Principles of Drag Force Flow Sensor

Abstract

Abstract Drag force flow (DFF) sensor is a process analytical technology (PAT) for real-time inline monitoring of wet mass consistency during high-shear wet granulation. The DFF probe is a hollow cylindrical pin, whose minute deflection is measured by optical strain gages. Time-dependent deflection of the pin can be connected to single granule impacts and bulk wet-mass action. When used in a granulator, sensor dynamic measurement can be characterized with force pulse magnitude (FPM), a quantity related to blade action. Time-dependent histograms of FPMs are described adequately by lognormal distribution and provide two principal outputs: mean (MFPM) and width (WFPM). These two parameters are indicative of fundamental material properties, such as shear viscosity and granule size and density, because they were changing during the granulation process. The dynamics of MFPM and WFPM could be correlated to granulation end point and used for scaleup.