Hi, Everybody

Just back from a fantastic weekend at Small World.I brought along the Tunnel Stove, a couple of 3 drum setups, the lash-up Drizzler, and a load of pallet scrap, found a suitable place and got burning. What I found out quickly was that the tunnel stove at around 150mm diameter has it’s niche as a “social” stove, the 3 drum burners at 300mm diameter are an awful lot faster. I can run them in pairs, and light the next one with the brands from the last. I produced 8.5 drums, them started the process of screening into grades. The potential grades were:

20mm and above-for barbeques and the Small World charcoal braziers.
10mm-20mm- for the blacksmith
3mm-10mm- for the gasifier
3mm and below- for the compost toilets

What emerged was that dust abatement- even on a farm site is a must -the attached photo shows the state I was in on Sunday morning. I’d got a dust mask-(potential gas filters anyone?) which worked well, but I eventually had to stop because of the amount of crud getting into my eyes. With the resulting softwood char, the consensus was, from barbie users and the blacksmith, “Burns very hot and very fast.”

I did get one brief, brief gasifier run on the Landy- to looks of total indifference from the people I was hoping to impress. I need more theatrics. But all in all a pretty good weekend.

Hey, thats a good look for you UKBrianH.
We must be related on my 1/4 “english” side. About 85% f.r. correspondences between you and me. We could spoof, double a lot of the CCTV nets.

Now when I get to looking in this blackened state and asked, “What ever have you been doing?”
My, response usually is, “Working. Working so hard that I’ve been rubbing the white off!” Makes them stop, pause and think.

We have all ran into this IC engine running disinterest.
I think it is because folks are jaded and expect engines to naturally just up and always run as a matter of course anymore.
They are disappointed why we can’t just made fuels drop-in, turn-key, make the same power.
Many of us have had to resort to very visible, easy for them see, do verifiable carburetors and fuel tanks stripping off and removals. And that leads to many start to stabilized running headaches and many premature worn-out, burnt up cranking starters.

Your theatrics observation is spot on. Why the woodgas breathing dragon at APL. And the system shaken, then rich soot forced yellowed flaring by many to try and get them to stop, look and listen. And at least think, and consider.

My life has gotten So-o-o-o much easier now no longer catering to the casuals and masses and only caring now for the willing to search me out, genuine interested.

Keep up the true burningman for a perpose,
Regards
Steve Unruh

Ah, yes, theatrics. The current startup procedure is: start on LPG, set the mixer valve half way, light up and let it purge out air and moisture, watch the lambda reading, and wind the LPG down and out as it gets richer. The theatrical procedure is clouds of water vapour and eventually a flare from the startup fan on the vehicle battery, and thirty seconds of cranking before the engine catches. With bonus points for a flat battery and burnt out starter motor. I need a couple of flares at least. Speaking of flares, has anyone used one of Steve Abadess’s ejectors? Do I understand that they’re a compressed air powered venturi pump? The implications are that the flare will have a lot of premixed air, and the holy grail pure blue flame will be much easier to achieve than with a fan. I’m not knocking either the ejector or the Drizzler, but I think that just quoting flare colour could be misleading.

I have used an air compressor driven Abaddess style ejector. It works fine… can’t see the flame in daylight… normally isn’t totally blue at night… some purples and reds…

I don’t think flame colour is the best representation either… I don’t like seeing yellows though.

Have a look…

Propane burns yellow, any gas can burn blue or yellow in a Bunsen. Flame colour isn’t the full story.

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Went to the Sunrise Festival over the weekend with the tunnel stove and two 3-drum burners, which I gave away to this gentleman:

and to Steve and Louise who run a rocket stove workshop at the festivals. I made some char, with the same results- softwood char is just too light and crumbly for good results in a forge or barbeque. Sooooooo… how can I get hold of some hardwood? Easy. … in uniformly sized pieces with a low moisture content? Not so easy. Kiln drying has to be the way ahead. The days are numbered for the tunnel stove, but it was never intended to last for centuries- the metal is thin and buckling, and I’ll build a better one. Lots to do.

