High Wireless

"When a manufacturer claims a certain ‘range' for its products, this claim must be taken with caution because it's usually a maximum range in an optimal environment—in flat terrain between transmitter and receiver, with no obstructions or interference. The user must also recognize that higher frequencies offering higher bandwidth come with much lower range limitations and increased susceptibility to noise. When comparing products, users should look at the tangible performance values for each device, namely transmitted power and sensitivity, instead of the maximum range claimed."

Starting Small

Another way that users begin to approach wireless is by trying it out in the smallest, non-critical application in their facility—often just a couple of signals via one or two transmitters, antennas and receivers. Several suppliers offer very basic packages that rookies can use to experiment with wireless, and then scale up as they gain experience and knowledge about how wireless works in their facility and local environment.

In fact, Emerson's Smart Wireless field starter kit establishes an out-of-the-box, secure, self-organizing WirelessHART network that delivers greater than 99% communications reliability in the steel-and-concrete setting typical in most industrial plants. The kit also contains discrete switches and vibration and pH transmitters.

"This kit makes it very simple and low-risk to try Smart Wireless," says Bob Karschnia, Emerson's vice president of wireless technology. "Companies who've never used this technology before can quickly and easily begin to reap the same benefits gained by their peers who are already using Smart Wireless." To provide even more help, Emerson also offers its Smart Start onsite program to help users with their initial wireless experiments.

Mostly Monitoring

To more reliably monitor, diagnose and maintain water equipment and processes at its plant in Calvert, Ky., industrial gas and specialty chemical manufacturer Air Products (www.airproducts.com) recently installed wireless remote monitoring equipment and services from GE Enterprise Solutions (www.ge.com/enterprisesolutions), including sensor and wireless technology, software hosting, alarm notification, application expertise, and installation services. These connect to Air Products' water treatment data and help perform liquid level monitoring of the company's large tank operations, eliminating manual tracking and improving productivity by providing timely information on chemical inventories.

Basically, a submersible level probe sensor from GE Sensing and Inspection Technologies is dropped into each tank to collect measurements. Using GE Digital Energy's wireless MDS technology, the raw data is sent to a Trinity gateway, which serves as the field data collection point for each application. This gateway sends collected data to secure hosting servers managed by GE Fanuc Intelligent Platforms, where it's translated into online diagrams showing liquid levels and consumption rates. In addition, experts from GE Water are on call in the support center to help analyze information, resolve issues and drive continuous optimization for the business.

"This wireless system helps us to be proactive as we monitor chemical tank levels that support our water operations, and we can access it at any time from anywhere," says Bruce Marshall, Air Products' site manager. "Wireless monitoring allows us to check the water treatment systems that support our chemical operations remotely, and the system can automatically alert us when specified process conditions are reached," explains Marshall. "It ensures that we're getting the right information at the right time to aid in our decision-making for our operation."

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.