sawdust blast furnace

been thinking..... one thing I'd like to play with is blacksmithing. I have a small forge and a trashcan full of coal, so it's not like I NEED another way to make iron turn red, but I regularly generate bunches of sawdust and I just happen to have a spare blower just laying about. anybody here ever built a sawdust fired blast furnace? seems to me the trick is gonna be to get the mix of sawdust and air right and to keep it lit. it might need a "pilot" of a propane flame and some sort of sifting mechanism to act like a carbeurator to keep a steady amount of sawdust entering the stream of air.

hey, it might work....

Bridger

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nospam
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Hey, you better ground it or it'll explode.

Greg G.

Reply to
Greg G.

One of the local pine mills here burned sawdust to heat the kiln... come to think of it, the kiln burned to the ground 20 years ago:).

Reply to
Eric Ryder

See! I told you to ground it.

Greg G.

Reply to
Greg G.

Of course, coal is ground to dust and sprayed in new boilers, but except as some money sink, I can't see why you'd choose any method over anthracite. A lot of things must be kept within narrow limits to keep the right mix.

Reply to
George

You haven't checked prices and shipping rate for smith-grade coal, have you?

If you can show up at with a truck at the coal mine, even top-grade forge coal is cheaper than the gas to haul it. If you live too far to make that practical, then you don't even want to know the rate for a pallet of bagged Old Smithy coal.

Kevin

Reply to
Kevin Craig

It'll work just fine if you can figure out a way to control the transfer the sawdust to the burner.

I've tried to build sawdust burners for pottery kilns with limited success.

The main problem is feeding the sawdust into the burner. Fairly large volumes of sawdust are required & if you care at all about efficiency the rate of feed has to be constant.

I was pretty successful in making an auger feeder to mix the sawdust with the airstream but had problems reliably transfering the sawdust to the auger. I tried a funnel type supply to the auger, but was constantly faced with the sawdust bridging over in the narrow neck of the funnel thereby interrupting the feed rate.

Maintaining ignition is not a problem once the kiln is red.

A good strategy might be to build a fluidized bed for the sawdust then draw off the fluidized mixture as needed. It'd be pretty easy to do if the dust is coarse enough. The coarse dust from a two stage dust collector might work in a fluidized bed.

If you are interested I can post some numbers about air/dust ratios, dust densities, etc.

I'd really like to see a simple, workable sawdust burner design. It might help a lot of smiths and potters.

Reply to
dave martin

I can still get mine from off the tracks, so nope, I haven't.

Sounds like charcoal might be an option, depending on your hardwood availability.

anthracite.

Reply to
George

That's different from a blast furnace. A blast furnace reduces iron oxide ores to metallic iron, so you need a fuel that can give a reducing atmosphere. You also need an atmosphere that's free of impurities (particularly sulphur, the minor additions and any tendency to excess carbon) Sawdust won't do this - far too many volatile hydrocarbons.

Even for smithing, I doubt if sawdust is usable. Perhaps if you could burn it to charcoal first, but that's going to need a sealed retort as you cant burn sawdust in a charcoal burner's mound or a drum.

-- Klein bottle for rent. Apply within.

Reply to
Andy Dingley

Your'e right. I even thought about that difference as I was typing that, but I went ahead.... late night, I guess. I 'spose what I was looking for is more properly called a sawdust fired forge.... although to be frank about it, a lot of what I'm curoius about is what it would take to sustain a high volume sawdust flame.

Reply to
nospam

snip

well, you already have a blower going, so I guess some of that air could be used for the fluidized bed. if the blower outlet routes through the sawdust bin on it's way to the burner and has baffles and vents in it it just might work. could get exciting in a flashback though.

please

Reply to
nospam

Basically what you have to do is very similar to what coal fired utilities do with coal.

They grind the coal almost as fine as talcum powder, then blow it in the top of the boiler, which may be 5-6 stories high, and allow it to burn in the air while falling to the ground.

You face the same probelm with sawdust.

You need to aerate the sawdust so that it will burn.

Not an easy job to do in your typical shop.

Reply to
Lew Hodgett

Reply to
Mark

Wish I was. HB

Reply to
Henry Bibb

Reply to
Clarke Echols

Nope, recognizing the difficulties, I merely remarked that it did not seem worth the effort. A point which others have made over and over.

Oh yes, carb> I can't see why you'd choose any method over anthracite.

Reply to
George

HEY! cut it out with the off topic stuff already. Bridger

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nospam

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