Home | My Profile | Contact Us
Research Trends Products  |   order gateway  |   author gateway  |   editor gateway  
Register | Forgot Password

Author Resources
 Author Gateway
 Article submission guidelines

Editor Resources
 Editor/Referee Gateway

 Regional Subscription Agents/Distributors
Trends in Chemical Engineering   Volumes    Volume 8 
Hydrodynamics and applications of cylindrical spouted beds
María J. San José, Martin Olazar, Sonia Alvarez, Miguel A. Izquierdo, Javier Bilbao
Pages: 15 - 34
Number of pages: 20
Trends in Chemical Engineering
Volume 8 

Copyright © 2003 Research Trends. All rights reserved


The hydrodynamics and applications of cylindrical spouted beds were studied on a pilot plant scale unit by operating under a wide range of the contactor-particle system (base angle, inlet diameter to contactor base diameter radio, inlet diameter to particle diameter ratio) The peculiar hydrodynamic behaviour of spouted beds of conical base is attributed to the influence of the conical section of the base. Assuming that these beds, mainly shallow beds, are made up of the conical section of the base and the posterior cylindrical section, the correlations for calculation of minimum spouting velocity, maximum pressure drop, operation pressure drop, bed expansion, maximum bed height are presented for this method of contact.

The geometry of the dead zone (stagnant solid) in cylindrical spouted beds of flat base or nearly flat base has been studied using an optical fibre probe. 

It is proved that the maximum spoutable bed height can be calculated using the equation proposed by Morgan et. al. [1] for conventional spouted beds and for small particle diameters the equation of  Malek and Lu [2] is also valid.

The following local properties of the bed have been determined: spout geometry, bed voidage in the spout, annulus and fountain, particle velocity in the three zones of spouted beds: spout, annulus and fountain and particle trajectories by means of an optical fibre probe. The experimental results of the spout  geometry have been fitted to an empirical equation for calculation of the average spout diameter. Correlations are proposed for calculations of the local been voidage in spout and annular zones, along the spout axis and in proximity to the contactor wall. The experimental results of the particle velocity prove the validity of the equation of Epstein and Grace [3] for the prediction of the vertical component of particle velocity in the spout. From the values of vertical components (experimental) and horizontal components (calculated) of particle velocity, maps of velocity vector throughout the bed have been drawn and zones of preferential solid cross flow into the spout have been determined .

The versatility of cylindrical spouted beds for stable treatment of binary mixtures of glass spheres has been proven. The segregation is much lower than that corresponding to other contact methods. These contractors may be contempled  for applications conditioned by bed segregation, such as in exploiting wood or agroforestal residues (pyrolysis, combustion or gasification).

A model is developed to describe the particle dynamic behaviour of spouted beds, which is based on the continuity equation for the solid in the spout and annular zones, force balance for a particle along the axis and on soil mechanics equations to describe solid behaviour  in the annulus.

Buy this Article


Buy this article
Buy this volume
Subscribe to this title
Shopping Cart

Quick Links
Search Products
Browse in Alphabetical Order : Journals
Browse by Subject Classification : Journals

Ordering Information Ordering Information
Downloadable forms Downloadable Forms