Interesting compact concept

[thickstrings]

I was wondering if anyone has seen this before www.tamizsolutions.com/2012/09/10/the-rock-bucket-rocket/ This is just what I was looking for...I would ask if anyone knows more of the way the inside is laid out....And, do you think this principle would work with another 1/2 barrel? thanks

[satamax]

It's not a rocket. No insulation, smokes etc. Tho, i like the idea of getting the gases through pebbles. I had theorized that about two years back, in a more complicated maner. Gases would pass through the pebbles, then flaps would be closed and air would be allowed to pass through the pebbles, with a thermostat and a fan. I think you can find that description somewhere here or on permies.

[Daryl]

Or maybe a barrel with a pie cut surrounding the riser. The riser would be in the middle. Every other section would be an open chamber for the gas to travel down. On each side of a gas chamber would be closed chambers containing pebbles. That way the gas flow isn't interrupted so drastically and the benefits of stone mass can be utilized. The gas channels could connect on the bottom of interior of the barrel to exit a flue. Sort of a compact mini bench/barrel based more on the masonry stove design.

Sorry to jump in. I need a break.

[thickstrings]

Looking at this design. I was wondering if anyone has ever used a triangular riser? It would fit in nice with the tri"box" shape. Did you notice some sorts of 2ndary air in the form of a pipe with 2 elbows right and up from the fire box?

[satamax]

Aug 24, 2014 14:35:27 GMT -8 Daryl said:

Or maybe a barrel with a pie cut surrounding the riser. The riser would be in the middle. Every other section would be an open chamber for the gas to travel down. On each side of a gas chamber would be closed chambers containing pebbles. That way the gas flow isn't interrupted so drastically and the benefits of stone mass can be utilized. The gas channels could connect on the bottom of interior of the barrel to exit a flue. Sort of a compact mini bench/barrel based more on the masonry stove design.

Sorry to jump in. I need a break.

Daryl, i'm affraid the flow would be uneven. Some chambers would have all the flow of gases, one or two, may be, where there's the least friction and drag. Then the other ones might even act as an insulator. Happens also with this design, but; i think the gases act more like inside of a bell. There's a primary path in the pebbles, for sure. But convection flows between thoses might evenize the heat distribution.

[peterberg]

I'd think Max is right, that's not a rocket stove at all. It does consist of a mediocre burn chamber with a pipe on top and a multitude of convoluted downdraft channels between the rocks. He (the builder) admits it's necessary to take it apart once a year and clean all of the inside. Besides that, after having the stove ran for 18 minutes it does still smoke like mad. No wonder why it has to be completely cleaned annually.

Given a cleaner burning core, this cleaning could be left out for several years. That's where the batch box rocket could play a role when implemented carefully. Namely the exhaust end, somewhere around the burn chamber the space should be empty in order to provide ample room for the gases to enter the chimney entrance. The rocks inside the drum shouldn't be small like pebbles, more the size of 1 liter/1/4 gallon irregular soup cans, all in my opinion.

[thickstrings]

After looking at the video again, the narrator does say it is not a rocket stove, this is why I put this in the other types of stoves section. At about 3:15 the video shows no smoke from the flue and narrator has stated that the wood was not dry, emissions might be another story. Don't know, but the rocks in the video look to be about the size of a large baking potato. Sure it has flaws, but, for what it is ,I like it. Cheap, compact, could be a decent shop heater.

[satamax]

Hi vribidy!

Peter, the first idea i had about using pebbles, i said fist sized. My fists are about the size of a coke can. Yep, between that and a liter, and it's good. If i can scrounge a barrel from the chairlift company, i might give it a try. Mind you, i have one already burned, that i might not use. I haver a core ready. Only prob, too many projects on the backburner!

[aparker]

He presents a rather clever solution to client demands.

It looks vaguely like a vertical batch-box. Could such a configuration be feasible? He says he incorporated secondary air, but he gave no details.

I am not convinced that insulation is required in all rocket stoves, but I apply a fairly loose definition. In this particular application, the heat retained in the barrel would reduce transfer of heat from the riser.

I wonder if he insulated the top of the barrel that he would get less soot on the rocks?

[Daryl]

Aug 25, 2014 22:00:25 GMT -8 aparker said:

It looks vaguely like a vertical batch-box. Could such a configuration be feasible?

I wondered before if that could be done with an outdoor brick oven - have a vertical batch beneath a white oven.  Maybe even build a tandoor containing a vertical batch box with a buffer level overhead to simulate the back wall of the riser.  But wouldn't the positive effects of a double vortex be lost? 

The batch I am thinking of:

www.youtube.com/watch?v=GyR36Frbse4&list=UUD70qRUzo32jSbZj_D7VFsw

[ronyon]

This reminds me of the rockets that are insulated with sawdust and wood chips, etc. The Primary purpose of the insulation is compromised in order to achieve something else.
In this case once the mass is heated it seems to serve the same purpose as actual insulation.
I think others have used barrels filled with stones as bells to good effect.

[satamax]

Aug 25, 2014 2:53:41 GMT -8 peterberg said:

Namely the exhaust end, somewhere around the burn chamber the space should be empty in order to provide ample room for the gases to enter the chimney entrance. The rocks inside the drum shouldn't be small like pebbles, more the size of 1 liter/1/4 gallon irregular soup cans, all in my opinion.

Peter, how would you implement that in a barrel. I have a 6 inch J (well about 6 inch) core that i could put to the test? Laying the barrel above with a tube going in the barrel (like a plunger tube, but inverter )

Do i implement as a bell? With he tube barely going in, above exhaust? Or do i bring it to the top with a top gap? So the gases are forced to go down?

[peterberg]

Max,
As a bell I would say. In effect, the batch box in the barrel more like your green monster. Using a top gap above the riser, exhaust at floor level, something like a sturdy and supported grid above the exhaust opening and the rest filled up with stones. I fully expect the batch box will deliver too much power for just one barrel. In that case it would be also doable to stack two barrels and lengthen the riser so there will be a fairly large top gap still.

As an afterthought: maybe a press grid as used in emergency staircases, placed on a few bricks inside the barrel. On top of that the firebox and the rocks around it.

[ronyon]

So a clean burning core, a second barrel on top of the first,a lengthened riser,an empty space/gap above the riser , an empty space below the core that leads to the chimney.
Sounds like a Dragon heater with Matt's method of stacking mass inside of a barrel bell.

The empty space above the riser would be to allow the burn to complete and to boost the gas speed before the gas enters the area filled with stones, is this correct?
The empty space below the rocks and core boosts gas speed before the glasses leave via the chimney?

[satamax]

Hey guys! Thanks for your replies

Here's a quickie i have made with the old J core. The pipe in the gas bottle is stainless 150mm. Insulated with rockwool. Burns clean.




I was thinking of making a hole in the bottom of the burned barrel i have. Put a little piece of pipe between my heat riser and the inside of the barrel. Rest the bottom of the barrel on top of the blue gas bottle, with few legs. May be make the hole on the side of the barrel base. Then do another hole for the flue. And fill with stone, and atop of all that fit the lid.

The thing is, i a bit worried that the gases might bypass from intake to exhaust. The main question, is how do i avoid this? Rise the pipe from the heat rised a bit inside of the barrel? How much?


I have plenty of grid like this

 


Make the flue protection with it?

Thanks a lot guys.