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Simplified Layer Model for Solid Particle Clusters in Product Oil Pipelines

Pipe corrosion caused by the pressure tests using water before starting the normal operation occurs often in Chinese product oil pipelines because of remaining water. To explore the migration of the corrosion impurities in the product oil pipelines, this study started from the force balance principle and considered the entire particle cluster as the research object. This paper established a one-dimensional migration model, and proposed the Froude number equality criterion to calculate the particle cluster length in the equilibrium state. The proposed criterion was verified by experiments. A loop was built to conduct the tests and obtain the migration velocities of the particle cluster from the non-equilibrium state to the equilibrium state in the pipeline. The proposed model was verified using the experimental data. Verification results demonstrate that the model can describe the development process from the non-equilibrium state to the equilibrium state of particle clusters after sudden external disturbance and accurately predict some important parameters, including the velocity of the particle cluster in the equilibrium state and the critical velocity that leads to the transition from fixed bed flow to moving bed flow. The model provides the theoretical basis and calculation method to remove corrosion impurities from product oil pipelines.