Hydrogen Peroxide explodes in dosing vessel
Hydrogen peroxide was being added to a vessel via a glass head flask. This head tank had no emergency relief (only a vacuum port and vent to the scrubber). The procedure was to fill the head flask by vacuum, close the valve to the vacuum pump and then switch off the vacuum pump in that order.
In error the technician switched off the vacuum pump prior to shutting the valve. This caused some material (probably rust) to be dislodged from the vacuum header into the head flask and mix with the liquid. The technician was walking back from the remotely sited vacuum pump and saw the head tank fizzing!
The technician ran and head flask exploded! Nobody was hurt in incident but head flask was completely destroyed.
- The hydrogen peroxide is now pumped into the reactor with the vent open rather than via a vacuum charged head flask.
- A review is ongoing as to whether relief is required to glass head flasks (problem with flasks exploding before relief)
- PHASE and HAZOP reports considered decomposition in the reactor but NOT in head tank - this to be addressed in future reports.