Small Explosion in a Chemicals Manufacturing Plant
In a plant producing calcium carbide (CaO + 3C -> CaC2 + CO), a dust collector clogged, probably due to the failure of the cleaning device (nitrogen nozzles) which allowed the dust to build a plug.During the procedure of introducing a poker through an inspection hatch at the lower level, a small explosion occurs and a large amount of dust is ejected through the vent. The cloud containing carbon monoxide and hydrogen ignited. The fire spread to the electrical cables supplying the equipment.
Event Date
April 9, 1996
Record Quality Indicator
Region / Country
Event Initiating System
Classification of the Physical Effects
Nature of the Consequences
Causes
Cause Comments
The immediate cause is the manual intervention executed to free the dust collector. The intervention was inadequate, because executed at the wrong position (under the clogged zone) without the knowledge of the hazards involved (opening of a hatch and mixing hot reactive powders with air).Therefore the root cause is probably related to lack of adequate procedures and/or adequate operative and safety training
Facility Information
Application Type
Application
Specific Application Supply Chain Stage
Components Involved
calcium carbide reactor and its components
Storage/Process Medium
Location Type
Location description
Industrial Area
Pre-event Summary
The dust remover of the reactor had clogged and its cleaning required a manual intervention.
Currency
Lessons Learned
Lessons Learned
The source does not report improvement requirements. Nevertheless, the inadequate manual de-clogging intervention shows that better procedure and better safety training are needed.
Event Nature
Emergency Action
The disaster was controlled in 15 minutes thanks to the intervention of a dozen internal firefighters.
Release Type
Release Substance
Ignition Source
Detonation
No
Deflagration
No
High Pressure Explosion
No
High Voltage Explosion
No
Source Category
References
References
Event description in the French database ARIA
https://www.aria.developpement-durable.gouv.fr/accident/9944/
(accessed September 2020)