Pressure drop of centripetal gas flow through rotating beds

The pressure drop across packed beds that are rotating differs in significa nt and unexpected ways, compared to the pressure drop behavior across conve ntional packed beds. For a wide range of operating conditions, (1) the pres sure drop across an irrigated bed can be significantly lower than that acro ss a dry bed and (2) for a fixed outer diameter, increasing the depth (i.e. , more transfer units) of a rotating bed can result in a reduction in the p ressure drop across the bed. Furthermore, the power required to spin the ro tor diminishes as the vapor flow rate increases. Previously published corre lations on the pressure drop across rotating beds do not explain or predict these phenomena. Here, a semiempirical sectional pressure drop model is pr esented, where all of these phenomena are related to the gas phase conservi ng its angular momentum as it flows from the shell through the rotating bed toward the centrally located exit.