remember right, the pots are put on top of the insulated chimney of the rocket stove, and a "chimney" is put around the pot so there is about 1/4 inch all the way around between the pot and that chimney.  This allows the hot exhaust to not only heat the bottom of the pot but the sides also.
 
                                        
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I am mainly interested in the rocket stove because there is very little smoke and it uses less wood.
 
Kathleen Sanderson
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Location: Near Klamath Falls, Oregon
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Well, you would, of course, be able to heat water in a kettle on top of the barrel.  But I think it should also be possible to have a welder attach a water jacket around part of the barrel (I'd put it around the back and sides so you could still access the top easily for cooking).  Just make sure it's not closed up tight, or you could have a steam explosion.  You'd want a set-up like the water reservoir on the side of a wood cook stove, with a spigot at the bottom.

Kathleen
 
                                        
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The part of the rocket stove that has to stay hot so that the fire burns clean is the riser pipe, is that correct?

So the drum that covers the riser pipe (is it called the radiator?) could be cooled by water and not cause smoke to form?

My goal is to heat water, and then pump hot water into a thermal mass to raise its temperature. The thermal mass is barrels of water in an insulated box.  The thermal mass would be used to heat air to heat a small, well insulated house.  The rocket stove is intended to be a backup to a solar hot air system also using the thermal mass. The goal for the rocket stove is firing it up for a few hours and then getting heat out of it for a day or more  in cold conditions.

This would not be a pressure system, I am aware of that danger.
 
                        
Posts: 278
Location: Iowa, border of regions 5 and 6
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I think you may be confusing some things.

What you're asking about is a "rocket stove".  These are cooking appliances that are super-efficient -- able to boil a quart of water in 2 minutes.  You can buy them commercially (http://stovetec.net/us/) or build your own (http://www.youtube.com/watch?v=p0rywiPHZEw).  If you go to the Aprovecho Research Center website (http://www.aprovecho.org/web-content/publications/pub1.htm) you'll find a host of publications and videos that show how you can make a rocket stoves for a variety of purposes, from cooking to making charcoal to firing bricks.

What usually get discussed here are "rocket mass heaters".  These are ovens that use rocket stove technology and design to heat a large thermal mass, usually cob, and are usually used for heating living spaces.

I get annoyed at people like this guy (http://www.youtube.com/watch?v=9uh2VExcdbY) who has built a rocket mass heater but is calling it a rocket stove.  Things are confusing enough...
 
                                  
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In a classic rocket mass heater (with a heat riser and a barrel over the top,) the gas flow is down.

Having a coil of pipe inside would allow the water to heat and rise towards the hotter gas in a contra flow pattern will be efficient.   
 
Joel Hollingsworth
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There's also the strategy of building your kettle as a chimney, for example the Kelly Kettle (and a number of very old traditional designs, too).

The little portable rocket stoves, built from a 5 gallon square food canister, a stovepipe, an elbow, and a few gallons of wood ash, is pretty much designed to boil water.
 
Ernie Wisner
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there are several ways many of them blow up one has worked for two years so far and will be published soon. another i am working on in a little over three weeks and if it works it to will be published. this is an area everyone gets to and most dont get very far into because of the dangers of steam.
 
Jim Argeropoulos
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You keep teasing us with "will be published". I suppose we'll have to wait.
 
Ernie Wisner
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teasing my right foot  I just dont want you showing up at a permi convergence missing limbs. Not that i would mind you blaming me; but Erica has a soft heart and i would have to live with her looking at me with that angry wife look. 

we have research under way and i have one system proven so its on the way to you. this other one will take a few more weeks of testing before i am ready to let you folks have it to mangel and stress and reconfigure and break and and and LOL...

( in case you are new to the board this is me teasing silver and the other folks interested in this so dont take it wrong)
 
David Glenn
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Seems to me that the number of heat transfers from one medium to another you are speculating, turns into much more work and becomes increasingly less efficient with each step.?
Probably be better off just using RMH direct.
 
Ernie Wisner
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I dunno thermal mass is thermal mass. its all in how you apply it.
 
paul wheaton
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bee chicken hugelkultur trees wofati woodworking
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Somebody was saying they couldn't find my rocket water heater video on these forums, so I thought I would add it:



 
Michael Duhl
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Location: Ohio river valley
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Ok, so I have been testing the RMH traditional, mostly for heat, for all of this winter.  That said I also like to boil some water or maple sap this time of year.  Problem is, I cant get the top of stove hot enough really.  Hottest ever has been 200 degrees, and a most consistent 160-180 degree.  I have had rocks and bricks around pot on top and that helps. 

The Problem I think is the gap between the heat riser and the barrel.  Its only 1 3/4 inch.  By making it bigger I assume it would produce more heat at the top instead of much of it staying low. 

You want hot water plan ahead.  A regular built RMH will need some tinkering.  An open system of some sort with multiple tanks and a drain back.
 
                            
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Ernie Wisner wrote:
there are several ways many of them blow up one has worked for two years so far and will be published soon. another i am working on in a little over three weeks and if it works it to will be published. this is an area everyone gets to and most dont get very far into because of the dangers of steam.


I would be very interested in the basic heat exchanger design, they get real funky real fast and I have only been able to fathom one design that would meet my own criteria, and even then it is not field replacatable. Because of the significant dangers fooling with water in fairly short order, I tend to keep my head inside the box.
 
Saybian Morgan
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http://www.youtube.com/watch?v=YTnr8ua54Uw&feature=player_detailpage

This seems more compact and to the point of water heating, it's quite similar to a compost shower but it's fixed nature allows more durable components.
It's not building instructional, but if it was popular enough to be in a video there is surely a website for it's construction.
 
Too many men are afraid of being fools - Henry Ford. Foolish tiny ad:
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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