If settleable material is present in the liquid, such material is collected and concentrated in the troughs of the corrugations so that it will slide down in the plate pack smoothly and easily.

Very small separating diameters can be obtained in the CPI system, because the

disturbing factors, such as eddies and turbulences, which adversely affect large

conventional separating tanks (e.g. API’s), are eliminated in the CPI.

In formulating a design, the following minimum data are essential:

 the type of pollutants to be intercepted

the separating diameter of the oil droplet

the difference in density between the carrier liquid (waste water) and the pollutants to be intercepted

the maximum amount of water to be treated

the water temperature

the sedimentation velocity

origin of the oily liquid

 physical data, chemical analysis of carrier phase.

With the objective of not breaking up the oil droplets unnecessarily, the CPI system is

preferably fed by gravity. The oily water flows into the interceptor through the inlet compartment which has a dual function as a sand trap (1). A double slotted baffle (2) induces incoming water to flow evenly and uniformly to the entrance of the corrugated plate pack (3). In the plate pack the oil droplets are intercepted and coalesce into large droplets. They leave the pack rapidly in counter current mode and move upwards against the liquid flow, to the surface.