Abstract: A method and device for preparing a wet concrete mix. An elongated tubular swirl chamber has a generally cylindrical shaped interior. A shaft extends axially in the chamber and is adapted for rotation at about 100 r.p.m. or higher. The chamber contains an inlet end for the introduction of dry particles pneumatically carried by a pressurized gas and an outlet end. Blades are arranged in several rows circumscribing the shaft so that the blades overlap to form a helical spiral to aid in moving the particles through the chamber. The blades in the helical spiral form a turbulent swirling distribution of particles traveling through the chamber when the shaft is rotated at 100 r.p.m. or higher and simultaneously the particles are forced by the pressurized gas through the chamber. A liquid is injected into the turbulent swirling distribution so as to wet the particles.