Any new small charcoal retorts out there?

[richardwale]

Superb. Good luck with your sales, looks lovely stuff. 5 or 6 pallets per burn is brilliant, must be very efficient in the firebox? Does it work like a modern stove?

[Woodworks]

Good stuff HertsWood. How big is you charge chamber

 

 

My MK2 will be ready for another round in a day or two. Now got a thermometer and probe. Cant put it into the charge chamber but can get it into the fire box or touching the outside of the charge chamber. What sort of temperature should I be looking to have these at and should it be steady throughout the burn?

 

Thanks

[SteveA]

Good stuff HertsWood. How big is you charge chamber

 

My MK2 will be ready for another round in a day or two. Now got a thermometer and probe. Cant put it into the charge chamber but can get it into the fire box or touching the outside of the charge chamber. What sort of temperature should I be looking to have these at and should it be steady throughout the burn?

 

Thanks

 

Great stuff

In the Village Idiot thread I think it mentions keeping things at 500deg C.... and not beyond 550deg C but you might want to have a double check on that.

 

Got fingers crossed for ya....

cheers, steve

[Woodworks]

Thanks Steve

 

Will track down TVIs thread and have another look through. I thought the Exeter measured flue exit temperatures though but could be mistaken

[Woodworks]

Got MK2 fired up but only time for one charges worth. Got temperature sort of under control but better sealing required as it still climbed to 600C for a bit. Flue and firebox seem to get pretty much the same temperature so can see why the Exeter just measures here. Mine has a 6mm hole now drilled in the side

 

So much less exciting having things under control though and other than a bit of smoke you would not have known the thing was running. No heat issues this time apart from the stainless angle that support the charge has still sagged even at these much lower temps. Got to work tomorrow so will not get to check the charcoal until tomorrow night.

[Woodworks]

Well the charcoal is fine but looks no different from my other burns which presumably were hotter.

 

How does the temperature it's made at affect the charcoal?

[openspaceman]

Well the charcoal is fine but looks no different from my other burns which presumably were hotter.

 

How does the temperature it's made at affect the charcoal?

 

The proportion of fixed carbon increases but the yield decreases, so at 400C you can get a yield of 45% high volatiles char from scots pine but at 900C this reduces to 15% of the initial dry wood but its fixed carbon is nigh on 100%.

 

Also the size of the log matters, small particles will have a lower yield than a chunk as secondary reactions happen within the wood when vapours get cracked back to char but can escape before this happens if small enough. If you blow dry sawdust into a hot chamber such that it's temperature rises to 1000C in a second almost no char is formed, only vapours and gases.

 

There is also a change in state of the carbon matrix around 400C

[Woodworks]

The proportion of fixed carbon increases but the yield decreases, so at 400C you can get a yield of 45% high volatiles char from scots pine but at 900C this reduces to 15% of the initial dry wood but its fixed carbon is nigh on 100%.

 

Also the size of the log matters, small particles will have a lower yield than a chunk as secondary reactions happen within the wood when vapours get cracked back to char but can escape before this happens if small enough. If you blow dry sawdust into a hot chamber such that it's temperature rises to 1000C in a second almost no char is formed, only vapours and gases.

 

There is also a change in state of the carbon matrix around 400C

 

Thanks

 

So from the point of view of basic BBQ charcoal the lower temps produce a higher yield. Are there any advantages to a smaller yield with more fixed carbon? Don't really know what this means anyway as science is not my strong point

[SteveA]

Got MK2 fired up but only time for one charges worth. Got temperature sort of under control but better sealing required as it still climbed to 600C for a bit. Flue and firebox seem to get pretty much the same temperature so can see why the Exeter just measures here. Mine has a 6mm hole now drilled in the side

 

So much less exciting having things under control though and other than a bit of smoke you would not have known the thing was running. No heat issues this time apart from the stainless angle that support the charge has still sagged even at these much lower temps. Got to work tomorrow so will not get to check the charcoal until tomorrow night.

 

Well the charcoal is fine but looks no different from my other burns which presumably were hotter.

 

How does the temperature it's made at affect the charcoal?

 

Great to hear you are getting temperatures more under control. Are you finding that you can use less wood for the firebox now?

 

Maybe you won't have any sagging issues if you can keep the temperature at or below 500deg c?.... or maybe use some thicker more heat resistant material for the stainless angle, although 600deg C is probably much too hot if it's gonna stand up to the heat over time.

 

cheers, steve

[SteveA]

Thanks

 

So from the point of view of basic BBQ charcoal the lower temps produce a higher yield. Are there any advantages to a smaller yield with more fixed carbon? Don't really know what this means anyway as science is not my strong point

 

Don't worry.... I'm also on a learning curve with all this stuff.

cheers, steve