Pressure Losses of Air-Solid Mixtures in the Branching of Pneumatic Conveying

Abstract

In this paper the pressure losses of the symmetrical Y-branches in the horizontal flow of air-solid mixtures are treated. The branch angle is 30°, 45°, 60°, 90° and 120°. In case of air stream alone the pressure losses of the branches are given by a quadratic expression of air flow ratio and the experimental formulae, which give the pressure losses in branches, are obtained. By adding the additional pressure losses due to solids in the air stream to those of the air stream alone the equations for the pressure losses in the air-solid two-phase flows are obtained. The coefficient of pressure losses depends on the air flow ratio and the solids loading ratio. According to the experiment the solids are distributed into the branch pipes nearly in equal quantity independently of both air flow ratio and branch angle.