In a Control Engineering Asia article, Plant operations – from good to great, Emerson’s Jonas Berge highlights specific examples of how pervasive digital sensors and networks can reduce time spent in traditional practices while improving operational performance. I’ll highlight a few examples and invite you to read the article.
Field operators walk the plant with a clipboard or handheld terminal, manually collecting data from mechanical pressure and temperature gauges, sight level glasses, variable area flow meters, and gauging levels using a dip stick in some plants. This is time consuming and there is potential for human error in reading, writing, and typing the data. The amount of time people spend in the field should also be minimized to reduce exposure to potential hazards. Manual operator rounds can be automated using wireless sensors for improved productivity with the additional benefit of faster and more accurate updates, which enables quicker reactions to avoid developing issues.
For cooling water intake pumps located away from the plant, they are:
…typically in an automatic standby arrangement with local controls, but are not connected to the main control system since it is expensive to run cables for 4-20 mA and on-off signals. Field operators are required to make inspection rounds to check on the pump status to see which are operating, which have stopped and if they may have failed. By installing wireless transmitters that communicate with the control system, the pump operating status is displayed to the control room operators. As a result, productivity is improved, operators save time by not having to make manual rounds, and pump issues are revealed sooner.
For plant equipment with local control panels:
A common mechanical pressure gauge application can be found on pumps, fans, and compressors, which operators can manually start and stop from a LCP. Modernizing with a wireless, rather than mechanical, pressure gauge provides not only an indication for the field operator, but also transmits the reading to the historian and DCS for indication, trending, and alarming. This helps control room operators and crew enhance the situational awareness around manual procedures, which reduces mistakes.
Read the article for other examples such as offsite tank farm storage tank, oil & gas wellheads, wellhead control panels, rotating kiln and reactors, valve and damper positions, and additional process troubleshooting. Jonas concludes:
For operations, start by identifying time-consuming or expensive tasks, such as reviewing clipboard round log sheets or handheld data collection terminal tag lists. These tags should be automated beginning with shift and daily rounds, especially for sites that require a vehicle for travel or rely on boat or helicopter. Next, look at offsite locations, such as pump houses and tank farms. Since all departments can benefit from a shared wireless sensor networking infrastructure, make sure to speak to them all to determine their measurement needs. A common approach is to engage an external party to conduct a plant modernization audit to assess various department needs.