MODELLING OF MIXING COMPONENTS BY SCREW CONVEYOR-MIXERS

Abstract

Mixing of bulk materials is widely used in different industries, including agricultural production. The efficiency of the method of discrete elements as a tool for studying technological processes with bulk load is substantiated, which is a good tool for studying mixers in the mode of a calculated experiment, but does not link the parameters and modes of operation of the mixer with the criteria of mixing quality. The estimation of the smoothing ability of the screw conveyor-mixers when using the method of impulse disturbance is carried out, and the results of modeling the smoothing ability of the screw conveyor-mixer are given. It has been established that the distribution of the volumetric concentration of the indicator (key component) along the length of the conveyor operates as a continuous mixer, is determined by the coefficient of load transfer between adjacent loops and corresponds to the law of binomial distribution. It has been found that with an increase in the length of the screw mixer-conveyor and its flexibility, the number of mixing cells increases and the mixing capacity of the conveyor increases. It is shown that the highest smoothing capacity is possessed by screw mixing conveyors with a load transfer coefficient equal to 0.5, in which the excess concentration of the key component is reduced by 8 times. It has been proven that it is possible to achieve such a miniature overfilling of the mixture in a screw mixing conveyor by a combination of factors such as the gap between the screw belt and the casing (its maximum increase), the filling factor of the conveyor (rational should be maintained at 0.5), the rotation speed of the working body transition from low-speed transportation mode to unstable mode (mixing mode), as well as making certain holes along the periphery of the screw.