The importance of characteristic time in the measurement of small particle impact forces

The issue of impact forces in pneumatic conveying bends is a subject of interest to academics and industrialists alike (Destoop (2006), Ernst (2006)). Measurements have been made in-situ to attempt to quantify the effect of these forces on the pneumatic conveying system, but in order to understand these measurements, work has been done on an investigation of single particle impacts. The authors’ previous investigations into experimental measurements of impact force for a single small particle impacting a steel plate using a piezoelectric force sensor have shown unwanted influence by the measurement system on the desired force measurement (Cowell et al, 2009). This paper reports on a simple model that has been developed to gain insight into the influence of the characteristics of the impacting particle, and of the combined target mass and force sensor, on the measurement. This will allow the measurement system to be developed to make measurements that more closely relate to actual particle-pipe wall impacts.