The Toms Effect of a Dilute Polymer Solution and Its Application

Abstract

We analyzed the turbulent pressure loss in the pipe flow of a dilute polymer solution by a method similar to that of Karman for Newtonian fluid or to that of Metzner et al. non-Newtonian fluid, and found that the friction factor in the pipe flow was expressed by two non-dimensional numbers: R_e and S(R_e=2ρRV/η_v, S=η_c/ρR², where η_v: viscosity, η_c: cross viscosity, ρ: density, R: pipe radius, V: mean velocity), and we showed that the analytical expression agreed with the experimental data well. In order to avoid the mechanical degradation, the concentrated polymer solution were injected into the water at the delivery side of the pump. Consequently, we obtained the same effect as the natural head flow. By way of an example, we tried an experiment on a hydraulic conveyor. Then the concentrated polymer solution was injected into a flyash slurry. Apparently, the Toms effect may be also recognized in the case of hydraulic conveyor.