• Post Reply Bookmark Topic Watch Topic
  • New Topic
permaculture forums growies critters building homesteading energy monies kitchen purity ungarbage community wilderness fiber arts art permaculture artisans regional education skip experiences global resources cider press projects digital market permies.com pie forums private forums all forums
this forum made possible by our volunteer staff, including ...
master stewards:
  • Carla Burke
  • John F Dean
  • r ranson
  • Nancy Reading
  • Anne Miller
  • Jay Angler
stewards:
  • paul wheaton
  • Pearl Sutton
  • Nicole Alderman
master gardeners:
  • Christopher Weeks
  • Timothy Norton
gardeners:
  • Matt McSpadden
  • Rachel Lindsay
  • Jeremy VanGelder

Rocket stove pool heater.

 
Posts: 7
1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Hi all,
I'm after some advice please. I have recently built, what I now know isn't actually a rocket stove, to tru and heat an above ground 12' round pool. The main parts (horizontal and vertical sections) are 6" x 6" hollow section and the fuel feed is 4" x 4". I have 3no 3mtr 15mm copper pipe coils running up the chimney.

Although this does a fair job of heating the water running through it, I dont seem to be getting "rocket effect" whilst burning.

Any suggestions on how I can improve this?

Many thanks
20200524_131815.jpg
[Thumbnail for 20200524_131815.jpg]
20200524_131830.jpg
[Thumbnail for 20200524_131830.jpg]
20200524_131843.jpg
[Thumbnail for 20200524_131843.jpg]
20200523_140206.jpg
[Thumbnail for 20200523_140206.jpg]
20200523_140158.jpg
[Thumbnail for 20200523_140158.jpg]
 
rocket scientist
Posts: 5895
Location: latitude 47 N.W. montana zone 6A
2846
cat pig rocket stoves
  • Likes 1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Hi Joe; Welcome to Permies!
Joe I have to tell you that if you ever get your stove up to true rocket performance you stand a good chance of a catastrophic failure.
In a standard well burning rocket, temps in the riser approach 1500 F Your water would flash to steam and bad things happen to copper pipes and bystanders.

Sorry to start out on a down note but we really stress safety around RMH's and water.
Here is a link to a super cool rmh water heater that might be a better option for you.
https://www.permaculturenews.org/2012/11/23/rocket-stove-hot-water/

Try building a rmh with clay bricks and mud. Metal only lasts so long before spauling into oblivion.
Stick with 6" dimensions throughout , with a standard J tube design.  Seal any possible air leaks with cob (mud)
Stand back as this design will rocket like you expected from your design.  
 
gardener
Posts: 1790
Location: Kingman, Arizona
522
building solar woodworking rocket stoves wood heat greening the desert
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
I would agree with Thomas on the safety factor. An open system is way more safer and there are many people that have built one with great results.
I suspect your getting such poor draft due to the fact that you've plugged up about 1/4 of the heat riser with the coil, adding a whole lot of drag to slow down combustion.
 
J Partridge
Posts: 7
1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Hi Thomas,

Thanks for your advice. Do you think it would be safe to use this temporarily as I'm not getting "hot" temperatures until I build something else?
 
J Partridge
Posts: 7
1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator

Gerry Parent wrote:I would agree with Thomas on the safety factor. An open system is way more safer and there are many people that have built one with great results.
I suspect your getting such poor draft due to the fact that you've plugged up about 1/4 of the heat riser with the coil, adding a whole lot of drag to slow down combustion.



Ah right, I hadn't thought that the pipe would restrict air flow. Obvious now!
 
gardener
Posts: 3132
2082
  • Likes 1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
It looks open enough to me to be safe; I don't see any valves or anything. If it were to reach the boiling point, the pressure should go out each tube if the pump were to fail or something. I imagine the problem has something to do with the restriction as mentioned, or the area where the fuel meets the air may not be optimal.
 
thomas rubino
rocket scientist
Posts: 5895
Location: latitude 47 N.W. montana zone 6A
2846
cat pig rocket stoves
  • Likes 1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Hi Joe;   With care I think it will hold up until you can make changes.
Just don't get carried away trying to get a roaring fire. If you get it to hot...We call it squish boom...
The thing about water in an enclosed pipe. If it spot heats to steam  it collapses the copper pipe (this is the squish) The pipe splits allowing the steam and super hot water to explode outward(this is the Boom)
You might think that the hot water would just squirt out the pipe as Jordan suggested.  Things happen in split seconds going from a liquid to a gas. No time to push water out a pipe, its less work to blow a seam.
So please be careful ... Oh and welcome to the wonderful world of Rocket Science!
 
