Food processing companies can improve the reliability of their dissolved air flotation (DAF) system and also reduce maintenance costs by replacing their compressor and air
saturation pressure vessel with an EDUR multiphase pump.
Distributed by Hydro Innovations in Australia, the EDUR multiphase pump is uniquely capable of pumping an air/water mixture, allowing
DAF system owners to disconnect their compressor. They also don’t need the ongoing
maintenance and re-certification for the air saturation pressure vessel, which
can be removed, bypassed or incorporated into the new system. If they choose to
incorporate it, the pressure vessel becomes part of the pipe system and will
not be a pressure vessel requiring certification.
The heart of the new system, the EDUR multiphase pump is set up with a
throttle valve and an ‘air snorkel’ on the suction side of the pump, as well as
a solution line (the existing air saturation vessel can be re-used) and
throttle valve on the discharge. The pump draws water from the ‘clean’ side of
the DAF tank, and with the negative pressure created by partially closing the
suction throttle valve, also draws atmospheric air into the pump. The pump shears
and mixes the air with the water and discharges it (under pressure created by
the discharge throttle valve) through the discharge solution line. The pressure
created and the time spent in the solution line ‘forces’ the air into the solution.
When the air/water solution reaches the lower pressure in the DAF tank,
the air comes out of the solution to form tiny micro bubbles measuring about 30-70
micron. The micro bubbles attach to fat, oil and grease (FOG) particles and
float to the surface of the DAF tank. A FOG blanket is formed and mechanically
scraped away – similar to conventional systems.
An EDUR system has a simple ‘set and forget’ arrangement and delivers
savings on ongoing maintenance costs. Maintenance costs on the compressor are
also reduced since the process doesn’t need a compressor. The removal of the
pressure vessel eliminates both maintenance as well as the need for yearly