Explosion in a Process Gases Line of a Fertilizers Production Plant
A gas release occurred in the building for the recirculation of processes gas. The gas was a mixture of hydrogen and nitrogen. It occurred at the outlet valve, during works aiming to replace it. This caused the creation of an explosive gas mixture and the surrounding spaces. The defective valve has been identified several years before, its poor design and ageing caused the gas leakage. The ignition took place with 9 minutes delay after initial leakage.
Event Date
February 27, 2001
Record Quality Indicator
Region / Country
Event Initiating System
Classification of the Physical Effects
Nature of the Consequences
Cause Comments
the immediate cause was a leak of a mixture of hydrogen and nitrogen from a defective valve. Since the ignition occurred several minutes later, the hydrogen had the time to form a large flammable cloud within the building. The delayed ignition very possibly led to a detonation. Causes of the ignition was probably the air conditioning (spark) in the neighboring workshop.
Facility Information
Application Type
Application
Specific Application Supply Chain Stage
Components Involved
process gas line, (probably recirculation loop compressor)
Storage/Process Medium
Location Type
Location description
Industrial Area
Operational Condition
Pre-event Summary
The incident occurred when a defective valve was being replaced.
Currency
Lessons Learned
Lessons Learned
Effective safety measures should be immediately taken after leakage to prevent fire and explosion; risk design should avoid releases escalation, such as formation of an explosive cloud, availability of ignition sources, engulfment. The defective valve should have been replaced once the problem was found.Finally, it seems that the replacement took place while the lien was pressurised. If true, this is case is similar to the event 1047
Event Nature
Emergency Action
unknown
Detonation
No
Deflagration
No
High Pressure Explosion
No
High Voltage Explosion
No
Source Category
References
References
ZHANG Xi-ru et al, Causes Analysis and Lessons of An Explosion Accident of 10m3 Hydrogen-HolderChinese Full Text, Metallurgical Power. 2004 (04) 23-26+34
available at the site of the kns.csnki.net:
https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFD200…
(last retrieved 20.02.2023)