120c is much too high for reheated gas! Max just pointed out the maximum point they can take.
The idea is you cool the gas as much as possible, then coalest all the foggy droplets out of it, then reheat just a few deg just to dey the gas. Nothing more, as hot gas looses its volumic energy.
Allso, l think a good idea is to paper filter air/gas mix rather thain just gas, becouse adding dry air to the gas, dries the gas, so less reheat is neded. Such system l had on my Seat.
The temperature has to be high enough that as the gas goes from the rear of the vehicle to the front, it does not drop back below that dew point. I would suggest that steel piping from back to front requires more heat than plastic
You have to add heat to the air to get “dry” air. Atmospheric air will be damp compared to gas that has gone through the gasifier and cooling process. In cooling I never come close to atmospheric temp.
I don’t think it is a good idea to mix air and gas in the reheat box before the paper filter. Any sparks through the hot filter into the box will cause an explosion. Then there is the idea, that you mix the air and gas in the reheat box, and you won’t know if you have the proper mix until the mix travels to the engine compartment. Reaction time will be slow.
Can you explain the air/gas mix system you had on the Seat?TomC
Hi, Kristijan!
5.2.2017
O, Yeah! You are not the first one who forgets two important facts.
If you try to do that in the motor compartment, like M. Larosa and some others, you will lower the the temp toward the dew point with cold air. That is unhealthy for the paperfilter.
The filter is cold at startup.
Additionally you provide a bigger volume of bang, bang mix!
If you do it further back, the bang mixture volume is further increased…
The reheating source is in the middle or back of the vehicle.
Keeping the gas paper filter on the gasifier, it will be warm when the gas reaches useful quality. With direct heating.
The gas line keeps cleaner as the final filtation takes place before entering the transport line.
Mixing at the motor.
Those last few statements from Max , Tom and K thanks for the filter info that is the path too build by, I noticed picture was missing the proper conections, like max said filter back by the heat and by time gas gets too motor its back near ambiant temps.That is quit a peice of knowege Too reheat not much and have paper filter working.I am heading too note book of paper filter path. I know Waynes filter is good enough but the thought of mastering or makeing a paper filter work with wood gas is excellent hard too pass up capabillity.Thanks Again.
Tom and Max, l can only speak from my experiance and ideas being born in my mind. Again, it is never my intention to be a smartass.
Tom, atmospheric air has about 60% moisture. Woodgas at near room temperature has 100% moisture. Mix the two, you get a mixture of 80% moisture, wich is well without dewpoint eaven without a reheat.
But like you sayd, reheart shuld still be sufficiant.
My Seat had a small paperfilter on the intake manifold. I had a gasmixer before it and thats about it. Its true it was charcoal powered bus i did add lots of water at some point, and sometimes had moist charcoal, and while the cyclone and sack filter were wet, the paperfilter was dry.
Hi Kristijan
The water contained in the gas is deposited in the cyclone or in the cooler?
Thierry
Since we are talking about a charcoal gasifier, the gas holds just enough moisture to be moist. But yes, a few drops get out trugh the cyclone and filter.
Hi, Kristijan!
5.2.2017
The numbers are arithmetically quite OK!
But, in practice mixing wet woodgas and normal % humid air has never been a success in the same filter, (not even separate) just ahead of the motor inlet!
It may have to do with “vacuum shocks” (in the gasline) when stomping the gas pedal into floor position; the relative humidity shoots to 100%+ momentatrily (in the arriving gas) and condensing on the filter… Fresh air does not affect waterdrops.
After all, “normally” woodgas arrives 100%+misty into the motor-room!
Wet woodgas and normal % humid air can be mixed together just ahead of the motor inlet, but just in smooth (water-resistant) tubes.
…
To use paper filters for woodgas has to be done with reheated woodgas (after the cooler and wet filter) where the woodgas leaves the reheater, with the paperfilter “bucket” kept warm!
/Thanks Max, Just too recap the set up with out adding any outside of the gas stream hot air. The reheat mantel will work. Gas comes out cooling rails and wet filter about 150 f summer then comes through mantel that is keep near the heat about 220 f before it goes through paper filter and on up too the motor. Am i missing any thing there.?
Hi, Kevin!
5.2.2017
That is good for summer conditions, though you need not to keep up the temp after the paperfilter. Then as cooling again, from that 150F downwards it will become wet again, but it does not matter for the paper filter was passed dry…
Keep the paperfilter bucket warm!
Kristijan;
A person who has ideas and actually builds them can NEVER be considered a “smartass”. It is those who are always talking about things and doing nothing, win that name. Kind of like me this winter.TomC
Max, you make lots of sence with that shock wawes in the gas! They are not to be neglected! I see theese effect any time l decelerate fast. Te engine wants to sall from too rich mixture becouse of the inertia of the gas.
Yep, my rpm-needle is heavy too. When in neutral it can’t be dropped from too high too fast or it will hit the bottom.
Hi, Kristijan!
5.2.2017
For Kevin I tried to describe the water condensation in the motor end of the gasline, activated by vacuum “shocks”.
The dynamic pushing in a gasline is “exclusively reserved” for all T-mixer users!
It does not affect double-throat dispenser users at all.
Thanks Max i got the whole picture of how too make that all work, Thanks for shareing your experties experiance. I am about half way too driveing on wood I just keep saying few more days. A lot of pluming is getting wired up now today.caint be too much longer, too be fire in the tube.
Yes Max,
I understand what you ment. Relative humidity will rise when pressure highers in shockeawe. I just wanted to show how the chockwawe effect other things too.
Can it be that
The absolute humidity of the coal gas is in principle very low if the reactor is maintained at high temperature (over 1000C).
While in wood gas the water vapor is more abundant.
What do you think?
Absolutley. Wood has exess of chemical water that is able to crack to H2, while charcoal has not. This is why we can add water in a charcoal gasifiers reaction zone.
If we had 100% conversion from wood to woodgas, useing wood with 0% moisture, the gas wuld be dry. But, we burn wood with at least 10% moisture content, and some water produces with incomplete wood to gas conversion.
Coal is often the simplest solution!
Bump!
Tom, what’s happening in Crivitz? You’ve been quiet for a while. Snowed in or busy mowing the lawn? Maybe welding secretly? (which is forbidden)