The Richmond Wastewater Treatment Plant in Virginia has a strong relationship with Emerson. So much so that it’s working hand in hand, testing a remote monitoring system that will enable predictive maintenance via IIoT technologies.
“This is something we presented to the operator,” explained Steve Poling, northeast regional sales manager for Emerson’s EIM actuation technologies. He and Shimona Verma, senior product marketing manager, presented the results at the Emerson Global Users Exchange in San Antonio.
“Like many wastewater-treatment facilities, it was built in the late 1950s,” explained Poling. “It can process up to 75 million gallons/day, but it typically processes around 35 million.” The Richmond plant is the largest in Virginia, servicing 58,000 customers. It utilizes more than 200 electric EIM actuators and runs a master-station-controlled network.
Of particular interest is an automatic backwash process with filters, which is the final stage of water treatment, utilizing a media of sand or stones. “The backwash cycle is automatically triggered by differential pressure,” explained Poling. “Five electrically operated butterfly valves include the influent, effluent, backwash, drain and air valve. We upgraded these five valves to create connected services and give the plant a better idea of what was going on.”
The upgrade is designed to ensure the plant’s ability to protect the environment and public health by having a healthy sustainable wastewater system and to help the utility to make better decisions on when it is most appropriate to conduct repairs.
“The idea behind using Emerson Connected Services was to get information from the actuators in the field and pull it back to our facility in Houston,” explained Poling. Using on-premise sensing and data collection and the DCS system that is communicating to the EIM master station using the existing Modbus, the beta initiative involved using WirelessHART communications to an Emerson gateway, which then connected to a laptop on the sixth floor via fiberoptic cable.
The existing TEC2000 boards w/ACM were upgraded to TEC2 boards. Event logger monitors 68 different actuator functions. “It’s a lot of information for the user to have to decipher,” said Poling. “We asked them to let us review that data and pull out the important parts. The clock gives a real-time date stamp because many of these things happen at 2:00 in the morning. We used the Smart Wireless THUM adapter and the Smart Wireless Gateway 1420/1410.”
The software platform is a huge part of the system. DCMlink (diagnostic, configuration and monitoring) is the key feature from a maintenance standpoint. “Let’s say you have 1,500 actuators at your site,” said Verma. “You don’t have to go one on one. You can gather all of the data. For diagnostics, getting torque profiles was critical. We needed to detect emerging valve repair requirements. DCMlink archives torque profile and partial stroke test, and it can overlay test results for comparison with the baseline and help customers to determine optimal maintenance time.”
DCMlink also enables live trending of critical parameters, and it’s an AMS Device Manager Snap-On application. “You can save, archive and overlay PST/FST profiles. And it’s independent of any proprietary protocol,” said Verma. The results were a good first step, revealing where the system needs to improve, moving forward.
“These are rubber-seated butterfly valves,” said Poling. “We looked at the temperature in the actuator and run times.”
The asset monitoring revealed seating torque 26-40% average. Enclosure temperature was 86-95°F. Run time, strokes and motor starts varied by application and acquisition schedule. Stroke time was 32 seconds on average. Three “close torque” alarms were noted in the log.
“We looked at the close torque alarms,” explained Poling. “We recommended monitoring the alarm log, verifying mechanical stops are properly set and monitoring seating torque during closing if possible.”
When the initial project ended, some challenges with the setup presented themselves. “We didn’t have 100% success, but we learned some things we were lacking,” explained Poling. “The download of data takes over an hour because there’s so much data. We need to find a better way to download the data. It’s tough to access installation sites; there’s no historical data available for comparison and an absence of active torque curves for evaluating trends. On the positive side, we learned we were able to operate the system. The DCMlink asset manager gives you a lot of features. The issue is when we are uploading to Connected Services.”
Digital transformation would not be complete without the Emerson Plantweb solution, added Verma. “We were able to secure connectivity,” she said. “We had the analytics. We gathered torque profiles and event logs and alarms and configuration. The future state is getting the data into Plantweb and making it available through the cloud.”