[Smertrios]

Say I have 3-4 different engines and they may or may not all be running at once. Ranging in size from 12-40HP. How do I build the gasifier for them or would it be better to have one gasifier for each engine?

Maybe I would be better off using electric motors and just 1 generator to power all these different machines? I will have tons of wood and it would be just too convenient to use it to power my machines.

That said... Anyone here using a gasifier on a consistent basis?

[Smertrios]

Decided to give woodgas a try with a lawn mower. Have a welder bought on ebay for $130.00 on the way and was just looking at plasma cutters... OUCH! the "good" ones that have the pilot arc are a bit pricey => Good thing I dont need to cut rusty iron. That said my first experiments are probably going to be limited to paint and soup cans.

I have seen many designs and some that seem to work great but they dont give details about the insides.

[Smertrios]

A very useful document about wood gasifiers IMO...
http://taylor.ifas.ufl.edu/documents...ne_Systems.pdf

There is a rotary dryer shown on page 20. This is what I will need for drying wood chips and I know what % of moisture I want in the chips when it comes out but I don't yet know how to measure it as its drying to know if the dryer speed should increase or slow down =/ IE: Have issues with how to automate the dryers rotation speed, auger and furnace.

Also as the air is heated by the furnace it exceeds saturation (100%+ relative humidity). That water needs someplace to condense so it doesn't just get sent down the tube to be absorbed by the wood chips. This is another "problem" I am having with my mental design =>

[nickyroberts]

Good source.I read a blog related to FEMA simplfied wood gas generator in action.The guys did amazing work.Will post a link if i find that again.

[loneengineer]

From a few random explorations of my own in the past...

The FEMA gasifier directions are apparently actually pretty poor. There are supposed to be far better designs worked out by others - remember it's a SIMPLIFIED gasifier. I can't remember which ones offhand, but I seem to recall it lacks things like a way to clean the produced gas of tar and ash, which will gum up your engine alot quicker. The FEMA gasifier was a response to like "we have to JUST SURVIVE THIS SEASON and build the simplest damn gasifier possible", not "how will this affect the life of the engine?" A running time in the dozens of hours may be what you get before a rebuild, i'm trying to remember if the 100 hour figure I heard before a rebuild being needed was for a better (but still not perfect) WW2 type gasifier or for the FEMA one being even worse than that...

There is a minimum size needed for HP draw - some smaller diameter limit of airflow, you cannot size down gasifiers forever. 12-40hp may well be at that lower level already with the smaller figure possibly creating many problems trying to work at all. I've heard of one or two smaller tinkering gasifiers but apparently they are alot harder to get working at a smaller size, have issues with plugging up constantly and similar.

Gasifiers hate throttle i'm told. They like steady state. Think a stationary power supply, or cruising down the highway at 55mph for hours at a time. Not driving around town. The gasifier produces a reasonably constant amount of gas, and there's no real easy way to store it until needed. Not only may it be very difficult to size one gasifier to run "either just one or all engines", the smaller engines may well be too small to work at all. The impression I got in the past was that once the gasifier was producing gas, they started spluttering and puttering a car running it down the road until it got up to a steady rpm then usually at some speed (representing the rate of gas production only, not controlled by what speed YOU wanted to go) it would settle down and you could keep driving til you got where you wanted. Wasting a bit of the gasifier gas to drive slower was considered acceptable to be able to drive with wood at all.


FWIW if I get rural myself in the next year they will be one of the first projects I explore myself, at which point i'll dig back out my notes and articles on it and get active in forums I had bookmarked from the past. Just sharing this offhand for anyone considering it. It's one of a series of related projects i've talked with others about exploring on off grid discussion sites before.

Btw you can buy commercial gasifiers from china - but they cost a pretty penny off the shelf, think $8000+ for a mid sized engine like 35-50hp with nothing much smaller being made as I recall.

[ww_kayak]

I had dig back through my bookmarks, but the Fluidyne site has an engine table(s)

Site
Engine Table(s)


On a side note: A great forum post of the history of commercially available vehicles.

Also Yahoo has a woodgas group (even though I HATE yahoo groups)

[solidwoods]

I'd say the easiest for what you describe would be a single engine with generator. Just size the engine properly for a gasifers output.

Your woodchip question- Fuel needs to be as dry as possible. Air drying fuel will only dry it to a point related to the relative humidity. It's better to use a heated chip dryier. Size it large or make multiple to put time on your side.

Lawnmower- Single cylinder engines are hard to run on a gasifier compared to multi cylinder because the vacuum is not as consistent.

GEK company makes a killer 10kw and 20kw. Maybe look at that one but use a water cooled engine with exhaust gas to water heat exchanger. Use the hot water for fuel drying or heating an area (house/shop/ greenhouse).
Good luck
jim

[jakson]

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[jakson]

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[teyu]

S&A chiller is simple to use and maintain. The CW series model is kept in stock for immediate delivery.