The effect of temperature on the distributor design in bubbling fluidized beds

Abstract

In this paper the effect of the temperature on the distributor pressure drop ratio is studied. There is a lack of information in the literature concerning the effect of the temperature on the performance of the distributor plate, and its possible role on non-uniform gas distribution. The effect of temperature on the distributor pressure drop has been experimentally established for the first time for two different air distributor plates, multiorifice and tuyere. The distributor pressure drop curves were obtained at different temperatures by means of pressure measurements. The well-known orifice equation was used to predict the distributor pressure drop at different temperatures and a good agreement with the experimental data was found. A methodology to obtain the distributor open area as a function of the bed temperature for different bed aspect ratios was developed. It was found that when operating at higher temperatures the distributor pressure drop decreases for the same gas velocity due to the decrease in the gas density. The resulting decrease of the distributor to bed pressure drop ratio shows that gas distributor plates have to be designed at the operating temperature instead at the ambient temperature to avoid non-uniform gas distributions and to save cost in manufacturing and operation.