An Experimental Study of Pressure Drop Characteristics and Flow Resistance Coefficient in a Fluidized Bed for Coal Particle Fluidization

Jian Peng,Haisheng Han,Yao Xiao,Le Xie,Wei Sun

doi:10.3390/min12030289

Jian Peng, Haisheng Han + Show 3 more

Open Access

https://doi.org/10.3390/min12030289

Copy DOI

Journal: Minerals	Publication Date: Feb 25, 2022
Citations: 3	License type: CC BY 4.0

Affiliation: Central South University

Abstract

Liquid–solid fluidized beds have a wide range of applications in metallurgical processing, mineral processing, extraction, and wastewater treatment. Great interest on their flow stability and heterogeneous fluidization behaviors has been aroused in research. In this study, various fluidization experiments were performed by adjusting the operating conditions of particle size, particle density, and liquid superficial velocity. For each case, the steady state of liquid–solid fluidization was obtained, and the bed expansion height and pressure drop characteristics were analyzed. The time evolution of pressure drop at different bed heights can truly reflect the liquid–solid heterogeneous fluidization behaviors that are determined by operating conditions. With the increase in superficial liquid velocity, three typical fluidization stages were observed. Accordingly, the flow resistance coefficient was obtained based on the experimental data of bed expansion height and pressure drop. The flow resistance coefficient experiences a decrease with the increase in the modified particle Reynolds number and densimetric Froude number.

Highlights

Liquid–solid fluidized beds have been widely used in metallurgical processing, mineral processing, extraction, and wastewater treatment [1–9] for their excellent fluid–solid coupling as well as heat and mass transfer performance
This study aims to investigate the heterogeneous fluidization and flow resistance in a square liquid–solid fluidized bed where coarse coal particles and water are the solid and liquid phases, respectively
Various fluidization experiments were performed by apparen rate, the drag force coefficient with the increase particle size and density adjustingflow the operating conditions of particleincreases size, particle density, andin liquid superficial while

Summary

Introduction

Liquid–solid fluidized beds have been widely used in metallurgical processing, mineral processing, extraction, and wastewater treatment [1–9] for their excellent fluid–solid coupling as well as heat and mass transfer performance. The transition from the homogeneous to heterogeneous regime occurs at some critical operating conditions. The intensity of turbulence is much higher in the heterogeneous regime, resulting in higher rates of heat, mass, and momentum transfer and better mixing. Such conditions are preferable in many applications. Too much turbulence may be detrimental to the performance in operations such as flotation, causing higher rates of detachment of particles from the bubble surface. An insight into the heterogeneous flow structures of liquid–solid fluidized systems is critical

Objectives

Results

Conclusion