The main use of a burn pit is to dispose of liquid or mixed liquid-vapours relieves as emergency flows or on an intermittent basis when blowing down pipelines or vessels.
The shape of the pool should be selected in order to meet the following constraints:
- The Liquid burner must be angled to ensure that natural drainage occurs and often liquid relief or residual oil carry-over cannot remain in and it burns inside the burner.
- The pit floor should be sloped away from the flare so that residual burning liquid is kept away from the pit burner.
- The pit volume must be sufficient to contain the anticipated liquid loads accumulating over the design hold-up period.
At least two pilots are used for each pit burner head and for large pools extra pilots are spaced around the pit perimeter. For safety reasons it is important to monitor pilot flames and provide flame failure alarms. Burn pit flaring systems are located away from plant.