1. Filtration techniques

To separate the two prefilt components as effectively as possible, two techniques can be applied: support filtration and depth filtration.

• Supported filtration

The suspension is brought over a support (grid, cloth, membrane, etc.) on which the particles will settle in the form of a cake of increasing thickness. The filtrate will be more or less pure, depending on particle size, support texture and time.

Support filtration is also known as surface, membrane or cake filtration.

It is generally used to filter suspensions with a high solids content.

• Deep filtration

The suspension flows through a porous mass (layer of sand or gravel, agglomerated particles in the form of disks, cylinders,...