Patented Aerofloat Dissolved Air Flotation
What is Dissolved Air Flotation? Dissolved Air Flotation (DAF) is a common treatment technique used to remove solid particles (typically fats, oils and greases) from wastewater. The wastewater is generally mixed with suitable chemicals to flocculate the solids particles. The basic principle is that air is dissolved into a side stream, which is then allowed to suddenly decompress and the main chamber. This side stream mixes with the incoming flocculated wastewater. The decompression of the side stream causes millions of little bubbles to form as the dissolved air comes out of compression (the same as when you open a can of soft drink). The bubbles tend to form around contaminates in the water and then floats them to the surface where they are captured and removed.
Conventional DAFs use large open tank consisting of mechanical scrapers on the top and bottom of the tank to remove the built up scum layers. This waste scum layer is then disposed of and the remaining treated water is of a much higher quality.
The Aerofloat DAF has combined these proven DAF principles with some new unique design elements to make a truly innovative product suitable for a range of applications.
The Aerofloat™ technology uses a double hopper tank with a unique, patented hydraulic float removal system to funnel the waste float material from the top of the tank. Mechanical scrapers are not required. The patented system is compact, mechanically simple and a more affordable DAF solution.
The waste material is simply removed from the enclosed, hopper tank by using the hydraulics on the incoming feed stream – see cycle diagram adjacent for further information.
To ensure effective performance of the DAF, most industrial waste plants will require some pre-treatment screening, blending, hydraulic balancing and pH correction. Please see adjacent Typical Process Flow diagram.
Due to the compact nature of the tank and minimal mechanical components, the Aerofloat DAF has been able to be constructed from polyethylene tanks. This enables easy installation and manoeuvrability of the system, lowers the cost of manufacturing and enables the system to be fully sealed and vented. The larger Aerofloat models can also be made from stainless steel in the event that SS is the preferred material.
Initially designed for the houseboat industry, it was imperative that the Aerofloat DAF was compact and used a minimal footprint. This feature is a key design element across the entire product range as has enabled businesses to utilise effective DAF technology; previously thought impossible due to size constraints.
The elimination of mechanical scrapers by using the patented hydraulic float removal system, has drastically simplified the overall process. Other features contributing to the mechanical simplicity of the system include using a feed pump and coagulation coil instead of a pre-treatment mixing tank and the simple, low cost PLC instead of elaborate, purpose built control assemblies.
Due to the mechanical simplicity of the process (and therefore the elimination of complex mechanical scrapers) together with the compact hopper tank made from polyethylene, the Aerofloat unit provides a much more affordable DAF solution. The Hopper bottom also means no downtime and expensive pump outs for regular cleaning like traditional DAF Tanks.