Microwave drying of porous products with novel tomography-assisted moisture control

Fellow: Adel Omrani (ESR 7)

Host: Karlsruhe Institute of Technology (Germany)

Main Supervisor: Dr. Guido Link

Background:

Microwave heating technologies allow for efficient drying processes of porous products. Today, empirical methods, without knowing neither the initial nor the progressing moisture distribution, are used to optimize the process parameters. The Ph.D. student will assess and develop novel concepts for inline tomography measurements. Target is the development of concepts showing the best possible performance in the measurement of the moisture distribution, and, at the same time, showing the lowest kind of electromagnetic interference with the high-power microwave heating system. The research work includes detailed theoretical studies on possible antenna/receiver concepts for microwave tomography measurements using 3D simulation tools. Starting from specific examples of drying processes a generalized method for dielectric characterization of porous materials as a function of the temperature and the moisture content shall be developed. Concepts shall be prepared for a suitable human-machine interface. The final target is to implement and validate the most promising concept in a continuous microwave-assisted drying process in strong collaboration with the other scientific and industrial partners in the project.

Research Activities / Objectives:

    • Generalized method for dielectric characterization of porous materials as a function of temperature and moisture
    • Derivation of antenna concepts for microwave tomography including solution of the forward problem with FEM electromagnetic simulations
    • Experimental investigation and validation of MWT and ECT in a continuous microwave-assisted drying process. Qualification of the control concept.
    • Combination of tomography with an innovative MIMO control concept of a microwave-assisted drying process with distributed microwave sources