paul wheaton wrote:I think there is a bizarre bunch of things going on with all this stuff that most of you don't know about.
Ernie and Erica would teach people, for free, for years. I posted videos for free. And because there were places where a few people did not understand the physics or the math, they would say mean and hurtful things. But smarter folks would understand and have great success.
Eventually the message was optimized so that people had less fuel for their ugliness.
So the first message is, keep in mind that those people that try to help others for free tend to get an ugly shit storm for payment.
I am dumbfounded at the number of fire themed bucket-of-horrors that are created and the creator proudly yells "rocket mass heater!" --- no, that is not a rocket mass heater. You need to come up with your own name for that freak show of flaming death.
I have managed on-line forums for over 25 years. So I am used to people contacting me outside of the forums to ask me questions that really belong in the forums. And I am a mega hard ass about it and say: If you ask me your question in the forum, I will answer you in the forum at no charge. Outside of the forum, it would seem that you are asking me for a private consultation, and I charge $160 per hour for that.
It is bizarre the number of people who email me (or send a PM from all sorts of PM services) and say "you don't know me, but I have a question about rocket mass heaters." I tell them the above and their response is "I don't like forums, can't you just answer my questions over email?" "Yes, I can. Here is my paypal account, please send me $160." "That is ridiculously rude beyond words! How do you expect to change the world with an attitude like that?"
The answer, of course, is that I cannot help 20,000 people if my time is consumed by one person. Posts in the forums help thousands.
Ernie and Erica get bombarded with similar stuff in their email. I try to tell them to charge these folks or direct them back to the forums. Usually they remember, but sometimes they are too softhearted. And being softhearted is nearly always punished.
These are growing pains. This is a technology with a popularity that is growing exponentially. The people that are involved are being run ragged. There is just not enough time in the day to personally help everybody. And a lot of folks that have come to the forums to learn, and have left once their rocket mass heater is working well. They do not feel the same compulsion to help others. Especially when helping people seems to always come with so much pain.
It isn't really the fault of the newbie. They're new! They don't know all this stuff that is happening. Since they are new, they probably think there are only 12 of these build each year and they will be one of the 12! So, surely, the great experts will be excited to hear about their efforts! The reality is that there are thousands being build this year - probably five times more this year than last year. And a lot of those people are seeking help privately - and want it for free.
All of the people in the rocket mass heater world are trying to figure out ways to cope with the freakishly massive demands on their time. As the crowds grow ever larger, the previous techniques will fail, nerves will get frayed, and new techniques will need to be tried under the banner of "trial and error" - and the "error" part will surely lead to more stumbles.
An ever growing massive gob of less-than-perfect human beings trying to collectively move forward.
I would like to ask people to try to use a slight language differentiation. A "rocket stove" is for cooking - typically outdoors. A "rocket mass heater" is based on rocket stove technology, but is for heating your home - typically indoors. Calling it a "rocket stove mass heater" is okay. But when you say you want to heat your home with a "rocket stove" then a lot of people get concerned about the smoke and gasses that will build up in your house and then everybody will die. Adhering to this tiny bit of vocabulary stuff soothes a lot of problems.
Gerald O'Hara wrote:Jamie,
Not sure what happened. I was going back to answer one of your questions on the RMH string you posted and it was "GONE".Then I sent an email to you and it bounced.
I am, as you may remember in SDAK...Northeast corner.
I am just learning about permaculture and quite honestly haven't mastered the concept as yet.
Drop a line to Icu4dzs at gmail.com
Gerald O'Hara wrote:G'day Jamie,
At the risk of sticking my foot in my mouth I am going to offer some information that may or may not assist you with the "problem".
