Detailed experimental investigation has been conducted to study the single-phase (air-air) and two-phase (air-solid) flows through ejectors. An attempt is made to increase the amount of transported solids by introducing design modifications to the mixing section of the ejector. The mixing duct has been augmented by a tail section. Three different geometries of the mixing duct with tail section of ejector have been designed, fabricated and tested experimentally. The effects of the mixing duct and tail section shapes on the ejector performance have been investigated. In addition, the effects of air motive pressure and the solid particles mass flow rate on the static pressure distribution and the vacuum pressure produced have been also studied. The obtained results show that the geometry of convergent-constant-divergent for the mixing duct gives higher vacuum pressure and favourable performance of the ejector. (C) 2018 Elsevier B.V. All rights reserved.