DuPont Chooses PlantPAx DCS to Increase Operational Availability and Flexibility of Control

Eleuthère du Pont studied chemistry with none other than Lavoisier, and his surname now names what is today one of the largest industrial conglomerates worldwide. The history of DuPont is more than 200 years old and began with the manufacture of gunpowder.

The main industries in which the company operates include agriculture, electronics and communication, industrial biosciences, performance materials, nutrition and health; and protection solutions.

It was in the division of nutrition and health at the company’s plant in the Brazilian city of Esteio, Rio Grande do Sul where a project for modernizing the control system was developed and implemented. This plant, founded in 1958, was the first to manufacture margarine in the country.

The facility produces isolated soy protein, soy protein concentrate, extruded proteins and lecithin. Protein is an essential functional ingredient in the manufacturing processes of numerous other food companies. DuPont provides protein solutions for major players in two primary markets: meat (which uses it for processed meats) and nutrition (shakes, juices, cereal bars, among others).

Motivation and Challenges

The main reason for investing in modernization was the obsolescence of the existing distributed control system (DCS), according to Márcio Moreira de Barros, project team leader: “The system had reached the end of its service life and the supplier informed us that he would no longer provide support. This was the main factor that led to the replacement, because between the risk of having an unexpected halt and an extended downtime or investing in the system replacement, we opted for the latter in order to ensure the stability of the operating system.”

Additionally, there was no more room to add extensions, the programming/configuration language was proprietary and there was great difficulty in finding a local system integrator. The deadline was among the main challenges faced by Barros and the team working on the project.

The time to replace the systems was limited to three weeks of scheduled downtime. The plant was controlled by two different systems: a DCS with 1,670 points and PLCs with 408. The logic was highly complex because it was made up of both process and clean-in-place (CIP). Furthermore, the new control system needed to integrate with the existing historical system.

The system was implemented in 110V AC, but it was prepared for a future migration to 24V DC, with interface relays. “There were more than 2,000 process control points to be migrated, within a maximum of three weeks, during which the old points would have to be disconnected, the new ones connected, commissioned and tested," Barros said.

“Even with a plant shutdown, we knew there would be a lot of other maintenance, engineering and operation activities taking place in parallel - a lot of people working on different fronts,” he said.

“Even so, we were able to assemble and commission the system in two weeks, which gave us a week to put the operator face to face with the new system, simulating the process with water,” Barros said

Critical Item: Choosing a Partner

Even as a global supplier to DuPont, the proposal and structure from Rockwell Automation was evaluated side by side with those other vendors due to the complexity and budget constraints of the project. Barros said Rockwell Automation was selected because:

• The PlantPAx DCS system brings together unique features that distinguish it in the market, emphasizing virtualization technology with templates already delivered by the manufacturer, system scalability tools before they are even in operation, scalability, integration flexibility with other systems, remote access and easy and fast deployment
• Alignment of the project with the plant shutdown schedule
• Alignment with DuPont's medium- and long-term automation strategy
• A wide range of services
• Robustness of hardware and software and modularity of the distributed system
• Local support and engineering structure
• Wide network of local integrators

Tests and Adjustments

“We have our own simulator, developed internally by DuPont, in which we performed the PAT - Plant Acceptance Test - at the Rockwell Automation plant in Jundiaí, São Paulo. We took the simulator, connected to the DCS controller, performed the interlock, logic, control loop and screen tests, and then used this same simulator to train our operators.”

“This simulator has the ability to reproduce various process conditions, including unexpected ones, “Barros said. “The operators interacted with the screen as if they were in the process. And the operator’s feedback during the operation of the new system in the simulator allowed us to adjust the system before the startup, something that gave us valuable time ahead.”

Results

“Initially, the replacement would eliminate the risks of obsolescence, but we already saw other benefits beyond the operational stability guaranteed by the modernization, including several gains that even I had not expected," Barros said.

He mentioned alarm management as an example. “Now we can see grayscale screens, which makes them safer as it is easier and faster to spot when you have a red or yellow dot.” And he also highlighted another benefit: “As we can see the interlocks that are active on the operating screen itself, this makes it much easier for the operator and maintenance and saves considerable time."

The DCS modernization also provided additional flexibility, including ease of maintenance, ease of adding and adjusting logic, adding input/output points, AutoTune of control loops, description of loops, sequencing, among others.

The robustness of the system and improved control over maintenance and operating costs were also highlighted by Barros, including improved system monitoring, data acquisition and system history.

In the face of expressive results and the positive experience working together, DuPont has already planned next steps, such as the migration of other units to the PlantPAx distributed control system, the implementation of advanced control tools (APC), manufacturing execution systems (MES), and intelligent motor control centers (MCCs) over EtherNet/IP.

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