Transient Propagation in Slurries with Hold-Up

The relatively high flow velocities encountered in the hydraulic transport of solid-liquid mixtures aggravates the problems of pressure surge phenomena under fault conditions as well as during normal system load changes. The paper presents the basic theory for estimating surge amplitudes and wave speeds and extends previous work by investigating the influence of hold-up. It is concluded that hold-up reduces the amplitude of surge pressures and that further studies are required to establish a suitable relationship between the hold-up ratio and both solids concentration and the density ratio. Nevertheless, favorable agreement has been found between the limited experimental data available and the theoretical model.