Wireless Comes of Age

It is a truism that the process industries are slow to adopt the new. As Process Hall of Fame member Dick Caro says in a recent article on variable-frequency drives for this magazine ("A Failure to Communicate"), "We have always understood that process control . . . is very slow to accept new or innovative technology. In spite of the many innovators who thrive in the process control industry, the folklore is essentially correct. We insist on proof that some new or innovative technology offers a measurable user benefit and that it be demonstrated in several plant locations."

That's certainly been the case with wireless in process operations. In spite of the best efforts of some of the biggest names in process automation, such as Emerson Process Management and Honeywell Process Systems, organizations such as ISA and the HART Communication Foundation, and a lot of media hype and users' real-world experience with it in their private lives, wireless has been a tough sell in process plants. 

But that is finally changing. Earlier this year, Global Automation Research released the results of a survey of end users of wireless process instrumentation transmitters and found that 67% of those surveyed were using them, compared to 43% in 2008, an increase of 50% in just four years. Furthermore, wireless technology has moved from small test applications and simple monitoring to safety, asset protection and mainstream problem solving—and even some control. Furthermore, 63% of the respondents worked for companies that had considered using wireless, up a full 20 percentage points from 2008. The number of respondents working for companies that have decided against using wireless dropped to 4% (see Figure 1).

The survey also reported that 40% of the respondents' companies have been using wireless for more than a year, and 15% for more than 4 years (See Figure 2). The dominant application of wireless remains field monitoring, including tank farms, remote water and wastewater facilities, field data collection, temperature profiling, leak detection and flare monitoring. But safety and environmental monitoring is up, while wireless for process monitoring remains unchanged over the last two years at a little over 20%.

The benefits reported include savings on materials and labor, increased efficiency, increased data accuracy and easier maintenance. One of the respondents summed up the savings for his company this way: "[Wireless is a] very cost-effective method to bring additional points into the control system. We are seeing wireless installation costs about 70% less than a similar wired installation."

Joseph Citrano, global wireless product marketing manager for Honeywell Sensing and Control, says, "What we're seeing over the last year is that the early adopters have gone through the experiment and are implementing it [wireless] in a meaningful way. More people, who are followers, are just getting their feet wet. They're doing fewer applications, but there are quite a few folks doing more and more."

It looks like wireless is finally meeting Caro's criteria of measurable user benefit demonstrated in several plant locations. 

Remote Access

Getting necessary and, if not necessary, certainly useful data from remote areas of operation at a reasonable cost is a big driver for implementing wireless.

At specialty chemicals manufacturer Lubrizol's Deer Park, Texas, facility, wireless monitoring is in place in the tank farm. Keith Simpson, Lubrizol's I & E controls manager at Deer Park, explains: "The Deer Park tank farm is hundreds of tanks spread around the manufacturing facility, and some are across the road and in outlying areas. We're installing wireless transmitters for tank pressures and temperatures."

Cost was a big factor in making wireless an attractive option, and not only because the cost of running all those wires was eliminated. "People frequently forget that not only do you not have to pay for the wires, conduit, etc, but also, you don't have to do the engineering design. Wireless eliminates that cost as well," Simpson explains. "We had to decide where to put the wireless gateway and the switch, but that's what the engineering was restricted to."

Lubrizol went with the WirelessHART protocol for the same reason that many end users choose one protocol over another. "Most of our wired apps are HART," says Simpson.

Furthermore, Lubrizol uses Emerson's DeltaV automation system and its AMS asset management suite, both of which integrate seamlessly with the HART protocol. That AMS integration was another selling point for going wireless. "You can capture all that data and get it in AMS if you're using wireless," Simpson says.

Lundbeck Pharmaceuticals Italy, a producer of active pharmaceutical ingredients and cGMP intermediates in Padova (Padua), overcame its remote facilities problem in a similar fashion. The company needed to monitor and record groundwater levels at 10 monitoring wells around the facility.