PRESSURE PROBES IN THE MEASUREMENT OF BUBBLE PROPERTIES IN THE FLUIDIZATION OF FINE PARTICLES

Purged pressure probes and a data reduction method by means of a recta ngular pressure drop pulse (RPDP) have been developed to measure pierc ed bubble size and velocity for Group A powders using specially prepar ed size fractions of FCC powders in a 0.152 m fluidization column. Mea surement results show that there exists an equilibrium bubble size of about 4 cm for FCC powders smaller than 70 mu m, and the measured bubb le sizes are compared with the Geldart equation and Werther's correlat ion. The measurement results of bubble velocity show that bubble veloc ity can be correlated based on the Davidson and Harrison equation as: u(b) = u - u(mf) + 1.5 root gd(b).