Department of Farm Machinery, College of Agriculture, Shiraz University, Shiraz, I.R. IRAN
In order to increase the efficiency of the conveyance of the granular solids, a new experimental set-up is designed. The test rig has longitudinal trapezoidal slots in its conveying pipes. Through experimentation, a correlation for friction factor in terms of solid mass flow rate, fluid flow rate and Froude number is presented. It is shown that the mixture friction factor for pipes with inner trapezoidal slots is 40% smaller than that of pipes with inner rectangular slots. As a result, the arrangement helps to convey materials to longer distances for a given pressure setting.