Familiarity Breeds Creativity
The primary advantage of wireless that's beginning to emerge is that it isn't just a replacement for hardwiring, but is instead a way to gather signals and communication in ways and places that hard wiring could never do.
For instance, to increase production at its steel-recycling mills in Tuscaloosa, Ala., Nucor Corp.'s (www.nucor.com) engineers knew they would need to upgrade its operations and more reliably monitor temperatures around the furnace in areas not previously monitored. The application is a hot-rolled coil and cut-to-length plate mill, which makes carbon and high-strength, low-alloy steels for structural and pressure vessel applications.
In addition, a key requirement for the upgrade was to know instantly what temperatures were in the furnace, which can reach more than 1000 °F, to protect against a production upset if temperatures were to get too high. Another concern was the huge magnetic field that exists around the furnace, a result of running over 120,000 amps to it, and the field's impact on transmitter functionality.
To obtain accurate and reliable temperature readings more quickly in this extreme environment, Nucor's engineers determined they could install Honeywell Process Solutions' (hpsweb.honeywell.com) XYR6000 temperature and pressure transmitters just a few feet from the base of the furnace's flames. The transmitters were installed on the cooling circuits for the furnace, and encased in specially built protective boxes to withstand the extreme heat.
As a result, Nucor reports that its steel-recycling mill was able to increase production by 15%, prepare for future efficiency gains, improve safety with better process status measuring, reduce maintenance requirements compared to using wired transmitters, and provide a foundation to expand wireless across the mill to improve overall process reliability.
In fact, Nucor already has decided to install wireless devices throughout its entire facility, and eventually remove hardwiring, while still improving equipment reliability and overall mill performance. Also, Nucor is planning to use wireless to increase the amount of preventive maintenance performed by enabling field staff quick access to real-time information such as online maintenance checklists and drawings.
New Wireless Paths
Because initial exploration and use of wireless seems to spark unexpected ways to deploy it, this new appreciation of wireless' potential also is inspiring many suppliers to develop and launch novel products to help users make the most of wireless' capabilities in their applications.
Tom Skwara, director of technology at Electrochem Solutions (www.electrochemsolutions.com), a subsidiary of Greatbatch, reports his firm began by specializing in lithium thionyl chloride batteries, more recently got involved in producing wireless sensing, and now helps individual users implement customized wireless solutions.
Electrochem recently helped Rooney Petroleum Services (RPS, www.rpservices.biz) in Riverton, Wyo., to better monitor its gas wellheads by installing its PressureSensorOne (PS1) wireless pressure sensors on RPS' gas wellheads. The PS1s transmit wirelessly to Electrochem's BaseStationOne-U gateway, which is located in the RPS mobile command center.
"PS1 is ideally designed for hazardous oil and gas environments, and each sensor provides multiple readings of various elements. Reporting is configured for up to 20 sensors in the field simultaneously at speeds up to 10 readings per second," says Skwara. He adds that Electrochem's solution helped reduce RPS' operating costs by reducing manual labor by $80,000 to $250,000 each year, and that quality of service has improved by enabling more frequent measurements for users.
Similarly, Opto 22 (www.Opto22.com) has added wireless Ethernet capabilities to its Snap PAC programmable automation controllers and I/O components. "By adding an internal radio and antenna for a wireless local area network (WLAN) to our Snap PAC, we're basically offering wired and wireless at the same time and in the same way that they're available in any laptop PC," says Benson Hougland, Opto 22's marketing VP. "This makes it easy for a user to, for example, set up a quick pilot project in one day to monitor an electrical room for the energy their facility is using, and send that data wherever they want without having to drop in lines."
However, to make sure these and other wireless applications can run securely, Opto 22's "Overcoming Concerns about Wireless PACs and I/O in Industrial Automation" white paper cautions, "Wi-Fi Protected Access (WPA), including the Temporal Key Integrity Protocol (TKIP), replaced the older WEP algorithm in 2003. The more recent WPA2, introduced in 2004, uses the even more secure Advanced Encryption Standard (AES) 802.11i algorithm. WPA2's AES algorithm is compliant with the National Institute of Standards and Technology's (NIST) FIPS 140-2, required by some government agencies and corporations. These standards can protect a robust communication system. For secure communications, WPA2-compliant products should be used for industrial wireless implementations today."
Besides security, wireless devices need power, so Advanced Cerametrics Inc. (ACI, www.advancedcerametrics.com) recently introduced its Harvestor-III power modules that can capture mechanical vibration energy to provide perpetual electric power for microcircuit applications.
Finally, though vibration monitoring is more data intensive than other measurements traveling via wireless, KCF Technologies Inc. (www.kcftech.com) reports that its online vibration monitoring system uses a web-enabled wireless receiver and wireless sensors, which also can be powered by a power-harvesting unit. In fact, three of KCF's wireless vibration sensors were recently installed on each of two 1,200-ton chillers, and they transmit data on an assigned 5-minute to 12-hour schedule. This real-time data allowed KCF's software to perform continuous monitoring, and detect energy transients such as stall and surge. KCF estimates its wireless installation is about 48% less expensive than hardwiring. So what are you waiting for? Start walking the wire...less.
Jim Montague is Control's Executive Editor.