This is what I use .
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hello Wayne
How does this device measure the ratio of air to gas? I do not see any probe (lambda!). where does she connect?
I suppose this device reads the air / gas ratio to manually adjust the air restriction valve?
Thierry
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Hello Thierry .
Glad you brought that to my attention . On my vehicles I just tap in to the wire that runs from the probe sensor to the computer .
Kristijan vehicle may be old enough it may not have the sensor. He will need to also get the probe and mount it in the motor exhaust .
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I never noticed any smoke in my fuel hopper and no air is added to the hopper. Of course my lid seal could leak.
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Hi Kristijan, the hottest gas is going into the clycone first, maybe have the gases go into the tube heat exchanger first then into the clycone filter. That way the bigger pieces of char can collect in that area to be removed at the clean out. The finer soot and ash will go though the slycone and be collected in that clean out. You have to have two clean outs one before the clycone filter and one for the slycone filter. Both are separate from one another. My crude skiz did not make that clear.
Bob
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Jeff, have you shown us a sketch or something of this gasifier? Is it charcoal or wood? TomC
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+1. After seeing that, maybe I wasted my spare propane tanks on the foundry⌠
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Tom, a talented member made a drawing of it. He has a topic with his drawings on this forum. It is charcoal and has been at Argos.
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Wayne, thank you. The car has a o2 sensor, but the condition of it is questionable. Plus its most likely narrow band, and l understand the device needs a wideband sensor?
Jeff, neither have l, using pure engine grade charcoal. But l will try to make this sistem dual fuel, so it is possible to mix a few wood chips in, or use lower grade char.
Bob, in this case, caution must ne taken not to plug the pipes with char. The space limitation allso means small ash binsâŚ
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After a couple of days scraching my head, turning the cyclone in every posible direction on paper, combineing with cooler tubes, drop boxes, ashdoors etc l realised l dont even need a cyclone!
Sack type hot filter. But instead of the glass fibre sacks just hanging down in a filter box, they are suspended in pipes surrounded with intake air. Its a combo of a heat exchanger and filter.
The right high density glass fiber fabric (the one Johan from Sweden used on his Volvo) is teribly expensive, $200+ for a 2m2 peace, but the corse glasfibre canvas l used on my Chevy is cheap, around $5 for all the sacks l need. Its not 100% effective but neither is a cyclone.
This way the dust can fall down and be raked out trugh one ashport that reaches trugh all the gasifier. Sacks threaded in individualy from the bottom.
Any thod?
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Hi Kristijan, the sack hot filters, once they installed and the gasifier is weld up how will you service the filters if needed. For instance one develops a hole in it. The ash clean out are is about 2.5 inches in clearance at the bottom, and 1 inch at the top. May be I am not seeing something in the two dimensional drawing. I see how you thread the sacks filters in to place but not the attaching them at the top of the tubes. Are the sack filters on flexible pipe or a spring like Patrick Johnsonâs filter barrel? that can be threaded into the top of the tube?
This is your best compact idea yet. You could still have a slycone filter up front in the engine compartment for the final filter.
Bob
Bob makes a good pointâ is there any reason, that some parts couldnât be under the hood (bonnet or what ever you call the engine cover). TomC
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Hi Kristijan,
it maybe sounds a bit silly now that you just presented your idea, but I also thought about not using a cyclone at all.
As Bobâs point is right, I would suggest something different:
The flow velocity in the heat exchanger is lower, so bigger parts like pieces of char an clinker might settle down by itself. If you add some direction changes to the flow path, smaller particles might be sorted out as well (principle of the WW2 baffle plate cleaners). They just have to be arranged so that all particles fall down in the collecting box.
Of course the fine particles, dust and ashes are still in the gas. I would use a fabric cleaner after the cooler for them. No cyclone before that cleaner, opposed to what Bob suggested.
Why? You donât really need it here. It creates a pressure drop, many bigger parts are already sorted out and a fabric cleaner works better if there are more coarse particles and not just the very fine dust left to filter. This way the filter cake is less dense and falls off more easily. More char particles also makes the filter cake less sensitive to some moisture in the gas. A fabric filter can be made âbreathableâ in some respect, so some parts of the filter cake falls of from time to time, extending the range between cleanouts.
Downside: You will collect more dust in the filter tubes which you may have to clean from time to time.
In brief: Suggested setup: Gasifier, combined heat exchanger/baffle plate cleaner, cooler, fabric filter.
Til
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Bob,
Kristijan is using his old camera, which his kids obviously dropped in a glass of milk. If you klick on the pic two times, you can see the perforated tubes. From what I understand the tubes will be threaded in through the bottom floor with somewhat larger bushings and top ends sealing towards the heatex flanges.
Kristijan, am I getting this right?
