Scale up of heat transfer for dry granular material in a cylindrical bladed mixer

Heated bladed mixers are widely used to process granular materials. Yet, despite their ubiquity, unanswered questions remain regarding how heat transfer occurs in this system, particularly when scaling up the process. In this work, the discrete element method was coupled with a heat transfer model to investigate how the amount of material and the mixer size influence the particle bed heating time. The findings show that the relationship between the fill level and the heating time depends on the heating area of the mixer relative to the amount of material, the bed compression, and the mixing rate. The results also indicate that the heating time is directly proportional to the mixer diameter. The proportionality constant has an order of magnitude of one and depends on the impeller rotation rate. Overall, this work enhances fundamental understanding of the elements at play during the scale up of granular processes in heated bladed mixers.