Hydrolox Screens Tough Enough for the Mighty Mississippi

Customer Objectives

Entergy Corporation is an energy company that delivers electricity to 2.9 million utility customers in Arkansas, Louisiana, Mississippi, and Texas. Its Little Gypsy plant in Montz, Louisiana, is a natural gas-fired steam power plant. The plant gathers water from the Mississippi River through two intake channels.

Each of the plant’s units is outfitted with two water screens which, until 2005, were all equipped with traditional steel carrier chain and basket screens. Entergy’s Little Gypsy plant experienced excessive wear with the steel screens due to the abrasive nature of the intake environment, as river silt and debris are in frequent contact with the screen. Plant officials decided to search for a different screening solution that was long lasting, reliable, and cost effective.

Hydrolox Execution

In April 2005, Entergy replaced a 14-ft-wide, 53-ft-deep steel screen with a Hydrolox® Series 6000 Flush Grid traveling water screen to test the technology against their biggest circulating pumps. The prototype screen—equipped with debris-handling flights—was installed at the most abrasive point of the intake, where debris is the heaviest.

After installation, Hydrolox monitored the prototype screen mesh for operational feasibility, including its performance f low characteristics and the pressure differential across the screen as compared to the plant’s previous technology. Hydrolox also monitored the durability of the screen polymers by analyzing wear patterns and predicted screen life based on that analysis.

In June 2006, the prototype was replaced with a production version of the S6000 water screen.

Results

Entergy’s Little Gypsy plant has reported great success with the new screen installation, evident in the minimal amount of maintenance required for operation. Danny Vicknair, Entergy Maintenance Technician at Little Gypsy and “subject matter expert” for the Mississippi River intake equipment, has reported significant benefits from Hydrolox technology. The polymer screen material surpasses the steel screens in strength and durability; he says that no real screen wear has been reported.

In addition to screen quality and performance, Entergy is pleased with the level of planning that Hydrolox invested in the project, which contributed to a very easy installation process.