Just burning Ash and Walnut bark, and some yard trimmings. Since we are cutting timbers, both live edge and sawn, we can keep up burning our waste. The slabs that are thick enough are turned into firewood for my off bearers wood stove. The bark, sawdust and edgings from the few boards made outside of the timber, get burned in the vortex burn barrels. When you dump the wet sawdust in on top of a bed of coals, it dampens down the fire and takes awhile to heat the dust to drive the moisture out and start burning.
(https://forestryforum.com/gallery/albums/userpics/16191/17917517_10208722318363086_3069270326200175946_o.jpg?easyrotate_cache=1492394318)
how do you make them?
Brad has a post on building them someplace here. I made one fast and sloppy with an axe . Several diagonal cuts around the barrel in two rows . My barrel is only 30 gallon so two rows worked well.
Looks like you have some heat there.
Brad how do these work with green slabs?
Do these hold enough coals overnight tostart again in the morning? Or do you need to light them up each day?
I made them from a youtube video:
https://youtu.be/-0J0zRiDAmE
They will hold coals overnight if there's a good amount in the bottom plus some saw dust to slow the burn. This barrel design helps oxygen get in better so it will burn everything better. If you put any saw dust in, put it over hot coals against one side of the barrel and don't put too much that it smothers all the coals. Also, I'm assuming you guys know the dangers of dumping saw dust on a fire? Dry dust will act like pouring gasoline on a fire and climb up to where you're pouring from. Damp dust is a lot easier to work with and keep your face away from the fire. I have singed my my arm hair a few times, and my head hair once.
They will burn green wood, but I don't put any thick pieces in there only because my off bearer takes the thicker slab material for his wood stove, so only the thinner stuff is left to burn. But yes it will burn green slab wood fine. Green Bark will burn easily, and the heat of the fire will quickly dry the slab pieces and burn them. Sugars in the wood also help them burn.
Again, if you're production sawing boards on a hydraulic mill, two barrels probably can't keep up with your saw dust. But doing timbers plus a few boards and stickers from a log like I do, It can keep up. The other good thing about these barrels is that they are closer to my mill than what we used to do(haul the dust to the back pasture for a burn pile once a year). The barrels also burn much cleaner than an open burn pile because as the material gassifies, the added oxygen burns it like an after burner. So once you get them going you don't have much smoke to speak of (until you dump some wet dust and smother the coals). Open fires just create so much smoke, and are less safe. With the burn barrels I have them on the gravel so less chance of catching anything else on fire. Keep away from the grass to you don't get a grass fire! I also elevate the barrels on 3 bricks to make sure they get enough air from underneath.
Somehow it seems a shame to waste that many BTU's that could be drying lumber or heating something. Frank C.
I agree, If there were an efficient and economical way to capture it.... The problem is you are dealing with irregular material so it's not a consistent heat level and you cannot automate feeding the fire as you can a pellet stove. Making pellets from your scraps for one person/bandmill is not economically viable. If you figure out a good way... If you used to heat a shop or home, the building would have to be really well insulated and you'd have to run copper tubing in the barrel to run water through for heat transfer. But even doing that, it might get too hot at times for the copper and the tubing could hamper the vortex effect.
FYI, vortex burn barrels can be even more efficient by placing a second vortex barrel (with the bottom cut out) on top of the first one. It creates more afterburner effect and burns more of the gases coming off the wood. There's videos about that on youtube, but it's really not very practical for us because it would make it harder to feed material in.
Not mine ...But it's neat...
https://www.youtube.com/watch?v=Qj7X9X8LTe0
Two years ago, I made Vortex burn barrels. Well the bottoms of the barrels have finally rusted out from the heat. So I made 2 new barrels. But then I took the old barrels and cut out the remnants of the bottom. I then welded 3 angle iron legs on the bottom of the barrels to test them as barrel extension/chimneys. I was shocked at how well they worked. The problem with just single barrels is that if you load them up with dust or chips or bark, they have to burn down quite a bit before you get any vortex effect, because the material is covering the holes. By adding The barrel on top, you create a complete carburetor. Air can properly be brought in and mixed with the combustion gas created. You get a better draft from the second barrel. Thus you get a faster/hotter/more efficient burn. It lights fast and virtually no smoke. Compare the test below with two identical barrels loaded exactly the same with planer chips. No smoke and a faster burn from the one on the left versus the less efficient on the right.
