(57) A concurrent flow grain dryer of the type in which drying air passes through a drying column or tower in the same direction as grain falling down the column or tower the air being extracted through one or more ducts extending horizontally across the column or tower the ducts being open bottomed troughs having a closed top and sides extending downwards from the top wherein the boundary of the effective lower edge of each side of a duct is longer than the horizontal length of the duct.
The fact that the boundary edge is longer than the length slows down the air as it passes down and subsequently around the effective lower edge up into the duct so as to reduce the possibility of grain being carried into the duct by the air.