Flow Characteristics of Ice/Water Slurry in a Horizontal Circular Pipe.

Abstract

Based on our earlier works about the flow behaviors of ice/water slurry in pipeline elements, it was suggested that the friction of ice-particle clusters against pipe wall affects the pressure drop, and that the flow behavior is strongly influenced by adhesive nature of ice particles. However, the accuracy of the measurement on friction factor was insufficient, and no measurement has been carried out so far on the adhesive force of ice particles.In this work, a technique to measure the friction factor of ice-particle clusters against pipe wall was modified and applied to combinations of pipes and particles for which pressure drop data were available. A technique to measure the adhesive force of ice particles was developed and applied to particles with different sizes. Flow patterns of ice/water slurries through a horizontal circular pipe were observed using the same particles.The friction factors were confirmed to correlate well with the pressure drops. This result shows that the pipe material, roughness and diameter and the particle shape and size affect the pressure drop through the friction between particle and pipe wall. The adhesive nature was expressed by the compression yield stress of cylindrical ice-particle cluster. The compression yield stress was greater for smaller particles, the order of which corresponded well with the tendency to make clusters in pipe flows with an equal velocity. The ice particle cylinder was strengthened remarkably by increasing the compression stress step-wisely by a value lower than the yield stress.