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Sunday, March 17, 2013

Explaining How Wood Gasification Works Part2


Let’s now talk more about the process after it’s made into wood gas how to clean it and get all the crap out that is no good.
The filtering is where it’s all at others think but can’t prove at all that it’s in the burner design. They think that by making it over complicated burner that they will crack the tar and somehow reduce it. I say keep trying I have looked at a lot of very unique setups but for all the extra work that goes into it I don’t see anything different in there gas. I have tried a lot of odd stuff in making my burner units but out of them all it still comes down to these simple things to follow. Those are use heavy metal for the burner tube and only use stainless steel for the burner grate. There is just one other really big thing to control how much air gets into the unit if it’s not regulated it then burns like a fire but if it is closely regulated it burn without flame as a smolder. This looks like how charcoal burns hot embers but no flame. This heats up the wood above it drying it and starting the charring as it chars it gives off its gas and then it keeps going the hot red ember once burned up like charcoal then stops burning and the burning moves to the next chunk. This is how the inside of burner unit works the burning area is down by the grate as it heats up the wood above it that then moves down and then starts to burn it just starts to cycle like that over and over.
Now let’s talk about different kinds of filtering there are some that are proven good ones and others that are just pure crap and don’t do anything. One that I don’t like at all for several reasons is the water filter it really don’t do much for taking out tar and it also puts a lot of drag on the gas due to it’s hard to pull threw. Now I know some people are pissed off saying “I use a water filter” all I can say is sorry that you got fooled into it. Here is a way to show you just how bad water filtering is get a bowl of water and a straw and a cigarette or a cigar. Once you have those things light the cigar or cigarette take a big drag and blow it threw the straw but have the straw in the water as you do this the smoke just into the bubbles and when they break the smoke is still there. Now a real good way to see the smoke even better put some dish soap into the water mix it up then put the straw in the water and blow the smoke threw the straw. Now what you get is soapy water with a lot of bubbles on top full of smoke. If you break them the smoke comes out of it. The only part of that bubble full of smoke that gets any cleaning is the outside surface that’s it all the center has had no cleaning action at all. Now I have seen only a few people that have had screens and stuff in the water to help break up the bubbles into very small ones yes that does help. But the water as the gas heats it up just puts a lot of water vapor to the gas making it a really wet gas and all that water has to be taken out. If all that water is not fully taken out then if you run it in a motor you will junk the motor in a short time of running it. Here is how that happens the water condenses in the motor slowly working its way into the oil making the motor rust until it stops working. Now the reason for needing to get all the tar out it’s like glue to the motor over a short time. The tar will stick to everything in the motor and build up until the motor stops working. If this happens there is only one way to fix it you have to take it all apart and wash it all down and get all that tar buildup out of the motor. That’s enough on really the only one that I find useless most other things work some better than other and some just down right crappy but they all still are better than the water bubbling.
Now I will get on with filtering the old way for me was when I only used hard wood like red and white oak. Now I live where I only can get my hands on is pine and pine has the most tar in it and there for needs the most filtering. My old way was simple a few cyclone filters and a sawdust filter and I always had nice clean gas that burned like LP or natural gas nice clean blue flame. But that was also when I only burned oak so it had very little tar to deal with. Now that I have moved to a new state 1000 miles from where I used to live and here there is only pine. Pine is one of the worst to burn for making wood gas due to all the pine pitch makes a lot of tar and holds a lot of moisture. So I have had to spend a lot of time redoing how the filtering is done the heavy tar with my old setup couldn’t catch it all even though It was a good setup and the gas was cold or cool on the output. I still had tar that made it all the way through the system. So I looked around on the internet at premade units to see what’s out there for how they had made the filtering. Well after looking around for a few weeks I found that a lot of the ones for sale that you can buy premade had very little filtering. So I did some checking to see what they did there test fires on and looked at any that had videos up I also found some people that had bought some of them and had put up videos on them so I got to ask some but some I could just see for myself. I learned that most of the premade units work great on hard woods or a select wood thus if you try to use pine guess what same thing I had with my old setup a lot of tar unfiltered out.
I will tell you about what happened when I found this one that looked really good. I will give some details on it but for right now I won’t say who this place is not yet but I’ll tell you how nice it looked it was 100% stainless steel with a large style water filter on their units. I was shocked that they mainly where made for business use well after checking more into it than I found out why there cheapest unit was just over $10,000. Well I gave it some extra credit due to it is all stainless so I got into the video section where they showed the different units fired up it all looked good nice blue flame. Then in one I notice It looked like they were loading in wood pellets so I downloaded one of them yes I know I wasn’t supposed to be able to do this but I got it. So I looked at it really close on my big screen TV and I was right wood pellets most of them are made with hard woods some cheap ones are pine or a pine mix. I watch like 6 videos all them had nice blue flame then I started the next video and it was like 15 to 20 minutes into the fire time and the flame was still yellow and orange so I went back to the start of it and replayed it on this video they loaded in a bucket of wood chucks. I watched it over and one more time by the end of the video they never got a nice clean blue flame. I was signed up with them and I posted a comment on how yellow and orange the flame was even after 20 minutes of burn time I said if your setup is so good then why is the flame full of water and tar due to its so yellow and orange in color so I asked did someone mess up and not use hard wood in it and put some pine or other soft wood in it. Well they didn’t like how I pointed out how bad it really was they band me from there sight and sent me a really nasty message saying don’t ever try to get back on to comment and lie about our stuff. So I had to go see I got back in there sight and bingo that video was off and deleted in its place a brand new one showing a nice blue flame. So I did some more digging and found out they never even used the gas they made in the videos they had an LP line to the burner. 
I looked around and found someone who had spent the money on their setup he at first was all about how nice it was and it was brand new but he made a few different videos on it showing him test running it. On his 4th or 5th video he asked if anyone could see if he was doing something wrong due to he couldn’t get the blue flame and he had called them they told him all different things to change. He still had no luck I asked him if he had been told or tried hard wood pellets the answer was no and why use them? I pointed out to him in there videos I think that’s all they use. His flame was a lot better but still had some yellow in it due to how much moisture was in the gas. My whole point here is it may look flashy and all that but unless you can take some pine wood chips and see it run them and run clean don’t ever buy one always make it or make a design after you have gathered up a ton of info and have someone make it for you. If you have that done make sure if there is any option that you may want have at it and have them make it even if you don’t use it now you still have it in case you need it someday.