DEM study of dry and wet granular flows in a vertical bladed mixer

In this work, numerical simulations of both dry and wet granular flows inside a vertical cylindrical mixer were performed using discrete element method (DEM). Two different cases were considered by using four-bladed and two-bladed mixer setups. Effects of blade rake angle, blade rotational speed and number of blades on mixing characteristics for both dry and wet flows were examined under different conditions. It was found that blade rake angle of 90 degrees produces low velocity but with relatively high time-averaged mean interparticle forces. Moisture content also influences the flow and mixing behavior. It was found that dry particles have higher mixing efficiencies than wet particles but only with higher moisture contents like 4% (vol%) used in this study. The same is not true when lower moisture contents of less than 1% (vol%) are used and show better mixing performance at these low moisture contents. It was also found that a two-bladed mixer is a better choice for mixing at these moisture contents in comparison to a four-bladed mixer. Our results suggest that all these factors must be considered carefully for each specific application.

Automated summary

This study investigated the mixing characteristics of dry and wet granular flows inside a vertical cylindrical mixer using numerical simulations. The effects of blade rake angle and moisture content on mixing efficiency were analyzed, revealing that a two-bladed mixer is more suitable for mixing at certain moisture contents compared to a four-bladed mixer.Various factors such as blade design and moisture content need to be carefully considered for specific applications.