Discrete element simulation of particle mixing and segregation in a tetrapodal blender

• The performance of the tetrapodal blender is compared to that of the V-blender.
• The mixing time in the tetrapodal blender is shorter than that in the V-blender.
• The mixing mechanisms are more efficient in the tetrapodal blender than the V-blender.
• The tetrapodal blender is less prone to granular segregation than the V-blender.

One aspect that must be addressed when designing tumbling blenders is poor axial mixing, which can lead to non-homogeneous mixtures, especially when the particle physical and flow properties are different. To overcome these limitations, we recently undertook an interest in a tetrapodal mixing device patented in 1964. It can be described as two V-shaped pairs of arms connected at their bottoms, one of which is twisted by 90°. In this work, particle mixing and segregation are investigated using the discrete element method in both the V-blender and this tetrapodal blender. Results of mixing time and uniformity are compared for different loading profiles, fill levels and rotational speeds. Compared to the V-blender, this geometry is shown to provide better axial and radial mixing efficiency. Good behavior was also observed for size segregating granules, yet more investigation would be needed for worse cases involving granules with large size ratios and different densities.

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