Explosion of a hydrogen tank

A tank "filled with low-pressure hydrogen" exploded at a food manufacturing plant, killing three workers. The accident occurred when the workers were welding inside the tank after clearing hydrogen to install a hydrogen measuring device.
The tank, seven metres high and two and half metres wide, was destroyed by the explosion.

Police investigated the exact cause of the accident and suspected the sparks from the welding work caused the explosion with the remaining hydrogen inside the tank as the employees failed to completely remove the hydrogen before conducting the work.

Low -pressure hydrogen tank

DESCRIPTION OF THE FACILITY
The hydrogen tank was reported usually to contain 50 tonnes of hydrogen, used to make sorbitol, an artificial sweetener. The company produces starch, glucose, high fructose corn syrup, corn meal, oligosaccharide, and sorbitol.

The tank "filled with low-pressure hydrogen" exploded at a food manufacturing plant, killing three workers. The tank, seven metres high and two and half metres wide, was destroyed by the explosion.

An operational procedure should ensure that the tank is completely empty of hydrogen before welding. How this can be done in practice, depends on the tank and system configuration. One of the measures could be effective purging with nitrogen, a second one suing detectors to assesses residual presence of hydrogen, In any case, all the measures must be validated according to good engineering practices before being adopted.