Application close-up: Wireless devices support equipment monitoring
Also read : Wireless Communications for Industry , supplement to the November 2009 Control Engineering print edition, which contains:
Are there applications in your plant where you depend on operators with pens and clipboards to monitor some remote part of your process or equipment condition? Two companies, one in Brazil and another in Taiwan, found they could drop the operator rounds and get information more quickly. Both implemented their projects with wireless devices avoiding the cost of adding new conduit and cables.
The first situation is Petrobras’ Sao Mateus gas compressor facility in northeastern Brazil. In the past, technicians made clipboard rounds to the compressors every three hours around-the-clock to check local readings and record the data by hand on spreadsheets. The company needed a more efficient data collection method that would provide the information directly to its operating system, but the cost of wiring all the necessary devices and occasional weather-related flooding problems around the installation kept the company from acting.
"Connecting the existing monitors on the compressors to the central control system with cables was not financially feasible because of installation and maintenance costs," says Gabriel Lopes, Petrobras Sao Mateus maintenance operator. "Adding to this, because the installation is in a flood prone area, a wired installation would be less reliable and require extra maintenance."
The company solved the problem by using wireless devices from Emerson’s Smart Wireless product family and PlantWeb digital plant architecture, to automate the data collection.
It took Petrobras four days to install 56 wireless devices, including 24 Rosemount pressure transmitters, 26 temperature transmitters, and six CSI vibration transmitters. All devices communicate using WirelessHART. Emerson’s AMS Suite predictive maintenance software manages all the devices. Petrobras reckons it saved $200,000 by using this approach versus a wired installation.
"We now have online access to real-time data about the compressors’ operation, and can review historical data and trends," Lopes adds. "Alarms are generated when problems occur, enabling staff to take fast action in an abnormal situation."
For the second application, go about half-way around the world to Taiwan, to Formosa Chemicals and Fiber Corporation’s (FCFC) Rayon plant in Yilan. The company is one of Taiwan’s major manufacturers of chemicals, fibers, petrochemical and plastic materials. At the Yilan plant, management wanted a way to overcome having to take manual temperature measurements on three of its rotary machines and fix the deviation in infrared sensors it was experiencing due to weather changes.
"Unfortunately we faced several obstacles that we needed to overcome at our plant and decided to investigate several options," says C.M. Jeng, section chief, rayon division, FCFC. "Our plant data wasn’t reliable yet was still very costly due to the manual labor of collecting critical data and traditional hard-wired transmitters."
FCFC turned to Honeywell and its wireless solutions and implemented its OneWireless Starter Kit and XYR 6000 wireless temperature transmitters to help alleviate these issues. In the process, it experienced several important benefits from the project:
• Collected more accurate and reliable temperature data after replacing infrared sensors;
• Saved time and money over costly hard-wired cable and manual labor;
• Improved process measurement with increased reliable data gathering; and
• Deployed quickly for a fast return on investment.
"Honeywell gave us insight into the energy savings applications that were possible with wireless technology for more accurate and reliable temperature measurement, which in turn helped us save money, improve processes and increase safety," Jeng adds. "The solution provided us with the success we needed to perhaps look at implementing a wireless solution at our other plants."
-Edited by Peter Welander, process industries editor, PWelander@cfemedia.com,
Control Engineering Process Instrumentation & Sensors Monthly
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