The plant has achieved yearly savings of more than $500,000, a 50% reduction in batch programming time, better batch consistency, and improved safety though enhanced data monitoring. Moreover, switchover between production campaigns now incurs minimal downtime.
With the new system, a production engineer can modify procedures and load recipes at the same time while keeping everything synched. It has spurred improved consistency in both the control recipe and procedure. Arkema can constantly try new grades and immediately make changes to a batch.
Rockwell's latest offering is a local controller-based solution, the Logix batch and sequencing manager, which is part of its PlantPAx process automation system. On limited release for over a year, it reportedly already has proven itself in the chemical industry as a reliable way to solve the challenge of moving from simple R&D tabletop processes to full-scale production without re-engineering.
"The challenge in the chemical industry is that generally a scientist does the R&D in the lab. Feedback from this group is that servers, software and mainstream batch production systems are not optimal," says Stump. "Logix batch and sequence manager overcomes this by offering the scientist a simple HMI [human/machine interface] based view to configure product definitions, control batch execution and capture data for analysis. This same system then can scale up to full production when the time is right. In fact one of the world's top chemical companies is doing this today." That company's lab and pilot plant reactors rely on Logix batch and sequence manager to prove out a process prior to moving to commercial-scale production.
Rockwell emphasizes the need for scalability. The PlantPAx system allows the code that works on single reactors to be integrated into existing mainstream FactoryTalk Batch based solutions for large-scale multi-vessel systems. The latest release of FactoryTalk Batch software includes many new enhancements requested by customers, including: intelligent recipe features, improved run-time user control, expanded data collection and reporting, and better material management capability.
"Overall we are looking for quicker time to value. That means much tighter integration with the process real-time batch reporting and as much standard out-of-the-box functionality as possible," Stump stresses.
Batch processors face multiple challenges. Consider, for instance, a project that PVC Compounders of Kendallville, Ind., a producer of pellets for injection molding and extrusion, has just undertaken at its satellite plant in El Paso, Texas.
Because all pellets made at the El Paso plant are compounded to order, the plant stocks minimal inventory. Instead it gets daily deliveries of fillers and other raw materials. Operators must have immediate access to formulations so they can ensure the right ingredients for a particular product — including plasticizers, stabilizers, fillers and lubricants — go from the silos to the mixing line. After mixing, operators manage the cooling process and monitor the finished powder as it moves to the pellet extruder.
Scheduling of batches and confirming of formulas take place in the plant control room. The inventory control and scheduling systems connect with the parent facility in Indiana.
Besides ensuring consistent and accurate recipes, the plant must carefully control the manufacturing environment. Temperatures in El Paso can range from 40°F in winter to 120°F in summer — these extreme temperature fluctuations can't be allowed to affect the final product. In addition, because many operators are non-native English speakers, facilitating clear communications also is a priority.
To meet its needs, PVC Compounders selected a custom software solution from Wonderware, a unit of Invensys Operations Management, Plano, Texas. The Wonderware System Platform links El Paso to the main plant in Indiana, providing a unified environment for visualization of the plant floor, plant history, device communications and automation application integration. It also works with the plant's programmable logic controllers to form a smart system for continuous improvement. Wonderware's InTouch introduces point-and-click control to the process, including silos, storage bins and different ways of incorporating plasticizers, fillers and other ingredients. At the same time, Wonderware Historian gives operators the accurate real-time data needed to make adjustments to temperatures in the mixing process, the amperage of the mixing equipment and other parameters, ensuring that the finished product is consistent.