Post purge trip in purging of boiler

A post-purge trip can occur during the purging of a boiler when the system detects that the post-purge cycle has not completed successfully. The purpose of the post-purge cycle is to remove any remaining combustible gases from the furnace and flue gas system after the purging process is complete, in order to ensure that the system is safe to operate.

During the purging process, the induced draft (ID) fan is typically run to create a flow of air through the furnace and flue gas system, which helps to remove any combustible gases. Once the purging process is complete, the post-purge cycle is initiated, which typically involves continuing to run the ID fan and opening the dampers to allow fresh air to flow through the system.

If the post-purge cycle fails to complete successfully, the system may detect an excess of combustible gases, which can be a safety hazard. In this case, the system will typically initiate a post-purge trip, which shuts down the system and activates safety systems to prevent the ignition of any remaining gases. The system may also generate an alarm or alert to indicate that a post-purge trip has occurred.

To prevent post-purge trips from occurring during the purging of a boiler, it is important to ensure that the post-purge cycle is properly timed and that the ID fan and dampers are functioning properly. Regular maintenance and inspection of the system are also important to identify and address any potential issues before they become a safety hazard. In addition, it is important to follow recommended operating procedures and to ensure that only qualified personnel are involved in the maintenance and operation of the boiler and its safety systems.