Bye-Bye Buildup

In Orlando, Fla., a natural gas-fueled, combined-cycle electric-­generating plant with a capacity to generate 656 megawatts includes two natural gas-fired combustion turbines, two heat-recovery steam generators and a steam turbine.

In a condensing turbine, the thermal energy of steam is converted into mechanical power, which is converted into electric power by a generator. Any biological buildup within the condenser would greatly reduce the efficiency of the equipment producing steam, meaning less mechanical power. To combat that, the plant was injecting 12.5 percent sodium hypochlorite (250-300 GPD) into the wastewater to prevent biological buildup within the water tubes of the condenser.

Blue-White’s CHEM-FEED Skid System.

To do that, the plant selected Blue-White’s CHEM-FEED® Skid System equipped with two of the company’s Pro-Series® Flex-Pro® Model A3 peristaltic metering pumps. The skid system includes a calibration cylinder and Plast-O–Matic components (e.g., eight True Blue manual ball valves, two diaphragm check valves, a gauge with gauge guard, and a relief valve).

The peristaltic pump has proven to be superior to a diaphragm pump when injecting gaseous chemicals against moderate to low pressures. It maintains a smooth, constant flow rate while eliminating the potential for a vapor lock. Conversely, a diaphragm pump is adversely affected by offgassing, hence has the potential to lose prime. The degassing design of the peristaltic pump head, however, eliminates gas or air accumulation head; excess gas buildup is simply pumped through the tubing while the pump maintains a highly accurate and continuous flow.

The CHEM-FEED Skid System features a quality-engineered, compact, efficient design incorporating a high-quality, proven Flex-Pro peristaltic pump and Plast-O-Matic components that will maintain the integrity of the skid system’s performance. It encompasses a full chemical feed design, which is less expensive than purchasing the components separately, and the skid system is far easier and less time consuming to install, with no in-house engineering team needed.

Blue-White’s Pro-Series Flex-Pro Model A3 peristaltic metering pump.

In addition, the skid’s dual pump design used in this application offered an option to include an emergency back-up pump in case downtime was required on the primary pump.

Results

The electrical plant is extremely pleased with the performance of the Flex-Pro pumps and CHEM-FEED skid. They considered the ease of installation and the ability to receive the chemical feed skid system via UPS to be of excellent value. The system has exceeded expectations. Based on previous installations with similar chemicals and pressure ranges of less than 20 PSI, the Flex-Pro A3 peristaltic pumps are expected to see a minimum of 7,000-7,500 hours of pump tube life before replacement. WW

Blue-White Industries is exhibiting at WEFTEC.18, Booth 3829. For more information, visit blue-white.com.

Circle No. 298 on Reader Service Card