抄録
Sewage sludge pumping experiments were conducted by using a loop pipeline to establish the methods of predicting pressure drop. To avoid changing sludge viscosity during pressure measurement and to measure the viscosity exactly by the rotational viscometer, sample sludge was fully circulated and sludge particles were disintegrated to some extent before the measurement. In case of laminar flow, experimental Darcy-Weisbach's friction loss factor f was successfully expressed by Reynolds number Re for non-Newtonian fluid, such as Bingham Plastic and Pseudoplastic. The relationship between Re and f became f=64/Re like water. In case of turbulent flow, however, sludge did not have the same relationship as water except for dilute Newtonian sludge. The method proposed by Dodge and Metzner gave us a relatively good result. The applicable region of Chou's method, which has been used commonly in Japan and is based on sludge multiplication factor, turned out to be very limited. Then, we tried to improve on this method and proposed a new one to which the factor calculated with sludge concentration and average velocity was applied.
