Pervasive Sensing

Sensors Insights by Tom Moser

The sensors market in the process industries is undergoing a fundamental shift, primarily driven by the reduction of the cost of installed sensing points. Taking cost out of the equation has cleared the way for process industries to greatly expand their use of sensors, extending their focus beyond traditional process control and safety systems and entering an age of "pervasive sensing." Working with more information than ever before, refineries, chemical plants, and other industrial facilities will be able to achieve greater visibility into all aspects of their operations, allowing them to operate more safely, reliably, and profitably.

Limited Presence
In the past, process manufacturers and hydrocarbon energy producers had little choice but to measure the conditions of their operations to make quality product efficiently and safely. Processes were instrumented to an adequate level to accomplish this task. What was left undone due to the high cost of installing sensors was measurement of the equipment, piping, and areas outside of the core needs.

Potential equipment failure was dealt with by adding redundant capital for most rotating equipment and by conducting periodic manual maintenance checks of the production area, typically on a calendar-driven basis. To a large extent, these manual checks were a waste of time for plant personnel, who were essentially making sure that properly working devices were still working properly. Finding failures depended on the frequency of the checks, sometimes leaving improperly functioning devices, like steam traps, for as long as a year. While recognized as less than optimal, this process resulted in reasonably stable operations.

Higher Standards
Today, what used to be considered reasonably stable is just not good enough. A single day of unplanned outage at a major process manufacturing facility can prevent the entire staff from getting performance bonuses. More importantly, unplanned outages force continuously operating processes to go through shutdown and startup conditions, which is when serious incidents are likely to occur. Process manufacturers need to be able to anticipate impending equipment failures to prevent unplanned outages.

Similarly, energy conservation is a new and increasingly important frontier for extracting value from energy-intensive process operations. Most manufacturers know that on any given day 15% to 20% of their steam traps may be in a failed state, sending steam and profits literally down the drain, or worse, potentially leading to the damage of critical steam system equipment. Finally, the environment around a process facility can, as a result of equipment or piping failures, be exposed to toxic or flammable materials. Allowing this to occur for even the shortest periods of time can be dangerous and is not acceptable.

Lower Cost, Greater Opportunity
Until now, the cost of monitoring a wide range of pumps, motors, steam traps, relief valves, and other more complex equipment was cost prohibitive. That has changed. Manufacturers can now install and operate sensors much differently, and at a much lower cost. Plant engineers can use a variety of wireless, bolt-on sensors to detect motor bearing or seal failures, monitor steam trap performance and equipment temperatures, and identify a variety of other fault conditions that can ultimately impact plant or production field operations.

Because these devices can literally be installed in minutes, without wires or pipe intrusions, the cost of deploying wireless sensors can be as little as 10% of the cost of a typical wired equivalent. Also, sensors can now monitor wide areas for ultrasonic emissions typical of process leaks, permitting cost-effective early detection of potentially dangerous conditions. With the dramatic reduction of the cost of deploying sensors, leading process manufacturers are choosing to expand their sensor count by 50% or more. This new "pervasive sensing" approach to instrumenting a process facility can deliver significant benefits.

A Big Payoff
As process manufacturers implement this pervasive sensing approach, they will see early detection of pump and rotating equipment failure, a significant reduction of steam consumption, and nearly instant dangerous emission alerts. At the same time, because meeting these "business critical" needs is now practical, sensor providers need to refine the technology even further and take process manufacturers to the next level of business performance. Many of these solutions exist and are being deployed today. As sensors continue to evolve, additional "eyes and ears" will be available to solve the process industry's problems and increase its ability to maximize the return on its assets.

ABOUT THE AUTHOR
Tom Moser is Group Vice President, Measure and Analyze, Emerson Process Management. For more information, contact David Holmes at 512-418-7536 or [email protected].