Why my Rocket isn't working?

Dec 22, 2013 14:08:38

Hi all,
Sorry for my english, as it isn't my mothertongue. After long time reading this forum i decided to register.
This is my 2nd rocket stove
- 1st one was made of varmsen plates, and simply damaged after few minutes of rocket fire (varmsen don't like fire...)
So lesson from 1st stove is: rocket stove exists.

My current stove (2nd one) is made of schamotte bricks (230 x 114 x 64mm )
Heat riser inner dimensions are: 16.5*16.5 cm (272 sq cm)
Insulated using leca (75% of height) & perlite (25% of h), perlite covered (2cm) by cob;
Steel sheet around insulation has r= 22.5cm
and the barell is typical 200L one (r = 29.5cm).

Distance between top of HR and bottom of the barell is about 8cm.

Feed chamber is 16,5x16,5cm (the same as HR)
Total lenght of bottom plate inside the stove is 57cm (including feed chamber and HR).
Fire tunnel size: 16.5x (11.5+5.6) => W= 16.5 H= 18.5

Stove is non-insulated from the bottom,
covered by cob around fire bricks.

Distance below barrell for exhaust gases about 8cm (above the cob cover),

Tested:
Yesterday and today in my shed: outside/inside about +5C (41F), floor temperture about +1C (33.8F)...yes, it is very hot December here (stove is expected to work in -25C upto 3 weeks)
Tested with not so dry wood - 6months to 1year stored outside & dry wood as well (old fence rail) & even wooden briquettes....

Don't have exhaus pipes yet, but as i saw on YT people have rockets without any pipes, so i expect my stove should work

Tried to add more fresh air from the front (hole in the front wall)...tried to built higher feed chamber...nothing helps.

And the result is:
it is not a rocket stove: temperature at the bottom (top) of barell is just 110C (about 230F)
It does not sound like rocket, just like.. Cat purr

So the question is: What do i did wrong?
the only i can guess is to try it without barell...

Dec 22, 2013 14:20:18

And HR total height is 8*11.5+6.5 = 98,5 cm.

Dec 24, 2013 05:41:36

A.Z. : The 1st rule is : Don't watch Y-T, 90% is crap !

The second rule is : Do All your test building outside !

The third rule is : Use the very driest wood you can, and split it small !

The forth Rule is : When the barrel goes onto the Rocket Burner Base the vertical chimney goes up ! Never the barrel with out a vertical chimney higher than the
nearest tall object! This is a test to see if you have all the parts assembled tight enough to work. If It will not work then, with the Vertical Chimney in place, then
you have isolated your problem before you added more pipe and made it harder to test!

Before The barrel is moved indoors the Paint on the outside of the barrel MUST BE BURN OFF /Removed Completely !

For the good of the Craft As always , your questions are welcome and Solicited ! Big AL !

Jan 11, 2014 12:25:12

Thank You for basic rules.
My building is more windy than outdoor, no windows, no doors, just holes

How it looked today (outside/inside + 6c).
Additional air supply added (helps for full loads):

http://youtu.be/V4Kua2Bxpvc

Filmed after 20minutes after burn was started.
Inside fireplace : 542C
top of the barrel: 160C

Still no exhaust pipes, not insulated below the fireplace.

Are my temperatures too low?

Jan 11, 2014 13:19:46

http://donkey32.proboards.com/thread/967/rocket-debugging-facts

Jan 11, 2014 13:51:01

AZ,
It looks like you are feeding air in at the top AND the side of the feed tube. Please close the side gaps, seal it as rigourous as you can, any leaks in the core will hamper the functioning of the stove.

Check the manifold, the transition area from the barrel to the horizontal flue. Make that ridicously wide, twice as much as you think is sufficient.

And add a vertical stack, even when you have no bench length at all. A couple of lengths of bare stovepipe will make a world of difference.

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