Slurry transport in inclined pipes

Different approaches are present in literature for slurry transport in inclined pipes. Most models assume that the socalled solids effect, the hydraulic gradient of the mixture minus the hydraulic gradient of the carrier liquid, has to be multiplied by the cosine of the inclination angle to a certain power. These powers vary from 0.25 to 1.7. In addition, a potential energy term is added. The models are usually based on the heterogeneous flow regime and do not take different flow regimes into account. A homogeneous component is absent in the models, resulting in a zero solids effect in a vertical pipe.
In this paper an overview is given of the existing models, with the pro’s and con’s. In this paper, also a more
fundamental model is derived for each flow regime separately. The advantage of this is also that shifts of the transition of the flow regimes become visible. The cosine and sine of the inclination angle still plays an important role, but more complicated than just a power. The new derived model is compared with data from literature.