German Technology Cuts DAF Costs

A single “DAF Pump” is able to replace the entire air bubble system on DAF [Dissolved Air Floatation] plants, according to authorised distributor, Hydro Innovations. Their EDUR® “Multiphase” pumps draw in air through a “snorkel” in the suction line, sheer the air, then feed it into the DAF plant, producing a discharge stream into the tank that is saturated with 30 to 50 micron air bubbles.

 Conventional DAF systems normally consist of a wastewater tank, compressor, air saturation vessel, and effluent pump. The effluent pump draws effluent from the tank and pumps it into the air saturation vessel. A compressor pumps air into this same vessel. The air/water mixture is “saturated” under pressure, then released back into the wastewater tank at atmospheric pressure where tiny bubbles form and adhere to the suspended matter [fats, oils and other small wastewater particles]. The bubbles [with their attached suspended matter] float to the surface of the tank, where floatables can be skimmed off the surface.

By using EDUR® Multiphase pump technology, asset owners can replace the compressor, air saturation [pressure] vessel, control system and multistage pump with a single pump that can replicate [or improve] the performance of the “conventional” system. The EDUR pump is set up the same as a conventional pump, to draw liquid from the “clean” side of the DAF tank, but it also draws atmospheric air into its suction line instead of using a compressor for this task. “Standard” pumps are not capable of handling air this way. The air is mixed with the water as it moves through the pump, and the air goes into solution as it is saturated under pressure.

The EDUR® Multiphase [DAF] pump greatly simplifies the system, and because of this, capital costs and maintenance costs can be greatly reduced. No compressor to maintain and no pressure vessel to maintain and certify. There is also an energy saving, because there is no longer a running compressor.

EDUR® multiphase pumps can deliver flows from 1 l/s [for smaller DAF plants] to 15 l/s [which cater for wastewater in-flows of up to 150 l/s with a single pump, or use multiple pumps if flows are higher] and produce pressures to 12 Bar. A variety of materials and seal arrangements enable EDUR pumps to operate in a very wide range of applications. Available materials include ductile iron, “gunmetal” bronze, stainless steel and super duplex. Mechanical seals available as balanced, double and tandem. Click here for more information on these pumps or email or phone on 02 9898 1800. 

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