The Unique Case
The case is unique neither because of the monstrous magnitude of the accident nor for the cause of it. In the chemical industry where dealing with hazardous chemicals, pressures, and temperatures is an everyday business, accidents are inevitable.
What made this accident a unique case is because of the callous, criminally casual attitude towards safety, deplorable indifferent attitude of the concerned management EVEN AFTER THE ACCIDENT.
The Setup
The case relates to a company manufacturing unblocked phenolic resins in its five thousand litres reactor. The reactor was fitted with a lid having motor, gear box, stirrer, main hole for charging raw materials, vent pipe with valve, fifteen feet tall heat exchanger, sight glass, thermometer well, rapture disc, and other usual accessories associated with general purpose reactors.
About Rapture Disc: This is one of the safety measures for a reactor. It's a flange fitted with pre-calibrated metal foil. When the pressure inside the reactor exceeds the safety limit, the metal foil raptures and releases pressure.
The Fatal Mistake
Previous shift and previous batch ended, and a new batch started with a fresh crew. Here the human mistake took place.
During the previous shift and batch, the vent valve (which is normally kept open to maintain the pressure inside the reactor same as atmospheric pressure) was closed by the previous operator for applying vacuum to the reactor.
The next shift and next batch started with the VENT VALVE IN CLOSED POSITION.
Because the vent valve was in closed position, pressure started building up. Because of heavy deposition of gelled layer of phenolic resin, the inside surface of the rapture disc was strongly blocked, so also the inside surface of the pressure sensor. No one could notice the pressure build-up.
At the unfortunate and disastrous moment, the reactor exploded.
The Catastrophe
Let me stretch your imagination.
The explosion was so violent that the lid of the reactor—with motor, gear box, three meter long anchor stirrer, totally weighing approximately three thousand kilos—flew like a high-speed flying saucer and landed two kilometres away in a field.
Two buffalos who were unfortunately in the trajectory of this flying saucer were instantly killed.
In the factory, five workers who were in the resin department at that time were blown to pieces. Approximately twenty-five percent of the factory was razed to the ground. Regular operations could be resumed only after six months.
The Shameful Aftermath
This company was notorious for its poor safety record. Four to five accidents every year was a normal case. The factory's safety officer was efficient in "managing" the safety inspector in the usual way government officials are "managed."
This went on for decades before this fateful accident and at least for one more decade EVEN AFTER THE FATEFUL ACCIDENT.
A Call to Action
My friends, I am sharing this story as an eye opener. Management usually has the least concern for human safety and welfare.
If you come across such situations, PLEASE DON'T BE A SILENT SPECTATOR. Respect your conscience and stand firmly for the safety of your workers and colleagues.
More stories in coming articles!
— Mr. Chandrashekhar Pathak