Force characteristic of the large coal particle moving in a dense medium gas–solid fluidized bed

•A self-designed system was utilized to measure the force of large coal particles.•A spectral analysis approach was introduced to determine the force characteristic.•Three different approaches were combined to investigate the force characteristic.

Force characteristic of the large coal particle was investigated when it moved in a dense medium gas–solid fluidized bed with the 100–300 μm Geldart B magnetite powder as fluidized medium. We selected two groups of coal particles with the equivalent diameters of 13 and 25 mm as the studying objects. The theoretical force calculation model of the large coal particle was established by force analysis. The approaches of experimental measurement and numerical simulation were combined to determine the force characteristic of the large coal particle. The results indicate that the forces vary within certain suitable ranges and present uniform fluctuations when the dense medium gas–solid fluidized bed maintains a stable fluidization state. The spectral analysis method was introduced to compare the force results of measurement and simulation. Finally, we obtain the conclusion that the theoretical force calculation results provide good agreements with the measurement and simulation results, which also validates the accuracy of the measurement results and the reliability of the simulation results for the force characteristic of the large coal particle.

Graphical abstractA self-designed system was utilized to directly measure the force of coal particles of different sizes moving in a dense medium gas–solid fluidized bed. Then, a spectral analysis approach was introduced to determine the force characteristic of the large coal particle. Finally, the force results with three different approaches were compared, indicating good agreements.Figure optionsDownload full-size imageDownload as PowerPoint slide