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Tomato concentrate and baker's yeast suspension were dried in the laboratory scale Mechanically Spouted Bed dryer with inert packing. Due to a large contact d a c e provided by the inert particles, very fast drying process can be achieved, ifthe thickness of the wet coating formed on the surface of the inert packing is film-like. The d&ion resistance can be then considered negligible and dq4mg can be performed at "quad-constant" rate. Derived fiom hydrodynamic characteristics the contact time between hot air and the wet coating is very short, therefore gentle drymg process can be performed. The quality of the dried yeast was controlled by counting the living cells (relative viabilny) and by measurement of the dough rise time. During continuous drying of thermoplastic tomato purCe the "case hardening" periods could be shortened and tomato powder with insignificant quality loss was produced.

Conventional techniques for measurement of dielectric properties of ionic liquids or electrolyte solutions fail because the samples are largely short circuited by the high electrical conductance. The object of the author's research activity was to elaborate an apparatus (microwave dielectrometer) and method suitable to measure the dielectric constant (epsilon(')) and loss factor (epsilon(")) of well conducting ionic liquids and other solvents. This process is based on a revised waveguide method completed with an automatic calibration possibility. Contrary to conventional measuring methods this technique uses about 20 W/g power density. The measurements were carried out at 2.45 GHz frequency in the temperature range from 10 up to 100 degrees C. The obtained (epsilon(')) and (epsilon(")) values of different solvents were compared with several published (calculated and measured) data. Statistical analysis was used to determine the error of measurements and distilled water was chosen as a standard for study of data dispersion. To accomplish statistical analysis, namely, the dielectric characteristics have to be determined at the same temperature. The values of variances were less or equal 1 in case of epsilon(') and decrease with increasing temperature. In case of epsilon(") the variance data were much smaller.

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Comparison of experimental results with predictions of the main hydrodynamic characteristics used for the sizing of spouted bed dryers are made. Various new equipment constructions are demonstrated together with operating experiences, both with an emphasis on scale‐up.