Automation of a tank storage in Neuss
More than 165 years ago, Caspar Thywissen laid the foundation stone for the company C. Thywissen in Neuss, which is still owned by the Thywissen family today, in the sixth generation. Since that time, the group of companies has been trading and producing various vegetable oils.
Every day, people come into contact with products from Thywissen: whether as cooking oil, margarine, frying or deep-frying fat, mayonnaise or ketchup, ingredients for baked goods and confectionery.
Whether in medicines, cosmetics, dishwashing detergents, washing powder, in linoleum and cling film, lubricants or biodiesel: vegetable oils are real "all-rounders" and fundamental components of gentle chemistry. But only gentle extraction and systematic refinement allow further development for different products and consistently high quality.
The company employs more than 140 people and comprises several business units at different locations. These include the protein and oil plant in Neuss, Rhein-Ruhr Malz in Mülheim, Malz Fabrik Kalscheuren in Hürth, Trenntec in Hürth, and a shareholding in NEW, Natural Energy West in Marl.
The task was to find a holistic automation solution for the tank farm. The tank farm comprises eight tanks with a capacity of 30,000 tons, which are filled with various vegetable oils from the company's own refinery. Whereas previously the various pipe routes from the refinery to the tanks were specified by manually setting individual gate valves and valves, an automation solution was now to be implemented via which the individual routes to the tanks are controlled and monitored. This should prevent the mixing of different products due to an incorrect slide valve position.
With an S7 controller and decentralized peripherals from WAGO connected via Profibus, the states of valves, motorized slides and pumps are now controlled and monitored. Via the connected visualization (InTouch), the desired pipeline path is selected and the manual valves to be set are displayed graphically. Only when the position of all valves for the desired path has been checked by the control system and found to be correct, is the pipeline path released via the respective motorized gate valves and the pumps start to operate. The active pipeline path is displayed graphically in the visualization. Should a valve changeover occur during the process, the control system automatically shuts down the pumps and closes the corresponding motorized gate valves. The InTouch alarm system reports this error not only in the tank farm, but also at all other stations in production, so that the operator can react quickly accordingly. The software is designed so flexibly that several pumping operations can be processed in parallel. The system can only be operated in manual or semi-automatic mode by a specific group of people.
All operations are logged by the InTouch visualization software. Operation is kept simple and intuitive for the production worker. All pipe routes, from the source to the tanks, can only be defined by the production manager. This definition is made via a graphical operating matrix in the visualization, which means that all possible piping routes can be set without changes in the PLC program. The employees then have the possibility to select these defined routes in a mask. If there is a medium in the tank other than that supplied by the source, pumping is not possible. Contamination of the products by mixing with others is thus prevented.