水平管密相气力输送的附加摩擦阻力系数

ADDITIONAL FRICTION FACTOR OF DENSE PHASE PNEUMATIC CONVEYING WITH HORIZONTAL PIPE

本文沿用Barth稀相气力输送理论,在试验基础上,得到在水平管内作密相气力输送时,砂粒在各种工艺参数下的附加摩擦阻力系数的经验关联式。结果发现,附加摩擦阻力系数λz随弗劳德数Fr的增加而减小;在λz与固气混合比μ的关系曲线上,存在一个使λz取最大值的临界固气混合比μm;当μ<μm,λz随μ的增加而增加;当μ>μM,λz随μ的增加而减小。μm随流动型式的变化而有所不同。经验关联式中,Fr的指数大于μ的3倍。该研究为进一步研究密相气力输送奠定了基础。

Based on the experiments and along with Barth's dilute pneumatic conveying theory, several empirical equations for calculating the additional friction factor are obtained with the various technological parameters in the dense phase pneumatic conveying system with a horizontal pipe. It has been found that the additonal friction factor λz decreases with increasing Froude number Fr; the curve of λz with solids/gas mass rate ratio μ shows that a maxium critical solids/gas mass rate ratio μm exists where As also reaches its maxium: when μ<μm,λz increases with increasing ft and when n>um, λz decreases with increasing μ.The μm changes with the different flow modes inside the pipe. The exponent of Fr in the empirical equations is 3 times greater than that of the μ's. This work has laid the foundation for the research in dense phase pneumatic conveying in the future.