Another possibility - depends on what type of woodgas shut-off valve you’re using?
If that valve leaks through just a little, the gasifier could have been slowly smoldering - producing tary gas while you where running gasoline???
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I think the valve is quite tight, the throttle is for a v50.
It worked fine the day after I ran the last load on petrol.
It was after I drove with the bubble can as it was tar the next day.
Can you turn your burner upside down and have a nice flame? (like a welding flame)
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I used to be able to do that, but the torch quit on me (plastic junk). I use an old brass valve with no nozzle now. I let a rich yellow flame get sucked down into the charbed at lightup.
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Ok, I thought it would be possible to reverse this one, but there is a yellow flame on this one.
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Yeah, some cans don’t like being upside down.
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From what I understand from what is written, the restriction is the main cause of tar in the engine?
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Even the charbed has much to do with the tars, even a perfectly pre-filled hearth with good charcoal needs a lot of time settling, get a good mix by small and bigger pieces of charcoal.
Could it be it keeps smoldering some time after shut-down, when next start-up wood chunks pass way down the nozzles?
(Happened to me sometimes with the Volvo)
How is gas looking when start up, and even if you run the blower some after shut-down? Yellowish traces/smoke?
And also what JO says, old tar in piping/filter?
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Jan, a tractor or work machine behaves much differently than a car on the road, so the tractor operates a lot with little load, then suddenly it needs a lot of power, but if we look at what happens in the gasifier, a small intake of gas causes the hot zone to cool down, and then suddenly increased consumption, which creates a negative pressure and tar gases and water vapor, which are located in the upper part, make their way through the already partially cooled coal. Would a smaller restriction opening prevent the passage of tar gases? I don’t think so, I have an advantage on my diesel tractor, because at low load I can throttle the air flow and thus increase the amount of gas, otherwise some of the pin is lost unused, but the gasifier remains hot and I haven’t detected tar in the pipeline yet, I also think that a large filter made of hay and sawdust packed tightly, catches a lot of tar.
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A tighter restriction can help, but like Tone sayd, its not a guarantee.
In my experiances, l got most of my tar from bridging. When a bridge forms, there is no longer a supply of wood and the gasifier uses up its charcoal. Sometimes down to ths restriction. Then the bridge collapses and there is no way to burn the tars anymore untill the charbed is astablished
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I cleaned down to restriction today, it looks like it has been very hot just above restriction, very gray ash in the middle.
I haven’t seen anything like that on the Cheva.
This also has a high temperature at the top of the hopper, around 80-90 degrees C.
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I wouldn’'t worry too much about the hopper temp. It will lower as soon as the funnel fingers tar/seal up and slow down the hopper’s internal circulation.
I think that would happen to any gasifier after shutdown if a little oxygen was present.
What’s the distance between nozzles and restriction? Looks a lot shallower than I imagined, looking at your building pics. I was under the impression you were running pretty much WK-depth.
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It’s about 16cm, measured today.
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Good Morning Jan A.
Up on post #79 you said something very meaningful,
“Yes, the problem is that I am standing in the middle of a forest.”
You were relating your frustration of being surrounded by wood but with none gasifer useable for you.
I do not know if you have any interest or experiences with the salty Seas and Oceans. It is the same. Surrounded by water but none fit to drink to maintain your life. I have life-long read in-the-ocean survival experiences stories. Those who could convert or capture a just a little bit, useable, survived.
The same here in our mountains (or yours along the Norwegian border). Surrounded by woods - over half of the year too wet to be able to use to easily life-preserving warm with.
Yet . . . those who can make-it-work have indeed survived. Having large wax candles pocketed is the trick here. The one rare waterproofed match lights the candle. The candle provided the continuous heating to dry the fire starter tinder. The next year done better. Even thrived, thereafter. No more one-use matches:
Has the needed cotton char-cloth too.
My point is your Iller has the ability to pre-dry condition at least some of it’s it’s own fuel wood if you shift designing to make it so.
“Let no Calorie Escape un-Worked!” becomes a make-work mantra to achieve this.
Regards
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Is this not the essence of being a prepper? If I were fortunate enough to have Jan’s Iller I would always have a bag of Bobmac rocket fuel in reserve and a design that would allow me to dry more fuel with the heat from that bag and on and on. Who would go out in the woods to cut firewood with only one saw or at least a way to free it when the bar get pinched? There is always something out there waiting to bite you in the ass. Always try and anticipate what it could be and KISS it.
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It wasn’t the wood I was thinking about in the middle of the forest, it was that I didn’t have enough electricity for a bigger spot, as Cody suggested.
I have firewood for Illern at home, but I didn’t take more than 2 sacks out to the forest, and Illern ate a little more before I had finished driving.
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Don’t know if I showed these, but it was before the Illern broke again.
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Your pictures of the hearth showed a familiar sight. I have seen this often, more often in charcoal gasifiers. Ash pugged charbed. When a litle ash starts acumulating, it gets to this point quite fast. And at this point you basicly dont even have a charbed anymore, whatever gasification happens happens above this ash plugged charbed.
I have since learned the importance of slipping char. The charcoal must be moveing down and away slowly to poop out any ash pockets.
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ok, so I have too far between the nozzles and restriction, or what is wrong?
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I dont think that shuld be a problem. Most gasifiers still work ok even if they are on the big side.
Whats your grate like?
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