In-line FBRM monitoring of particle size in dilute agitated suspensions

The use of laser light scattering technology, as applied by the Focused Bea m Reflectance Measurement (FBRM) probe from Lasentec, for the in-line monit oring of particle size was investigated. In particular, the effects of prob e position and orientation were studied for a dilute agitated aqueous parti culate suspension of known particle size distribution in a number of vessel s. In all cases, the normalised chord length distribution recorded with the FBRM system was consistent with the theoretically predicted distribution. However, the total number of counts measured was a function both of solids concentration and probe location. Optimum probe location is dependent on th e ease with which the solid phase can be suspended with the available agita tion system and on the associated dominant flow direction within the vessel .