The tubular push conveyor, which is developed and marketed by the Bühler AG under the brand name TUBO, is an innovative conveying system for the transport of non-mineral bulk materials. It sets new standards, especially in agricultural and food technology, in terms of flexible conveying routes and simple design. Unlike today's systems, the bulk material is transported in a closed tube without a tension device (rope or chain) but by the help of push elements [1].
The paper will present the general layout of such conveyors as well as the basic calculation approaches for the motion resistances. The calculations will be compared with experimental measurements on an industrial sized test rig. For the further understanding DEM simulations are used to study the detailed motion behaviour of the push elements interacting with the bulk material. To consider the load dependent movement of the push elements, the so-called Multilevel DEM approach was developed. In particular, the motion resistances in vertical tube bends will be analysed with the DEM as shown in Fig. 1. 
Fig. 1: Multilevel DEM simulation of the vertical bend of a tubular push conveyor
[1] Kamps, R.: Konzept und Realisierung eines Rohrfördersystems mit Schubelementen. PhD thesis. Bergische Universität Wuppertal. 2016
André Katterfeld
Professor
Otto-von-Guericke-Universitat
Magdeburg, Germany
