Abstract
Effects of operational variables such as liquid flow rate, inlet air temperature and inlet air humidity on the properties of granules, prepared by a tumbling fluidized bed granulation while controlling the moisture content with an IR moisture sensor, were investigated experimentally. An increase in the liquid flow rate, i.e. the increase of the droplet size resulted in a slight increase of granule size and size distribution, while little influence was found of the inlet air temperature and humidity on granule size, size distribution or the apparent density. Remarkably good reproducibility was obtained in the granules prepared by the moisture control method. It was therefore concluded that by applying this method to the wet granulation by a type of fluidized bed, the effects of external circumstances could be fully eliminated and good reproducibility maintained.