Passive acoustic emissions from particulates in a V-blender

Regulatory agencies are recommending the development of process analytical technologies (PAT) to improve the efficiency and product quality during pharmaceutical manufacturing.

The objective of the research was to investigate the potential application of passive acoustic emission monitoring of a V-blender.

Trials were conducted with sugar spheres, lactose or MCC in a V-blender. Vibrations from acoustic emissions were measured using PCB Piezotronics accelerometers with ICP signal conditioners.

A wavelet filter was applied to the measured acoustic emissions to remove vibrations from the tumbling motion of the V-shell, allowing a focus on information about particle motion and interactions within the V-shell. The ideal sensor location was determined to be the lid of one of the V-shell arms due to the impact of the tumbling particles on the lid and transmission of the vibrations from other particle motion within the V-shell. The amplitude of vibrations increased with particle size due to larger particle momentum before a collision. The fill level and the V-shell scale also influenced the measured vibrations as particle motion was affected which in turn affected momentum. Changes in particle flowability could be detected through variations in the measured acoustic emissions.

The measured vibrations from passive acoustic emissions reflected particle motion and interactions within a V-blender demonstrating potential as a monitoring method.