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Anatomy of DAF

1. Stilling Chamber (Optional)
The Stilling Chamber provides an opportunity for intimate contact between influent contaminates and the bubbles produced by the aeration/recycle system. Floc formed by the joining of the bubbles and contaminates is directed towards the surface by the Stilling Chamber Baffle. Turbulence caused by entrained air in the influent, or flow surges are damped here.

2. Recycle System Saturation Chambers
VanAire’s exclusive Saturation Chamber design is the heart of our superior aeration technology. Compressed air is injected into the recycle stream on the discharge side of the recycle pump. The resulting air/water mixture flows into the saturation chamber, where it is exposed to tremendous turbulence. This turbulence is used to maximize the amount of air that dissolves in the recycle stream. The Saturation Chamber also separates any undissolved gasses from the recycle flow, eliminating the disruptive effect that these undissolved gasses have on the DAF Clarifier.

3. Pumps
VanAire Aeration Units utilize heavy-duty single stage centrifugal pumps for simplicity and long-term durability. These pumps feature wear resistant duplex stainless steel internals, a dynamic shaft seal and cast iron impellers with optional type 316 cast stainless impellers available for years of maintenance-free operation. Also, VanAire introduces compressed air on the discharge side of the recycle pump, so the pump is not exposed to the erosive effect of pumping water with entrained air. Pumps are also available with all wetted parts made from stainless steel.

4. Breakout Valves
VanAire’s exclusive Breakout Valve design creates the most effective DAF bubbles in the industry. This design creates the violent, high-shear action necessary to release the dissolved gasses as microscopic bubbles. All wetted parts are stainless steel with diaphragms of Nitrile with other diaphragm materials available including Viton.

5. Skimming Mechanism
The concurrent top skimming mechanism and the continuous support of the float by our aeration maximizes float density, and minimizes the settling of previously floated contaminates. VanAire offers the option of corrosion resistant fiber reinforced polyester chain. Stainless steel type 304 or 316 chain is also available.

6. Plate-Pack
An optional and exclusive cross-flow plate-pack and a second stage of aeration can be located near the midpoint of the DAF clarifier. This plate pack provides a damping effect on the water in the DAF, and provides a surface for the coalescing of bubbles and microscopic particles. As the bubbles and particles build up on the underside of the plates, the particles agglomerate into larger particles, eventually floating to the surface. Our cross-flow design does not affect the normal flow patterns in the DAF; so hydraulic loading rates are not affected.

7. Settled Solids Removal
Depending on characteristics and amount of settled solids anticipated, settled solids can be removed above the waterline using a chain and flight removal system; below the waterline using an auger system with a blow down valve; or simply through a series of drain valves along the bottom of the DAF Clarifier.

8. Beach-Float Hopper
The concurrent skimming mechanism pushes the float up the inclined beach plate. An adjustable time delay feature is included to pause the top flights on the beach, allowing free water to drain from the float.

9. Overflow Weir
Allows the working level of the DAF Clarifier to be manually adjusted to position the waterline properly on the beach.

10. V-Notch Weir
A V-notch weir is standard on all VanAire DAF systems.  Electronic flow indication and measurement is available as an option..

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