Dissolved Air Floatation (DAF) Systems

A dissolved air flotation (DAF) system removes emulsified and dispersed oil, grease and fine suspended solids that are too fine to rise or settle by gravity alone. Part of the treated water is saturated with air under pressure. When it is released into the flotation tank, the air comes out of solution as a cloud of very fine bubbles that attach to oil droplets and flocs and carry them to the surface, where a skimmer removes the float layer.
In the Vens DAF system, chemical dosing and a pipe flocculator first break emulsions and gather fine particles into flocs. In the contact zone the flocculated water meets the air-saturated recycle stream. A chain and flight skimmer moves the float layer up a beach into the sludge trough, settled solids collect in the bottom hoppers, and clear water leaves over an adjustable outlet weir.
Supplied as a complete skid
Flotation tank in coated carbon steel or stainless steel
Pipe flocculator and chemical dosing
Air saturation vessel, recycle pump and air injection
Chain and flight float skimmer with geared drive
Sludge hoppers with drain valves
Control panel, and walkway with handrails where needed
Where it is used
Refinery and petrochemical effluent, after API, TPI or CPI separators
Food, dairy and edible oil processing (fats, oils and grease)
Automotive, machining and metal finishing effluent with emulsified oil
Textile, paper and slaughterhouse wastewater
Pre-treatment ahead of biological treatment or membranes
Oil skimmers and gravity separators remove free oil; a DAF system removes the emulsified oil and fine solids that remain. Many plants use both, with a skimmer or separator first and DAF after it.
Tell us the flow rate, the oil and solids content, where the effluent comes from and the treated water quality you need, and we will size the system.
Guide: Dissolved air flotation (DAF): how it works and when you need it
Vens has more than 10,000 installations. Every unit is designed by engineers who studied at MIT, Stanford, Cornell, the IITs, Arizona State University and the University of Cincinnati and have worked in the industries that use this equipment, so it is sized for the job, built in the right materials and designed to proper factors of safety.