Industrial plant in a small format

Some 1700 students are pursuing bachelors and masters programs in construction and engineering at the School of Engineering and Architecture at Lucerne University of Applied Sciences and Arts. In the mechanical engineering program, the specialisation in process engineering gives insight into the processes of material transformation. Rectification is one of the basic operations of thermal process engineering - it is used in biofuel production and in whiskey distilleries, for example, where liquid mixtures are separated in a multistage distillation process. To promote a fundamental understanding of such material separation processes, staff at Lucerne University decided to replace the existing rectification plant with a larger system that would allow all the important process parameters and their interdependencies to be reproducibly analysed and presented.

The school’s competence centre for thermal energy systems and process engineering wanted to implement a plant for the education of students that would be constructed similarly to an industrial plant and controlled and monitored with a process control system suitable for industry. Prola AG was commissioned to provide the electrical design and configuration of the control technology. The engineering company from Emmenbrücke has broad experience in the configuration and programming of control systems and process control systems for process plants. As a Siemens Solution Partner, Prola had frequently used Simatic PCS 7, but never the Microbox version.

“The plant also serves the students as a subject of study and demonstration in the field of process automation. For this reason, we chose the Microbox version of the PCS 7 process control system - it is an ideal solution for plants of this size,” said Heinz Müller, managing director of Prola.

Ensuring occupational safety was one of the main requirements during the implementation of the control software. The manual options for intervention therefore needed to be designed in a restrictive manner. The operator runs the specified formula and can adjust individual set points and parameters within the limits of their authorisation. The thermal conditions and the design of the system as Ex Zone 1 determined the basic requirements for measurement and control technology. The constant monitoring of the temperature values defines alarm and tripping values, and the system is automatically brought into a safe state when these values are reached.

In order to promote process transparency, the system has many measuring points. Thanks to the Advanced Process Library (APL) modules in use, all the process parameters and actuators can be clearly displayed on the screen. In addition, all the components are made of glass, which allows visual tracking of the process. Reporting was also of great importance, and the batch history is stored in a database with all the relevant data. This data can be output in Excel, which makes it easier for the students to create lab reports.

“PCS 7 handles a great deal of routine work for the programmers. This allows them to focus on the system, processes and operator interface,” says project manager Simon Wernli, describing one of the advantages of the process control system.

The system was put into operation after a configuration time of only about three months. In collaboration with Lucerne University, Prola developed a special user interface that intuitively supports and guides the user in their actions, making the system easier to operate. The result: after a one-hour introduction to the process control system, the students were able to operate it themselves.

Prola AG is a qualified Siemens Solution Partner in the area of process control applications. In the Lucerne University project, Prola was responsible for the electrical design as well as the design of the control platform, including industrial PCs, frequency converters and distributed I/O devices. The functional specifications also included the programming of the control software, operator interface and formula management