MEASUREMENT OF MOISTURE-CONTENT BY IR SENSOR IN FLUIDIZED-BED GRANULATION - EFFECTS OF OPERATING VARIABLES ON THE RELATIONSHIP BETWEEN GRANULE MOISTURE-CONTENT AND ABSORBENCY OF IR-SPECTRA

In this study, the validity of moisture measurement by an IR sensor wa s investigated in fluidized bed granulation, The effects of operating variables on the relationship between granule moisture content and the absorbance of IR spectra were examined experimentally. It was found t hat the air Bow rate of purge air used for preventing powder adhesion, fluidizing air velocity, agitator rotational speed and spray mist siz e had no effect on the relationship, However, if the dampening speed w as extremely low, the effects of fluidization air temperature and liqu id flow rate on the relationship could be recognized, This was because the surface drying due to the extremely low dampening speed caused wa ter to transfer from the inside to the surface, As a result, it can be concluded that the measurement of moisture content by an IR moisture sensor tan be conducted with high accuracy, free of operating conditio ns, unless the granulation is conducted under an extremely low dampeni ng speed.