(https://forestryforum.com/gallery/albums/userpics/16191/IMG_5990.JPG?easyrotate_cache=1539755609)
What you couldn't see during the day is the fireflies from the planer chips. The ground was damp while I was burning this and the temps were in the 40's F. Video below.
Double Vortex Burn barrels - YouTube (https://youtu.be/dfSvvNui2Uk)
Not all that different from making charcoal/biochar. If it is top lit and quenched before turning the charcoal to ash there can be another product there.
Made a vortex barrel today. It definitely works better than the average barrel. Hot. No smoke even when burning some damp SYP.
(https://forestryforum.com/gallery/albums/userpics/39962/Vortex_Barrel2.jpg?easyrotate_cache=1541716007)
And what I found is that if you pack the barrel with dust and bark etc, the vortex can't work until it burns 1/2 to 3/4 of the way down. So putting the second barrel on lets the vortex action work when you've packed the first barrel. Giving it both barrels so to speak, burns the material in 1/2 the time or less. That's good when you don't have time to stick around and monitor the burn and need to get it done fast. Be very careful when burning everyone. Burn when the ground is wet, and the wind to low. Don't burn when it's too dry. Planer chips will fly burning so make sure they can't catch anything on fire, like grass, or trash bean or hay field. I had to fight a field fire once. They move fast, usually much faster than you! Took a number of guys with shovels, a big Front end loader creating a fire break, and some luck that the wind slowed a bit at just the right time.
btulloh, wondering how your spark arrestor works? I need some similar material to try to keep planer chips from flying so much.
Brad, it's just 1/2" rat wire. I expect red hot planer chips wouldn't hardly notice it on their way up. I was burning solid stuff - 1x and 2x off-cuts and culls, so not much in the way of sparks.
I'm not planning on burning any sawdust or chips. For the amount of chips and sawdust I produce, I can just throw them on my leaf and sawdust pile and let them do their thing. I'm not putting a lot of nitrogen material on that pile, but it cooks down and it's functioning for the amount I'm dealing with.
I'd still like to add the second barrel. It would make it better for longer stuff. Yesterday I had some 4,5,6ft stuff in there and it kind of fed itself down but a few ends fell on the ground. It was raining, so all good. I only plan to use it while it's raining or right after because of where it's located. Once I get caught up it won't be a problem to wait out the weather and beats starting a field fire.
Yesterday I was burning stuff that was pretty wet from sitting dead stacked in a little trailer out in the open for several months. I got a good hot fire going and then started feeding the wet stuff. It worked amazingly well. That vortex deal really does increase the performance, and it doesn't take much more effort than using the 338 Lapua to punch holes. The torch is a lot cheaper than using the 338, and it's a lot quieter too.
If I wanted to really get rid of a lot of stuff on a regular basis I think I'd scale it up. Old oil tanks are pretty easy to come by these days. Maybe a couple 275's end to end.
(https://forestryforum.com/gallery/albums/userpics/10017/charcoal5op.jpg?easyrotate_cache=1511918745)
This is a retired I guess 500 gallon tank I've used for charcoal. The last few times I've done top lit updraft and it worked fair for slabs and trimmings converting them to charcoal although a few times I've gotten occupied and just let it burn it all. It works better if I push it over, stuff it full then tip it up and light. We have another drum and I've thought about welding some stacking hardware and using the k-boom to swing that up top, that does help clean up the unburned gasses. This one is too tall for convenient feeding when its upright, it would be better at around 5' if you vortex fire and continuous feed it.