We have come a long way since then, however, the principle of storage and transport have remained largely the same, the only difference is we started looking at the micro and nano aspect of solids to better control the outcome and usability of products, creating better storage facilities and advanced transport methods.
Conveying and particle alteration
For example, in these industries, pneumatic conveying represents the core method of their bulk material handling systems, where solids are moved utilizing air (or some other form of gas) through pipelines. This is convenient, safe, and efficient. Other types of conveying methods are belt conveyors or screw conveyors to transport solids. However, particles act differently when moving and when stationary. In such cases, shear testing can play a crucial role in understanding caking in, for example, silo storage as solids tend to become more cohesive when pressure is applied due to the weight of the particles in bulk. Whether on the belt, in pneumatic pipelines, or a silo, the behaviour of the solid can always change.
This is often an unwanted side effect, but it is inherently an aspect of solid material handling due to the many factors being imposed on the particles in transit and their interactions with each other, the equipment, and flow dynamics.
The unintentional change of the solid particles could cause alterations in particle quality and even increase the risk of dust explosions downstream of the systems, often due to particles getting agitated, while in transit, colliding against the transport walls and each other.
Storage brings with it other challenges, such as stickiness and bridging, which is a seriou issue when dealing with metric tons of material.
Shear testing
For investigations of particle storage behaviour, the shear testing method can bring insight into the powder flow properties upon consolidation. The flow behaviour is tested under varying pressures by shearing the particle mass to failure. Testing solid products is critical to shedding light on possible issues in:
- Flow issues in a present, retrofitted, and or new machine application
- Improved technical silo/bin container designs
Hopper designs
Hoppers and feeders play another integral part in the transport of solid matter. The design feeder stroke, the relevant angles, wall material, dimensions, and optional feeder vibration frequency all affect how material flows from the hopper to the feeder, to pumps, pneumatic piping, and/ or conveyor bels. Clearly it can greatly impact on how the material transitions along the production line.
Failing to consider the particle flow density, the bridging phenomenon, and equipment designs can create a myriad of flow problems in the whole system.
This and many more can help in the understanding and improvement of particle storage and transport in an ever-growing automated industry. The scope of particle transport and storage is a wide subject of research and is continuously evolving. So is the research to improve the particle stability and storage thereof. New technological innovations happen at a rapid pace.
