Use of biomass furnace for direct air-drying of grain and other particulate

A heating apparatus for supplying heated air to a dryer for particulate materials, said heating apparatus comprising:

• a biomass furnace comprising a burn chamber having an interior space in which combustible biomass material is receivable and combustible to generate heat, thereby resulting in heated exhaust air;
• and
• a chimney attached to the furnace and having a lower end that is in fluid communication both with the interior space of the burn chamber, and with an opposing upper end of the chimney that is situated in elevated relation to the lower end and outside the furnace to release a waste fraction of the heated exhaust air from burn chamber to a surrounding ambient environment;
• air ducting having an output end connected or connectable to the dryer, said air ducting being in fluid communication with the chimney at a location upstream from said output end to direct a useful fraction of said heated exhaust air from the chimney to the dryer via said air ducting;
• a fresh air inlet in fluid communication with both the air ducting and the surrounding ambient environment to admit fresh ambient air from said surrounding environment for mixture with the useful fraction of the heated exhaust air to create a mixed airflow composed of both said useful fraction of the heated exhaust air and said fresh ambient air;
• and
• an airflow control system configured to control said mixed airflow to the dryer through said air ducting, including temperature control of said mixed airflow by varying a ratio between said fresh ambient air and said useful fraction of the heated exhaust air within said airflow;
• wherein the output end of said air ducting is connected to the dryer at an air intake thereof that is in fluid communication with an internal grain space of the dryer to which grain is introduced for drying, whereby the airflow from the biomass furnace is fed into said internal grain space for direct drying of the grain by permeation of said airflow through the grain.