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Jet‐spouted beds characterised by high velocity gas jets (above 1.7 Umsl), and shallow bed depths H0 of around 2 D1 were investigated on laboratory scale beds and industrial scale beds and the results obtained thereof are correlated and presented in this work. Compared with the classical spouted beds, important differences in bed structure, solid movements and basic hydrodynamic characteristics were observed. The minimum spouting velocity, bed voidage and pressure drop during stabilized spouting are described in terms of dimensionless equations. Bed expansion was used as the basis for the classification of different jet‐spouting regimes (incoherent spouting, fast spouting, pneumatic conveying) and changes in the slope of the bed expansion curve are correlated with regime changes. This classification could be useful in the optimization of industrial scale jet‐spouted beds. A typically applicable regime of fast spouting was identified.

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The time course of injuries and electrolyte leakage as well as changes in leaf water content and relative turgidity during chilling at 5°C, 65 or 100 % relative humidity (RH) were determined for seedlings of two maize hybrids differing in chilling tolerance. In the course of chilling of entire seedlings the statistically significant injuries and increased leakage of electrolytes occurred first, followed by significant water deficit in leaves which was independent of RH and genotype. However, during prolonged chilling high and significant correlation between the level of chilling‐induced water stress and the extent of injuries was observed. Thus it has been assumed that the main factor responsible for primary chilling injuries in maize seedlings is the immediate influence of chilling temperatures on the cell membranes, and not the secondary water stress. The level of the water stress and the extent of the dehydration injuries under chilling conditions depended on the chilling sensitivity of the genotype. Differences between the examined genotypes consisted not only in delayed chilling injuries in a chilling tolerant hybrid, but also in significantly lesser effects of these injures on water relations. However, exposure to low temperature of the aboveground part or of the roots of the seedlings only, caused first the chilling‐induced marked water deficit in the leaves and next increased leakage of electrolytes. A direct effect of chilling temperature on the membranes in a situation when only a part of the seedling is being chilled, may be less harmful to the plant as a whole owing to normal functioning of the non‐chilled part.

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A conical jet‐spouted bed dryer with inert bodies was used for drying of animal blood plasma. The effects of the operating conditions on the product properties, final moisture content and throughput of the dryer were investigated. A drying rate model using the conventional rate equation, where the overall effective driving force is based on the surface temperature calculated from the unsteady‐state heat transfer Fourier equation, was proposed. Satisfactory agreement between calculated and experimental results was obtained.