What factors influence moisture migration?
The behaviour of air currents in grain bulks is complex with several contributing factors. A key influence is the peak or ridge present in grain stored in bins. The peak or ridge acts as a chimney effectively channelling warm moist air. Channelling leads to the accumulation of water in the ridge or peak region. Peaks tend to be more predisposed to water accumulation than ridges due to their localised nature. Spoilage by moulds and insects in the ridge or peak of a grain bulk is often associated with moisture migration. Moisture migration can still occur in level grain bulks but the accumulation of moisture tends to be spread across the whole surface of the grain bulk. The bulk density of the grain type influences natural convection. The type and size of grain, and the amount of fine screenings present affect bulk density. Natural convection currents appear to establish at a faster rate where clean grain of low bulk density is held in well-sealed storage bins. There have been numerous r
