[外文翻译]混合动力行星混凝土搅拌中颗粒转变为流体的特性化描述.doc

[外文翻译]混合动力行星混凝土搅拌中颗粒转变为流体的特性化描述


收到2007年7月2日，
经修订2008年5月30日
接受2008年6月5日。
可在线2008年6月7日。
摘要
    在混凝土搅拌机中增加产品投放会在混凝土搅拌过程中产生一个强大且快速的冲击作用。据可靠实验数据显示，一个实际的行星式混凝土搅拌机在实验室条件下将全面的展示一定状态的混合物在混合搅拌过程中的混合转化情况。更确切的说，一个侦测颗粒状物料转变成颗粒浆状过程中相应的混合物凝聚力变化（如下，所谓的“过渡时期”）的方法，就是通过使用混合功率测量仪，这个过程就会很好的表达。而且，这个过渡实现以后，搅拌功率的消耗是与混合物流变学有关，可以用一个简化的几何假设表达。通过无量纲分析，同样可以得到这样一个几何假设。最后，这个几何假设将表明混合物的发际线以外的行为可以被很好地拟合成双曲线方程。在这个过渡时期，相应的混合粉状进化情况就可以用层面力量来预测。这些结论适合推广应用在生产监控过程中。
关键词：混合；混凝土；搅拌机；颗粒状物料。

Characterization of the granular-to-fluid state process during mixing by power evolution in a planetary concrete mixer
Received 2 July 2007; 
revised 30 May 2008; 
accepted 5 June 2008. 
Available online 7 June 2008.
Abstract
Adding product into the mixer exerts a strong and rapid impact during concrete mixing. Experimental data obtained from a planetary mixer in a full-scale concrete plant under laboratory conditions show that the state of mixture progress with mixing time is well described by the mixing power evolution. More specifically, a reliable method for detecting the time corresponding to the transformation of a mixture from a cohesive granular material into a granular paste (i.e. the so-called “transition time”), through use of a mixing power measurement, will be presented herein. Moreover, once this transition has been achieved, mixing power consumption will be related to mixture rheology and then to mixer geometry by means of a simplified hypothesis. This equation can also be obtained via a dimensionless analysis. Lastly, it will be shown that mixture behavior beyond the transition point is well fitted by a hyperbolic equation. The corresponding mixing power evolution can then be predicted by the level of power at this transition time. These results are suitable for application to online process monitoring.
Keywords: Mixing; Concrete; Power consumption; Complex fluids; Granular materials