Оценка электростатических свойств средств защиты головы, применяемых во взрывопожароопасных зонах

Abstract

Problems of prevention of explosions and fires caused by the accumulation of electrostatic charge and the following discharge able to ignite an explosion and hazardous medium are well known in global practices. These conditions are specific, inter alia, to engineering industries and determined by the technological necessity to wash or process product surfaces in the medium of flammable liquids. At the same time, explosion and fire safety is primarily ensured by the requirements for non-excess of the minimum value of ignition of medium containing flammable liquids. As a potential source of accumulation of electrostatic charges, personal head protection equipment (safety helmets) required for mechanic safety is considered. Their base and tooling are usually made of polymer materials naturally prone to electrification. The article aims to resolve the problem of assessing the potential accumulation of electric charges during the contact of the scalp with elements of safety helmets. In conditions of current production, the electrostatic potential relative to the earth occurring on the scalp, cheeks, chin, and elements of safety helmet during putting on and off has been studied; the results of the study are provided. The energy of accumulated charges has been determined and compared with the value of minimum energy of ignition of different gasoline brands; conclusions regarding the sufficiency of energy to generate a discharge capable of causing an initiating ignition of flammable liquids have been made. The impact of the length of the employee’s scalp hair on the level of accumulation of electrostatic charges potentially causing ignition of the working medium containing flammable liquids has been determined. The results of the study can be used for the development of a methodology to assess a potential spark hazard occurring due to contact electrification during the use of safety helmets in conditions of explosion and fire-hazardous media and potentially causing fire and explosion.