Woodchips in Tarm 40?

[DenaliChuck]

Does anyone have experience with burning dry woodchips in a Tarm 40?

I like the idea of wood almost being a renewable resource up here in Alaska, but since our growing season is only 4 months (at the most) the regeneration does not keep up with the consumption. Burning woodchips that would be generated from truly renewable plants (willows, aspen) or brush that is a waste product would make the Tarm as close to a zero carbon heat source as I could hope for.

Anybody try this?

 

[jebatty]

The Tarm manual recommends not using small pieces that can fall through the nozzle. My thinking is that if the chips are large, maybe like a brush hog might produce, and dry, they should work. Just so they don't fall though the nozzle or clog the wood gas path to the ceramic tunnel. Try and see what happens.

 

[chrisfallis]

I had a Tarm and found that small chips, bark, floor sweepings, etc. could be added to an existing coal bed that had bridged over the nozzle. If the material does not have enough structural integrity (i.e., sticks, logs, lumber) or "clumpiness" to bridge the nozzle, it will collapse and fall into the tunnel where the gasses are burned. A little glowing material down there was OK, but you don't want the flow of unburnt gasses impeded.

 

[DenaliChuck]

So it seems like loading a base of logs and then adding a cubic foot of chips might work?

Does the fuel burn from the bottom up after it has been gasified? In other words after the logs have burned through would the chips on the top fall through the bottom or does the wood mass get consumed from all directions?

Thanks!

 

[chrisfallis]

My Tram burnt pretty much from the bottom (where the nozzle is) up to the top of the firebox I believe that you could start a "regular" wood fire and once coals were established, shovel in the chips. I think that if your chips had the ablity to lock together, they would be able to bridge the nozzle almost all the way through the burn cycle. I am thinking of chips that are not nice and "mulchy", the kind that my wife buys for her flowerbed, but the nasty ripped and shredded chunks that our electric company gives away after tree trimming in the city. These are one-pass-through-the-shredder chips and are from 1 to 4 inches long with uneven thickness. This stuff interlocks and would bridge the nozzle. As the outside surfaces of the chips burn, the fairly strong draft in the firebox lows off the ash and exposes new heated and glowing wood. The ash flys down through the nozzle and into the combustion chamber where it eventually settles. The only concern that I wouudl have with chips is the high surface area. Once the fire gets going and the chips all ignite, you will think that Stana himself has set up residence in your firebox. Maybe in this case a slightly higher moisture content would be a bonus in moderating the combustion.

 

[DenaliChuck]

Thanks Chris,

Do you think a large holed screen (1" or 1.5") above the nozzle would support the chips and allow complete combustion? I've never seen inside a Tarm to know if this is feasible at all.

 

[chrisfallis]

I'm thinking that something about the strength of wire mesh in a outside barbecue grill would hold the chips up and out of the nozzle. It would have to be split in two sections to pass through the loading door. One quarter inch hardware cloth or window screen wouldn't stand up to the heat.

This would probably work!

 

[DenaliChuck]

Thanks for the advice!

Now...how much volume of chip equals a cord of wood!?!

 

[jebatty]

You've got some good ideas. While the Tarm does burn up from the ceramic nozzle, it also burns/chars throughout the firebox, and it forms creosote in the firebox, which just itself constantly burns off. So the firebox itself, once you get a bit above the nozzle, I don't think is super heated. Give it a try and let us know.

 

[leaddog]

Does anyone have experience with burning dry woodchips in a Tarm 40?

I like the idea of wood almost being a renewable resource up here in Alaska, but since our growing season is only 4 months (at the most) the regeneration does not keep up with the consumption. Burning woodchips that would be generated from truly renewable plants (willows, aspen) or brush that is a waste product would make the Tarm as close to a zero carbon heat source as I could hope for.

Anybody try this?

pm me and I will send you a couple files that I found of a guy burning chips in a tarm. I have burnt chips in my eko80 last winter by shoveling them in after I have a coal bed. worked very good.
leaddog (I'm very busy right now so it might take a couple days to send but will send them)

 

[free75degrees]

wow, this is good news. A house in my neighborhood was just torn down and they also tore down a bunch of trees to make way for a new house. I couldn't believe it when they proceeded to chip up the trees into a giant mount of chips I figured it was another lost opportunity to get free wood, but maybe not.

 

[Nofossil]

My brother burned 600 pounds of dry chips in his EKO knockoff with good results. I think he adds a load of chips after a bed of coals is established.