This article provide you basic information about fired process heaters safety features in the case of emergency.
The content explains different methods for causing burners flame out in the fire situation and avoiding heater explosion.
Snuffing Steam System:
If the temperature of fired process heater goes higher than design value, then there will be possibility for explosion.
In this case the burners should be flame out immediately. One of the methods is the elimination of required air for combustion process. In the emergency situation the steam is injected to the heater convection zone.
There are lots of steam nozzles in different location which will start to spray the steam and flame out the heater burners.
Steam Curtain system:
Steam curtain system is used to avoid for spreading of fire to the other section of the unit. In this case the curtain valve will be opened and the steam will be generated to the steam curtain header.
The header formed with lots of nozzles which will spray steam upward and create a thin curtain.
This curtain will isolate the heater from rest of the unit.
Firefighting Water Monitor Nozzles:
The firefighting nozzles are installed almost 15 meter away of heater. In the case of the fire the water will be used through this equipment extinguish the fire.
These doors are installed in heater walls. In the case of explosion the door will be raptured and will cause the combustion and explosion gases to be exited and avoid from destruction of heaters walls and other different parts.
In some models these doors is designed based of weight mechanism and will be open by high pressure which caused by explosion inside of the heater.
Safety Precaution in Process Heater Start-up
In start-up process and before the burners to be switched on, all fuel piping system to the burner should be purged by nitrogen gas to remove non burnt and remained fuel from shut down process.
Lack of attention to this precaution caused a lot of explosions in heaters. .