Solid friction coefficient in a horizontal straight pipe of pneumatic conveying

Abstract

Pressure drop prediction model has been well concerned in pneumatic conveying system design. The Barth’s additional pressure drop prediction model is one of the most widely accepted and applied models, in which the solid friction coefficient in horizontal straight pipe is particularly important. In this work, a regression model of solid friction coefficient was addressed on the basis of two dimensionless numbers (the inlet Froude number and the solid-gas loading ratio), which were conducted based on fly ash pneumatic conveying experiment data in a 16 m length pipeline. Then, the prediction accuracy of the regressed model was verified by the pressure drop of other pneumatic conveying pipeline system, 123 m and 139 m pipelines, respectively. The results show that solid friction coefficient gradually decreases with inlet Froude number, conversely, it increases with solid-gas loading ratio. And the regressed solid friction coefficient maintained relatively high accuracy in the prediction of pressure drop, for both fly ash pneumatic conveying pipelines of 16 m length and 123 m length. However, a different prediction accuracy appeared for the different loading ratio of 139 m length pipeline complete pneumatic conveying system. The pressure drop prediction accuracy sharply declines when solid-gas loading ratio is larger than 85.