solid mixing assessment of mixture quality; FPT Ch12 Q2 Pt1

The basis for the worked solution for Question 2, Chapter 12 (available as free download at www.particles....) in Fundamentals of Particle Technology. The question asks for an analysis of mixture quality when mixing solid powders together. The expected mixture quality comes from the Pool, Taylor and Wall equation which predicts the variance between samples withdrawn from an industrial mixer, at the point when the powder is randomly mixed. This value can be compared with the data obtained of the standard deviation between samples withdrawn from the mixer at various times. Concepts covered include: the Scale of Scrutiny; Specification of the mixture; and the Confidence in achieving that specification. These are all important concepts in powder mixing. Finally, the question uses a binary mixture model (Pool equation) to solve a ternary mixture of powders, as it is possible to focus on only the powder of interest (normally the Active Ingredient) compared to the remaining less important powders. This video shows the concepts behind the solution, in the video:
solid mixing - assessment of mixture quality; FPT Ch12 Q2 Pt2,
the calculation using these concepts is performed. Please do look at that video to see how the concepts work in practice. Powder mixing is a very important process, the simple Pool model provides a straightforward way to model the expected results from the process.