Integrated monitoring solution
Published: 06 May, 2015
An easy to implement monitoring solution is helping to reduce slowdowns and shutdowns due to cooling water tower issues. PWE reports.
An integrated solution to monitor the water cycle of the cooling tower that services process plants, has been introduced by Emerson Process Management as the latest addition to its Essential Asset Monitoring capabilities.
Cooling Tower Monitoring helps operators ensure that make-up water and chemical costs are optimised while minimising scaling and fouling of cooling water exchangers facility-wide.
The solution provides a complete set of pre-engineered applications for 24/7 online monitoring and analysis of the cooling tower and its related equipment health. It uses wireless instrument networks with existing wired instruments to provide affordable, easy-to-implement, automatic monitoring.
Cooling water quality and availability is critical for maintaining production at most operating facilities. Process plants and refineries circulate thousands of litres of water through cooling water systems. Plants in hot climates are particularly susceptible to cooling-limited conditions during summer months. Conversely, plants in cold climates are concerned with equipment freezing and damaging cooling tower internals. Poor water quality can lead to rapid fouling in the entire heat exchanger network, reducing cooling effectiveness, potentially limiting production, and requiring additional maintenance services and outages for cleaning.
A problem with a cooling water pump or a fan failure forces operators to react to an immediate loss of cooling capacity. Even if a plant shutdown is not required, interruption in cooling water supply can cause pressure relief valve releases and require temporary reductions in throughput, resulting in underutilisation of the plant assets.
Since chemicals, additives and fresh water treatment are some of the largest variable costs for cooling tower operation, optimising purge and make-up rates is important. Proper control of water cycles and chemicals to maintain water quality requires on-line measurement of water quality. Many plants operate based on daily or even weekly analysis of their cooling water. On-line monitoring of cooling water quality can result in lower make-up water and chemical costs, as well as elimination of fouling events in the exchanger circuit.
Pete Sharpe, director of applications development for Emerson, commented: “To confront common challenges of operating cooling towers, Emerson has developed a new essential asset monitoring module that analyses process and equipment data to determine an overall cooling tower health indicator and generate alerts when something abnormal is detected.”
He added: “Cooling tower equipment is located in wet, slippery environments, so it is not the ideal location to send maintenance technicians out with a handheld to take manual measurements. By installing wireless monitoring devices on their cooling tower fans, customers can eliminate manual rounds − increasing worker safety, saving time, and freeing technicians for higher level tasks. Further, continuous monitoring delivers alerts that enable planned maintenance, which is quicker and more cost effective than reaction to failures.”
“All told”, said Sharpe, “we estimate that on-line monitoring and analysis of a large 350,000 gpm (1.3 million litre per minute) cooling water system can add up to €330,000 (£240,000) in savings annually due to reductions in lost production, lower energy bills, and a reduced chemical and water usage.”
Cooling Tower Monitoring adds to the range of Essential Asset Monitoring solutions, which include monitoring solutions for pumps, blowers, compressors, and heat exchangers, with other asset types under development. The Essential Asset Monitoring solution from Emerson includes the software and any new devices required and commissioning services.
For more information please visit: www.emersonprocess.com
