The paper covers theoretical investigations of the movement of bulk material flow when it is fed by a pneumatic screw conveyor. Process calculation of the impact of bulk material particles during their transportation in guiding covers has been conducted. A mathematical model, which characterizes the overall energy spent on the impact of two particles, depending on impact velocity, physical and mechanical properties of bodies and impact conditions, has been developed. The limits of design and kinematic parameters that provide the effective application of pneumatic screw conveyors for transporting bulk materials have been defined
