cube-like wood chunk-ettes for gasifier starting?

[pybyr]

Folks have pointed out to me that having coals near the nozzle is a key to getting gasification going- and that seems to indeed match my gradually increasing experience.

Fine-split kindling, which starts well, seems by nature to go up in flame, with not too much left behind in the way of coals.

Several suggested commercial grill charcoal briquettes as an option.

What do folks think of the idea of mixing a bunch of blocky small chunks of wood in with the kindling, so that they'll hopefully also light off, but burn slower, and then tumble down towards the nozzle as the kindling itself disintegrates. I know that it is important to not _block_ the nozzle, but if they're lumpy and random enough in shape, they shouldn't matt themselves across the nozzle.

Is this something that you experienced gasifier types think I should try- or is it better skipped?

Thanks!

 

[Eric Johnson]

Try it and report back, Trevor.

I think I neglected to answer your question the other day about where the coals should be in relation to the nozzles. The answer is: in, around, on top of, etc. The point is to get red hot coals between the nozzle opening and the wood gas being generated in the firebox. If coals get lodged in the nozzle slot, that's OK, so long as they're not completely blocking it. Those with gasifiers may have noticed that if you poke the burning chunks around mid-burn, you'll get better gasification immediately. That's because you've knocked coals down off the chunks of wood and onto the nozzles, providing the necessary red-hot "filter" through which the smoke must pass. I've concluded that a gasification boiler loves nothing better than a nice bed of coals.

 

[Nofossil]

More research is always good. I agree with the whole coals concept. I've found that a very small amount of kindling will start larger wood quickly as long as it's all dry enough. A couple feet of pallet decking split up small will get a couple of pieces of 2x4 pallet stringer that's split into 2x2 cross section all in flames really fast, and that will ignite a layer of small rounds and splits. My all-time record is 120 seconds from match to secondary combustion, but usually it's more in the 4 minute range.

 

[pybyr]

More research is always good.

Since my dad is a retired research professor (although in applied sciences), and I seem to have inherited the genes... (even though some'd say I resemble a redneck on-line ) I can't disagree with that!

I'll try to use a radial arm saw to whack up some relatively dry wood into some cube-ettes, give it a try, and see what I find. I'll probably try both hardwood and softwood to see if there are differences, and then also try a smattering that combines the two.

 

[antknee2]

I have a good trick to super easy starting and maintaing good gasification in my Ecomoburn , I let the ash build up in the upper loading chamber to about 4''-5'' deep , it tends to make a nice tapered , self maintaining , hot coal burning chamber and prevents a big split from causing problems with a nice secondary burn . This tapered space is a perfect place to drop your small scraps of wood directly into and avoide use of paper to start a fire , if you don't mind using a good old soldering torch directly up into the nozzle .
Anthony

 

[pybyr]

Interesting, Anthony- I tried a method that I'll report on separately below, and got great results, but did it after getting home from being away at a series of things, and didn't do my usual raking of the upper box down through the nozzle. Some folks have said to me that keeping ash out of the top box is important to attaining fast heat up of the refractory, but some combination of my experience and your observations now have me thinking it may not be so clear cut. Stay tuned for my next post.

 

[pybyr]

So, tonight, getting home late after a series of other things to a cool boiler, a cooler house, and a dropping outdoor thermometer, I decided to try my first test of my "cubist" lighting theory.

Took a piece of kiln dried pine about 1x6x30 and whacked it into 1" wide pieces with a hatchet, and then stomped them apart in the middle to half length. Piled them criss-cross over the nozzle. Threw a bunch of very, very short end pieces of 1x6 and 2x6 cut-off spruce and hemlock lumber scraps on top of the bits of pine. Put some very small splits and branchwood over that. Lit it from the bottom with my torch- left the bottom door open- went do to something else for 3 minutes- and suddenly heard something sounding like a diesel hotrod truck thundering past the house- went back to peek at the boiler, and it was Roaring! kicked on the fan, closed the bypass damper, and immediately had a secondary flame the likes of which I'd never seen before.

Not sure how much of this is due to the cubist method, or how much is that I did not have time to rake out the top chamber's ashes, as I'd previously thought was a good idea- but Anthony seems to suggest that the ashes may be beneficial, within limits. Whichever variable it is, this is the best light-off I've seen yet, so one or the other of the factors (or both) seem promising.

 

[Duetech]

I clean ashes down or out every week or so but "so" could be two weeks with dense hard woods. If I burn catalpa it's usually every couple of days and pine is 3-4 days. Like Anthony the ashes in my primary make a "nest" for coals and kindling but my refractory is usually hot because I'm burning 24-7.

 

[antknee2]

You found the sweet spot for lighting the Econoburn , their is no turning back now . Once you let the ash make a pre fire chamber a 100 second form torch to serious secondary combustion is common occurrence for me .
Anthony
PS A powerful torch tip and not being afraid of blasting the wood from the bottom is my secret .

 

[pybyr]

You found the sweet spot for lighting the Econoburn , their is no turning back now . Once you let the ash make a pre fire chamber a 100 second form torch to serious secondary combustion is common occurrence for me .
Anthony
PS A powerful torch tip and not being afraid of blasting the wood from the bottom is my secret .

I have a TurboTorch that goes on the neck of a disposable propane or MAPP cylinder. I like it, and it is good for what it is, and for stuffing up the snout of the gasifier to light it off... but I hanker for even more firepower.... like oxyacetylene, arc, mig, tig. lathes, milling machines BUWAHHAHAA...! I have an irresistible magnetic attraction to metal I am gladly accepting contributions to "Trevor's home for wayward iron"

 

[pybyr]

but my refractory is usually hot because I'm burning 24-7.

suddenly I am realizing that I've come further than I previously thought at insulating and air sealing my 1830's 2800 SF VT farmhouse, because, with my Econoburn, and my willingness to throw on some layers now and then, and even during a particularly cold January, I've been able to run one steady fire per day starting in the late/ afternoon/ evening, let it die down overnight, and then the primitive passive solar carry it during the day.

This is only going to get better once I have storage and once I put the air-sealing in overdrive given some new techniques that I stumbled into in December 08....

 

[antknee2]

I am 100% with you , love working with metal , welding , and keeping lots of random parts around . I feel it is important to react quickly to brain storm's and create things before you forget your ideas .
Anthony

 

[Tree farmer]

What do folks think of the idea of mixing a bunch of blocky small chunks of wood in with the kindling, so that they'll hopefully also light off, but burn slower, and then tumble down towards the nozzle as the kindling itself disintegrates. I know that it is important to not _block_ the nozzle, but if they're lumpy and random enough in shape, they shouldn't matt themselves across the nozzle.

Is this something that you experienced gasifier types think I should try- or is it better skipped?

Thanks!

I use scrap 2x4 chunks over a little fines and found it works as the best kindling so far and reach gasification quickly from a cold start.