Metoda oceny struktury hydraulicznej cyrkulacyjnego złoża fluidalnego

Przedstawiono metodę oceny struktur w cyrkulacyjnym złożu fluidalnym, opartą na wartościach parametrów i rozkładach funkcji stochastycznych wyznaczonych dla spadku ciśnienia statycznego. Podano przykłady rozkładów funkcji stochastycznych charakterystyczne dla poszczególnych struktur złoża oraz określono przedziały liczbowe zmian parametrów stochastycznych opisujących kolejne struktury.

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The investigations of heat and mass transfer, occurring in a fluidized bed, require, as it is common for multiphase flow, determination of the flow pattern. For fast fluidized bed with the inner and outer circulation of solid, it is possible to apply much higher gas volume fluxes in relation to classical fluidized bed. The method of estimation of the bed condition was proposed by means of the analysis of pressure fluctuation on the wall of a fluidized apparatus. The test section was a transparent tube with the inner diameter of 59 mm and 2700 mm long. The gas velocity was changed up to 10 m/s, whereas the solid flux was changed from 50 to 400 kg/h. As the solid phase., eight types of solids were used of the density from 540 to 3340 kg/m3 and the diameter from 0.49 to 1.79 mm. The changes of mean value of the pressure drop measured in the zone of the bed in the channel, and standard deviation of pressure from the mean value in the function of gas superficial velocity, served to determine the boundaries between particular flow patterns. The bed structure may be determined on the basis of the estimation of the shapes of the probability density function PDF and autocorrelation function ACF.