Woodchip moisture content

[tree monkey]

could you not setup a heat exchange system using pipes put through the pile of chip thats heating up and have some old radiators set up so it could be used to aid the drying process ?

[openspaceman]

could you not setup a heat exchange system using pipes put through the pile of chip thats heating up and have some old radiators set up so it could be used to aid the drying process ?

 

Probably better just to blow air through the heat and let the heat from the microbes lower the rh of the air directly.

 

Most big chip consumers just take the hit and lose the vapour (and enthalpy of vapour) up the flue it's only small boilers that don't cope with high moisture. Local firm to me just stockpiles logs in the round during the summer as chip heaps respire energy and the mould clumps the chips.

[renewablejohn]

The more efficient wood boilers use woodchip of less than 20% which I achieve by chipping split logs that are already at that moisture content although it does cause more wear on the chipper. As a compromise boilers have been designed to accept upto 35% moisture which we achieve by storing trees undercover for 6 months prior to chipping. Finally power stations which are very inefficient accept moisture content upto 55% which virtually any green tree will be less than. Piling chip in a heap to dry it is a recipe for spontaneous combustion. Normal method of drying chip commercially is adaption of equipment used for corn drying but generally its better to chip the wood at the right moisture content rather than trying to dry chip.