Mechanical Process Technology Like a long, quiet River
If there were no mechanical process engineering, there’d be no processing industry. It frequently provides the start (crushing, for example) and the end (sorting) of a process. Nevertheless, it´s role has changed in recent years. Whereas previously it tended to be seen more as supporting act, now it takes on the leading roles.
Nothing much has changed in the fundamental techniques used in mechanical process engineering. Whether you’re running screening machines, mills or centrifuges, the technologies they use are centuries old. However, things are bubbling away furiously under (or, more appropriately for mechanical processes, at) the surface, and so many development engineers are currently attempting — if not to outsmart the physics — then to push it to its outer limits at least.
“Generally, we can say for sure that in the past 20 years our understanding of processes has increased substantially. At the same time, the level of process automation has increased, and the theoretical mapping of processes is becoming more and more important. For example, simulating solid matter processes, if we take the discrete element method as an example, is much more realistic today due to the improvement in computing power,” says Dr. Lars Frye, Head of Solids Processing at Bayer Technology Services, giving his impressions of how the sector has developed.
Moreover, in his experience mechanical processes are becoming much more interrelated with other disciplines, such as interface physics. An example of this is electrostatic or steric stabilization in wet grinding attritors, which allows ever-smaller particles to be produced. While 20 years ago this process would have operated in the micrometer range, nanotechnology has since arrived and has now become the practice.
“The material properties of particles can be controlled more precisely“
The opportunities available today in particle analysis also extend significantly further now, and not just in relation to identifying size distribution. The great advances that have been made, for example, in imaging processes reveal detailed insights into a process. While attempts to optimize mechanical processes involved a great deal of empirical work 20 years ago, our understanding of why and how a process operates in practice has grown considerably.
“Today, we’re more likely to know what is happening at the interfaces and the impact this has on the process. At the same time, we’re now able to measure the size of particles and even sometimes the shape of particles inline. As a result, the material properties of particles, such as size, crystal morphology and shape, can be controlled more precisely to suit the purpose,” explains Frye.