6散粒体食品的力学特性 國
Sources of Cohesion (Binding Mechanisms) Solids Bridges Attraction Forces -Mineral bridges -van der Waal's -Chemical reaction -Electrostatics -Partial melting -Magnetic -Binder hardening Interfacial forces -Crystallization -Liquid bridges -Sublimation -Capillary forces Interlocking forces
农业物料的摩擦力 物料压力 物料湿度 颗粒表面状态（物理、化学性质） 接触时间 物料温度
摩擦性 休止角-注入法 Grain Bin ll Grain Surface at Filing Grain Surface at Emptying ○X Bin Floc -Angle of bin wall from horizontal -Filing angle of repose.usually less than emptying angle of repose -Emptying angle of repose.usually taken os the internal angle of frictior Flgure 1:Angle of Response
摩擦性 休止角-排出法 600 20 0 黑
What about angle of repose? Pile of bulk solids U C L
Pile of bulk solids
颗粒度 水分 The Angle of Repose 35 fine sand dry s sand 40 coarse sand moist sand angular 45 pebbles 35883ma water saturated windward leeward sand
形状与粒度
内摩擦角 WxA Bracket Cover Ring SXA Bulk Solid Shear plane
Ring Cover W x A S x A Bracket BBuulklkSSoolildid Shear plane
内摩擦角 F=fF+FA IN
Fs f iFN Fc A