Thread: getting rid of sawdust

Originally Posted by Stumpkicker

What about a steam power plant.

Too difficult. Gasification is the go, but sawdust is too fine. What is needed is a way of making it into chips about 5-10mm across.

Originally Posted by BobL

You're obviously not using enough hand tools. Get the #7 jointer out and a 6+" wide piece of karri should warm you up nicely!

Oh I would Bob but the amount of karri that I have to plane. Boards that are 10"s wide and miles and miles of it. I am just so sick of the stuff.

What about a steam power plant.

that would work. thats how coal plants work just heat up watter and drive turbines.

hmmmmmm. i might do some digging.

Originally Posted by Exador

Too difficult. Gasification is the go, but sawdust is too fine. What is needed is a way of making it into chips about 5-10mm across.

Millions have been spent on trying to make gasifiers that will work with chip without success. Clogged pipes and toxic biproducts have been the problem. If you can make a gasifier work take out a patent on your setup.

cheers
Steve

Originally Posted by InterTD6

A few sugar mills in Northern NSW are going over to burning their waste & generating power from it then selling the power back to the grid, the hip word now is "co-generation"
years ago big remote sawmills used to be powered by burning sawdust or small hydro plants
regards inter

my father used to work in the sugar mills in qld and northern nsw.

they used to have to go out and chop wild apple to burn to fire the boilers. the mills would mix this with the processed cane fiber and it would burn incredibly hot. they used apple cos its so soft and easy to chop. althow it dosent burn well on its own miked with the cane pulp it was a great fuel.

i live about 800mtrs from condong mill and yep they do not buy in any electricity and sell excess back to the grid, they burn absolutely huge amounts of camphor laurel as it is a weed down here and the smell is absolutely beautiful especially when the mill is crushing and mixes with the odour of molasses, cheers peter (grandad)

Peter(grandad), Exador says dust is too fine to burn and I can appreciate the challenge, but the mill next door, is that burning dust or chips? I've heard of a mill that did burn its dust but that may of been just overnite to keep the boiler warm. If you've ever emptied a dust bag from a floor sander, or such, onto a fire you'll certainly know that aeroated dust certainly burns real well. Didn't they convert deisles during WW2 to burn coal dust.(may seem irrelavant but a boiler would seem alot more primative than an engine. Would blowing the saw dust in aeroate it suffice?

Yeah the Germans had a system for turning brown coal dust into diesel that an coal shale oil There was some talk of trying it again how ever it all fell in a heap with no explination why

Originally Posted by Stopper

Millions have been spent on trying to make gasifiers that will work with chip without success. Clogged pipes and toxic biproducts have been the problem. If you can make a gasifier work take out a patent on your setup.

cheers
Steve

There is quite a large amount of power being produced in Europe using wood gas. The secret is good filtration and the right-sized chips, as I understand it. I looked into doing an export arrangement at one time, but the plants over there want supply agreements that stretch to 10s of thousands of tons and it has to be basically kiln dry, which meant it wasn't for me.

Here in Brisbane, Thiess will no longer accept wood waste bigger than 450 diameter, apparently because the tub-grinding they have to use ro reduce it produces the wrong-size chips and too much dust.

I also recall glock (Trevor) mentioning that they had installed a chipping plant for their waste at the plant he works at in Grafton which they then export to Europe.

I have started working on a modified downdraught FEMA-style unit, using forced induction and an open hopper. I plan to filter through a small cyclone, followed by a pipe filled with coarse perlite (expanded obsidian), followed by a bed of woodchip . I've experimented a little with this setup and it seems to work pretty well, as well as being easy to clean (just dump the filter material and refill). The perlite also has the advantage of being non-flammable, so if sparks get through the cyclone, they're not a problem, as well as being quite sibnificantly basic chemically, thereby providing a counter to any acidic by-products. It's also very light.

I'm still trying to work out the best way to keep the grate clean, but I'm moving toward a simple vibrator consisting of a motor driving a shaft with an offset weight, such as is used for cement hoopers and the like.

If this works as i hope, I should be able to burn around 10-20kg of blocks/chips an hour and generate at least a few kilowatts of power. If it doesn't, I'll have learnt something... I'll keep you posted.

Coal seam gasification is used all over the place. It even occurs naturally, such as down near Picton in NSW, where a seam has been smouldering since it self-ignited years and years ago due to a bush-fire or lightning strike hitting an exposed part of the seam.. Occasionally enough gas makes it to the surface to produce a visible flame when it hits the air.

Stumpkicker, during WW2 they had a lot of vehilcles fitted with gasifiers, which included the large canvas gas bags you sometimes see in pictures of the time. They used coal, mostly, but could be run on almost anything organic, including grass clippings or vege scraps if they were dry enough. Too much green waste makes a lot of nitric acid and various other toxic nitrogen-based products., though.

Diesel production from both coal seam gas and wood gas has been tried, but not very successfully. It's simply not a viable process while fossil fuel is cheap.

Here's a good overview: http://www.gasificationaustralia.com...d=10&Itemid=34

there is an old bloke up teh road with a truck he used to do teh carrying run (before my time) it has a small tank on the side that eh burns coal in and teh gas from the coal runs teh vehicle. teh bin that the coal goes in is no bigger than a 4 gallon drum.

Why not use it to fire a steam plant for a kiln then you can turn over a thousand times more wood and thus generate a ship load more saw dust?

Originally Posted by weisyboy

there is an old bloke up teh road with a truck he used to do teh carrying run (before my time) it has a small tank on the side that eh burns coal in and teh gas from the coal runs teh vehicle. teh bin that the coal goes in is no bigger than a 4 gallon drum.

They used a system like that during the war.

I wonder what the CO2 emissions would be like?

Originally Posted by artme

I wonder what the CO2 emissions would be like?

do i care?

Originally Posted by weisyboy

do i care?

No but Al Gore does