A vibrating tube method for evaluating flowability of a small amount of sample particles

Advanced Powder Technology

Yasuda

Matsusaka

2014

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a b s t r a c tThis paper presents a microscopic analysis of the saltation of particles on an obliquely oscillating plate driven by sine waves with an amplitude on the order of tens of micrometers and a frequency on the order of hundreds of hertz. To examine the effect of the diameter of a particle on its motion, the trajectories and velocities of different-sized particles, from 0.5 to 500 lm in mass median diameter, are analyzed using images captured by a high-speed microscope camera. The results show that larger particles bounce higher, whereas smaller particles easily agglomerate and bounce only slightly, owing to the low restitution caused by their loosely packed structure. In addition, larger particles bounce forward and backward repeatedly, while the agglomerated particles always bounce forward, and consequently have the highest transport velocity among these particles. The particle motion and the transport velocity can be explained by a theoretical probability model.

Section: Introductionmentioning

confidence: 98%

Microscopic analysis of saltation of particles on an obliquely oscillating plate

Advanced Powder Technology

Yasuda

Matsusaka

2014

Self Cite

“…Particle fluidization under vibration has numerous engineering applications, such as fluidized beds (Tatemoto et al, 2004;Tatemoto et al, 2005;Limtrakul et al, 2007;Quintanilla et al, 2008), conveyors (Gallas et al, 1992;Rademacher and ter Borg, 1994;Sloot and Kruyt, 1996;Simsek et al, 2008), micro-feeders (Matsusaka et al, 1995 and evaluation methods for powder flowability (Jiang et al, 2006(Jiang et al, , 2009Ishii et al, 2011;Zainuddin at al., 2012).…”

Section: Introductionmentioning

confidence: 99%

Microscopic analysis of particle detachment from an obliquely oscillating plate

Chemical Engineering Science

Kiriyama

Yasuda

et al. 2015

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Particle detachment from an obliquely oscillating plate was studied experimentally and theoretically. The plate was placed in a horizontal position, and vibrations were applied in the horizontal and vertical directions by piezoelectric vibrators. The frequency of vibration was constant at 280 Hz. The amplitude of vibration increased with time and approached a constant value in each experiment. The movement of micrometer-sized spherical particles was analyzed using images captured by a highspeed microscope camera, which showed that the particles rolled on the plate before detaching from the surface, and that the rolling significantly reduced the adhesive force between the particles and surface. Furthermore, the removal efficiency, defined by the number ratio of detached particles to total particles, was analyzed as a function of the horizontal and vertical vibration accelerations. It was found that the removal efficiency was significantly affected by the horizontal vibration acceleration. These experimental results can be explained by the force and moment balance model.

“…Granular materials subjected to vibration exhibit various unusual behaviors, like convection [1][2][3], bubbling [4][5][6], segregation [7][8][9] and vibration-induced air inflow [10]. Particle fluidization under vibration has numerous applications, such as fluidized beds [11,12], conveyors [13][14][15][16][17], micro-feeders [18,19] and evaluation methods for powder flowability [20][21][22].…”

Section: Introductionmentioning

confidence: 99%

Numerical and theoretical study of particle saltation on an obliquely oscillating plate

Advanced Powder Technology

Fujimoto

Sakata

et al. 2014

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Particle saltation on an obliquely oscillating plate is simulated using a mass-point model that considers gravity, fluid resistance, restitution, and friction. The calculated results are in good agreement with results obtained experimentally for particles with different diameters and restitutions. A large particle with high restitution bounces forward and backward repeatedly, whereas a particle with low restitution only bounces forward and consequently has a high transport velocity. The mechanism for the difference in the motion of the particles can be explained by taking into account the phase angle of the oscillating plate and the impulse during particle collision.