my first prototype which seems running very well

[fdelam]

hi all
first, sorry for my english, french people are known for their bad english.
i'm playing with rocket stove for 2 months now in search of a source of heat for my home instead of an old fuel heating device that sucks me more than 400l of fuel only for hot water from april to september.

i put a hand on a set of spare firebricks which comes from a porcelain factory and i made this which is my fifth prototype:


my goal is to have a clean wood burning device with a cooking table instead of the Saint Georges cast iron plate and exhaust to a butt warming bench.

i don't know how to be sure i have a clean wood burning device.
the only parameter i can measure is the exhaust temperature at the base of the stainless steel tube. max temp is 325°c (record) but it often run at 260°c.
the other thing i can see when i dismantle it to do some modifications is the color of bricks and inside the stainless stell tube which is clear brown, no soot or tar inside, the bricks of the burning tunnel are pretty clean.
is the color of the exhaust tube a good indication of the quality of combustion ?
when i will have found my final setup and then put insulation and masonry around this, will it modify a lot the quality of combustion ?

many thanks in advance for your more experienced advices.

[Dan (Upstate NY, USA)]

Your English is OK, it is not like any of us can speak French well.

I would say that the color and quality of the exhaust(smoke) leaving the chimney on the OUTSIDE of the house would be the best indicator of a clean burn.

Are you using an exterior chimney to make draft?

I worry about all the cracks in the fire brick not being sealed well pushing a lot of CO2 into your home.

Are there any French sites for things like this?

[fdelam]

thanks for your reply

there are french forum talking about rocket stove, by example www.ecologie-pratique.org, i'm reading it.

i choose to post here because i think there are more experienced people here, rocket stove are a bit new in france and as i can read here, there's a more scientifical approach of this type of stove here.

i know the spirit of rocket stove is to make a very efficient but cheap source of heat, and it's my goal too as in my present economical situation i cannot even afford the rocket stove book.

as a technician, i'm looking to make something different of a classic rocket stove with cooking area and maybe an oven and well fitted for the house where i'm living.

i made 3 prototypes inside the hearth of the chimney but not directly connected to the chimney pipe.
for the 4th, i made an adaptator for the 1m x 0.2m chimney pipe where i can plug a 200mm pipe :


so now, i'm using the 9 m heigh chimney natural draft. i think it sucks all between the bricks, even the CO2

it's a very old house and very well ventilated, too much for my taste , and i'm working on this point too.

my CO2 fire estinguisher is near the stove and i have a detector in this room.

[kirkerik]

Wolf has agood point on the cracks. Im glad to hear that they are sucking pretty good anyway. That has been my experience in most spots on the stove but once we measured a slight pressure just after the heat riser and down draft barrel.

It's not a bad idea to take alittle clay sand grout and apply it to the cracks a little at a time building up after they dry. That should help seal things up and likely improve your combustion. Dillution air is best sealed out for many reasons...

I bet that the lighter in color that the residue is on the interior can indicate cleaner conditions. But it's just a clue! I have seen the interior of my heat riser to be very light gray or practically white. Its well insulated and low density insulating fire brick.

I think it will help to make your heat riser taller.

[fdelam]

thanks for your reply
it's sealed now with clay and wood ashes mix and it's sucking a lot more at the intake.
exhaust temp is higher, around 350°C.

i have to modify my design to keep warmth inside the house instead of burning birds on top of the chimney. ;D

maybe it depends on the design but at your sense, what is the appropriate temperature to enter in a warming bench ?

[Dan (Upstate NY, USA)]

The bottom of my barrel on the outside (before it enters the bench) gets to about 350F or 180C.

I would imagine the gases inside are hotter.