Continuous disruption in the plant or field is a fact of life for manufacturers in 2018. Factors playing into this constant change scenario include all types of business drivers, such as emerging regulations, shifts in consumer behavior and new process manufacturing requirements like those in the pharmaceutical industry.
Reduced automation costs and the rise of real-time analytics are additional factors pushing executives to make the critical decision to future-proof their plants. Luckily, some are finding they can update their old brownfield processing plants and legacy control systems with minimal disruption and implement new digital architectures to optimize efficiencies and put process data first.
One example is evident at the Dow Chemical processing plant in Carrollton, Ky., which produces silicone fluids, blends, emulsions and intermediate materials. The facility has been a staple in the Carrollton community since 1966 and is a workhorse for Dow. The silicone producer’s challenge was how to modernize its plant without interrupting current processes and even allow the company to proceed with plans to increase polymer production at the facility.
Dow’s modernization initiative took a phased approach to implementing Schneider Electric’s open, interoperable EcoStruxure Plant architecture, including the Foxboro distributed control system (DCS). The DCS platform provided a digital roadmap for the plant to allow the manufacturer to achieve better data visibility for pumps, valves and motors.
The initiative began by replacing older field control processors (FCPs) with newer Foxboro 270 and 280 FCPs. In addition to preserving the existing control logic, the new FCPs can handle 8,000 blocks of control, providing better block processing and execution levels in phasing. Other new processing features include the ability to rerun the control database and assign function blocks in a more optimized way with the database.
The company was also able to reduce the amount of control hardware with the upgrade. “Dow was able to collapse multiple control processors into the 270 and 280 controllers and still provide process isolation, for example, between the utilities and a feedstock area,” says Graham Bennett, senior principal migration consultant at Schneider Electric.
Much of Dow’s existing infrastructure—including nose cones and field wiring—remained in service, but the two companies replaced plastic IE32 cabinets with metal 1x8 units configured to match up with existing nose cones for ease of installation. This plug-and-play approach not only contributed to an accelerated timeline for commissioning but also reduced capex by about half, according to Dow.
“Having an open DCS architecture allows a system to keep moving forward,” Bennett says. “From workstations to I/O, the open platform allowed Dow to keep all interconnectivity between the field wiring for the first phase.”
“The initial timeline for the upgrade was far shorter than a traditional approach, and the team still managed to complete it early—even conducting a second 100 percent checkout in the field,” says Dave Caldwell, tech center Foxboro subject-matter expert for Dow Performance Silicones. “Getting back online early granted us two full extra days of production.”
Asset visibility and a continuous workforce
With a sprawling continuous-process plant, the need for better monitoring and actionable data for an ever-changing operator workforce is a top requirement with Dow. With Schneider Electric’s open DCS architecture in place, Dow can now upgrade monitoring to maximize plant utilization.
The roadmap also includes the addition of Schneider Electric’s HART devices to enable operations and maintenance teams to remotely view equipment health or thresholds for valves in order to manage them better, according to Bennett. The HART technology adds a digital signal on top of the 4-20 mA current loop analog signal and can transmit instrument status, additional process variables, configuration data and diagnostics.
“The ability to also enable HART devices on a channel-per-channel basis is crucial for minimizing risk with the new platform,” Bennett says.
The main goal for this modernization initiative was to reduce risk while preserving current production volumes. Dow was able to minimize the risk in the early phase by keeping its human-machine interface (HMI) and documentation the same for now.
Later, new HMI designs might include alternative color palettes, compressing piping and instrumentation design windows, actionable alarm management prompts, situational awareness levels and critical data relationships. Dow’s efforts in the future will also include advanced HMI approaches, such as situational awareness graphics.
“With an aging workforce retiring, tribal knowledge is disappearing, and more companies are relying on third-party asset management support,” Bennett says. “There's a huge gap in plant knowledge.”
With workforce challenges appearing in many industries, enterprises are recognizing the advantages of open architectures like Schneider Electric’s EcoStruxure DCS—for business analytics and better tracking of key performance indicators. Manufacturing business drivers are coming fast and furious, and the success of this first phase is a promising development for Dow.
