Best/Fastest seasoning of firewood

[Woodworks]

On 11/12/2017 at 09:30, richardwale said:

I'm the same, just need a small kiln to finish off the last bit of seasoning. I have a stack of timber, seasoned but uncut and rain wet, chuck into a small kiln set up and ready to sell.doesnt have to be top spec at all, stacks of pallet wood etc to feed it. Must be a way.....

Just thinking out load here but how about a baby vertical kiln. Thinking a woodburner at the bottom with say a couple of stacked IBCs above it all in an insulated tube. Have a small vent at the top and bottom so convection will be your fan. Sure I read on here somewhere if you the temperature up high you can dry very quickly. Say it takes 24 hours to finish your logs thats still 14 m3 a week.

[SbTVF]

It’s all very well getting temperature up very quickly but if you case harden it you’re stuffed. Yo need to hold moisture in for a period at the start or it’ll not work.

[skyhuck]

I used one of these.

 

https://www.ebay.co.uk/itm/insulated-storage-containers-better-than-steel-Secure-Strong-No-Condensation/162720565423?hash=item25e2e6c8af:g:OwMAAOSwfcVUHTyJ

[richardwale]

16 hours ago, Woodworks said:

Just thinking out load here but how about a baby vertical kiln. Thinking a woodburner at the bottom with say a couple of stacked IBCs above it all in an insulated tube. Have a small vent at the top and bottom so convection will be your fan. Sure I read on here somewhere if you the temperature up high you can dry very quickly. Say it takes 24 hours to finish your logs thats still 14 m3 a week.

I was thinking along similar lines. Building a concrete block chamber with a stove ( workshop stove )  in the centre, flue pipe out the top, couple of IBCs in there, keep the stove running for a few days....it's got to work, hasn't it?

[openspaceman]

53 minutes ago, richardwale said:

I was thinking along similar lines. Building a concrete block chamber with a stove ( workshop stove )  in the centre, flue pipe out the top, couple of IBCs in there, keep the stove running for a few days....it's got to work, hasn't it?

Yes it will work but the logs at the bottom will become dry whilst those at the top, exposed to colder, wetter air will remain wetter. Also the stack will need to be high enough to ensure the heat is all used.

 

The woodchip drier developed by border biofuels for Arbre  worked on this principle but they recycled the top layer to the bottom of the incoming batch, it was fairly efficient use of low grade (40C) waste heat, I think around 50% of the input heat went into evaporating water.

 

In general unless it's running constantly you need to aim for the heated  volume and sides to be low mass, otherwise you spend a lot of heat raising the concrete to temperature.

 

Two other points:

 

Themo convection isn't a good heat engine, so the heat necessary to create the buoyancy doesn't promote much air movement. A small fan would allow a FIFO system with horizontal stacking and a bit better recirculation for a more homogeneous drying cycle.

 

There’s really not much point having a batch with less than 20% moisture in some logs and more than 30% remaining in others.

 

Have you worked out the figures for what you want to achieve?

[openspaceman]

If anyone is still thinking about this for next season I have a redundant 150kW Talbot woodchip/logwood boiler which needs a new home. It has had little use from new (about 2009) as I bought it to heat our offices but the boss preferred gas, despite having a wood disposal problem at the time. I held on to it to use at my brother's house in Crediton but he is terminally ill so will have no need.

 

It is not a fit, fire and forget device as it has a crude grate and  manual ash removal but it is an excellent means of disposing awkward chunks of wood.

 

It's fully containerised with a chip hopper on top, the bare container and boiler weights 7 tonnes

 

I'll sort out some pictures and put it on arbtrader

[richardwale]

Hi, interested in pictures and prices please, thanks

[Haironyourchest]

A tip from the Norwegian Wood Firewood Book - (though maybe not relevant to your set up) - is don't buck up the tree straight away, leave it lying with the branches and leaves on for three weeks before processing. The leaves continue to draw moisture out of the wood through the capillary system before they whither and die, and can speed the curing time by several months. Works better with broadleaf trees, but conifers do this too.

[sandspider]

Doesn't the above only apply if the tree is felled in summer? If winter (and broadleaf) sap levels will be low anyway, and transpiration fairly minimal?

[andy cobb]

1 hour ago, Haironyourchest said:

A tip from the Norwegian Wood Firewood Book - (though maybe not relevant to your set up) - is don't buck up the tree straight away, leave it lying with the branches and leaves on for three weeks before processing. The leaves continue to draw moisture out of the wood through the capillary system before they whither and die, and can speed the curing time by several months. Works better with broadleaf trees, but conifers do this too.

The problem is it's not very practical to leave all brash on trees unless you have masses of room, would be easier to ring bark the trees to be felled 6 months before felling.

neither system is workable if your buying the timber standing though as the landowner wants you to buy as much moisture as possible.