Planning to get something to take to the Off-Grid Festival next month. I’ve had a bit of a shift towards a different design of gasifier, using 25 litre ring latch drums, plentiful from the factory next door, with a tuyere about 75mm diameter, rather than the scaffolding pipe tuyeres I was using before, approaching the design of Luk’s Drizzler. I’m running it through a simple cyclone before flaring it to gauge the amount of dust and to try out filter media. Hoover bags were a big disappointment- I could tell by just trying to blow through the paper that it wasn’t really what I was looking for. Plain old polyurethane sponge seemed to work… but there’s always the worry that if it catches fire, it burns dirty. Still to try: the oil bath cleaner off the Landy, and dust masks. Throughout are the questions: Where do I stop with gas filtration? How much filtering is needed above and beyond the existing air filtration? How abrasive is the ash- can it do a lot of damage very quickly, or is it no worse than what’s in the air already?

The wide tuyere is working well- I just chuck water or wood chips in to reduce the temperature to orange, and the plain steel end seems to be doing fine. It’s still constant vigilance, but I’ve got to the stage of putting long, straight, wet sticks in as fuel and moderation. I’m hitting a wall getting a demo engine running- I’m aiming for two separate engine systems- the Kawasaki suitcase has a pull start, and is murder to get started, and my preferred option, the Landy, seems to have air leaks everywhere. I’ll get through the wall…eventually.

Good Morning Brian Hughes
You raise an interesting questions critical to all of us real engine running woodgassers:
“Where do I stop with filtration? How much filtration is (actually) needed? How abrasive is the ash? Can it do a lot of (engine) damage quickly? Is it any worse than what is in the air already?”
From direct exprences I can help define the outer edges of these questions.
Where a person wants to center between these still must remain a personal decision.

In 45 minutes of hot dry August Honda Merry tilling between garden rows I unintentionally destroyed a 3 year old small 37cc? fourstoke Honda engine with churned up garden dust. Theses late model Honda outdoor equipment engines use a soft plastic easy snap-on/off air cleaner cover. I’d bumped against a garden stake, snapped off the plastic finger catches, the cover opened up just enough to filter by pass the dusty air. I noticed the problem when I could not shut off the hot Honda engine. Fueling itself on rings by passed hot oil vapors and ignigting on hot glowing oil carbon deposits then in the cylinder head.
I had to load stall kill it to get it to stop. The engine oil was a silvery soup from the aluminum cylinder and aluminum piston dust abrasive wear.

Pevious to that I’d intenionaly ran to destruction as a look-see an old set-aside Tecumseh lawnmower single cylinder four stoke on direct HOT out of hearth charcoal gas. About 2 hours to wear stopping point. I attributed the majority of the excessive wear to the HOT producer gas vaporizing off the cylinder wall lubricating oil.
Next sacrificial Tecumseh goat engine died again at about 2 hours on then cooled, but unfilter charcoal gas. For sure then had to be pulled through ash abrasion.
So setting aside that there is morning settled pretty clear rain and dew washed air, versus afternoon dryed dusty air I’d say about the same horrid wear rates dusty air to direct unfiltered producer gas.
You really do not want to run IC piston engine without adequete air cleaning.
Really do not want to IC piston engine run without adequete producer gas cooling and filtering.

Begs the question of what is adequate?

Depends on who you ask, what are their motivations and goals.

Ask any engine manufacturer and they will give you specs in dust microns sizing per volume of air. They MUST be conservative for reputation and warrantee purposes. Realists they are very conservative knowing that out in actual field service conditions be lucky if even half of their spec is on-going achieved.
Ask most modern Finn woodgassers and they will say, “Producer gas should be cleaned and purified to be clear exactly the same as the air that the engine expects to normally see!”
Ask most hard charging modern American woodgasers and they will say good enough to get the job done!" The job being defines as making the power to compete with gasoline as well as possible, one to one in the same usages.
And this American, ME will say continue to say that the soots that are NOT ashed cored but carbons chains are a power fuel. Carbon is a combustion fuel. Better fuel density as in carbons makes for better IC engine shaft power. And certainly for better raw fuel to shat power efficiency. Diesels!!!

