Grease manufacturer’s new facility achieves world-class performance with modern DCS
By Steve McNamer
A major Midwest grease manufacturer was experiencing continued growth to the point where sales exceeded the capacity of its existing facility. It acquired a manufacturing facility adjacent to its current plant. The existing facility relied on mostly manual controls for its manufacturing process, with little to no automation. With the size of the investment in the new facility, management wanted to make sure the new facility was state of the art.
The company’s engineers were tasked with finding solutions that would increase capacity and quality. The system would also need flexibility and scalability for future growth and expansion. Data would need to be available to management, quality control, and research and development.
Partnering with a local process control systems integrator, which was certified by the Control System Integrators Association (CSIA), it developed a plan that was a perfect fit for the expansion. A control system design would be created to fit the new process equipment, which included three new grease kettles that were 50 percent larger than the kettles in its existing facility. The plan would also take into account the possible expansion of up to seven more kettles for a total of 10 at full capacity.
With the process equipment identified, the systems integrator identified the priorities of the control system design. These priorities included centralized control with modular expansion, securely segmented networks using Ethernet, virtualization, and operator interfaces that fit the task and environment.
A centralized process automation controller was installed as the base piece of the modular control system. The controller was sized in a manner that met the scalability requirements of up to 10 new grease kettles. Small localized I/O panels were placed near major process equipment and connected to the process automation controller using Ethernet. This arrangement created less I/O at the controller, saving construction costs by shortening wiring and conduit runs.
A virtualized software infrastructure was put in place to accommodate all software required for completing the automated system into a single computer. This setup included software for human-machine interface (HMI), batch management and control, historical data collection, and reporting. Virtualization allowed the system to be highly available to minimize downtime due to software or hardware failures. It was also the most efficient route for future expansion.
Operator workstations used thin clients to provide HMI visualization to operators in harsh and dusty environments not suitable for normal PCs. Using thin clients also allowed for quicker replacement in the event of a hardware failure. The workstations had batch control, recipe management, historical data, and reporting to the operators in their work areas. Operator terminals were placed throughout the facility, so operators continued to control task-oriented pieces of the process in areas where they did the work.
Engineering workstations were provided for troubleshooting and development of the system. Supervisors could also remotely access these workstations for a limited control display that showed them what was happening in the new facility from their offices in the existing facility.
Ethernet was used throughout the process control strategy via remote I/O, variable frequency drives, and soft starts to simplify controls and reduce the costs of electrical construction. Segmented and secured networks allowed maximum bandwidth efficiency and communication across the three levels. New device control and process control networks were added to the existing business network in a way that allowed data to only be available to the device or person who needed it.
The results of the new system went beyond the manufacturer’s expectations. The first batch was produced within its quality specification, and that quality was very repeatable. The plant was immediately able to produce at a high rate to allow it to not only keep up with product demands, but also maintain its inventory requirements. The automated system has brought major cost savings by reducing quality issues and material waste.
The new kettles not only produce 50 percent more product than the existing kettles, they also take as much as 25 percent less time to produce the larger amount. This savings allowed the company to increase capacity and efficiency without having to increase staffing. Operators brought from the existing plant to run the new plant can produce as much or more in one day than they could in the existing plant. Due to the automated processes, operators are now more efficient. They can prepare materials and do other duties while the kettles are in phases that run automatically.
Large customers have been impressed with the system’s data collection and reporting. Its ability to assist with ongoing quality improvements and the ability to run experimental test batches have been very beneficial to the research and development department.