Wall slip behavior of sludge is studied experimentally by using a rotational rhehometer and a capillary rheometer in order to test whether the city sludge (80% moisture content) has same wall slip characteristics of the HDPE polymer. It is found that, in the oscillatory shear flow experiments, while strain γ0 = 0.68, the shear stress / rate curve with three spaces is dependent on the spacing in three different angular frequencies when the strain and stress amplitude decreases with time. So that the wall slip happens. In the pressure oscillation curve of capillary rheometer test, the shear stress / speed curve in different diameters are significantly dependent on the diameter and the second critical shear rate is the real rate when the wall slip happens. This test also shows that wall slip occurs. The tests of two kinds indicate that there exists a wall slip phenomenon on city sludge and that the angular frequency, concentration and other factors will affect the wall slip.%为了检测城市脱水污泥(含水率80％)是否存在和聚合物HDPE一样的壁面滑移特性,采用旋转流变仪和毛细管流变仪对其壁面滑移现象进行分析研究.结果发现,在旋转流变仪试验的总应力波形中,当应变γo=6.28时应力幅值随时间逐渐下降,不同角频率在三种间距下的剪切应力/速率曲线对间距有明显依赖性,发生壁滑现象.在毛细管流变仪试验的压力振荡曲线中,第二临界剪切速率是滑移产生的真实速率,不同管径下的剪切应力/速率曲线对管径有明显依赖性,也发生了壁滑现象.两种试验都表明,城市脱水污泥确实存在壁滑现象,角频率、浓度等因素都对其有一定影响.
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