[Stoves] RE Clogging chimneys.

[Vreni Uhle]

Dear stovers,

there is no miracle , just plain good practice and a lot of experience of people who know more than I.

First of all : Firebrick lined burning chamber. Mine is 45cm wide, 60 deep and 45 high + a 15 cm dome on top.
The burning chamber is insulated so as to stay hot. A metal box does not work, since it takes the necessary heat out of the fire.
The hot burnt gases leave on top of the dome and give their heat to the (metal)heat exchangers above. 8 Pipes for air, 4 double walled ones for water heating.

Second: No grate, the log burns best in it´s own ash bed.

Third: Primary and secondary air are preheated between the air xchangers. Primary, about 70 %, is led into the b.chamber short above the ash level on both sides of the bc. Secondary air is added just below the "dome", through 2 offset pipes pointing downwards at roughly 35 ° and creating a hot swirl above the log. The swirl keeps the smoke from leaving the hot chamber immediately, giving the tars a chance to burn completely. 

We live in a cold and damp valley 8 km from the Mediterranean Sea. Our wood is mostly white pine ( pinus halepensis ) 
We dont split logs under 40 cm diam, which makes it a lot easier. The smaller branches prepare the embers for the big log.
Before we go to bed, we put one big log in, close the dors, wait  1/4 h to let it catch a good fire and then almost close the primary and half close the second. air. This gives us an 8 h burn, sometimes even longer. Next morning another big one on top and off to work. The children find the house warm and enough embers when they came from shool at 15 h and just added another big one.
Saterday morning ash removal. Cleaning the heat exchangers  at the most 2 a year. 
The smoke stack is simple sheat metal running through the upper storey´s bathroom horizontally. cleaning every other year. 
Mostly white fly ash, sometimes grey, never black.

b.r.
Rolf from hot Spain  



On Thu, 14 Jul 2016 10:45:42 -0500
Paul Anderson <psanders at ilstu.edu> wrote:

> Dear Rolf,
> 
> Always good to hear success stories.  Now to understand why it is 
> working differently.
> 
> I suspect it is because of the primary and secondary air ducts. Would 
> you please provide details about those ducts.
> 
> Another factor could be if it is virtually always with a hot chimney, 
> such as if burning wood continuously 24 hours each day. Please tell us 
> about your operational details.
> 
> Using DRY wood is important.   Is your wood "exceptionally" dry? (such 
> as if you live in a desert area).
> 
> Thanks,
> 
> Paul
> 
> Doc  /  Dr TLUD  /  Prof. Paul S. Anderson, PhD
> Email:  psanders at ilstu.edu
> Skype:   paultlud    Phone: +1-309-452-7072
> Website:  www.drtlud.com
> 
> On 7/14/2016 9:10 AM, Vreni Uhle wrote:
> > Sorry Frans,
> >
> > we burn  pine all the time in our  brick stove.
> > It takes whole round logs of 40 cm in diam. and 55 cm long and never builds up any residues except for ash.
> > It has a single wall sheet metal pipe 20cm diam, but good 1. and 2.ary air ducts.
> > The wood must be dry and the fire hot!
> >
> > I prefer pine to any other wood.
> >
> > best regards
> >
> > Rolf
> >
> >
> >
> >
> > On Thu, 14 Jul 2016 02:18:21 +0200
> > "Frans Peeters" <peetersfrans at telenet.be> wrote:
> >
> >> Dear Paul and All,
> >>
> >>      Pine wood is most dangerous for 10KW heating stoves .
> >>
> >> Brick chimneys of  0,2x0,2x 7 m get a stop at 5 m hight, from destilated  resin:
> >>
> >> Also birds  can obstruct a chimney .
> >>
> >>   
> >>
> >> Regards
> >>
> >> F.
> >>
> >>   
> >>
> >>   
> >>
> >>   
> >>
> >>   
> >>
> >
> 
> 
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-- 
Vreni und Rolf <vruhle at hotmail.de>