A cure for hammer rash: Measuring powder flowability with shear cell testing
This article explains how a shear cell tester can simplify and speed tests for measuring a powder's flow behavior. With built-in software to quickly analyze the test results, this instrument is moving shear cell testing from its established place in R&D labs into the world of quality control for day-to-day bulk solids production.
The hoppers of storage vessels and containers in bulk solids processing plants often appear to be afflicted with mumps or measles. But on closer inspection, it's clear that the rash-like disease isn't biological. Rather, it's caused by humans who bash the hopper sides with sledge hammers, steel rods, baseball bats, or anything else that can help dislodge powder buildup inside the hopper and get it flowing again. Not only can this violence lead to arm or back injuries for the worker swinging the hammer, but the noise it generates is ear-rattling. The worst tragedy resulting from a plugged hopper, of course, is when a worker climbs inside the hopper to clean out the blockage and instead is trapped under collapsing powder, with sometimes fatal results.