This review provides an overview of the tomographic sensing methods that can be utilized to study particulate behaviour and their particular attributes (speed, sensitivity, robustness etc.). The process benefits arising from such techniques are now becoming recognized -
- Detailed spatial and temporal information of components within process equipment to provide for modelling and model verification purposes (e.g. solid concentration profiles in hydrocyclones, chaos analysis of fluidized beds). Improved process knowledge provides more reliable models and hence greater confidence in scaling of process plant with consequent time and cost savings.
- Characterization of flow and porosity in structure materials (e.g. magnetic resonance imaging of porous solids). In-situ three-dimensional analysis is not available using other instrumental method.
- On-line monitoring of structured materials in a pipe (e.g. microelectrical imaging of emulsions and concentrated dispersions, moisture detection in powder flow). Rapid feedback of information provides new opportunities for control and enhanced efficiency, reduced wastage.
The review provides literature citations and sources of information which potential users may consult. Particular emphasis is placed upon electrical methods, due to their inherent suitability for widespread on-line use. Future possible measurement capabilities (component specificity, mass flow measurement etc.) of the family of electrical methods are discussed and likely dates when the technologies might be sufficiently mature for process use are provided.