V-blender (V-mixer) is found in most of solid processing industries. They provide reliable and easy mixing of dry powders in batch mode. This mixer can be found in many industries such as food and pharmaceutical processing. You see a list of V-blender applications here:
- Food processing : mixing of dairy powders, vitamins, coffee blends, and dry food mixtures.
- Pharmaceuticals : mixing prior to granulation and mixing of excipients and APIs of different size and density
- Plastics : mixing of pellets and master-batch
- Chemicals : mixing of minerals and metallic powder
The blender consists of a V-shape welded cylinders with angle of 70º to 90°. It rotates around off-center axis which allows mixing. Since there is no agitator or blades in the blender, the blender works well for dry powders. The mixing is quite gentle and this makes it a good candidate for shear-sensitive materials. At the same time, the tumbling motion of powders in the mixer may lead to de-mixing (segregation) and long mixing times.
In this video, you see a DEM simulation of a v-blender filled with two types of particles (they differ in color only) to see the process of powder mixing. V-blender rotates at 30 RPM. This simulation has been performed by cemfDEM code.
Some of the problems with these blenders is de-mixing of particles with various size, shape or density. Particle breakage is another problem, which occurs when the rotation speed is high for a shorter mixing time. Therefore, each specific application requires a custom-designed blender. With DEM, you can perform simulation to investigate effect of operating, geometrical, and physical properties on the blender performance.