rocket heater idea

This is my rocket heater idea , we have dubbed it the angry bird . The stove and the heat exchanger are detachable so my plan is to insulate the stove and heat riser with reflective hi temp ceramic exhaust coating and wrap the heat riser with exhaust wrap too , for the heat exchanger tank I plan on using a hi heat ceramic heat dispersing coating . I test fired it the way it is in the picture and it worked good , it makes a sound like a buzz bomb or a pulse jet . I will post more pictures and video as soon as I get around to go-pro it in action .

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I'm very happy with this heater ! When it's all stoked up it has a wicked base sound .



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Nice stove. It is simple in its conception and seems to be very efficient. If you are going to use this stove inside a house, you need no insulation. You want maximum heat output at all levels, even at the bend level. To maximize heat production you can insert heated air where the flange with the riser tube is located. At the base of the riser tube you can insert as well a vortex. These two bits o technology will allow you to get more heat from your fuel.

Two questions, what diameter pipes did you use for this construction? how do you clean ashes?

Thank you , I'm very happy with it . It is constructed of exhaust pipe , the lower portion of the stove is 4" lobster tail welded to a fabricated 1/4" plate flange with a 3" hole in the center with the heat riser welded to it made to fit inside of the duramax turbo diesel 3 1/2" downpipe flange that is welded to two freon cans with the tops cut off and welded together and the flue pipe is 3" mandrel 90 with a 3 1/2" exhaust stinger style chimney . This stove is just a fabrication exercise the real one I'm planning to build will need to warm a 1400sf shop . I designed this stove to be simple so I could make changes on the fly . Thank you for your suggestions , I will post up pictures of the changes I make

caotropheus , what size secondary air inlet would be right for this stove , would one be enough or should I place one on each side ? Also do you have a picture of what you are using as a vortex generator ?

Pretty darn cool man, great way to stealth heat!
I am interested in how the ceramic paint holds up to heat, your idea gives me an idea for a light weight durable stove using the ceramic heat to create a heat shield in places where the stove will need it for durability.
Thanks for posting the video man and the pics, nice fabrication work.

Creative use of the materials man, I am liking it.

Great looking stove...Secondary air ...you should only need one inlet no bigger than 4 sq inch or 2x2 ...4x1 etc should be more than enough to feed the riser at the base... flue outside reminds me of a submarine periscope ..well cool !

rocket booster wrote:

caotropheus , what size secondary air inlet would be right for this stove , would one be enough or should I place one on each side ? Also do you have a picture of what you are using as a vortex generator ?  

This is one of my videos, you can see how I create a vortex inside the riser pipe. This system will suite well a stove like yours.
https://www.youtube.com/watch?v=g5xnp_X_P38

ppotty1 Admin wrote:

Great looking stove...Secondary air ...you should only need one inlet no bigger than 4 sq inch or 2x2 ...4x1 etc should be more than enough to feed the riser at the base... flue outside reminds me of a submarine periscope ..well cool !

I have to disagree with ppotty. You only need a small amount of secondary air. If you use a 3.5 inch riser pipe, its area is 9.6 sq inch and 4 sq inch is almost half of it and you do not need so much secondary air supply. You need to insert very hot secondary air to allow spontaneous ignition of gases and smoke. I see here several possibilities. First, I would use one "J" shape bent pipe, half an inch diameter and tack welded to the inside top  of the feeder tube, all the way to where the flange is, just below the vortex device you will weld. You can see this idea on Tryin2hard's videos. A second possibility may be to cut out one of the faces of  a square tube, to make "U" shape canal out of it. Weld this canal along the outside top of feeder tube, the combustion chamber (where the bend is),  and then up to the lower flange.  There you make a couple of 12 mm holes in the combustion chamber wall  to allow air to be drawn in. The edge close to the feeder tube entrance is left open to allow outside air to be drawn in. In these two systems air is exposed to high temperatures of the fire. You can double the amount of secondary air if needed if you build two canals on both sides of the stove.

I see here one other possibility in your stove that is to build a combustion chamber with glass just where the bend is, below the heat exchanger but this can reduce the stove efficiency. To compensate this reduction in efficiency you may need a bigger diameter chimney to increase flow of air and gases.

Thank you caotropheus , I will try a pipe on the inside of the stove first like Trying2Hard has done as it looks the easiest . I can then try both your style setup and ppotty1 suggestions as well . The idea that I get watching the stove burn is when the fire is all stoked up combustion is fine but when the flames die down it back drafts a tinny bit and smoke collects in the hopper . I was thinking this smoke is rich with syngas that is normally burned by the fire when the draft is constant so my idea is to take hot air and syngas from the cold side of the fire and inject it on the hot side of the fire before the heat riser to raise the efficiency of the burn and raise the heat in the heat riser . The vortex generator you designed is perfect and I will be adding one soon . Thanks again all for all the great ideas .

If you restrict a bit the air at the entrance of the hoper, that will avoid back draft. Also if you increase chimney diameter, it will also decrease back draft.
We are looking forward for a video with the new setup.

caotropheus wrote:

If you restrict a bit the air at the entrance of the hoper, that will avoid back draft. Also if you increase chimney diameter, it will also decrease back draft.
We are looking forward for a video with the new setup.

Agreed with the air restriction that caotropheus pointed out, the issue with an open feed chamber that rises is that it can and will under right conditions become a chimney and fill the interior of the living space with smoke, just as Jeff Crutchfield, I warned him of this right before he had his garage filled with smoke due to this.

He did a video on it and got a handle on controlling his drafting.

This is just a suggestion, I think in the future it would be better instead of saying I disagree to just point out our idea of what can improve or impede performance I think this will be a more positive tract to take to get our ideas across rather than come across as a challenge? This way we do not make it personal, I know it was not intended my friend.

On my camp stove there isn't any secondary air except for the grate is slotted and perforated with 1/4" holes to allow air to bypass the fire and hot coals . The cavity under the grate is pretty large and I control the air in let with a hinged door in the lower portion of the clean out hatch and a lid for the hopper . This setup works extremely well when it is up to temperature , the hopper is full of fuel and the lid is on I can control the temp of the stove with the door under the grate in the clean out hatch .
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My thinking for the 2x2 sec air feed are that the wall thickness of the tube reduces it to around 1 1/2 and I like to control the air feeds anyway, you cant give the riser more air with a small pipe if you need to, but you can give it less with a larger one if you have to, the latest one i made has a 2x2 tube air feed on a 5 inch riser and it worked really well, when i closed it off the burn got dirty due to the amount of fuel in the firebox. My tests say big firebox more sec air needed for combustion in the riser, i think 2x2 would be essential if you plan a larger stove to heat your shop, I would use a 6 inch riser also to get the output and the clean burn.