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Post by alergyfree on Dec 11, 2010 8:46:58 GMT -8
OK,
I'm completely new to the idea of rocket stoves as mass heaters. It's a must in my next dwelling
What I keep seeing over and over again is how efficient they are, anywhere up to 98%.
So my question is has any one considered using the same basic design. With one modification, setting it up for propane or natural gas.
Yes, it would take a bit of engineering but ....
So you have all the advantages of the RMH with no ash, no baby sitting and maybe kicks on every other day?
Thoughts?
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Post by Donkey on Dec 11, 2010 11:03:59 GMT -8
Umm.. I don't know of anyone doing propane or natch gas.
I know a guy who's put a waste veggie oil drip in his rocket.. Personally, I'd like to see someone improve THAT..
I don't know that the rocket stove thing is necessary for these fuels. They tend to be fairly clean as it is, one fuel temperature does it and it's done.. With wood, there are multiple fuels in there, each with it's own burn temp, etc.. I imagine the design would change completely, you don't need the burn tunnel or feed tube. The heat riser would be shorter, or eliminated entirely, the burner would be placed very low, out of sight in the bench or some such place..
Hmm..
I suppose it would work.. Hell, maybe adding thermal mass to a natch gas or propane heater may be a pretty good idea..
I expect when yer done, it won't look much like a rocket stove.. Maybe worth a try.
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Post by canyon on Dec 11, 2010 11:06:25 GMT -8
Well, a friend of mine who hosted a rocket workshop did just that in a temporary fashion. He rigged up a propane weed burner to his bench as he couldn't tend a wood fire for a bit and yet needed to dry out his newly constructed bench before it froze. He liked the effect so much that he continued to burn propane for a while. Of course when it came time to fill the bottles (at $4.60 a gallon here) the work of wood looked to pay. It was efficient in that propane can burn pretty efficient and then the mass bench can store the heat efficiently. Although not my personal focus as I am interested in renewable energy, it could be rigged up for a very easy and low tech (relative to modern boilers etc.) comfortable heating system for smaller spaces.  |
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Post by alergyfree on Dec 18, 2010 6:56:47 GMT -8
Sure the propane was not cheap by any means. My thinking is if you have it firing only a few hours every day as opposed to every few hours continuous. The net gain would be quite a bit long term compared to a conventional furnace.
I think the waste oil and glycerin (as mention in another post) burn has some real possibilities.
Hopefully the shop will be set up by spring and we will start on some prototypes.
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Post by alergyfree on Dec 18, 2010 7:03:25 GMT -8
Umm.. I don't know of anyone doing propane or natch gas.
I know a guy who's put a waste veggie oil drip in his rocket.. Personally, I'd like to see someone improve THAT..
I don't know that the rocket stove thing is necessary for these fuels. They tend to be fairly clean as it is, one fuel temperature does it and it's done.. With wood, there are multiple fuels in there, each with it's own burn temp, etc.. I imagine the design would change completely, you don't need the burn tunnel or feed tube. The heat riser would be shorter, or eliminated entirely, the burner would be placed very low, out of sight in the bench or some such place..
Hmm..
I suppose it would work.. Hell, maybe adding thermal mass to a natch gas or propane heater may be a pretty good idea..
I expect when yer done, it won't look much like a rocket stove.. Maybe worth a try.
I was thinking to adjust the burner setup to match the RMH and not really change it.
So theoretically you could pull out the burner and just add wood.
So a multi fuel rocket maybe?
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Post by Donkey on Dec 18, 2010 9:06:33 GMT -8
Maybe.
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Post by alergyfree on Dec 18, 2010 9:09:54 GMT -8
A maybe is good, though an out right no would just be a challenge.... Thanks |
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Post by canyon on Dec 19, 2010 14:00:23 GMT -8
I suppose it would work.. Hell, maybe adding thermal mass to a natch gas or propane heater may be a pretty good idea.. I expect when yer done, it won't look much like a rocket stove.. Maybe worth a try. I was thinking to adjust the burner setup to match the RMH and not really change it. So theoretically you could pull out the burner and just add wood. So a multi fuel rocket maybe? The experience with my friends rocket being fired by a propane weed burner got me thinking about it as a multi-fuel potential for those that it appeals to and lots of ideas come to mind that could be tuned to work. Just putting the weed burner in the end of the burn tunnel does work though so I kind of liked that simple easy build in option with perhaps a cleaner burner. If the intense radiant heat coming off a heat riser barrel isn't needed when on propane it could be built into the post barrel clean out and tuned to exit up the end stack just above the condensing point. Lots of options that depend on the needs of the particular situationl. If a mass heater makes sense for a space and the occupants than it is a matter of preference what the fuel choice is. I could see the advantage to having the option (and it was clearly an advantage for my friend) of it being multi-fuel. I think it is important to identify what the primary fuel is and design the unit based on the most efficient use of that fuel as anytime you multi something like this it is at a cost or compromise of something and that ought to be more on side of the least used fuel IMHO. |
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Post by josephjcole on Dec 21, 2010 5:28:49 GMT -8
Donkey, how was the vegetable oil system run? I've seen electric vegetable oil run burners that vaporize the oil then blow it through a burner system, efficient, but loud. A simpler method is something like this: www.pottery-magic.com/pottery/tools/clay-kiln/veggie_firing.jpgA ladder system where the oil is progressively heated up as it moves down the ladder. Of course the oil can't ignite itself, so you need to preheat the stove with another source. Wood or gas... off the top of my head I think it needs to be around 700 F? A drip system could be added right before the riser tube, and turned on after the thing was warmed up. It's certainly an interesting idea. Joe |
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Post by Donkey on Dec 22, 2010 8:31:08 GMT -8
That's what he did.. Ran it on wood and added a WVO drip just inside the burn tunnel.
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