Characterisation of two industrial deluge systems designed for the protection of large horizontal, cylindrical LPG vessels

Abstract

The deluge systems on two industrial LPG tanks (of 50 and 60 tonnes capacity) plus that on a “full scale” experimental facility (nominal 13 tonne tank) have been evaluated in terms of the water distribution produced on the tank surface. The water distributions have been characterised in terms of water film depths and surface water flow rates at a number of locations across the tank surface using techniques described previously by Davies and Nolan (J. Loss Prev. Process Ind. (2004)). Vertical bands of high water density corresponding to zones of interaction between adjacent sprinkler spray envelopes were found for the 13 and 50 tonne LPG tanks, for both of which sprinkler nozzles were in alignment in adjacent rows. However, for the 60 tonne LPG tank, the sprinkler nozzles in adjacent rows were staggered, being offset to a distance of half of the longitudinal spacing between sprinklers. For this system, no distinctive water distribution pattern was observed, and the tank surface received a relatively uniform water coverage.