A new model is proposed for obtaining the velocity profile of the particle ejected from the bubble dome in a freely bubbling 2-D fluidizedbed. Its basis is the supposition that the initial velocity of the ejected particles, with a direction perpendicular to the dome contour, dependson bubble velocity and bubble growth velocity. This model differs from those previously appearing in the literature in that it is valid not onlyfor vertical-ascent circular bubbles.Experiments were carried out in a freely bubbling 2-D fluidized bed using a high-speed video camera to measure the velocity profile. Uponcomparing these results with the proposed model, it was established that, excepting some isolated cases, the model properly predicts themagnitude and direction of the maximum particle ejection velocity and the velocity profile.Using the work of Shen et al. (2004. Digital image analysis of hydrodynamics two-dimensional bubbling fluidized beds. Chemical EngineeringScience 59, 2607–2617), we obtain two general equations for the bubble velocity and the bubble growth velocity in a 2-D fluidized bed. Theseexpressions, together with the proposed model, can be used to calculate the initial velocity of the ejected particles
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