[TheForge] OT - wood stove catalytic combustors, heat extractors, etc. (was: Barrel Stove Kits)

[Jerry Frost]

I'm still working my way UP to only having senior moments. <grin>

Catalytics are afterburners, the idea being complete combustion is a win 
win, more heat and less polution. Catalytic stoves typically place the 
catalytic between a baffle and the top of the stove. Once hot you close the 
bypass and the partially burned exhaust gasses pass through the catalytic 
converter and are then burned in the gap between the baffle and the stove 
top.

What happens to make them fail is plugging the catalytic either simply by 
age or closing the bypass before the catalytic is hot. I don't know why but 
a plugged catalytic is actually worse than no catalytic for soot and 
creosote.

Multiple burn zone stoves do the same basic thing by simply supplying fresh 
per-heated combustion air in designed zones. The space between the baffle 
and stove top is almost a universal zone in multiple zone stoves. It still 
won't work until it's good and hot BUT so long as it doesn't go nuts a 
little burning creosote only falls onto the baffle and is burnt in a 
controlled manner. an uncontrolled stack fire often involves a torch-like 
flame 15'-25' high out of the stack. This is BAD.

Putting the "T" in your stove pipe isn't a bad idea, it'll work like a drain 
cleanout. Just be sure to use either the heavy gage or SS for the "T" and 
section above it. Anywhere there is a connection other than a simple section 
joint there's a chance of air leaking. An air leak into a stack WILL cause a 
stack fire and it'll be uncontrollable from the start. Dry carbon soot will 
burn though not as spectacularly as a good layer of creosote.

Having an ignition burner of some type in the stack or a designated burn 
zone might be a super idea. I've never seen nor heard of one so I don't know 
and this can be entirely too dangerous to speculate without making sure 
nobody thinks I know what I'm talking about. I have done similar with coal 
fires at public demos though. I make a crater shaped mound and poke a hole 
to let the fire burn off the smoke too but sometimes it takes too long to 
get the smoke burning flare going so I just hit it with a Bernzomatic torch 
to get it burning. Once it's hot it'll go on it's own so I just light it 
with the torch. That experience makes me think your idea may be well worth 
some CAREFUL experimentation.

The kit I bought is either the same or really similar to a Vogelzang kit. 
I'll shoot you a pic of my stove and heat exchanger off list so you'll have 
an idea of what I'm using in the shop. I haven't painted it yet but forget 
"Stove Black" it's basically soot or suspended soot. I use stove paint or if 
I'm feeling colorful I'll use header paint from the auto supply. Stove paint 
is easy and intended for stoves so that's the only thing I recommend. On the 
other hand I AM open to hearing about other stove coloring products. I'd 
have to pass on oiling the stove, especially a barrel stove. You WILL cherry 
it out now and then, meaning parts will be well into red heat and oil is 
just going to burn off. Stove paint is designed to take it at least if you 
don't cherry it out all the time.

Jer
----- Original Message ----- 
From: "Bruce Freeman" <freemab222 at gmail.com>
To: "Blacksmithing List Sponsored by ABANA" <theforge at mailman.qth.net>
Sent: Thursday, October 14, 2010 5:02 AM
Subject: Re: [TheForge] OT - wood stove catalytic combustors, heat 
extractors, etc. (was: Barrel Stove Kits)


> Jerry,
>
> I've been having senior moments all my life, but they're more frequent now 
> 8^)
>
> Good info.  I'll skip the catalytic afterburner.  I'd concluded that
> anyway after contacting the manufacturer, which now recommends they
> ONLY be used in stoves designed for them.
>
> I am thinking of putting a T in the flue, with a cap over it.  Not
> really a clean-out, more an inspection port.  In fact, I expect NOT to
> have to clean the flue annually, because I will not be heating my
> house with this stove.  It's for warming my garage shop, so -- lower
> temperature, fewer days running, fewer hours per day.  But it would be
> nice to be able to check up on creosote easily.
>
> I'm also wondering about a NON-catalytic afterburner.  When starting a
> coal fire in a forge, I always break a hole through to the tuyere so
> that a flame shoots through to burn up the smoke.  Imagine a small
> burner (miniature of the aspirated burners used in gas forges) that
> would shoot a flame into the flue whenever there was smoke.  Should
> burn up the smoke quite reliably.  Just a thought at this point.
>
> My stove is identical to the Vogelzang standard that's sold by HF in
> this state.  That suggests to me that it's legal here, but I suppose
> it's not certain.  But in three test burns in it, the flue gas ran
> smoky only a very short while, so I don't expect problems.
>
> On another subject, I've looked up stove black in "receipt" books (as
> they called them) and found them mostly graphite and/or lamp black,
> sometimes with oils or turpentine.  So they apparently are for
> appearance only.  On that note, I painted my stove with vegetable oil.
> That will turn black-ish when it bakes on.   It may remain sticky in
> places, burn off in others, and turn to soap where ash hits it.  But
> on the whole it should provide some protection against moisture.
>