Pressure Chemical Deoiler Pressure Dissolved Air Deoiler |Chemical Deoiler for Oily Wastewater

Working Principle Oily wastewater first enters the reaction zone, where demulsifiers and flocculants are added. Fast mixing destabilizes the emulsified oil, and slow mixing lets small flocs grow into larger agglomerates. The reacted water then enters the pressure dissolved air zone. Dissolved air water is made by a dissolved air pump and tank, and after pressure release through a release device, it creates a large number of micro-bubbles. These bubbles attach to flocs and oil droplets, float to the surface, and form scum. A skimmer scrapes the scum into a collection trough, and clear water discharges from the bottom. The pressure chemical deoiler operates under closed pressure, giving high dissolved air efficiency and fine bubbles. Its removal of emulsified oil is more stable than atmospheric flotation. Application Fields 1.Cold rolling oily wastewater: removes emulsion and iron powder, easing downstream biological load. 2.Machining wastewater: separates oil and suspended solids from cutting and cleaning fluids. 3.Oilfield produced water: removes emulsified oil and solids to meet reinjection requirements. 4.Refinery oily wastewater: pre-treatment deoiling to reduce downstream load. FAQ Q1: What types of oily wastewater can a pressure chemical deoiler handle? A: It mainly handles emulsified and dispersed oil, such as cold rolling emulsions, machining cutting fluids, and oilfield produced water. It has limited effect on floating oil. If the influent contains a lot of floating oil, it's best to use an oil separator or skimmer first. Q2: What are the requirements for the dissolved air system of a pressure dissolved air deoiler? A: Dissolved air pressure is usually kept at 0.3–0.5 MPa, with a recycle ratio of 20%–30%. The release device should produce micro-bubbles of 20–50 μm. The finer the bubbles, the better the chance they attach to flocs and the better the flotation. Q3: What chemicals are typically dosed in a chemical deoiler? A: Polyaluminum chloride (PAC) and polyacrylamide (PAM) are common. A demulsifier is added first to neutralize the charge on oil droplets, then a flocculant to bridge them into flocs. The dosage should be determined by jar tests. Too much increases sludge volume; too little means incomplete demulsification.