Wouldn't it be nice to get off the walkie-talkies and bring your control room interfaces right out to where your process applications are running? You could get off the radios, stop playing telephone tag with coworkers, punch changes into the system directly and see orders carried out seamlessly. It'd be even better for configuration and turnaround work, and you'd probably save a bunch of time and money too.
Well, some process operators are making "control room in the field" a reality. For example, Ergon Refining Inc. recently deployed mobile operator stations enabled by wireless networking to speed up turnaround at its plant in Vicksburg, Miss., and saved 60% on labor, or more than 1,400 hours worth $187,000.
Steve Giddens, Ergon senior systems analyst, Kirk Giles of John H. Carter Co., an Emerson distributor, and Thierno Gueye of Emerson presented Ergon's story, "Wireless Mobile Workers Perform Loop Checks During Turnaround," at the 2013 Emerson Global Users Exchange this week in Grapevine, Texas.
Ergon is the world's largest manufacturer of naphthenic process oils with a processing capacity of up to 25,000 barrels of crude oil per day. Eight units at the Vicksburg facility make six different products. The site also includes two tank farms, one flare and three barge docking areas.
Giddens reports that Ergon's mobile worker project started with buying two Panasonic Toughbook laptop PCs and connecting them to the plant's DeltaV system. "We wanted the laptops to work as complete DeltaV operating stations, so one person in the valve area could ask for a valve to be stroked and collect the signal right there," says Giddens. "Instead of using walkie-talkies to ask the control room to do these tasks, we could do them all in the field."
The refinery tested out its wireless set-up this past January and February during a turnaround project that had two main objectives. First, Ergon wanted to perform a standard four-to-six-year maintenance turnaround of its hydrogen gas plant and propane de-asphalting (PDA) plant, which consists of servicing about 130 valves. Second, Ergon planned to commission, site accept and loop check its crude Hydrogen Processing Unit 2 after migrating it to DeltaV and Emerson's CHARMs electronic marshalling and I/O components. This project included five cabinets, each with two CHARMs I/O carriers (CIOCs) and 96 channels for a total of 550 loops.
"This was a total shutdown and refit of this part of the plant, but there was also a difference between a traditional wireless field network and the wireless plant network (WPN) we planned," explains Giles. "A wireless field network has transmitters talking back to controllers and periodically reporting data. However, our network has mobile workers with wireless PCs talking to controllers and commanding valves and other devices. We can even add video monitoring, asset management, staff tracking and wireless mustering. We wanted to eliminate the disconnect between the guy at the console in the control room and the guy in the field. We wanted to make them the same guy, who could be in the middle of all the action and get both jobs done with less manpower."
Ergon turned the Toughbooks into DeltaV stations by using remote desktop protocol (RDP) or remote access service (RAS) servers to provide redundancy, access to multiple DeltaV DCSs, and automated disconnect/reconnect with visual feedback. As a result, RAS was implemented on the two laptops' Pro+ sections; a remote node was created in Ergon's DeltaV Explorer software; DeltaV was implemented on the laptops; and a license was assigned to them.
"The proof-of-concept and setup wasn't that difficult because we were already familiar with the remote access client (RAC) in DeltaV, which is common on wired, business LANs," adds Giddens. "So we initially bought the DeltaV license, used a Cisco wireless router to help build the system, and made sure it was feasible by first bringing it up in our conference room. After building a little confidence there, we began implementing Cisco and Emerson radios in other locations in the field."
Giles reports that Ergon's engineers originally thought their mobile workers would just have a control room-style kiosk in the field, but quickly realized that DeltaV and wireless networking and coverage by the four access points (APs) could allow their colleagues to work anywhere.
"We wanted the people in the field to be in real control of what they're doing, instead of being driven by someone back in the control room," adds Giles. "Our mobile workstations are a good tool for our operators and maintenance guys. They don't have to rely on their radios as much anymore because they can see what's happening for themselves."
In the future, Ergon may add other devices and capabilities to its WPN, such as wireless cameras and video for flare monitoring. "We have good coverage now, but we may add another AP to the PDA or to the terminal area," says Giddens. "We're also talking about expanding the WPN into other assets and applications, such as using more remote video, doing human access tracking or using wireless in blending operations."