Controlling Electrostatic Hazards Associated with Liquid and Powder Processing

Electrostatic charge is normally generated whenever two materials (solids and/or liquids) make and then break contact. Therefore, electrostatic charge generation is expected during operations such as liquid and powder flow through piping, hoses, and chutes, agitation/mixing, and filtration. Electrostatic charge can accumulate on liquids and solids (powders and processing equipment) if they are insulating or electrically isolated from ground. The accumulation of charge on liquids, powders, and on insulating (plastic) and ungrounded metal plant and equipment can give rise to electrostatic discharges sufficiently energetic to ignite flammable atmospheres. Electrostatic discharges from charged liquids could also cause pinholing of glass-lined and plastic-lined piping and vessels, resulting in leaks, corrosion of the piping or vessel, and contamination of the liquid. Consequently, it is essential to identify and control potential electrostatic charge generation and ignition hazards.

This presentation will discuss the conditions under which electrostatic charges can generate, accumulate, and cause incendive discharges during liquid and powder processing/handling operations. Practical techniques for identifying, quantifying, and eliminating/controlling electrostatic ignition hazards will be presented.