Pressure Drop in a Horizontal Pneumatic Conveyance Transporting Solid Particles Consisting of Different Sizes

Abstract

This paper deals with the pressure drop in horizontal pipelines, through which solid particles consisting of two different sizes are conveyed.Two kinds of glass beads, the mean diameter of which are 0.45mm and 1.85mm respectively and the mean density of each is 2500kg/m3, were used.The following results are obtained: When grounded brass pipelines are used, the differences between the pressure drops caused by large and small conveyed particles are in inverse proportion to the mean air velocity and particle mass flow-rate. When large and small particles are simultaneously conveyed, the pressure drop increases at a particle supply ratio of 50-75%.When acrylic pipelines are used, the material and boundary condition of the pipes and the particles extremely affect the pressure drop. The effects of particle size are not evident in the acrylic pipelines. When large and small particles are simultaneously conveyed, the pressure drop decreases by mixing small particles with large particles. With a large mass flow rate (5kg/min), the pressure drops rise in the vicinity of a supply ratio of 50%.