Determining the pattern of loose material movement in screw and tubular-comb feeders

Abstract

The object of this study is the relationship between the structural and technological parameters of feeders for loose materials and the characteristics of particle flows at their outlet, namely: productivity and the magnitude of pulsations. The existing designs of this type of equipment were analyzed, and the most common methods for simulating their operation were determined. A structure of a tubular-comb feeder has been proposed, the performance of which is compared with the well-known screw feeder. Computer models of both structures were built based on the discrete element method. The simulation was carried out in the EDEM 2017 software environment. It was established that the resulting models take into account the discrete nature of the movement of loose materials and allow conducting research taking into account the physical and mechanical properties of individual particles. An experimental bench was fabricated for experimental verification of the modes of operation of the tubular-comb feeder. The performance of this type of feeder was determined for two pipe rotation speeds (6 and 10 rad/s). The amount of material flow pulsations in the outlet nozzle was also determined. The correspondence of the results of calculations based on the computer model to the real process was confirmed. The current study was carried out the steady modes of operation. It was established that with equal overall dimensions and speeds of rotation of the working bodies, the productivity of the screw feeder is 5...5.2 times greater than that of the tubular-comb feeder. But the latter provides 7.3...16.4 times smaller magnitude of pulsations of the flow of loose material. This makes it possible to reduce the heterogeneity of mixtures, especially in the case of using such feeders as part of continuous mixing systems. The results make it possible to analyze the operation of bulk material feeders and reduce their design time