Are you having trouble with your gasifier?
Because of the large volume of e-mails i recieve on this subject i decided to devote an entire section to common gasifier problems and potential solutions i have found, the following list covers most common problems that first time gasifier builders encounter. If you dont see your particular problem listed here with potential remedies feel free to drop me an e-mail and i will do my best to help you solve your gasifier issues.
My Gas won’t light/flare
This is by far the most common subject i am asked about when new gasifier builders attempt to start thier gasifiers for the first time.
- Oxygen…..air leaks are almost always the culprit, an easy way i have found to detect air leaks is to slightly pressurize the gasifier by using a shop vac set on blow mode or a mattress inflator to blow into the system while squirting all seams with a soapy water mixture, note that you must plug off all openings to allow slight pressure to build, if you see bubbles come from any seam or weld fix it, a gasifier must remain air tight everywhere at all times, any leak will compromise your gasifiers ability to produce woodgas and greatly reduce its effeciency.
- Time…..A gasifier takes time to produce gas. The F.E.M.A. gasifier featured on this website takes around ten minutes from a cold start up to reach temp and start producing a usable volume of gas. When the gasifier is first lit the smoke from the flare pipe will be noticably bluish black, after ten minutes or so the gas exiting the flare pipe will turn whitish in color almost fog like and will be able to light.
- Temperature……Wood gas must be below 90 deg f. to ignite, much above that and the molecules of the gas are too few to create an effecient burn, the colder the gas is the better it will light, cold gas contains more molecules, think of a cold air intake on a vehicle, cold oxygen is more dense and creates a better burn.
- Fan speed/CFM…..This is also a common area that causes some confusion when it comes to gasifiers, i have seen several cases where the gas exiting a flare pipe will only stay lit if a flame is applied to the gas, as soon as the flame is removed the flare dies, this is almost alway because of fan speed or too much flow actually blowing itself out, this can be cured by slowing either fan rpm, or by restricting flow through the fan by means of a valve or by partially plugging the flare pipe exit to restrict flow.
- Wet biomass/fuel…..while not all to common wet fuel can cause a gasifier to not light, not only does the steam produced from heating wet wood cause flare issues it also cools your char bed resulting in dirtier gas (tarry)
My Gasifier “PUFFS”
- What is a puff? a puff is when the gas to oxygen ratio inside your gasifier is around 50% and is exposed to a spark or flame resulting in a whoosh sound usually blowing smoldering material out the flare pipe and or blowing the top off of filter drums or other semi sealed areas of the gasifier. While this may not be particularly dangerous it certainly is an uncomfortable experience that generally results in a change of shorts.
- Time…..The gasifier featured on this website will puff everytime the flare is lit if too short of an amount of time has passed since startup, the gassifier must be allowed ample time to heat up as well as remove residual oxygen from the system before you attempt to light the flare, i would say ten minutes is a bare minimum before attempting to flare gas, you will definately know if you rush it by the whoosh and ember shower that follows.
- Oxygen…..If ample time has passed since startup and you continue to get puffs everytime you attempt to light your flare I’m 99% sure you have an air leak/leaks, find them and seal them up.
I can flare my gas but cannot get my engine to run on my gasifier
- Air/fuel mixture…..Most commonly the cause of not being able to run an engine on woodgas. generally a ratio of 1:1 or 50/50 works as an all around air fuel mix, This varies slightly from engine to engine but is a great starting point. This means if your oxygen valve is open half way your fuel valve should be set the same.
- Air leaks…..This is a reoccuring theme with gasifiers, air leaks are the enemy, remember that you want total controll of the oxygen your engine is recieving so you must find the air inlet holes for your engines air cleaner/box and plug them off, leaks in your carb/plumbing setup can be adjusted with your carb ball valves but a leak at the airbox cannot be controlled.
- Plumbing diameter…..Another important thing to remember is that the diameter of plumbing you chose to connect your gasifier to your engine must be at least the same size of your selected engines intake port or larger, a good rule of thumb is no smaller than 1″ for your hookup plumbing, making sure to correctly size your hookup plumbing will save you headaches down the road.
Hopefully this will answer some more common problems faced by new gasifier builders and provide insight for the potential builder, again if you have any questions feel free to contact me by clicking on the “contact us” tab and send me an e-mail.