Measure of a flow electrification potential profile with the Capacitive Traveling Method

International audienceIn a solid/liquid interface, different physicochemical reactions lead to a charge transference that produce a charge distribution known as electrical double layer (EDL). For the dielectric pipelines, with a constant inlet flow, the positive charge in the liquid is described by the Stern model in two zones: compact layer and diffuse layer. Whereas, the negative charge in the solid is described electrically as an arrange of resistance and current generators. The EDL has been studied at the Pprime Institute with a close-loop hydraulic circuit that allows the control over the flow conditions. By the electrical isolation of a pipeline segment it has been possible to study different parameters of the EDL in function of the liquid, however the behavior of the local charge accumulation in the solid remains unknown. In order to analyze the solid behavior, a method called `capacitive traveling method' was developed. It consists of a capacitive arrange placed in front of the charged surface. As the sensor moves, a mirror charge is induced in function of the potential over the surface and a current is generated. By the system modeling, it is possible to convert the sensor output into the potential profile due to the charge accumulation over the surface which is the objective of this work