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
