Abstract: An apparatus for the entraining of powdery materials in a gas stream consists essentially of two sets of rotatable horizontal vanes disposed vertically of each other and separated by a horizontal partition. Powdery material arriving at the upper set of vanes is pushed around to a communication conduit in the partition through which it falls to the lower set of vanes. These move the material around to an exit conduit whose cross section does not overlap with that of the communication conduit when the apparatus is viewed in plan. The material falls into the exit conduit to be entrained in a gas stream. Preferably the gas stream enters the apparatus adjacent to the exit conduit.