搅拌强度对浮选机内液-固两相流场特性影响

Effects of Stirring Intensity on the Flow Field Characteristics for Liquid-Solid Two Phases in Flotation Machine

采用标准k-ε湍流模型和流体颗粒模型对容积为20 L的KYF浮选机内液-固两相流场特性进行了数值模拟.研究结果表明:浮选机内流场呈上下两循环分布,混合、上升区流速高于分离区;在混合及上升区,颗粒运动速度与其粒度呈反比关系,在分离区则呈正比关系;定子、转子表面高压区均位于叶片迎风面,其表面绝对压力与搅拌强度呈正比关系;搅拌强度增加,混合、上升区的矿物颗粒体积分数降低,分离区体积分数增加;混合、上升区固相体积分数与其粒径呈正比关系,分离区呈反比关系;转子转速为600 r/min的搅拌强度更有利于提高该浮选机工作性能.

The internal flow field characteristics of KYF flotation machine of 20 L for liquid-solid two phases were numerically simulated using standard k-εturbulence model and particle model.The study results show that the flow field in the flotation machine distributes into two cycles up and down,the flow velocity of the mixing and rising zones is higher than that of separating zone.The velocity of mineral particles in mixing and rising zones is inversely proportional to particle size,while the velocity in the separating zone is proportional to particle size.The higher pressure distribution zone is located at the windward of the stator or impeller respectively.Besides,the absolute pressure is proportional to the stirring intensity.The volume fraction of particles is proportional to the particles size in mixing and rising zones and it decreases with the increasing of stirring intensity,which is contrary to the separating zone.Therefore,the rotational impeller speed of 600 r/min is more advantageous to improve the working performance of the flotation machine.