But hey. I speak from the Land of Engines. We been domestically IC engine oil fields well head gas fueling for over a hundred years. We literally tripping over cast off IC piston engines over here. Millions more made every year HERE US and Canada and Mexico in-continent. Millions more across salty sea imported every year. To me, and most Americans an engine is just a tool to get the job done. Job’s acomplished is the first priority. Then you count the costs acomplished. Then you next refine in getting the job done at a lower operating cost on-going. More efficiently . . .THEN. An engine is just a tool to job accomplishment.

You Brian are speaking from “the Land of Lister” engines. Lister Co developed and sent their IC piston engines out throughout the Britsh Empire for 60+ years. Horrid India, Pakistan, Iran, Auzzi and African dusts. Horrid Burma, NE AUZ, NZ and tropical conditions. Lighthouse horrid salts sprays conditions around the world. For near a hundred years you wanted the best lifeboat engines, you wanted British.
The German MAN’s → Japaneese Yanmars → Chinese CangFa’s are a completly different IC piston configuration engine sent out for survive under these same harsh field conditions.
They ALL knew these also could NOT be consumable high tech filtraration dependent. Could NOT be highly trained attentive operator filtration dependent. Both engine families used oil baths as a field seviceable “good enough” able to use the same filter “consumable” as the actual engine crankcase would need.
Thier tricks to engine service longevity useabilty?
Wet sleeve field replaceable easy lubrication iron cylinders liners. Easy lubricating HARD iron pistons. Neither will readily abrasives embed like soft aluminum. Intended consumable/sacrificial cast iron piston rings. Very simple constructions any wench monkey can work on.
Brian these are the two engine families you are going to find at an Off-Grid get-together by the real hard core in the UK.
For these just get the ash out. Cool the char gas a bit and let THESE engines eat the rest. These guys are a special case.
USofA Land of Engines a special case too. We’ll just use up the pass-through engine/vehicles on the way before the to melt-down, “we’ll make more” engine cycle…

The places where an IC piston engine is a rare, valuable, ALL had to be expensively imported, along with ALL repairs spares; so make last as long as possible; THEY DO need to go what you and I would consider a bit overboard crazy for multistage filtering. Have to make those engines last and last and last.
And the over-filtering, over-purifying GTL folk just can’t do the hard costs to end results energy maths. C’s,H’s,O’s and their own efforts. Investors ROI moneys.

“Needs Must, when the Devil drives” will be an absolutely foreign concept un-understandable to most not core American born and bred, and still living. Ha! Many Russians do get it too I’d guess. We just balance out our internal peoples and machines values applications of this a bit differently at times. Same concepts though. Same results.

You OK UKBrian - you DO IC piston engine run your results for a usable purpose.

Regards
Steve Unruh

Hi Brian, A couple of comments. Do not confuse charcoal with ash. Charcoal is carbon and combustible. Ash is mostly carbonates and some silica and non combustible. Ash in an engine is abrasive. Charcoal dust is not as bad since some (most?) burns up when the spark burns the gas.
How much do you filter??? Good question. You can get so much filtration that the engine has a hard time pulling gas. I like what the Aussie research found out in the 1940s and that wool makes a good dry filter. It is easy to make from old blankets, easy to shake out and does a good job in my opinion. The only problem with them is if the gas stream has a lot of water and the filter gets wet. This tends to pug it up quicker. No problem, just replace it with another while it dries out. The open cell foam is also a good insurance that supports the wool and does a secondary job of filtration.
The use of a stick poked into the air nozzle is a good one. The hydrogen in the wood really gives your charcoal gas extra kick to help get your engine started. Try not to use your engine starter as a suction fan. As you note, it will wear them out and I can relate. If your gas cannot be flared coming out of the suction (start up) fan, then it is not rich enough to run the engine. This is a lesson I have had to learn time and time again. Keep having fun,
Gary in PA

Thanks for the replies. The filter that I’d have the most faith in is the oil bath filter, right there in place in the Landy- the general consensus is that they’re large but effective and low maintenance- not quite maintenance free- AIUI, the oil reservoir level needs to be maintained at the sweet spot, and a millimetre will make a difference to the filtration.

I may have given the wrong impression about starting up the Landy- my current practice is to start the engine on propane, and let the running engine suction purge and warm up the gasifier, relying on the lambda readout to gradually wean the engine off propane, and hopefully hand the propane cylinder to someone in the audience with a theatrical flourish.

