The PPG Lake Charles, La., facility is one of the world's largest producers of chlorine, caustic soda and vinyl chloride. The site always is looking for operating economies and views more efficient control of its chemical processes as crucial for achieving many savings. So, the plant has been breaking new ground in the past few years, using wireless communications to obtain more high-value measurements than operators ever dreamed possible — allowing them to respond quickly and effectively to changing process conditions.
The case for wireless was compelling because, in a well-established plant like this, it's both very expensive and time-consuming to get new measurement points online using conventional instrumentation. The cost for introducing wired instruments in many remote areas of the 765-acre site is prohibitive; wiring would run from $20/foot to many times that depending on the amount of engineering and construction involved. Wireless devices now supply data from numerous points that never could have been justified otherwise.
Thanks to these devices, the plant has achieved savings of at least $500,000 over the past two-and-one-half years.
For example, operators use wireless information daily to control steam header temperatures across the entire site, watching for cold spots and making load balancing and sharing adjustments to maintain superheated steam plant-wide.
PPG formed a cross-functional team in January 2005 with six persons from the Lake Charles plant and three from corporate IT to investigate wireless protocols for their utility, reliability, safety and security. This led to a written proposal in mid-2005 for a wireless pilot installation; the first wireless effort started in early 2006 with WiFi and WiMax installations. It was thought that WiMax could be used to blanket the plant with video cameras to monitor key locations — but this initiative was abandoned, partly due to the high cost of WiMax stations and partly due to lack of compatible products.
In early 2006, the focus instead turned to blanketing the plant with hundreds of WiFi access points rather than two or three WiMax.
The plant installed points from January 2006 to April 2007 in "A Caustic," one of three units producing sodium hydroxide. Although the points were supposed to be weatherproof, they couldn't withstand the industrial environment. At that time no vendor was making true industrial WiFi access points. However, the site now has more than 70 WiFi access points and, in the future, the entire facility, including parking lots, will be WiFi-friendly.
In the meantime, the plant established automated long-distance wireless communications with remote brine fields that are eight to 13 miles away. It later replaced the original WiMax stations with proprietary 5.9-gHz access stations — eliminating telephone lease line costs of $35,000 to $40,000 per year and enhancing personal productivity.
The learning continued via investigating and testing every wireless system available. Along the way, the wireless team adopted the PPG Corporate IT security policy calling for WPA2 encryption and authentication.