I have no idea what kind of heat this kind of fabric can take. Heat and live char would be my main worries here. After all itâs pretty close to the grate. Other than that it seems a very clever and compact design.
Also the threaded bushings in the bottom could have nipples installed for blowing compressed air in. Not even pulling the pipes and socks would then be necessary for cleaning.
Edit: @Til, what about moisture in a fabric filter downstream the cooler? Wouldnât the filter get clogged if Kristijan is planning to run water injection or wood in this gasifier?
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Hi Jan-Ola,
indeed a problem. Fabric filter downstream of the cooler can deal just with a bit moisture, but not wet gas.
In my thoughts this is a charcoal gasifier, with some water or wood added just to create enough hydrogen using the excess heat. Here, the right balance has to be found not to get too moist gas.
This would not work as a wood gasifier with lots of condensate water.
If the gas is moist, warm filtering as Max suggets it (cooler with condensation, reheat, fabric filter) would be the best option, but more complicated
Til
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I love it when you guys get to talking âdirtyâ.
Design compromises. All real working workable designs will have these.
Kristijan your biggest uncompromising factor is fitting a whole system into your rear vehicle shoe-box envelope.
No choice. You MUST carve down the whole systems footprint to squeeze it all in. You must carve-down some of the system expectations like long travel range to do this too.
The clean-talker, purists, idealists, hate any compromising; refusing them, from their assumed perfections.
B-o-r-i-n-g reading ass-you-meâs. Painful to watch their almosts-nevers.
Almost â good enough. Never quite â good enough. Spend more money. Spend more man-hours. Next time we will get it right perfect! Nope. Never-ever. Ainât no perfect.
Best Regards
tree-farmer Steve Unruh
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I always think of engineering as the art of compromise.
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Okay, thanks JO, now I see the perforated tubes.
Yes if you could remove a plate where the ash is sitting on the bottom in the drawing, you would have access for maintenance needs.
I am now seeing it in the 3 dimension in my mind. This is exciting. It is very simple concept, but may be a little more involved when welding it together. I can picturing this complete gasifier with a big shaker attached to it. Shake the filters, hopper, reduction ring all at the same time keeping everything flowing.
Bob
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Interesting!!! My thoughts almost exactly. There are only two grades; pass and fail, or good enough and not good enough.
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JO is correct on all aspects. Specialy the milky camera 
Indeed, the sacks are supported with perforated pipes. The perforated tubes are threaded at the end and simply thred in the top.
JO, the sacks being close to the grate is what concerns me allso. This material is tough thugh. On my Chevy occasionaly l found white ash spots on the cloth wich indicated a burn of soot up there, yet it apeared undamaged. What happens with hot char hiting it, l dont know. I need to test it.
Yes, there shuld be a detachable floor under the sacks.
Well a legit question Tom. The thing is on my previous build l had dirthy raw gas passing stright from the gasifier to the cooler tubes under the car, then in a felt sack filter and in the engine. Couple of problems showed up:
- cooler was too hard to rinse sucsessfully, and on one point half of it pluged on me completely ad l had to dismatle it to clean it.
- cooler lowered the car, on a couple of occasion l scrached the ground with it.
- the ash insulated the cooler making it ineffective!
So the under the car cooler needs to go. I am planing to pipe hot gas trugh 2 smaller pipes next to the driveshaft to the front, then to the cooler. The cooler will need to be placed between the engine and radiator (where the sack filter was now). This means the only place fo the new sack filter is in the engine compartment. The space there is limited so the final filter needs to only take care of the finest dust and as litle of it as possible. That is the reason l would like to keep as much dust as possible at the back.
On moist gas, Til is right. The goal here is never to have much moisture in the gas. Do this with chacoal and just enough âmoisturisersâ to achive good and complete H2O to H2 conversion. If it all works well on some point l will try a mix of charcoal and wood, but theoreticly that shuld resault in dry gas allso.
JO, yes, l was thinking to add nozzles for compressed air. I thunk that Swedish guys Mercedes you once showed us had this? Btw you still have the link to the site?
But l like Bobs shaker idea too! A sturdy shake avery 10min or so shuld get the job done. Perhaps more forgiving to the fabric too.
Steve, yes, compromise. My curse⌠right from the begining of my woodgas days. This is my third atempt on this car and while the first one kind of worked, the second one worked reasonably well, l am looking forward to the third one
Actualy range is the least of the problem here. I am happy with a 30mile hopper range but this new hopper l am building holds enough fuel for about 60 (that is if the auguer will be able to fill it all the way to the top) while not taking allmost no trunk space (a BIG + with 2 small kids).
Bigest problem is heat. I had terible problems with it on my first atempt, and still some with the second try. This time l am going all in in terms of insulating/cooling the system but more of that later.
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