Analysis of interparticle forces and particle-wall interactions by powder bed pressure drops at incipient fluidization

A novel method is proposed to evaluate the interparticle forces and particle-wall interactions based on the pressure drop measurements at incipient fluidization. In the first experiment, we used the liquid bridge force as the model interparticle force of the glass ballotini (53 μm–105 μm). The theoretical relationship between the model liquid bridge force and the liquid addition volume was successfully presented. In the second part of experiment, the interparticle forces and the particle-wall interaction of cornstarch powders in a Perspex cylinder are determined. While the particle-wall interaction shows a linear relationship with the apparent bed-wall contact area, the interparticle force follows a logarithm relation with the bed mass for the Warren-Spring-type cornstarch powders. The results were also compared to the cohesion values obtained by a conventional shear tester. The results conclude that our method serves as an economically and accurate alternative to conventional shear testers.