Solvent Extraction Plant - Laos
Our brief was to deliver a fire suppression system to Factory Mutual approval that would enable a speedy return of a settler to service following a fire. This required an extinguishing system fast enough to avoid collapse of the settler’s roof and prevent fire spread to adjacent parts of the SX plant. The system was also required to design a system that could be installed without interrupting production.
Based on the flame spread across the surface of the organic solvent, the whole settler would be involved in a fire in approximately 16 seconds. In this particular settler design it was considered that the roofing would not sag significantly were a foam blanket to cover 95% of the settler surface area within 30 seconds of igintion. It was therefore clear at an early stage of the concept design that traditional low expansion foam deliveries could not achieve the necessary suppression performance, overhead foam deluge would impose too greater load on the existing roof structure and that any type of spray nozzle would be prone to blockage by crud.
A combination of flame detection and medium expansion foam was chosen as the ideal delivery method that could meet the required performance reliably and could be installed, serviced, tested and cleaned from outside the settler without interrupting production and minimising hot work.