浓相气力输送中变径管道优化设计方法的研究

针对浓相气力输送中由于气流速度过高所引起的管道磨损和物料品质降级等问题，提出了一种变径管道系统设计方法。基于变径管道与同径管道压力损失相同的变径原理，推导了变径管道设计参数的计算公式，给出了变径管道的弗劳德数法和临界速度法两种变径定位方法及管段结构参数的选择依据，并讨论了变径弯管渐扩渐缩和垂直下流管渐缩的特殊变径原理。实例计算结果表明，采用变径管道设计方法可以将管道终端的气流速度由26.40 m/s降低到7.28 m/s，系统的输送压力由0.65 MPa降低到0.36 MPa，系统的输送性能提高，能耗降低。

Optimization design method of stepped pipeline in dense phase pneumatic conveying

A stepped pipeline design method was presented to resolve the problems of erosive wear and particle degradation in dense phase pneumatic conveying.Based on the stepped principle of the same pressure drop between stepped pipeline and single bore pipeline,the method clarifies the calculation of design parameters,and then gives the methods of Froude and critical velocity for step location and selecting basis of pipeline parameters.In addition,the special periodically converging-diverging stepped principle of stepped bends and the periodically diverging stepped principle of pipelines conveying vertically downward were discussed.The results of a design example adopting the stepped method show that the gas velocity reduced from(26.40) m/s to 7.28 m/s at the pipeline end,and that the conveying pressure decreased from 0.65 MPa to(0.36 MPa.) The performance of the system was greatly improved and the energy consumption was greatly reduced.