In most drying operations, the air is heated to increase its moisture holding
capacity, and a fan is used to create air flow through the seed mass
to remove moist air which has already absorbed moisture from the seed. Air
to absorb moisture from seed surfaces and then carry the moisture away
from the seed is provided by forcing air to flow through the seed mass. This
requires an airtight system to take air to the seed, a fan to force air into and
through the seed mass, and a system to hold the seed in a manner so that the
drying air can flow through the seed mass.