High-Efficiency CPI Oil Separator | Compact & Custom

A high-efficiency CPI oil separator is a compact oil-water separation unit used to remove free oil, floating oil, grease and some settleable solids from industrial wastewater. CPI stands for Corrugated Plate Interceptor. Unlike fine filters, CPI equipment mainly relies on gravity separation, plate coalescence and flow distribution to separate oil from water.

In many industrial plants, oily wastewater may come from petrochemical production, machinery processing, vehicle washing, steel plants, power plants, shipyards, food processing or surface treatment processes. If free oil enters downstream equipment directly, it may foul filters, reduce DAF performance, inhibit biological treatment, clog pipelines or increase membrane cleaning frequency. Therefore, CPI oil separation is often used as a pretreatment step.

The working principle is simple but practical. Wastewater enters the inlet distribution chamber and flows slowly through multiple inclined corrugated plates. Since oil is lighter than water, oil droplets rise toward the upper surface. The corrugated plate structure shortens the rising distance and helps small droplets collide and coalesce into larger droplets. These larger oil droplets float to the surface and are collected by an oil outlet or skimming device. Heavier solids settle at the bottom and are discharged through the sludge outlet. Clarified water then flows to the next treatment stage.

A typical process is:

A complete CPI oil separator may include an inlet chamber, flow distribution device, corrugated plate pack, separation chamber, oil collection zone, oil discharge pipe or skimmer, sludge hopper, sludge discharge valve, outlet chamber, inspection cover, pipelines, valves and optional control components. Depending on wastewater quality and site requirements, materials can include carbon steel with anti-corrosion coating, stainless steel, FRP or other suitable options.

For B2B buyers, selecting the right CPI separator should not depend only on flow rate. Important parameters include influent flow, peak flow, free oil concentration, oil droplet size, suspended solids concentration, wastewater temperature, pH, viscosity, density difference between oil and water, required outlet oil level, available footprint and downstream treatment process.

It is also important to understand the application boundary. A CPI oil separator is effective for free oil and separable oil droplets, but it is not designed to directly remove stable emulsified oil, dissolved organics or soluble pollutants. If wastewater contains surfactants, emulsified oil or complex chemical pollutants, the CPI unit may need to work with demulsification, coagulation, DAF, filtration, biological treatment or membrane treatment.

Maintenance mainly includes regular oil removal, sludge discharge, inspection of corrugated plates, cleaning of blocked channels, checking valves and monitoring corrosion conditions. Proper oil and sludge management helps maintain stable separation efficiency and reduce downtime.

Qingdao Jinwantong provides customized CPI oil separators and supporting wastewater treatment equipment. Buyers can send flow rate, oil concentration, TSS, pH, temperature, water quality data, site layout and treatment target for technical selection and quotation.