Gasifier finished and it works can't see the flare but it's there

Has anyone else ever built a down draft gasifier without air nozzles.

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Hello Drue and welcome to the site .

If you are talking about drawing your combustion air down through the fuel , Yes they are quite common and are referred to as the FEMA type gasifier . The FEMA type gasifier was developed for emergency situations and don’t have a good reputation for daily use.

They can be operated tar free but must be regulated by the fuel supply .


No not a fema type that was my first gasifier 3 years ago. As soon as I figure out how to get my video from my phone in the right format I will upload it.

Hi Drue, and welcome. Load your video on your own You Tube site channel, this your personal area on You Tube. Then copy the link and paste it here. Make sure you have it playing on public and not private.

Ok . Thank you. I’m rather excited about my design. Have not seen it before. I’m pretty sure the gas is clean. Can’t see the flame. 2" flare tube and the flame was about 20" long based on holding a paper towel in front and it catching on fire. 21 mph wind and flame would not go out. Flame did bend around in the wind and curl my eyelashes and eyebrows. I’m in alaska my current temperature is -16. I new with my temperature I was going to have to preheat my intake air so I took that into account when I designed my air intake without nozzles. Closed sealed top on hopper.


As I said before I live in alaska. Me and my wife live totally off grid. Solar and wind are our primary source of power. Except in the winter when we only have a couple of hours of visible sun and have to run the generator. $ 100 dollars of fuel a week. So that is why I built a gasifier and it was fun. Even with the curled eyelashes and eyebrows


Video. Hope it works


Looks more like a charco flame, i mean most of are wood gas flares are yellow light orange with maybe 20 percent blue depending on how wet the wood is or how much wood is in the hopper, and how hot the toltal gasifier / hearth area is at the time of the flare,all factor in.Allso the size of the restrictor too vacuem soarse power. Good luck with your new found soarse of engine fuEL, AND BE CAREFULL IT IS ADDICTIVE.


Hello Drue .

The flames can be hard to see in daylight but can see them much better at night .

Don’t do like me and walk into the flame :grinning:


Is it good or bad that it looks like a charco flame

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Welcome fellow -stumbeling in the dark this time a year- friend.

Daylight unvisible flame is good but gas quality can be tricky to judge only by flame color. Check your hoses/pipes for sticky soot. If you can wash your fingers clean with water only you are tar free.


Hi, Drue!
There is usually a marked error between flame testing straight from the gasifier (natural)
more or less filtered and cooled (prepared)

If you want opinions on how your gasifier performs, let it flame straight!
Night and day.

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Overview of my build


Thanks Drue, yes you do have a nozzle and it goes all the way around the top of the fire tube. Kristijan did this type of design in his build.
I see you are using wood pellets for fuel. To get a tar free gas make sure you fill the burn tube up from the grate to above your slot ring nozzle with cold charcoal pierces out of your wood stove no ash in it or very little. Then put your wood pellets on top of the charcoal. This way you will get a quicker start up and be producing a better tar free gas on start up.
I do not burn wood pellets but there are others on this DOW site that have gasifier that do. Hopefully they chime in. Looking forward to seeing your progress.
I like your gas cooler barrow, use what you have and make it work.


OMG!! First welcome to the group. Unusual for some one to come here AFTER building a working gasifier. I say OMG because it seems to some of you newer guys you don’t understand that the number of nozzles, dia. of nozzle openings, and dia of fire tub, etc etc all have an affect and have to be in balance. This balance is in old WWII books. And yet, you jump into this with One continuous nozzle and it doesn’t appear that you designed it for a specific engine— you just broke all the rules that I have studied years trying to make sense out of— and yet yours works (and appears to work quite well) Congratulations!!!
As far as the color of your flame and size etc. I have had my build at the point where it ran my truck but would NOT flare, so I don’t know much about colors etc. I end up hooking them up to my engine and trying them. ( I have gummed up 3 engines valve trains with my wonderful method.) My one comment would be after it has run for a while and the gasifier seems stabilized, blow the flame out and put a piece of white cloth over the pipe while still running. Look to see how much black tar/soot stick to the rag. ( experience has proven that using your white handkerchief can get you in trouble with your wash lady)
One other comment, I don’t know why you hesitate to use a light dimmer to control your shop vac. I have been using them for years and I think are important (remember I hardly ever get a flare ) because you need your gasifier to work for the engine size you are going to use, so by slowing down and speeding up the vacuum you will get a better idea of the size engine your gasifier will work best with. Make a simple manometer using a board with a yard stick and a piece of plastic tubing. ( very cheap, easy to build, and very accurate) Again Congratulations. TomC
I see your welder sitting out side and it makes me wonder how you have been able to build this in the last three months. I have spent the last three months in the house by the fire. I admit WE have gone through a long spell of sub zero weather and I heard on the news that Alaska has had the warmest winter on record — your warmest is still lower than our coldest.


Thanks tom. I just went and tried your advice about the white rag. What an experience that was. Could not get my flare to blow out. 17mph winds don’t even phase it. I have a metal suction dredge nozzle I’m using for a flare as it easily fit my shop vac hose. I thought I would quickly remove the metal nozzle and it would go out. Boy was I wrong. Flame jumped to my shop vac hose. I could see that the end was now starting to melt so I quickly went to slinging the end of the hose to blow it out nope didn’t work. Had to stuff it the snow to stop it. My question. Why so much gas and why could I not blow it out like all the other videos I have seen. After getting the flare extinguished I put a paper towel over the opening for about a minute. Nothing can’t tell the paper towel was even on there. No moisture either. Could it have anything to do with my temp here -17 degrees


I gess the more experiance gasifier guys will have too chime in as i am not sure of the actual color meanings, as far as tar goes. Though Wayne Keith the auther of (HAVE WOOD WILL TRAVEL )BOOK. HAS I THINK OVER 200. 000 miles under his wood gas vehicles.And put his book together from all those miles of engine grade fuel gasification experiance.

If you caint put out the flare you most likely have air geting past your flare tube, or there is excess air in from another leak.Seal up all posible leaks and try again,is my best gess.

Wow. That must have been exciting. I believe you can’t blow the flame out because you are running the shop vac at top speed. Get the light dimmer. Nothing on the paper might be a good thing, but paper is hard to blow through. Use a cloth, but I really believe you have a good thing going. JO has been running his VW rabbit every day this winter in Sweden and it has been cold there so I’m not sure the -17 has much to do with it.
Put a dimmer switch on the vac,AND make and put a manometer about where the gas comes out of the gasifier. Set your vac so you are pulling about 10 inches of water. I would say that is a kind of average pull on a properly made gasifier. ( other chime in if I am wrong) TomC