Effects of flow speed, flow pattern and air bubbles on pressure loss in slurry pipelines

Pressure loss is an important factor in the design of a pipeline transportation system. To investigate the effects of flow speed, flow pattern and air bubbles on pressure loss in pumping a slurry or grout, a pipeline transportation system was established, and experiments that focused on the effects of flow patterns were performed. Curves describing the relationship of pressure gradient to velocity have two distinct segments, indicating laminar flow and turbulent flow. No significant difference in pressure loss was observed between the different flow patterns, although the straight and tangential flows showed a slight improvement to the whole system, and better performance was observed over a short distance. In terms of energy usage, bubbles introduced into the slurry require extra energy. A larger-diameter pipe is more efficient in a pipeline system.