Valmet RB leak detector has advanced analytics
Valmet, Espoo, Finland, has introduced a predictive tool for detecting recovery boiler leaks: the Valmet Recovery Boiler Leak Detector. This innovative diagnostics application’s advanced analytics enable boiler owners to detect even the smallest tube leaks in an unprecedented way, resulting in significantly improved boiler safety and reduced damage risks.
Typically, distributed control systems (DCS) have only relatively primitive tools for recovery boiler leak detection. These include simple differentials between the feedwater and the steam or alarms for low drum level and high furnace pressure that are activated only in the case of very large and sudden leaks.
With these traditional tools, it is virtually impossible to notice a minor leak in the boiler furnace. A small undetected leak may grow, rupture a tube and lead to severe damage or even to a major smelt-water explosion.
The Valmet detector advances leak detection by combining advanced mass and chemical balance calculations. Currently, the leak detection solution is used by several pulp mills, and the results gained with it have been very positive.
The Valmet Recovery Boiler Leak Detector typically recognizes a 0.25-0.50% difference between the feedwater and the steam in the feedwater flow. Additionally, the application features an advanced chemical balance calculation which enables higher accuracy and identification of critical leaks and separation from non-critical leaks. The balance is typically calculated using phosphate as a tracer.
Alarm levels can be set low enough for a leak to be diagnosed before a tube is ruptured. As boiler load swings are taken into account, there are no unnecessary alarms because of changes in load.
Leak rate monitoring and alarms can be tested safely during normal operation by using a blow-out line for leak simulation. Operator instructions and training for boiler leak detection and management are included in the delivery scope.
The RB leak detector is part of the Valmet recovery boiler optimizer product portfolio and can be implemented on any DCS.