Q:Can de-mixing occur in an impeller-driven or multiple motion mixer?
A:While de-mixing is less likely in an impeller-driven or multiple-motion mixer than in a tumble blender, it can still occur. During mixing an impeller driven or multiple-motion mixer fluidizes the materials. If the batch is discharged during operation, mixing – while not totally random – is relatively uniform, without segregation. However, when the mixer stops operating, the fluidized mass settles, and heavier particles drop to the vessel’s bottom, creating stratified particle concentrations. You can avoid such de-mixing by discharging the mixer during operation. If the normal mixing speed creates discharge problems, such as dusting, try using a two-speed motor to decrease the impeller speed during discharge.