Pneumatic conveying system of abrasive materials: how to reduce wear
Tips on how to protect line systems and materials from abrasive wear.
Abrasive wear is one of the most concerning issue when using pneumatic conveying system, especially when abrasive particles are transported.
Dense phase pneumatic conveying can offer some benefits in such instances. This method can handle large flow rates at relatively low speed, which makes it possible to minimize pipeline wear and material degradation.
In fact, conveying speed is the most important parameter affecting wear in pneumatic conveying.
We know that some powders are particularly abrasive.
How to identify the abrasive power of a powder?
Hardness is a key indicator of the erosive power of powders. You can identify a threshold value in the hardness of the powers, beyond which the abrasiveness remains approximately constant. This is shown in the graph in picture 2. Here you can see that the specific erosion rate increases with respect to the material hardness and the threshold value is 800 kg/mm2.
The best-known abrasive particles of natural origin include corundum, quartz, silica, diatomaceous earth and salt. Among synthetic abrasive particles, glass and some types of oxides are also well known.
How the pneumatic transport of abrasive products works
When designing a pneumatic conveyor system, the chemical composition of the abrasive material needs to be taken into account since it will affect its behavior when in contact with another material.
If you need to handle an abrasive powder, besides choosing a low-speed transport with full pipeline, you can also opt for specially designed curves, made of suitable alloys to prevent wear over time.
Francesco Pozzi
R&D Manger at Air-Tec System