滚筒筛筛分生活垃圾的理论研究

Research on theories of the trommel screen separating municipal solid waste

滚筒筛是生活垃圾分选中常用的工具,但筛分理论目前还不够清楚,导致滚筒筛的设计多依靠经验进行。从生活垃圾在滚筒筛内的受力分析着手,考虑了物料与滚筒筛筛壁间的摩擦力,其为一有限值,推导出物料的提升角与滚筒筛转速的关系,且物料提升角的大小取决于物料静摩擦角的大小;认为无论滚筒筛的转速多大,物料的最大提升角都是固定不变的。经过一系列分析得出与已有的垃圾滚筒筛理论不同的结论:滚筒筛是否存在临界转速,取决于被筛分的物料:物料的静摩擦角≥90°,滚筒筛存在临界转速;否则,滚筒筛不存在临界转速。这一结论对滚筒筛的设计具有理论上的指导意义。

The trommel screen is one of the important facilities applied in municipal solid waste（MSW） separating process. However, the designation of the trommel screen mainly depends on the operation experience due to the limited mechanism knowledge. In this work, the finite friction force between the refuse and the trommel screen was taken into account, and the relationship between the hoisted angle and the rotary speed was corelated. It is found that the the hoisted angles depends on the static friction angles of grains instead of the rotary speed in a trommel screen. The critical rotary speed of a trommel screen is based on the characteristics of separated materials. When the static friction angle between the separated materials and the trommel screen is below 90°, it does not exist; otherwise, it does.