Kinematic characteristics of banana screen surface and operational parameter optimization for coal classification

Abstract

ABSTRACT Screening is an indispensable unit operation that is used extensively in many industries to separate particulate materials into different size fractions. A banana screen has high screening efficiency and is widely used for coal classification. In this study, the kinematic characteristics and velocity distribution of the banana screen surface during equal-thickness screening were investigated. High-speed dynamic test system results showed that the migration velocity and distance of different screen surface stages increase with running time from point 1 to point 5. Based on the experimental data and Box–Behnken response surface methodology results, the best screening effect occurred when the angle of eccentric blockψ was 100°, the excitation frequency f was 34 Hz and the feed rate Q was 3 kg/s. Furthermore, the sequence of influencing degree of various factors on screening efficiency η followed the order: f > ψ > Q. The actual screening efficiency was 92.993% when the operating conditions wereψ = 103°, f = 32 Hz, and Q = 3.5 kg/s, indicating a satisfactory screening performance of coal using a banana screen.