Charcoal

[Max sawdust]

I've been making charcoal for grilling, out of oak scraps, have yet to build a nice drum set up like Todd.  I use a metal garbage can with the lid screwed on and a several holes punched in the side does the trick, toss it in my fire pit and build a fire around it until flame come shooting out of the holes then let it the fire dye down.  Made 30 gallons or so, works good enough ;)
Once the holes plugged with tar, and I heard the BOOM, as the can blew up from in the shop with the planer running and hearing protection on
max

[Don P]

Sounds like maybe a large 4" or so vent hole somewhere with just a lightly weighted cover on it to be an unblockable pressure relief if it plugs up?

If you run the gasses that are normally flaring off through a worm, is that in part wood alcohol?

[Todd]

That exploding thing is what I've been wondering about.  Every time i'm sitting there watching the barrel I wonder what's going on in there that I don't know about. (but ought to know!)

[SwampDonkey]

That exploding thing is what I've been wondering about.  Every time i'm sitting there watching the barrel I wonder what's going on in there that I don't know about. (but ought to know!)

That would be me.  ;D :D :D :D

[Max sawdust]

Sounds like maybe a large 4" or so vent hole somewhere with just a lightly weighted cover on it to be an unblockable pressure relief if it plugs up?

If you run the gasses that are normally flaring off through a worm, is that in part wood alcohol?

I am quite positive a 4" or larger size hole would be too big, you would be making ashes instead of charcoal :D  Note that in all designs the vent hole on top of the barrel!  Also not larger than 2" on a 55gal drum.  My lesson was to not put the vent hole DOWN ;D
Not sure about the wood alcohol, I hope their is a chemist amongst us to answer.  I do know it is a good way to make tar, each load must produce a good 1/2+ cup even with oak, imagine pine!  Should get TW from Finland to chime in about Terva.

As far as different species for charcoal, I believe I read softwoods were the best for foundry/blacksmith work because the burn hotter and cleaner, just not as long as hardwood charcoal..  Just what I read somewhere, no experience with that.
max

[Don P]

I'd agree the big lesson is to not put the vents down. The idea of a pressure relief was not an open hole to the air but a hole covered by a weighted cover, so its sealed from admitting aire, the cover would be displaced if pressure builds up though.

Taking 4" X pi= roughly 12 square inches of area of hole. If we wanted the cover to "pop off" at 5 psi... 12x5= 60lb cover would give a 5psi pressure relief valve. When the pressure builds to 5 pounds of pressure per square inch in the 60 lb cover, it will lift off and vent, then drop back into place when the pressure falls below that level. If the regular vents never clog, it would remain sealed. A backup that shouldn't have to open but might be nice if ever needed 

[Modat22]

also note that if you make a pressure relief as don suggest, sharpen the mating surface that the flat lays on. you want as little surface area making contact with the plate possible to keep the creosote from gluing the plate in place

[Todd]

I posted a video of the charcoal retort I made  charcoal retort burning

you can see the gas comming out of the lid because the pipe was partially blocked.

[Todd]

Sorry the video is so dark...I didn't realize it until I showed it to a friend that wasn't there when I filmed it.
(oh well...the fire looks bigger in the dark!)

[Dave Shepard]

I thought I'd bring this back to the top because of the charcoal discussions in the blacksmithing thread. I have to build somekind of reliable way to make charcoal for smithing and smelting this summer. The charcoal has to be broken down to a consistant size for smelting. I have an old grain grinder that I think I can modify to do the job, I've got to dig that out of the junk. ;D


Dave

[woodbowl]

I use a metal garbage can with the lid screwed on and a several holes punched in the side does the trick ....

Once the holes plugged with tar, and I heard the BOOM, as the can blew up ....

This is from holes in the bottem that got plugged with tar right? What if there was a hole in the bottem that had a 2" pipe welded in place and it extended to the top of the barrel? Wouldn't that be a straight shot to provide the heat without clogging up the bottem holes?

Just want to know if it goes boom before I try it.  :

[Fla._Deadheader]

 Where's yer spirit for adventure, Olen ???  :D :D :D
  I wanna know what Dave is "Smelting"  ??? ;D

[Radar67]

Olen, everything I've read on the subject says to place the hole in the top side. The hole is only to release the gases that build up while the wood is heating and drying. The key here is for the barrel to be air tight, except for the vent hole. Some people route the vented gas back into the fire to help heat the burn. This is where the tar build up occurs, in the pipe going under the barrel.

I've been wondering about passing the gas through a filter and using it to power a generator while the charcoal is cooking.

[Paul_H]

You wouldn't be able to filter out the tars that are in the gas.The woodgas generators draw the gas through the reduction zone which is around 2300F,and that "cracks" tars and other impurities.
When I made charcoal for the woodgas truck,I ran a hose out through the bung and there was some nasty crud driping out of there.The hose was too hot to hang onto after 10 seconds or so and the condensate formed in the low point of the hose and blocked off the gas.

A haywire setup but it worked for what I needed.

[Dave Shepard]

FDH we are smelting iron ore. There is a picture of the short stack smelter in the blacksmithing thread.


Dave

[Fla._Deadheader]

 Yeah Dave. I saw that, right after I posted here  : : ;D ;D

  Where I grew up, in NJ, There was clinkers and spots of iron ore laying all over the ground. Used to have a couple chunks of iron ore.

  In the BIG woods, where I started Deer Hunting, you could see the mounds left over from the massive charcoal "Burns" that took place in the late 1800's, early 1900's.  Some were 50 yards across, and in a circle. Small pieces of charcoal, you could rake out of the ground with yer boot.

  Also know of some 30' dia iron or steel bands, that were used to hold the "Mash barrels" together, for the "shiners" to make their hooch.  ;D ;D  Bands are 6-8 inches wide.

  Them old days must have been interesting.

[Dave Shepard]

We have some charcoal pits on our property. They aren't really pits, but round spots carved into the mountain. Supposedly the turn of the last century there was hardly a tree in the valley. It has grown back up to good oak forest again. From what I have read making charcoal was a dirty solitary way of life, with the occasional explosion of course. :D


Dave

[johnjbc]