SmOP – Smart Overpressure Protection Device
A smart pressure relief of chemical reactors and vessels offers a great possibility to improve the productivity of plants and a chance for a safer relief of hazardous substances. Therefore, a new Smart Overpressure Protection Device (SmOP) is being developed at the CSE. Instead of classic safety devices, like safety valves or bursting discs, the SmOP has an adaptive set pressure and relief area. So, the system works dynamically depending of the process state.
The construction development of the SmOP is done in two steps. The first version is a smart safety valve with a pressure-controlled unit, that allows a process-dependent adaptation. The second step will be a ball valve is used instead of a safety valve. That offers the advantage of a larger and process-adaptable opening of the relief area without huge redirections of the flow. For that matter, it is important to exclude cavitation and to ensure a high leak-tightness.
The SmOP, either the safety- or the ball valve, is controlled by a PLC, which contains different process safety models. Different adaptation models are possible. The first one is an early runaway reaction detection model to calculate the future state in the chemical reactor to distinguish between the normal operation or runaway situation. Depending on this, the SmOP opens and lowers the pressure in the reactor to stop the runaway reaction. In a second mode, the SmOP predicts online the state of the flow like two-phase or one-phase flow. With such a mode, two-phase flow can be prevented by a premature one-phase flow relieving. In a third mode, the set pressure and relief area can be adapted to the recipe. Optimal relief conditions are possible for each recipe, which is an advantage for multi-purpose plants. The main benefit of the SmOP technology is that the process limits are better utilized with a high safety level.
In the last months there has been a lot of progress in the development of the smart safety valve, including a test rig with an adaptable safety valve controlled by a PLC device at the CSE. Therefore, the capabilities of the SmOP for different processes, reactions and tanks have been examined. Also a comparison of different mechanical devices such as gate valves, ball valves, safety valves ect. with the aim to search for the most appropriate safety device has been performed. Moreover, progress has been made in the development of safety models to calculate the future state in the reactor with a PLC.
In 2019, the development of an adaptable ball vale will be examined as well as testing and validation of the smart safety valve. Also, different early detection systems will be reviewed and evaluated including sensors and artificial neural networks (ANN). The aim is to develop a possibility to detect the purposes of overpressures in assets (Fire, Blocked outlets etc.) as early as possible, so that the SmOP can adapt to resulting overpressures as needed. Furthermore, safety models to calculate the future state inside a reactor will be tested and connected to the safety device.