Development of Particle Sizing Based on Dynamic Image Analysis

Dispersion of particles in multiphase-flows can be both quantitatively and qualitatively characterised using modern optical or nonintrusive devices. The development of a nonintrusive particle sizer (NPS) is performed. This device employs a high intensity pulsed laser as a light source and a digital camera to capture the particle images. The dynamic image analysis (DIA) software is designed to analyse the captured images and control the inputs and outputs of the data. The NPS has the ability to operate using shadow sizing, direct illumination (DI) and particle mixture shadow (PMS) techniques. The architecture and working principles of each technique are described in detail. A novel technique, which is Particle Mixture Shadow has been developed for the characterisation of solid/liquid mixture dispersed in air. The capability of the technique to distinguish and size the solid and liquid particles is demonstrated. The sensitivities of laser intensity, image magnification factor and scattering angle on the accuracy of particle size have been investigated. In order to evaluate the repeatability and the accuracy of the NPS device, the measurements of certified microsphere particle sizes are repeated several times. The results are then validated against proprietary particles with specification data provided by the manufacturer. The particle size error of the developed device confirms that it has a good repeatability in sizing the particles. The device is applied to solid and liquid particles dispersed in fluid media using shadow and DI techniques. The results comparison between these techniques is also demonstrated.