Article ID Journal Published Year Pages File Type
6475485 Fuel 2017 10 Pages PDF
Abstract

•A variable amplitude screen was proposed for classification of coal.•Kinematic characteristics and screening process analysis of a VAS were studied.•BBRSM was used to analyze the influencing degree of various operating factors.•The optimal operating conditions were validated by sieving test.

Screening is an indispensable unit operation for the large-scale separation of materials. A variable amplitude screen (VAS) has a high screening efficiency and reliable performance in coal beneficiation and is widely used for coal classification. In this study, the kinematic characteristics and process analysis of a novel VAS for coal classification were investigated. The vibration test results show that the y axes amplitudes of acceleration and displacement gradually decreased along the material flow. This strengthened the loose and stratification of materials and improved the screening efficiency (η) of the VAS. Furthermore, the effects of several operating factors on the screening performance were studied using Box-Behnken response surface methodology (BBRSM). Based on the experimental data and analysis results, the quadratic model was selected to describe the relationship between η and the operational factors; the sequence of the influencing degree of various factors on η was α > Q > kf > lreb. The optimal operating conditions were obtained by BBRSM analysis and verified by screening experiments, and the actual screening efficiency was 97.18% when the operating conditions were α = 15°, kf = 1.19, lreb = 47.54% and Q = 10.12 t/h, indicating the satisfactory screening performance of coal in a VAS.

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Physical Sciences and Engineering Chemical Engineering Chemical Engineering (General)
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