A process explanation of orifice choking caused by calcium detergent in lubricating oil

In orifices at the average fluid flow of 15-50 m/sec, the phenomenon of piling up of particles contained in oil (1-5 μm) was detected. The testing for adhesion considering the effects exerted by Ca-base detergent and water content indicated that the adhesion of calcium carbonate to the orifice needs the presence of calcium and water. The relationship between the average flow velocity and the site of adhesion was established. The process of orifice choking was considered in relation to the electrification occurring during the flow of fluids at a high velocity through the orifice. The adhered products were calcium carbonate and the coarsening of calcium carbonate particles occurring at the admixture of water to oils containing Ca-based detergent contributes to the adhesion. The Van der Waals force governed the adhesion of calcium carbonate particles to orifice metal at the initial stage, and the growth of the adhered calcium carbonate layer was due to the electrostatic attraction generated by the electrification of fluid.