Folded Flow® Dissolved Air Flotation Separator

Source: Siemens Energy, Inc. - Water Solutions

The Folded Flow® DAF system’s simple and innovative design “folds” the flow by removing effluent from the same end of the tank as the influent is introduced, resulting in a higher hydraulic loading rate.

In the Folded Flow® design, as the density current travels laterally, clean water, being heavier, peels away from the bottom of the density current and flows downward. At the bottom of the tank, the downward flow gathers in a laminar fashion to form a horizontal return current, which accelerates as it nears the outlet. The downward velocity of liquid from the surface layer to the return stream at the bottom is relatively constant along the length of the tank and is uniformly close to a minimum flow. This ensures that the bubbles are moving upward throughout the entire volume of the tank.

Circular DAF separators can be an economical alternative in many applications, as at this petroleum refinery. Circular units are available as standard package units or as modular build units.

Features and Benefits 

  • High Overflow Rate 
  • Small Footprint 
  • Low Cost 
  • Easy to Cover 
  • Excellent Oil and Grease Removal 
  • Excellent TSS Removal 
  • High Float Concentration 
  • Easily Handles Settled Solids 
  • Tolerant of Large Flow Changes Tolerant of Large Concentration Changes