The only thing I could think of would be oil-lite(bronze) bushings. You want as tight of a fit as you can get, and pack the area with grease. But if it’s getting hot there, I’m not sure. Can’t tell much without photographs.
1 Like
Thanks I’ll have a look
1 Like
Forgot to mention, you’d want a tight fit between a pipe and the shaft of the shaker arm. Then weld the pipe to the body of the gasifier, or weld in a coupling and thread in the pipe there.
This is where I think Tone is really onto something, it needs more testing by others of course and in other systems, with other types of wood, but if I am understanding things correctly a lower air nozzle may just be more efficient to keep the grate clear and free flowing then a grate shaker. Not to mention less char slipping, more energy harvested. Win Win, while also eliminated the need to seal up a moving component in the gas production area which could be a potential hot leak
3 Likes
I agree. I think Stephen A and Tone are on the right track. Both have a row of nozzles, with a finisher nozzle near the restriction. I might adapt my mini gasifier to the idea.
Also, Ashley, more often than not shaking the grate too much can make things worse. My mini gasifier that I had linked a video to actually has a fixed grate, welded to the reduction zone, but that’s only because it was designed for it, not all gasifiers are made for that.
3 Likes
What Ive always done was weld a pipe half couple center on the hole for the shaft to go through. I then would drill a hole in a pipe plug for the shaft to go through. Then I install the shaft then pack ceramic rope seal around between the shaft and the pipe couple. Then thread the plug into the couple compressing the rope seal. It will make a nice sealed bushing that will hold up to the heat for a long time.
8 Likes
If I understand you correctly you want something like this.
Replace the compression ring inside with some graphite rope packing to make a seal.
Processing: image.png…
tighten down the nut the packing will seal around your grate shaker shaft.
Use graphite not anything else or it will melt/
If you run a steel rod from your engine to your gas generator the vibration from the motor will help with fuel flow ifyou find you have some flow issues.
4 Likes
Yes Wallace that graphite rope is the thing for his shaker rod for sure , when i made my very first FEMA coff coff i used a stove rope wrapped around the shaft and packed with grease and a end cap squashing it in place , worked good never leaked for the couple of times i ran the unit before throwng it in the metal bin
7 Likes
You like that?
This is a teck cable connector.
I don;t know what they call them in the rest of the world but they come in many sizes.
remove the rubber gland and replace that with rope packing.
Now you can remove your tyuer from the out side change sizes with a minimum of fuss. Change depth all kinds of tricks…
Admittedly they are kind of expensive.
cut away so you can see the rubber part of the gland you want to remove.
There is a lot of wiggle room in there you can squeeze down on what ever nipples of pipes you want.
Cut off the threaded end weld into place to prevent leaks…
Here a table from Thomas and Betts for the outside diamter range of some of the more common ones. ( not listed but they get even smaller ones to 3/8 of an inch communication cables )
1 Like
I bet you could even use a copper fitting the type that uses a olive and use that graphite rope with it too .
I see lots of fittings come into Brians scrap yard and i have to admit i am amazed i know so little about the range of things that’s in everyday use around the world and yet we use them most days in our life
The secret life of machines
I have a tin can ( well a small 60 liter drum really ) out in the garden , i’m going out side to build something while its not raining seeing’s as its the first day of spring I am full of enthusiasm 
2 Likes
Thanks again. Great info as always!
I know there’ll be many answers to this question but what design/build type would you guys recommend for small scale gasification of raw wood? Bearing in mind the input will be around 15% moisture and won’t really fluctuate.
I’m always planning to re-build something and once I have this system up and running I’m sure I’ll start again!
2 Likes
Over to you Steve 
Sorry Ash i’m not allowed to answer as i have no, non, zilch, experience in the subject you are after but there are many on here that will guide you along the way mate
Dave
1 Like
You have a look in the library section of this site you will find some gasifier designs
The Doug Williams pioneer works and there is a complete list of instructions
It’s a bit fussy about fuel block size and moister content but because you have control over these issues it will not be a problem
You can buy Wayne’s book and become a member
Then you can learn his methods of things and you will have access to members areas and support
The FOA wood gas as fuel book very good full of tables to design from
And keep asking questions
3 Likes
If you want a very comprehensive system with a book that has troubleshooting guides, I highly recommend The Wood Gasifier Builder’s Bible. 20 dollars on Amazon, and it shows a sizing chart based on engine size, materials involved in Ben Peterson’s design, the works.
Even for just a study material it’s worth it.
We have a free sample of his book in the Library section to get an idea of it.
While the sample shows how his gasifier is laid out, you really need the book to understand how it’s all put together.
I have yet to build a Peterson gasifier but I’ve used this book many times in my builds for hearth sizing and other things.
Edit: Forgot to mention this design has ran everything from Small generators, to V8 pickup trucks. They were all appropriately sized to each respective engine of course but the design works well.
6 Likes
3 Likes
Good. Good. Now I can’t be hyped for shilling BenP’s book.
A bit more that $20 USD now. For in the US it will set you back in the mid-$40.'s USD with mail and now mandatory taxes.
Ashley the good news is there is now a metric measurements version to this book too. A German language version soon out next. (I voted for Spanish).
The bad news is mailed into the UK with VAT or equivalent it will cost a bit more.
Yes. Get it.
Worth it even in the grate movement sealing shown in it. Up from the bottom shaft supported and moved grate. That seal is just a metal collar on the center shaft. The grate and char stack weight bearing down onto this collar edge onto a welded bottom plate socket/flange. Just as found in others this way; early GEK’s, Mikkonens, that movable joint buried down in the ash accumulation being constant weight pressed down seals up just fine. And the ash protects from heat damage to the bronze bearing.
Regards
Steve Unruh
5 Likes
Thanks, the book sounds like a great idea. I’ll have a look on Amazon now.
Another question, now I’ve got the new filter system in I decided to swap the air pump to suck instead of blow, mainly to take pressure off as there is a little more resistance now.
The good news is the filter system and cooler work brilliantly, the gas is literally cool to touch, there no condensation and it’s burning a pure purple/blue colour.
The issue I have is the flare, I’ll add a picture, due the size of the air pump outlet I opted for a 22mm pipe (left over from the cooler). The gas lights and lights well but it it blowing out, I managed to keep it lit for a few seconds by really reducing the airflow but obviously this isn’t a long term solution as I’d loose to much heat. Any ideas? I’m thinking either the flare is being blown out by the pressure of the air pump or I’ve got a leak! I’ll also add a picture of the full system. Thanks
2 Likes
