Flotation System Process Description

The Or-Tec Flotation System will include the following items:

  • Flocculation System (For chemical/effluent mixing, coagulation and flocculation)
  • Aeration Zone (for aerating, mixing and fusing the air bubbles to the flocculation waste stream)
  • Flotation Zone (to ensure sufficient retention to allow for separation and flotation of solid material from the waste stream)
  • Solids Discharge Scrapers (to direct the skimming to the auger discharge)
  • Discharge weir and channel (for final effluent)

The Or-Tec DAF System is designed to reduce FOG, BOD, COD and TSS. It can be supplied with pH correction equipment, and coagulant dosing equipment if necessary. In most cases the system uses an Or-Tec Blend Polymer Dosing system which automatically makes up polymer and doses it as needed into the wastestream to create flocculation. The polymer solution and waste travel though a serpentine which aids in the flocculation process.

Prior to entering the DAF tank a cavitation aeration pump uses recycled water to create and inject perfect whitewater into the flocculated wastestream. This combination of whitewater and flocculated solid particles in the wastestream cause those particles to float. Floated solids are removed using a variable speed scraper system which skims the surface of the tank. These solids are removed to the side of the unit for disposal. Settled solids are removed by augers, scrapers or bottom dump valve depending on the model selected.

Treated effluent flows from the flotation zone via pipes to a double weir chamber. The double weir chamber minimizes flow velocity which helps stabilize the liquid level in the DAF flotation zone. This ensures that the top float scrapers are effective at all times. From the weir chamber the majority of the flow will discharge to the outlet chamber and, from there, to the city sewer. A smaller portion of the flow is recycled back to the DAF's whitewater/aeration system.