Evoqua's VAF LCFX system was selected as the system of choice for the following reasons:
Only one 10HP pump required to provide basin cleaning for the entire 1200 ton cooling tower
55% reduction in pump size required by reducing from 22.5HP to 10HP
70% reduction in filtration flow rate per tower basin from 159 m3/hr to 45 m3/hr (700 gpm to 200 gpm)
75% reduction in operating time from 24 hours per day to only 6 hours per day for all three towers resulting in total volume turned twice a day
87% reduction in energy cost (energy cost for the LCFX-500-10 was $2,426.82 using a 74% efficiency and $0.11/kWh)
95% reduction in flush waste compared to a single tower media filter system
The footprint of the single LCFX system skid was 122 cm x 132 cm (48" x 52"), which was a much smaller footprint than for the two media systems option
LCFX’s flexibility of basin cleaning times based on dirt load
LCFX’s BACnet interface for remote monitoring and operation capabilities
LCFX General Operation
The LCFX system has unsurpassed conservation operating efficiencies over conventional cooling tower filtration systems while providing both basin agitation and cooling water cleaning. By combining the patented V-SeriesTM filters and the reduction in energy usage and water saving components of the LCFX system, an ROI can be achieved in less than a year. In addition, this system will help eliminate the environment where Legionella and other bacteria can grow by keeping the basins clean from organics and light silt that provide the habitat and food source for bacteria to thrive. Corrosion and fouling issues were also noticeably alleviated.
The zone control system maintains a pressurized mainline that has zone control valves placed at each defined zone. Each zone has a specified number of eductor turbulator nozzles, placed inside the basin that agitates particulate and keeps it in suspension for removal by filtration.
The VFD/PLC control provides energy efficiency by operating the pump only at the minimum 1.4 bar (20 psi) required for the eductor nozzles’ basin agitation, and then provides the minimum of 2 bar (30 psi) required for the filter’s 30 second flush cycle, thus maintaining low energy usage for an extended time period.
For the medical center installation, the zone controller was initially programmed to monitor the cleaning of each tower for a minimum of two hours per tower per day. This equated to a full turn of each basin volume twice a day in just six hours of operation. The system then sleeps for the remaining 18 hours each day.
The extensive features and conservation benefits of the LCFX system provides the facility with clean cooling tower basins at a lower system cost, lower energy costs and saves 80% in maintenance expense.