Predictive model for frictional pressure drop in settling-slurry pipe with stationary deposit

In the literature, many models can be found for a prediction of the frictional pressure drop in a slurry pipe. However, a vast majority of the models is proposed to predict slurry flows without deposits in pipes. In practice, some slurry pipelines operate with a stationary bed at the bottom of a pipe. Models covering this type of settling-slurry flow are lacking. In the article, a structure of a predictive model is proposed for the frictional pressure drop and the thickness of the stationary bed in a pipe flow of settling slurry at velocities that are too low to maintain all particles in motion. The governing equations of the model are described and the additional semi-empirical equations formulated. The proposed model is validated using experimental data from own laboratory tests and from the literature.