Making wood pellets?

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jdboy9

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Anyone try their hand at making wood pellets? I have a lot of sawdust from my woodworking and sure would like to use it somehow.
 
Are you looking to sell the pellets, or just use them for your own heat? If it's for your own heat, there are easier ways to burn the sawdust than turning it into pellets first.
 
Are you looking to sell the pellets, or just use them for your own heat? If it's for your own heat, there are easier ways to burn the sawdust than turning it into pellets first.

If you know of a good way to put sawdust to use, let me know. I have a good bit sitting around my little mill. I have tried burning it in the past, all it does is just simmer away.
 
If you know of a good way to put sawdust to use, let me know. I have a good bit sitting around my little mill. I have tried burning it in the past, all it does is just simmer away.

I have several burner designs that I think would work okay with sawdust (I'm a bit of a pyromaniac in my spare time). The trick is getting the dust to mix with air (in the right proportions and without exploding). I've never studied one, but probably something akin to a pellet burner would work, except you would probably have to be more careful how the sawdust was introduced to the combustion chamber. Putting it in the air stream of the blower should do the trick. Definitely a little engineering involved, but if you had a large supply of sawdust it would be worth tinkering with for a shop heater.
 
Yeah I just want heat from it and I have thought about using a blower type system but it didn't get past my skull :) I will have to try something out because its a shame not to get some heat out of it.
 
I would't try to blow it into the fire, once saw an experiment with custard powder blown over a flame.... lets just say the tin lid hit the roof. I guess maybe try burning it like a coal fire, air from below and through the fire
 
I had the same idea a couple months ago and did the research. I talked to the owner of the biggest pellet mill seller in the US (in Chicago). He was quite honest and said he does sell the small $2000-$5000 mills, but warns that they invariably fail- not built to withstand the pressure and they're all imported from China.
He said to do it economically, you need at least a $150000 machine and do about 5 tons daily (figures come from my ever-faulty memory, but they were prohibitive).:cry:
 
I would't try to blow it into the fire, once saw an experiment with custard powder blown over a flame.... lets just say the tin lid hit the roof. I guess maybe try burning it like a coal fire, air from below and through the fire

Blowing it into a combustion chamber is the best way to burn it-but it has to be engineered correctly. Every fuel oil furnace gun in the world blows highly combustible particles (droplets) into a hot environment without blowing anything up. The trick is to be sure the combustion process is continuous and you don't get a buildup of dust without flame.

What I was envisioning was have a combustion chamber preheated with a gas/fuel oil flame (or even a small kindling fire), then turning on the blower and admitting the sawdust to the air flow. As long as the combustion chamber is hot enough, the dust/air mixture will combust upon entry. The most difficult part of it is getting it to start up and shut down easily. The simplest solution is just to be able to meter the dust/air mixture so you can have a continous burn going as long as you need the heat, then shut it down and be done with it.
 
I could just light it on fire like they did on mythbusters it would heat for a few seconds..

I couldn't imagine those china imports would last very long either I would think there is a lot of stress involved in smashing wood into pellets. I guess it looks like need to come up with a safe burning system. You would think someone out there had a good system. Where my mom teaches they heat the whole college with sawdust I'll have to go check out their boiler next time I'm there.
 
Most of my sawdust goes into the compost pile...
Planer shavings go into the OWB....they light up really well.
 
Blowing it into a combustion chamber is the best way to burn it-but it has to be engineered correctly. Every fuel oil furnace gun in the world blows highly combustible particles (droplets) into a hot environment without blowing anything up. The trick is to be sure the combustion process is continuous and you don't get a buildup of dust without flame.

What I was envisioning was have a combustion chamber preheated with a gas/fuel oil flame (or even a small kindling fire), then turning on the blower and admitting the sawdust to the air flow. As long as the combustion chamber is hot enough, the dust/air mixture will combust upon entry. The most difficult part of it is getting it to start up and shut down easily. The simplest solution is just to be able to meter the dust/air mixture so you can have a continous burn going as long as you need the heat, then shut it down and be done with it.


thanks for the that. makes sense! guess you have to get the flow right to ensure clean burn!
 
...guess you have to get the flow right to ensure clean burn!

Combustion is relatively simple-all you need is heat, fuel, and an oxidizer. But, getting all those things in the right proportion at the right time is not so simple, unfortunately.

I know the situation you were referring to in your original post. I've had that very thing happen once when messing with an oil burner. The chamber was still hot and my valve failed allowing oil to flow in. But the blower was off so with limited oxygen the oil vaporized and just sat in there. I realized oil was still flowing so figured I should turn the blower back on. When I clicked the blower on, the predictable thing happened and the chimney quickly became airborne. Startled me a bit and scared my wife-who just happened to be out watching-to death.
 
I would follow the links above and see how commercial units work. No sense reinventing the wheel. I have no experience with handling sawdust, but guess it might be worse than the plastic materials I have done a lot of pneumatic conveying with. One problem is metering the solid into the air stream. For stuff that flows good, a simple hole in the bottom of the hopper works OK, especially if attended. Air locks work, but are a pain to keep working. Belt feeders may be the most reliable, but I might try an augur.

At least you skip the biggest problem in pneumatic conveying, separating the solids and air at the end.
 
saw dust stove

I once saw a do it yourself saw dust stove. It was a chamber with a top lid and solid bottom except for a 2 inch or so round hole in it. You inserted a round wooden tapered form into the hole in the bottom, then packed saw dust around the form to fill the chamber. then remove the form and wad up some news paper in the hole left by the form and close the lid. Reach into the ash drawer and light paper. The round hole in the bottom opens into the ash drawer which also served as the damper. Don't recall the overall size of it but seemed to be normal stove size give or take. Might Google saw dust stove and find it. Think it was some university study that developed it but was a long time ago, brain fade and all.
 
I have a customer that makes wood pellets, it took them 5 years and 100s of thousands of dollars to perfect it. I have watched the machine work, its pretty impressive. The heat generated from the pressure is surprising. Your pellets have to be pretty specific to burn right, I'd be surprised to see if someone could duplicate it at home.
Sawdust burning has been figured out several ways. Take a look at bio-mizer
http://www.biomizer.com/ part of wood-mizer. Small units have been built by at-homers before. I wouldnt want one in my house, but something like an OWB could work wonders.
 
here in Tulsa, we have a free green waste dump... they generate football field sized mounts of free wood grindings.

semi-trucks roll in, then city of tulsa loads it for free.
quite the wind fall if you can use it... something like biomizer could burn that type of shredded wood.

Sawdust burning has been figured out several ways. Take a look at bio-mizer
http://www.biomizer.com/ part of wood-mizer. Small units have been built by at-homers before. I wouldnt want one in my house, but something like an OWB could work wonders.
 
well if you could get rabbits or sheep to eat nothing but wood.. you would have all kinds of wood pellets... :hmm3grin2orange: :hmm3grin2orange:
 
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