J Partridge
Posts: 7
1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator

Jordan Holland wrote:It looks open enough to me to be safe; I don't see any valves or anything. If it were to reach the boiling point, the pressure should go out each tube if the pump were to fail or something. I imagine the problem has something to do with the restriction as mentioned, or the area where the fuel meets the air may not be optimal.



Thanks Jordan,

I haven't 100% got my head around the science behind all of this yet but I'm having fun finding out. Just dont want to blow myself up in the process haha
 
J Partridge
Posts: 7
1
  • Likes 1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator

thomas rubino wrote:Hi Joe;   With care I think it will hold up until you can make changes.
Just don't get carried away trying to get a roaring fire. If you get it to hot...We call it squish boom...
The thing about water in an enclosed pipe. If it spot heats to steam  it collapses the copper pipe (this is the squish) The pipe splits allowing the steam and super hot water to explode outward(this is the Boom)
You might think that the hot water would just squirt out the pipe as Jordan suggested.  Things happen in split seconds going from a liquid to a gas. No time to push water out a pipe, its less work to blow a seam.
So please be careful ... Oh and welcome to the wonderful world of Rocket Science!



Hi Thomas,

Thank you for the welcome. It seems I have a lot to learn! I'll be giving your suggestions a try as soon as I can source material.

Joe
 
J Partridge
Posts: 7
1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator

Kevin Vader wrote:In my opinion, as a rocket man who has been engaged in rockets for the past 8 years, I can say that some additional atomizer or candle is missing. And also there is a lack of air. Try to make cuts outside



Hi kevin, can you elaborate on the atomiser/candle please? And where do you think would be the best place for cuts?

Tia
 
J Partridge
Posts: 7
1
  • Likes 1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator

thomas rubino wrote:Hi Joe; Welcome to Permies!
Joe I have to tell you that if you ever get your stove up to true rocket performance you stand a good chance of a catastrophic failure.
In a standard well burning rocket, temps in the riser approach 1500 F Your water would flash to steam and bad things happen to copper pipes and bystanders.

Sorry to start out on a down note but we really stress safety around RMH's and water.
Here is a link to a super cool rmh water heater that might be a better option for you.
https://www.permaculturenews.org/2012/11/23/rocket-stove-hot-water/

Try building a rmh with clay bricks and mud. Metal only lasts so long before spauling into oblivion.
Stick with 6" dimensions throughout , with a standard J tube design.  Seal any possible air leaks with cob (mud)
Stand back as this design will rocket like you expected from your design.  



Hi again Thomas, I've been thinking about this a lot again today. Can you explain to me in layman's terms how the method shown in your example would create more heat in the water than having the copper pipe in direct contact with the heat from the fire? I 100% understand the safety issues. But please forgive my ignorance as I'm an absolute newbie to this.

Many thanks in advance, Joe.
 
thomas rubino
rocket scientist
Posts: 5895
Location: latitude 47 N.W. montana zone 6A
2846
cat pig rocket stoves
  • Likes 2
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Hi Joe;  Its not that it creates more heat than your design. Your design would by all means get hotter faster.
It does so with no chance of  flashing the water to steam.

Here is a different link. http://walkerstoves.com/index.html   That is Master builder Matt walkers site.
Matt sell complete build plans for his designs.  He has just recently built a stand alone water heater, that might be to your liking.

Here is a link to Geoff Lawton building a heater like the first design I showed you https://www.youtube.com/watch?v=z-Cdx0W3Eqc
As you can see his rocket stove is very crude but works great!
 
Gerry Parent
gardener
Posts: 1790
Location: Kingman, Arizona
522
building solar woodworking rocket stoves wood heat greening the desert
  • Likes 1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
There's also one at Wheaton Labs. See here for video: rocket hot water heater
 
master gardener
Posts: 2846
Location: Upstate NY, Zone 5, 43 inch Avg. Rainfall
1052
monies home care dog fungi trees chicken food preservation cooking building composting homestead
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Welcome to Permies Peter!
 
Aaaaaand ... we're on the march. Stylin. Get with it tiny ad.
Rocket Mass Heater Jamboree And Updates
https://permies.com/t/170234/Rocket-Mass-Heater-Jamboree-Updates
reply
    Bookmark Topic Watch Topic
  • New Topic