Explosion in an incinerator Plant
The explosion occurred in an incinerator for non-industrial wastes, during inspection and repair works. These were due to a large quantity of aluminum which produced a solid lump of ash. The explosion occurred during clean-up operation of this lump piled in a hopper chute at the lower part of the incinerator. In an attempt to favor the cleaning process, large quantities of were injected, which reacted with the aluminum to form flammable atmosphere consisting mainly of hydrogen. The hydrogen entered then in contact with air when the inspection door was opened, ignited and exploded.
Event Date
July 6, 1995
Record Quality Indicator
Region / Country
Event Initiating System
Classification of the Physical Effects
Nature of the Consequences
Causes
Cause Comments
The immediate cause was the reaction between hot aluminum and water, which formed hydrogen. Two root or contributing causes: 1) A large quantity of aluminum, was brought in as non-industrial waste, while it should be which has to be managed as industrial waste. Its incineration without knowing this fact resulted in the generation of a hot clinker, which stopped operations. 2) Workers lacked safety knowledge regarding possible reactions in the incinerator. This brought to the decision to use water for clean-up.
Facility Information
Application Type
Application
Specific Application Supply Chain Stage
Components Involved
incinerator ashes
Storage/Process Medium
Location Type
Location description
Industrial Area
Operational Condition
Pre-event Summary
Inspection and repair works were ongoing. In 1983, and an identical accident had occurred, and a related report was published in 1994. Although the publication was delayed for legal reasons, it had been made public before this accident occurred.
Lessons Learned
Lessons Learned
LESSON LEARNED(a) It is crucial to be able to learn from previous cases. There was an identical accident in 1983 (although the source does not tell if in the same facility), but apparently the plant management was not aware of it, or did not recognize the return of experience. (b) Non-industrial wastes such as domestic wastes is a mix of diverse materials, including hazardous ones. T should be possible to execute some sort of control on the materials arriving. The lack of control on the type of waste was at the basis of this incident: a facility for non-industrial waste accepted a large quantity of aluminum, which should have been labelled as industrial waste.CORRECTIVE MEASURES1. As waste including aluminum easily forms a clinker, which causes an ash blockage, it should not be incinerated in large quantities.2. A camera and a temperature sensor to monitor ash blockage was installed in the chute.3. Instead of forced cooling, natural cooling was adopted by water for ash removal work.4. Guidelines for safety work were written.
Event Nature
Emergency Action
The injured workers were taken to hospital by ambulance.
Detonation
No
Deflagration
No
High Pressure Explosion
No
High Voltage Explosion
No
Source Category
References
References
JST failures database:
https://www.shippai.org/fkd/en/cfen/CC1200025.html
(accessed Dec 2023)
M. Wakakura et al., in Failure Knowlede Database - 100 Selected cases:
https://www.shippai.org/fkd/en/hfen/HC1200025.pdf
(accessed Dec 2023)