Our monitoring system measures the amperage of each pipe trace heater. At a deviation of 0.5 A, a warning message is generated in the distributed control system and immediately displayed on the monitor in the control room and, alternatively, in the remote workshop. This helps employees detect changes at an early stage. It allows them to react immediately, thereby ensuring high system availability.
Wireless-based monitoring of pipe trace heating Paper and pulp mill Sappi Stockstadt GmbH
Above-ground piping systems are heated so that the raw materials transported through them always reach their destination reliably. At the pulp and paper manufacturer Sappi Stockstadt, the Radioline wireless system ensures that suspicious measured values are immediately displayed in the operator control room so that countermeasures can be taken at an early stage.
Sappi Limited is a leading global supplier of paper, paper pulp, and chemical pulp solutions.
At Sappi Stockstadt GmbH, more than 550 employees produce up to 145,000 metric tons of pulp and 230,000 metric tons of paper each year.
The location has its own power station and wastewater treatment facility.
The fine papers valued by the printing and media world are shipped to around 100 countries worldwide for the production of premium magazines, catalogs, art books, and high-end print advertising.
Up to 1,000 metric tons of paper leave the plant every working day.
Application Reliably avoid unplanned system shutdowns
The individual trace heating systems were previously inspected regularly during special inspection rounds. In addition, a residual current operated circuit breaker was used to monitor all of the trace heating systems. However, experience showed that, despite this, not all failures were reliably detected.
The unloading process had to be stopped again shortly after the start due to frozen pipes. This entailed time-consuming and expensive de-icing and cleaning of the affected pipeline, which in the worst case can lead to a temporary production downtime.
Solution Immediate display of suspicious measured values in the control room
The special challenge for the solution in Stockstadt was how to integrate the measured values into the existing distributed control system, because there were no cable routes between the different building parts. This demanded a simple and reliable signal transmission.
With the proprietary Radioline wireless system, the measured values can be forwarded wirelessly. Depending on the application requirements, different topologies are used. After finding a solution for the wireless path, the trace heating system signals were integrated into the distributed control system via the Modbus/RTU server module.
Due to the particularly thick concrete walls, there was uncertainty regarding the feasibility of wireless communication. An on-site wireless test was performed to determine which transmission frequency and antenna type were suitable for the deployment scenario.
The required components were quickly identified, and proof of reliable wireless transmission was provided as the basis for budget approval.
Summary Regular inspection rounds no longer necessary
The data from all pipe trace heating systems is forwarded to the control room and visualized there. Besides the amperage in the individual trace heaters, a warning message is also displayed to employees in case of an emergency.
Complex cabling between the building parts is not necessary. The measured values are transmitted wirelessly to the distributed control system using our Radioline wireless system. The data is available centrally in a monitoring solution of the process control system for the control room and the workshop. This eliminates the need for time-consuming inspection rounds.
With the monitoring system, several pipe trace heating systems can be monitored simultaneously and changes can be detected immediately. In this way, the solution not only helps to increase system availability, but also reduces the workload and costs.