Saint-Gobain Takes Advantage of New Better Plants-Diagnostic Equipment Program
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Accumulating accurate and reliable energy data is very important for identifying cost-savings and energy-saving opportunities in industrial systems. Having the right equipment can be critical to making the demonstrable case to management that an investment in energy efficiency can boost productivity and manufacturing competitiveness, and lead to significant dollars saved. However, plant operations personnel do not always have access to the instruments needed to collect such information. Late last year, Better Plants launched the Field Validation and Diagnostic Equipment Program (DEP) to help partners address this challenge. Saint-Gobain Corporation, a Better Plants Challenge Partner, was one of the first to leverage the new program’s resources, which enabled it to uncover as much as $20,000 in potential annual energy savings.
CertainTeed, a subsidiary of Saint-Gobain, manufactures a variety of building construction products for the residential, commercial, and public sectors. CertainTeed operates a polyvinyl chloride (PVC) plant in Lake Charles, Louisiana, and supplies six additional CertainTeed manufacturing facilities throughout the country that produce vinyl siding, trim, fence, deck, and railing systems.
The production process utilized at the plant involves an exothermic reaction, making a reliable cooling water supply critical to safe operation of the plant. Over the years, changes in the production process, accumulation of scale in the piping mains and heat exchangers, and normal wear and tear degraded the ability of the cooling system to remove heat from the reaction vessels. While the system continued to meet all health and safety requirements, there was clearly an opportunity for energy performance improvement. The problem was that facility staff lacked information on system energy performance and lacked the equipment to acquire that information.
Through the DEP, and with direct technical expert support from the Oak Ridge National Laboratory (ORNL), the Lake Charles site borrowed a flow meter and was able to collect a host of valuable data on the cooling water pumping system. Using the flow meter, staff at the plant were able to determine the actual flow rate. Prior to this, pressure measurements were used to estimate pump performance. Analysis of the data provided by DOE’s flow meter helped support suspicions held by the site personnel regarding possible inefficiencies. For example:
- Data was collected from a normal production day and applied to the summer season, when process cooling is most needed. From the data, CertainTeed determined that each pump produced slightly more than half the design flow rate. The system appeared to have been designed such that one of three parallel pumps could meet the flow requirements of the system. However, degradation in the system combined with process changes now requires the operation of two pumps at partial capacity to meet system requirements.
- If the measurements can be confirmed, it may be possible to install one properly sized pump that can meet system needs over a wide range of operating requirements.
- The addition of a Variable Frequency Drive (VFD) may provide additional operating control and increase energy savings. This will require additional measurements and analysis.
The plant is evaluating the findings to determine appropriate next steps. Additional measurements may be required, but the Field Validation and Diagnostic Equipment Program opened the door to understanding that significant savings were possible - preliminary results indicate the potential for as much as $20,000 in annual energy cost reductions.