Experimental study of fluidization characteristics of Geldart-D particles in pressurized bubbling fluidized bed

The pressurized bubbling fluidized bed shows great advantage in retreating municipal solid waste because it could effectively capture CO2 and enhance the reaction rate of the process of combustion and gasification. In the present work, fluidization characteristics of Geldart-D particles at elevated pressure were experimentally investigated, such as flow pattern, pressure drop, minimum fluidization gas velocity. At the same fluidization gas velocity, as elevating operating pressure, the fluidization of Geldart-D particles became more intense, the bubbles got larger, the standard deviation and the power density of dominant frequency of the pressure drop signal increased. While, under the same fluidization number, as increasing operating pressure, the fluidization of Geldart-D particles became smoother, the bubble size decreased, both the standard deviation and the power density of dominant frequency of the pressure drop signal decreased. It seems that, under elevated pressure, the fluidization behavior of Geldart-D particles would transition to that of Geldart-B particles. Finally, the minimum fluidization velocity of the Geldart-D particles was found decreased with the increase of the operating pressure. A new correlation for the prediction of the minimum fluidization velocity of Geldart-D particles at elevated pressure was also formulated based on the present experimental results. (c) 2022 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.

Automated summary

The pressurized bubbling fluidized bed is advantageous for treating municipal solid waste due to its ability to effectively capture CO2 and enhance the combustion and gasification process. This study experimentally investigated the fluidization characteristics of Geldart-D particles at elevated pressure, including flow pattern, pressure drop, and minimum fluidization gas velocity. The results showed that the fluidization behavior of Geldart-D particles changed with increasing operating pressure, indicating a transition towards the behavior of Geldart-B particles. A new correlation for predicting the minimum fluidization velocity of Geldart-D particles at elevated pressure was proposed based on the experimental data.