5. Conditions for good filtration quality

To achieve good filtration quality, it is essential to ensure that filtration flow rates are respected, and that alluvial action is appropriate to the contaminant load (solid matter to be retained). Pressure build-up must be gradual and regular.

Here are a few examples of situations to avoid when carrying out filtration (figure 11 ).

• Abnormal increase in pressure due to excessive alluviation (figure 11 a). This curve reflects an alluvial flow rate higher than required, resulting in a low pressure rise gradient. This type of filtration pipe has no impact on filtrate quality. Only the economic cost per m...