Controlling a giant
The OK 81-6 mill at Shah Cement Industries Ltd in Bangladesh is a giant: at 25.6m tall and weighing 1,904 tonnes, it holds the Guinness World Record for largest vertical roller mill at a cement plant. But size doesn’t guarantee performance. You also need plant control system and advance process control that will support your operators in achieving the best possible results.
"In our search for the best automation solution, we considered a number of specific criteria for suppliers, namely technology, service and quality. We are convinced that FLSmidth’s state of the art solutions set our plant on the right path to digitalization."
ECS/ControlCenter: underpinning digital success
The ECS/ControlCenter V8 software platform is the digital heart of an operation: an advanced, reliable, adaptable and secure software platform that is the foundation to control anything from a machinery to full plant. By collecting data from Programmable Logic Controllers (PLCs) around the plant (motors, drives, field instruments, process values etc.) and displaying the information in an easily-accessible format, ECS/ControlCenter helps to empower operators and eliminate human error – which is still a significant cause of unscheduled downtime.
“FLSmidth is known for making efficient and clear process displays that help the operator to keep the process running smoothly. The feel of the latest version is tailored perfectly to meet the needs of the operator, with new equipment symbols based on the company’s ACESYS standard and root cause analysis of faults, making it quick and easy to understand and prevent stoppages.”
The system also includes individual product control systems located on the equipment, such as the hydraulics or gearbox. This allows operators to view or operate the specific equipment locally, with operator displays showing trends, alarms and reporting tools, for easy maintenance.
Usability also extends to the commissioning of ECS/ControlCenter with several features allowing quick and easy integration and set-up of the system at the plant. For example, we’ve included several engineering and processing tools that ensure a consistent and uniform structure of the PLC inputs that feed data to the control software. These tools enable faster modifications, updates and troubleshooting during both commissioning and operation.
The ECS/ControlCenter platform also includes a device simulation mode in which the operation of the entire plant can be simulated and tested as per process requirements. This helps to ensure smooth and quick commissioning, without impacting the real-world operations of the plant.
ECS/ProcessExpert: the ultimate assistant
Building on the foundation provided by ECS/ControlCenter, the ECS/ProcessExpert advanced process control system at Shah Cement optimises mill performance to achieve maximum efficiency. Using a mathematical model of the process, the control system is able to predict future conditions and continuously adjust a range of setpoints to reach optimum performance and avoid negative performance conditions. For example, in the event of mill vibration, ECS/ProcessExpert takes immediate corrective action by reducing mill feed to optimise bed thickness.
Typically, setpoints on a vertical roller mill are separator speed, fresh feed and mill fan. But the selection of process measurements, control variables and setpoints is customisable to the given process configuration of the mill.
In the event a process measurement is lost – for example due to hardware failure – the system will automatically switch to second-priority signals or estimated values, based on the process model, in order to continue operations. This temporary measurement can also be selected manually by the operators, if a device is scheduled for maintenance.
“In many way, ECS/ProcessExpert is the ultimate assistant. Able to adjust the process far more frequently and accurately than can be achieved by manual interventions, it better manages and corrects process disruptions to minimise wear and reduce energy consumption.”
A trustworthy partner
Shah Cement now leads Bangladesh’s cement production with its OK 81-6 mill exceeding guaranteed performance to produce 525 tonnes per hours of Portland composite cement (PCC) at 3500 Blaine with 15% slag, compared to a guaranteed performance of 510 tonnes per hour. Power consumption is also better than guaranteed at 28.2 kWh per tonne, compared to a guaranteed performance on 28.8 kWh per tonne.
“The OK 81-6 mill has proven to be the best of its kind with its colossal capacity fulfilling our increased market demands. We are proud to have this Guinness World Record holder at Shah Cement and we thank FLSmidth and its dedicated team for making this happen and providing incredible support on all fronts. With this success, FLSmidth has proved itself to be a trustworthy partner.”