When the Grant County Public Utility District (Central Washington)
offered Environmental Management Corporation (EMC) a financial incentive to
save energy in the operation of its wastewater treatment plant at Quincy,
Washington, BioChem Technology was there
to show them how.
Working closely with PACE Engineers; BioChem studied the
process operations of the plant's two sequencing batch reactors, and specified
that two 320-hp positive displacement blowers, equipped with variable frequency
drives (VFDs), replace the single 600hp centrifugal blower.
While the addition of VFDs allows for blowers to be turned
down to save energy during periods below peak loading, they are of little use
unless you know how much air you need, and when and where you need it. So in addition to adding the VFDs, BioChem's
Bioprocess Aeration Control System (BACS) was installed at the plant. Only BioChem's patented BACS, can derive the
precise amount of air required from the real time oxygen uptake rate (OUR). While other systems chase setpoints, BACS hits
and maintains them using minimal blower energy and valve oscillations, also
considerably extending equipment life.
The documented energy savings was just over 2.3 million kWH
annually, prompting Grant County PUD to give EMC a check for $234,452.10. To see a technical memorandum prepared by
PACE Engineering documenting the complete project click here.