Method and device for mixing a flowing gas and a pulverulent material

Abstract

A method for mixing a pulverulent material in a main gas flow with a view to achieving uniform distribution of the pulverulent material. The turbulence in the main gas flow is increased in a vortex-generating zone. The pulverulent material is introduced into the main gas flow, in a mixing zone, with a carrier gas flow whose net motion during introduction is essentially opposite to the main gas flow. The mixing zone is positioned downstream of the vortex-generating zone and in the vicinity thereof. The carrier gas flow with the pulverulent material is in a rotational zone given a helical motion, whose axis of symmetry is essentially parallel with the direction of flow of the main gas flow, and is introduced into the mixing zone in the form of a divergent hollow cone. A device for carrying out the method comprises a gas duct ( ) for the main gas flow with vortex-generating means ( ) and an introducing means ( ) for introduction of pulverulent material in dispersed state into a carrier gas flow. The introducing means ( ) comprises a cylindrical pipe ( ) with an open and a closed end, a tangential inlet ( ) in the vicinity of the closed end of the cylindrical pipe ( ), and a divergent axial outlet ( ) at the open end of the cylindrical pipe comprising a truncated conical jacket ( ) and a centered insert ( ) adjacent to the axial outlet so adapted that an annular opening ( ) forms between the truncated conical jacket ( ) and the insert ( ).