The suction excavator uses as transport agent the air. In order to make this physically possible, seen the enormous difference among the specific weight of the air and the sediment, the  air volume must be far greater than the material volume to suck.
About suction excavator it doesn't use a technology that sucks material by a high pressure difference in special containers, but an open system with low pressure difference.
This pressure difference varies according the model from 0.17 bar to a maximum of 0.4 bar. The sucked material is eliminated through the air current in the vehicle  by the gravity force; through two filters systems, the air is cleaned and immediately expelled toward outside.


 ESE Description