Before I started building a rocket stove, I spent quite a while trying to find out if there was a specific proportion to the rocket stove components. After "kissing a lot of frogs" I finally found a site from M.I.T. which described the specific proportions required. I will start by saying that my original piece of equipment was a 30" piece of exhaust pipe steel 5" in diameter. The steel was cut into two pieces on the 45 with the short peice being 10" and the longer piece being 20". This was welded together and actually made a reasonably credible rocket stove in that simple configuration. I did take a piece of 4" flat bar and weld that to the inside of the combustion chamber to provide a shelf for the fuel as it entered the stove. As I said, it worked pretty good but not great. It still seemed a bit "smokey" and I wanted to know what I had done wrong.
I found this website and on it was the equation necessary to have a very successful rocket stove. The entire stove depends on the area of the opening into the combustion chamber which in my situation was 5" x Pi. (3.1416) In the equation from M.I.T. the important feature was the diameter of the fire box, such that the diameter of the opening to the fire box is considered algebraically as "X" The horizontal portion where the combustion chamber is situated will now be considereed 2x and the total height of the riser should be x + (1.5 or 2 x) + 5 cm. So in my case the horizontal combustion chamber which was 12" long had to be cut down by 2" and the vertical stack had to be cut down to about 17 ". This gave a much more satisfactory burn and allowed the wood to keep burning as long as I tended it and added more fuel periodically.
Therefore, when looking at the opening in your RMH where the first thing is the rocket stove, it would seem to me that the proportions of the stove opening and the length of the exhaust stack might be mis calculated yielding a goodly amount of smoke.
As I said, I am NO engineer as may be a few of the gentlemen here but in either case, you may want to play some tricks with the math and see if your design meets with important principles needed to fix the problem.
I certainly hope this computes and adquately relays the thought process somehat more clearly.
I hope this helps in your quest to find a good resolution of your rocket stove difficulties.
Marcos Buenijo wrote:
Jamie Corne wrote:I appreciate your pessimism. It drives my want to experiment so I can come back and say, "guess what? it worked!"
I am not interested in traditional methods. I am interested in new and improved methods.
Thank you for your input.
Well, you did make the same observation in the original post ("restricting the very top of the chimney to increase the velocity of the steam in order to turn a turbine fast enough - but that would seem to also restrict draft and become counter productive"). There is great value in learning how certain things can't work. It's not pessimism to point these out.
In principle, it is possible to get more form the rocket mass heater than heat. However, this must come at the expense of simplicity and at the expense of direct space heating. For example, there is a large piston steam engine near where I live that was used to power a sugar processing plant during the late 1800's and early 1900's. Piston steam engines have a reputation for poor thermal efficiency. However, it turns out that this well designed Corliss engine was literally too efficient in its particular application. What the plant really needed was process heat. So, while the plant did use the engine for mechanical work applications, and it also used some electricity generated by the engine driving a modest generator, it really made the most use of the steam exhausted from the engine. It often needed more heat than what the engine exhaust would provide, so they would often take additional steam directly off the boiler. There are also good examples of this principle on Navy ships. The steam generated from the reactor of a nuclear powered vessel is used for many applications, and this steam is generally taken after it passes through at least part of the engine. So, the heat in the steam is used to generate work, then the remaining heat is harvested for other useful applications like water distillation, space heating, and water heating. It's even possible to use heat to provide refrigeration applications such as air conditioning. It seems you're contemplating on the same basic principles here, so that's why I mentioned these things. I've thought along the same lines, and have considered many possible configurations for a residential setting.
Claire Skerry wrote:Why not just sink the rmh lower and set a closed system of a water reservoir over the barrel where the steam goes up to a turbine or something then back to the base. If you sink it lower enough you could probably use the top of the second barrel [water reservoir] as a cooking surface? That way you're not obstructing the flow etc.
Just an idea. Good luck!
Allen Jackson wrote:This isn't going to work, and any restrictions in the flow of your Rocket Mass heater exhaust will backfire, or at least smoke you out - best not to do it.
Probably best to look to a hybrid combo of solar & traditional wind turbines for electricity, unless you wish to be running a RMS-powered boiler to generate higher energy steam, which is probably much less efficient than just putting up a windmill.