Posts : 246 Join date : 2013-12-26 Location : nomad
Subject: Starting the draft for a down draft questions Sun Mar 30, 2014 7:34 am
Caotropheus and Tryin2lhard, how do you get the down draft started on a stove with the paper? Do I light two fires? I am working on a horizontal drown draft today.
Well, I spent most of the day on this. I had to not add any additional air after the main burn chamber because the fire was drafting through the openings. Which was kinda cool in a way. I am going to start all over...some other day.
I am confused about the paper. Do you start it before or at the same time as the main fire?
Another question, it was in the 40s here today. Will it be harder to get the down draft going in a colder climate?
caotropheus Subscribers
Posts : 333 Join date : 2013-10-07
Subject: Re: Starting the draft for a down draft questions Mon Mar 31, 2014 2:28 pm
If you see my videos, my idea of downdraft rocket stove is to insert the "L" shape downdraft rocket stove core inside a "big drum" that will work as the heat exchanger. The top part of this "drum" has to be a couple of inches above the rocket stove core. Chimney is inserted at the top of the "drum", also above the rocket stove core. Like this way you have always have enough draft to start a fire without smoke exiting through the stove opening. Take a look at my videos on youtube
gadily Moderator
Posts : 1477 Join date : 2013-12-08
Subject: Re: Starting the draft for a down draft questions Mon Mar 31, 2014 8:01 pm
for my knowledge in downdraft has to be started one way or another
either by lighting 2 fires one to warm up the exhaust until it pulls through from the main fire after that it shouldnt have any problem in continuing after this or have a main fire burn with a direct control to heat the exhaust before switching to downdraft
twistedkarma
Posts : 178 Join date : 2014-01-04 Location : East coast USA
Subject: Re: Starting the draft for a down draft questions Mon Mar 31, 2014 8:20 pm
its starting a syphon, but upside down.
Hitchhiker
Posts : 246 Join date : 2013-12-26 Location : nomad
Subject: Re: Starting the draft for a down draft questions Mon Mar 31, 2014 11:34 pm
caotropheus wrote:
If you see my videos, my idea of downdraft rocket stove is to insert the "L" shape downdraft rocket stove core inside a "big drum" that will work as the heat exchanger. The top part of this "drum" has to be a couple of inches above the rocket stove core. Chimney is inserted at the top of the "drum", also above the rocket stove core. Like this way you have always have enough draft to start a fire without smoke exiting through the stove opening. Take a look at my videos on youtube
I did watch the one. I will search for the others. It does look like an upside down rocket.
Hitchhiker
Posts : 246 Join date : 2013-12-26 Location : nomad
Subject: Re: Starting the draft for a down draft questions Sat Apr 19, 2014 1:10 am
This what happens when I have a few too many spare tin cans lying around in the recycle bin. I added a outer layer to the standard riser. Sort of like a gasifier. This little experiment has me leaning more towards using channels than bells when I build my little brick ovens.
Yes, it was falling apart. Yes, I shouldn't have used the tape but I threw this together at the last minute.
Hitchhiker
Posts : 246 Join date : 2013-12-26 Location : nomad
Subject: Re: Starting the draft for a down draft questions Sat Apr 19, 2014 4:16 am
I did two versions of this today. One with holes at the bottom of the outer riser and one without. I leaning towards making this more of a gasifier stove by using the riser/chimney and centering the riser in the midst of the coals.
T2H Admin
Posts : 913 Join date : 2013-10-07
Subject: Re: Starting the draft for a down draft questions Tue May 06, 2014 3:37 am
In one of my downdraft designs I had to start a small piece of paper on fire in the chimney section.
I had built in a door just for that reason.
Glad to see you adding your own ideas to the downdraft theme.
Looking forward to your developments. Would like to see the internal parts along with your description of the flow of gasses.
Hitchhiker
Posts : 246 Join date : 2013-12-26 Location : nomad
Subject: Re: Starting the draft for a down draft questions Tue May 06, 2014 4:36 am
I decided to experiment with the rising gases from a standard fire. The riser was extended down to about an inch from the bottom of the can. I surrounded the riser with a cylinder that reached to an inch from the top. The gases from the top of the can were drafted down to the bottom and then up the riser. I tried this with and without holes in the bottom of the outer cylinder to see if the "gasifier effect" made a difference.
I was attempting two goals: increase the heat in the can (because the gases are staying longer) and downdraft using a riser/flue instead of a second combustion/burn chamber.
Possibly down the road, I would like to have one burn chamber with an elongated riser ending below the main floor. That would eliminate the need for two chambers and drafting issues. Because of the natural draft, I did not need to start a secondary fire. By the way, the smoke did clear up a bit after the fire got going.
Honestly, this was a little science experiment to see what would happen if. This is also my ongoing effort to try to figure out the Intesifire. I will search for a picture. The set up is pretty basic.
gadily Moderator
Posts : 1477 Join date : 2013-12-08
Subject: Re: Starting the draft for a down draft questions Tue Jan 05, 2016 9:11 am
im about to start another 2 versions of a downdraft system as i already have one version on the site
I think I know the answer to this question so im giving it a go and see if I can create the downdraft and also make it self starting as well
will post on the builds as soon as i can do but im already building both versions and only short of some materials to finish off both versions
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Subject: Re: Starting the draft for a down draft questions