Check Atmosphere in Fire Box Before Igniting the Burners

Image © EPSC


When the firebox of a furnace or boiler has an explosive mixture by accumulation of large amounts of flammable gases, this will explode when igniting the burners.

When Important

  • Upon start and restart.
  • Cold start.
  • After a furnace trip.

Challenges in the Field

  • Reliability of instruments.
  • No good procedure / practices.
  • Fast restart required to avoid shut down.

Options to Get it Right

  • Furnaces/boilers need to be purged well with air to remove all gasses and to avoid an explosive atmosphere, before igniting the burners.
  • Procedures for start of furnaces and boilers must be available and up-to-date.
  • Report problems with fully automated systems (burner management systems) or deviation from start-up procedure immediately.
  • Limit the number of attempts to ignite a furnace/boiler (and keep sufficient time between attempts).
  • Perform a leak test on the gas supply before igniting a furnace/boiler.
  • Check atmosphere in the fire box before igniting the burners with a LEL meter
  • Bypassing of safety instrumentation (flame eyes, gas detection, sensors) must be managed carefully.
  • Limit the number of people in the vicinity when starting furnaces/boilers to those necessary for the start-up operation.
  • Avoid time pressure when starting or restarting furnaces or boilers.

This page only summarises the guidance – refer to the EPSC website for further information.

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