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Permies likes wood burning stoves and the farmer likes secondary burn? permies
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secondary burn?

Alan Mikoleit

Joined: Oct 13, 2013
Posts: 106
Location: Sandpoint, Idaho
I just joined permies and this is my first post and intro. I have read the RMH book and just watched the 4 DVD kick starter set. I have 2 questions. My understanding now is there is no such thing as secondary burn. Either a heater is burning hot and clean or cold and dirty and the whole burn can happen in one area. Is this summation correct?
allen lumley

Joined: Mar 16, 2012
Posts: 3871
Location: Northern New York Zone4-5 the OUTER 'RONDACs percip 36''
Alan Mikoliet : It is probably more accurate to say that after the Rocket Mass Heater R.M.H. has reached its maximum temperature within the Burn Tunnel / Combustion chamber
that there is for a time an area where the hot exhaust gases continue to burn, as volatiles and carbon and hydrogen are turbulently combined with oxygen at temperatures around
1600 F, this continues through the Heat Riser, and Interestingly increases as the hot exhaust gases slam against the underside of the top of the barrel, here they spill over the
top of the Heat Riser Turbulently tumbling in a toroid or doughnut shape.

I said that what happens here is interesting because, a Hydraulic Engineer was dismayed when the Turbulence in this location was described to him, He was worried as a good
Hydraulic Engineer should be, about the increased vibration induced noise and heat, these to additions to the environment at this location do increase heat production and the
(mostly) final area with a peak in combustion after the Combustion chamber !

I am aware that I have split a fine line between the two extreme view points, but I Believe I have accurately answered the Question asked and the conditions within the
R.M.H. at the points described! For the Good Of The Crafts !

Think like Fire, Flow like a Gas, Don't be the marshmallow ! As always your comments and questions are solicited and are Welcome ! PYRO - Logically BIG AL !

Success has a Thousand Fathers , Failure is an Orphan

allen lumley

Joined: Mar 16, 2012
Posts: 3871
Location: Northern New York Zone4-5 the OUTER 'RONDACs percip 36''
Alan Mikoleit : I want a second bite at the apple, I found a link here to a different Rocket Mass Heater, Which is a 'horizontally loaded and fired 'Batch Stove. this is a significantly
more difficult build, The people in this group really turn the science of Rocket Mass Heaters, into " Rocket Science"! These are all one off builds, with sometimes very esoteric
proposals as to why they work, most are very close to the efficiencies of our J-Tube R.M.H.s, but at our current leveL of efficiencies ~90%~ a 20% improvement would have to
come out of the remaining 10%, making that 20% improvement a difference of 2% !

Anyway, look at the primary burn here and see if you think this stove can get to the high 90%s without an after burn ! video

In any case enjoy ! For the good of the craft ! Don't be the Marshmallow ! Big AL
richard valley

Joined: Aug 18, 2011
Posts: 216
Location: Sierra Nevada mountain valley CA, & Nevada high desert
Greetings allen, I haven't read all the above answers. Secondary burn does happen. In the winter we live in the mountains and heat with wood. Secondary burn can be achieved without a system that delivers air to the upper part of the firebox but not as well and for not as long.

I'm talking about a wood burning stove not a rocket stove. Adding an air delivery system, a arrangement of pipes or tubes that brings warm air to the upper part of the fire box works very well, the stove burns cleaner. longer and produces more heat from the wood. I'm building one now.

There are examples that can be found by googling,

I'm using square steel tubing for mine, most of the ones I've seen are made with 3/4" pipe.

I just reread your post and see you're talking about RMH.
Hope you have good luck with it if you build one. I've looked them over, on line, and was interested but at this time is doesn't fit us. Maybe one day I'll try it in the greenhouse. Again good luck, have a great day.

It's in the permaculture playing cards. Here's the link:
subject: secondary burn?