Wood Chip Bunker Drier
1. This small bunker was set up to test dry Coppice Willow chips at Long Ashton Agricultural Research Station, Bristol, UK. A central phlenum chamber received hot air from a CHP engine and then into floor ducts across the bunkers. There was no control on the ducts to shut them off, but they provided the information to build larger bunkers.
2. At Rural Generation in Londonderry, Northern Ireland, this grain drying shed is used between harvest times as a wood chip dryer. Grilled channels can be seen across the floor which are fed by a long phlenum chamber outside the wall. Hinged doors cover the duct ends so that the bunker can be dried in segments depending on how full the bunker becomes.
3. On top of the 9 foot stack, the boundary line can be seen between the Coppice Willow and larger wood chips. The willow has just been cut and is the harvest from 10 acres. Wood chips were stacked in to fill the storage area to maximum capacity.
4. Close up you can see the edge of the Willow boundary drying and then the surfaces darken as moisture increases as it passes out of the surface layer from the wet pile.
5. To separate fines out of the wood chip at RGL, we used a potato machine to shake the fines out of the chip. These fines on examination contained a lot of dirt and rotten wood, which in a gasification process results in an increase of ash and slagging.