Hi, Pete Anson here, and today I’d like to tell you about a very interesting application of wireless technology.
Industrial users are finding many reasons to choose wireless technology for a range of applications, but wireless is most frequently qualified in situations where communication and measurement are required at remote points to the plant infrastructure. An extreme example of this is seen in the case of Weyerhaeuser, the large paper mill in Port Wentworth, Georgia.
Weyerhaeuser was required by the EPA to report all overflow events into the Savannah River, which required measurement and continuous reporting of pH values to be included to the EPA in the event of an overflow. The distance from the site to the plant’s DCS is a startling 4,000 feet. No continuous monitoring was originally installed at the site since the EPA did not require such recording recently. The plant personnel had been dealing with the requirement by sending a technician to the site for manual sampling often several times a day at a cost of approximately $100 per visit. Cost was a huge issue but even greater was the potential for non-compliance since the manual sampling was prone to errors including sample handling, accuracy and logging problems.
After suffering the costly manual process for over a year, Weyerhaeuser executives decided to look for a better solution. They specified that the system selected had to have:
Continuous monitoring for near-real-time reporting
Logical integration with the plant’s DCS overcoming the 4,000 ft. distance, and requiring burial or pole suspension
High transmission integrity with a 60-second update rate, minimal loss of signal strength, and immunity to environmental influences (storms, RF, mobile equipment, etc.)
Reasonable commissioning time
Two wired solutions were evaluated including 4,000 ft. runs of twisted pair wire from three devices to the DCS, and rerouting analog signals through the OPC server to the host at a distance of about 1,000 ft. Interestingly to all industrial plants considering the use of wireless, the wireless solution in Weyerhaeuser’s application was cost equivalent to the two wired solutions. Weyerhaeuser decided on a network including two Rosemount Analytical 2-wire transmitters and a Rosemount level detection device all retrofitted with Wireless THUM Adaptors. The wireless solution was chosen based on cost, the integrity of the wireless transmissions, the practicality of wireless vs. copper to deliver data to a distant DCS, and the opportunity for easy future expansion.
Since it’s installation in 2009, Weyerhaeuser has reported excellent logical integration, high data reliability, near-real-time reporting of level and water condition, and immediate response at the remote site for waste neutralization. Weyerhaeuser demonstrates the potential of wireless to significantly reduce long-term costs while not increasing initial costs, and most important, delivering the best data reporting system available.