Oil separator

CORRUGATED PLATE INTERCEPTION SEPARATION (COALESCING PLATE SEPARATORS) INTRODUCTION CPI Packages are commonly used to separate oil and fats with low specific gravity. The water flows through corrugated plates (also defined as "coalescing plates") manufactured in polypropylene. Prefabricated units in steel can be provided for flows up to 500 m3-hour. Oil and fats particles adhere to the plates and, due to low density, move upward. A skimming device collects the oil/fats from water surface. Any eventual sludge is collected in a separate section for extraction and disposal. When the wastewater contains both low density and high density oils/fats, an Air Flotation Package (DAF) must follow the CPS package. Based on the German standard "DIN 1999 part 5" or the new European standard "EN 858" < 5 mg/l of oil in the effluent water can be easily achieved. Separation of dissolved and stable emulsified oils or hydrocarbons is not possible with CPI. WORKING MECHANISM OF THE COALESCING PLATES The high efficiency of the system is based on 6 mm or 12 mm short rise distance of the oil droplets which is the exact distance between the plates. E.g. an oil droplet of 20 micron diameter at a density of 850 kg/m³ and a temperature of 20 °C has a rise velocity of 2 mm/min. Just above 3 min retention time within the plate pack the oil droplet will be captured by the under side of the next plate ensuring separation. In standard sedimentation separators a 20 micron oil droplet will need several hours retention time and because of turbulence an upward movement of the oil droplets will not take place.