De-Aeration Of Powder
The superimposed pressure compacts the bed of powder to compress air in the voids between the particles. Relaxing the ambient pressure then generates an increase in the differential pressure between the void pressure and the unconfined surface atmosphere, to provide a greater driving force for expressing excess air from the bulk. ■
De aeration of fine powders
Out pneumatic tanker truck drivers have their own method for de-aeration of our 100 micron Hydrated lime powder which we load into pneumatic tanker trucks.
We wish to load maxium load on the tanker truck allthough the BD of the material is very low (0.4-0.5).
After loading they pressurize the tank up to 1.8 bars and they abruptly release the pressure. They repeat that several times and the BD of the material increases and then there is more space free to load more material to the tanker truck.
Can you find a physical explanation to that drivers "wisdom"?
Amit Segev
Negev Industrial Minerals- ISRAEL ■