23.8% aeration savings from B.A.C.S. Bioprocess Aeration Control System
Background:
The Camelot WRF located in the City of Kissimmee Florida
was upgraded from a 3 MGD MLE process to a 5.5 MGD (average annual daily flow)
facility.
To extend the facility's aeration capacity, the plant
installed a bank of (4) 125 hp turbo blowers - each theoretically capable of
delivering 2650 SCFM at 8 PSI with a rise to surge of 1.5 psi.
 |
| Birds Eye view of facility |
The facility is unmanned at night and requires robust
automation and remote monitoring capabilities. Additionally, the facility experiences a hydraulic and ammonia loading
peaking factor of approximately 1.5 and 1.6 respectively, presenting an excellent opportunity for a
DO/aeration control system. To accommodate these requirements and
opportunities, the Bioprocess Aeration Control System (BACS) was integrated
into the plant's existing SCADA network and commissioned over a 1 week period.
Precise Aeration Control:
The BACS adjusts the valve position of each of Camelot's 6
aeration control zones and trims the blowers up and down in order to maintain
the plant's user defined zone specific DO setpoints using BioChem's patented
Oxygen Uptake Rate Factor (OURf) technology and energy saving field tested Most Open Valve logic.
The OURf is calculated based on the real-time metabolic rate
of the biology and then fed through a predictive algorithm. As a result the plant controls to within .5%
of the user defined DO setpoints on average 96.8% of the time (see figure below):
 |
| DO Setpoint tracking performance of BACS |
This kind of precise matching of actual DO to the
operational setpoint, simply cannot be achieved with conventional (Proportional
Integral) based control schemes. The
environment is too dynamic, the relationships nonlinear, and the time delay too great. The BACS represents unparalleled control
performance.
Substantial Energy Savings = Excellent Return on Investment:
The data reveals an aeration savings of approximately 23.8%
over a manual control baseline. Given
the facility's electricity cost of .11 $/kWh, this translates to a savings of
approximately $21,300 annually.
 |
| Total airflow to secondary treatment. Red line represents running at a static airflow capable of treating 95% of the plant's demand scenarios. |
Given this information - the BACS installation at this site,
under these loading conditions, fully pays back the investment in two years.
User Friendly Control Interface:
The BACS System comes with a very user
friendly HMI which can be customized on startup to the operators specifications. All vital information and
controls are literally at one's fingertips.
 |
| "Process Overview Screen" - Modified to accommodate the lead operator's preferences |