Process optimization

The consideration of conductivity in flammable and potentially explosive atmospheres

By Amy Rigby, Innospec Ltd

Wherever there is a flow of liquid, there is the potential to generate static. As fluids are pumped, stirred or mixed, solids dissolved or crystallized, a charge is generated at interfaces. The rate of flow, the conductivity of the liquid, and the diameter of the vessel or pipe have a dramatic effect on the electrostatic build-up. In non-conductive fluids, this charge can build and accumulate even when the system is grounded and bonded. If a static charge is generated more quickly than it can be taken away, there is potential for static discharge. If this charge discharges as a spark it can lead to a number of problems in terms of process manufacture from pitting of the vessel to an explosion.