White ash or black charcoal fines- they’ve got to be taken out of the game. I can see trouble in allowing them to accumulate in the reduction zone, and obviously in getting into the engine. In addition to gas filtration, I’m aiming to screen out anything below 3mm from the feed charcoal for biochar- but as I’ve mentioned before, it’s a horrendously messy, dusty process. I’m hoping to build a dust abatement system using a bouncy castle fan.

The oil bath filter seems to be working well- I’ve had a couple of spark free flare runs with the setup in the photo. The gasifier’s on the left, followed by a cyclone, followed by the oil bath filter, followed by the flare fan- the two drums on the right are just for support. By opening the gate valve for an air bleed before the fan, I can get a premixed flame with a pale blue core and a pink/yellow mantle. The messy bit… there seemed to be a fair bit of mayonnaise in the oil bath from the water that it’s trapping. I can’t speak for the solid debris that it’s trapping just yet, as there was 14 years of atmospheric debris collected in the bottom. The thing is, as long as I keep the oil level constant, it’s pretty much zero maintenance, and more importantly zero judgement calls- I can move on to setting it up on a vehicle. The 3" diameter tuyere quite happily takes a length of 2"x 2" which self feeds into the combustion zone, and an occasional squirt of water moderates the temperature. The flame seems to be quite a lot hotter, and I quite easily boiled up a pot of water for pasta last night My guess… the hydrogen content, either from moderation water, or from hydrocarbons, makes an even bigger difference than I first thought- I thought that charcoal gas was basically CO with a bit of hydrogen- I’m starting to suspect it’s the other way round.

Brian, how does that cyclone work when both the inlet and the outlet are at the top of the pail? Will you dare to run an engine on that yellow flame? It looks like you might be burning some of that oil from the bath!

What I’ve done is cut the outer/inlet pipe to exit sideways to induce a vortex- I’ll try to get a photo tomorrow. I’m not pushing the limits of cyclone technology, I’m just hoping to catch the biggest chunks and condense some water on the cool sides of the drum. Re. the yellow flame… I’m not sure that flame colour tells the full story without specifying diffusion or premixed flame- remember, propane burns with a yellow flame straight from the hose. I’m using a combi boiler fan to get a diffusion flame, which with fresh charcoal, on first lightup gives a practically invisible in daylight pale blue flame. The yellow colour comes when I start adding water, and I strongly think it’s from sodium in the water

Most likely its as Don states, vapors from the oil-bath-filter, if your gas enters it at higher temperatures ( >200°C ? )
In the old day, oil was sprayed into a pre-heated tube and mixed itself with the syngas to obtain “carburated gas”

Re. oil vapours… it’s possible, but the flame colour didn’t noticably change from before I fitted the filter.

Then test your charcoal on a small pot-barbeque
wait for a first batch completely fume-less burning-glowing ( only blue flames )
Then put a few new pieces on it, if it starts yellow, then you have a lot of “undesirables” ( volatiles-tar ) and or your charcoal is not cooked hard enough…
if start with white vapor = moister, white smoke = volatiles…
The blue flames can have a few yellowish tips, but should turn to only blue in a matter of minutes…
( there is always a tiny percentage of volatiles in charcoal )

I’ll try that… one other possibility is the calcium in the tap water- it’s a very hard water area. I might get one of these:

to eliminate the water from the process- it would probably be a useful tool for fast controlled shutdowns.

If I understand that the worst scenario is tars condensing in the engine inlet valves, then surely the test of gas quality is to put a heavy chunk of metal in the freezer, then put it in the gas stream, and see what condenses on it.

Simple test, put a piece of white cotton near the engine in the gasstream…
Black is soot and carbon
Brown is tars

@Don… attached is a shot of the interior of the cyclone- I’ve actually managed to get a photograph in focus, so you can fully appreciate my bird s**t welding in all it’s glory

@Koen… the flame colour when I light up on pure charcoal is a pinkish blue, the yellows and oranges appear when I add water or wood chips- the white cotton test seems like a good way of laying the question to rest.
http://jamclasses.drbanjo.com/static/dimages/cyclone_1.jpg

Brian, that welding comment made me laugh. You are not the only one with that gift:-)