Hydrocyclone effectiveness vs. absolute pressure

Question

Some sources say that higher pressure in hydrocyclones implies better performance it leads to a finer filtration. But why?

Is it because water is almost incompressible and the particles can be pressured and their density increased?

Answer 1

The use of the word performance might be misleading since a connection to pressure loss is quite reasonable. However, in this context I guess performance is connected to the filtration.

Using higher pressure implies in deed a higher pressure loss but it also results in a higher circumferential velocity. Since the main working principle of a hydrocyclone is to divide a solid-liquid suspensions by density a higher circumferential velocity will increase the radial acceleration. Since small particles will encounter higher drag du to their smaller Reynoldsnumber it will take longer for them to travel to the outside wall (based on Svarovsky (1981), residence time theory ).

In order to have a better filter a higher radial acceleration is needed which (all other things kept equal) asks for higher pressure to produce higher circumferential velocities.