Ultrasound Tomography for control of Batch Crystallization

  • Panos Koulountzios

Student thesis: Doctoral ThesisPhD


The main objective of this thesis is to develop a better understanding of materials’ interfaces in spatial and temporal domains over dynamical industrial processes via 2D and 3D visualization and quantitative acoustic measurements using Ultrasound Computed Tomography (USCT). USCT is an imaging method that permits the determination of the spatial distribution of materials based on their acoustic properties. Tomographic techniques are usually based on a number of sensors that are located in a meaningful order around the region-of-interest (ROI). In the particular tomographic technique, piezoelectric transducers that emit signals of a standard frequency have been used. The main advantage of this imaging modality is the low-cost development but also its non-destructive and non-invasive behaviour to the process.
The control of industrial processes is becoming crucial as the research and engineering community aims at fully automated solutions. Thus, monitoring and control of tank reactors play a significant role in the overall developments. In general, this thesis focuses on improving the performance of static/dynamical USCT visualization and quantitative measurements for industrial processes. The developed studies aim to investigate in depth the USCT developments and the application in industrial reactors processes and dynamical complex processes involving high mixing. This work aims especially, to investigate USCT functionality in the batch crystallization process, where there is a great need for real-time measurement and integration of imaging and control systems towards the process automation. Detailed applications and further work are suggested. Although USCT is a new imaging technique and lots of issues are still preserved to be solved, it is believed that such research would have contributions to the future development of USCT research.
This thesis includes a number of novel approaches that constitute contributions to the USCT imaging field. At first the quantitative sound-speed imaging was developed, providing good correlation with concentration in concentrated solutions. Then the same concept transmission imaging tested in many crystallization scenarios establishing a thorough investigation of USCT in batch crystallization. In continuation, the developed transmission imaging extended in 3D and finally in 4D imaging using a spatiotemporal Total Variation algorithm. Lastly, a new triple-modality imaging is introduced as a fast and accurate method for industrial imaging proving to be more efficient than the single methods.
Date of Award16 Nov 2022
Original languageEnglish
Awarding Institution
  • University of Bath
SponsorsMarie Skłodowska-Curie Innovative Training Network
SupervisorManuchehr Soleimani (Supervisor) & Pedro Estrela (Supervisor)


  • Acoustics
  • tomography
  • inverse problems
  • image processing
  • Sensors
  • ultrasounds
  • Acoustic Imaging
  • crystallization
  • Monitoring
  • Industrial processes

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