Laboratory studies of cleaning screen of centrifugal sieve separator with vane activator

Abstract

The horizontal centrifugal sieve separator with a vane activator being developed at the Polzunov Altai State Technical University contains cleaning and head screens designed to separate small and large impurities from the grain heap, respectively. The research goal is an experimental study of the operation of the cleaning screen of a centrifugal sieve separator with a vane activator. A laboratory installation was developed and manufactured to evaluate the quality of the cleaning screen operation in the horizontal centrifugal sieve separator. Initially, the operation of the cylindrical screen without activator was investigated. Increase of the rotational speed of the cylindrical screen and, accordingly, increased kinematic mode leads to the intensification of fine impurity separation. The increase of fine impurity separation completeness occurs according to a linear dependence, and with further increase of the rotational speed - according to a quadratic dependence with the maximum at a rotational speed of 74 rpm. With the considered rotation frequencies of the screen, the modes of movement of the grain heap were determined - from rolling to waterfall modes. The intensity of fine impurity separation is achieved by loosening the segment of the grain heap as well as increasing the distance “traveled” by the grain heap through the screen. The design parameters and operating modes of the proposed separator with an activator are determined: the parameters of the cleaning screen - 0.61 m in diameter and 45 rpm in rotation; vane activator - 0.2 m in diameter and 500 rpm in rotation; vane spacing and width - 60 and 100 mm, respectively. Fine impurity separation completeness in comparison with the cylindrical screen at a rotation speed of 45 rpm increased from 0.52 to 0.94, i.e. 1.8 times. With increased moisture content of the grain heap from 10.6% to 25.3%, fine impurity separation completeness decreased from 0.94 to 0.83.