Andy Dingley wrote:

An incinerator needs draught and this ought to be natural draught, not
faffing about with a fan.

Natural gas is a sight easier to burn than wet biomass and most of us expect
to have fans in boilers. Fans provide turbulence, one of the 3Ts needed for
good combustion.

Have a look at air curtain burners, one way of burning tonnes of waste wood
fast, I have built several, including using a 45 gallon drum and an Earlex
vacuum with thyristor speed control.

AJH