气流参数对再生骨料风选的理论探究

综合水平与垂直2种气流场的风选特征,建立任意倾斜角度流场风选模型,推导出风选气流参数(气流速度与方向)与固体物料沉降轨迹之间的关系。研究结果表明,风向一定时,随着风速增大,密度不同的物料水平风选位移差增大,风选精度增高;风速一定时,随着风向倾斜角度增大,风选精度先增大后减小,最佳倾斜角集中在45°～60°之间。通过计算与试验分析,得到建筑废弃物再生骨料精确分离的最佳风选参数:8mm粒度级骨料采用风向60°、风速16m/s;15mm粒度级采用风向45°、风速24m/s;24mm粒度级风向60°、风速28m/s。该研究结果为研制建筑废弃物风力精选设备提供了参考依据。

Theoretical study on influences of airflow parameters on air classification of recycled aggregate

Combining characteristics of horizontal airflow field and vertical airflow field in air classification,the paper established air classification model of airflow field at any obliquity,and deduced relationship between airflow parameters(airflow velocity and direction) with sedimentation trail of solid materialStudy results showed:at fixed air direction,the displacement difference of horizontal air classification of materials differing in density increased with the increase in air velocity,thus the air classification precision enhanced;at fixed air velocity,the air classification precision enhanced first and then reduced with increase in airflow obliquity,and the optimal airflow obliquity was within 45°～60°.After calculation and test analysis,optimal air classification parameters of precise separation of recycled aggregate from building waste was determined:air direction of 60° with air velocity of 16 m/s was suitable for air classification of aggregate of 8 mm granularity;air direction of 45° with air velocity of 24 m/s was suitable for air classification of aggregate of 15 mm granularity;air direction of 60° with air velocity of 28 m/s was suitable for air classification of aggregate of 24 mm granularity.The study results offered references for developing air classification equipments for building waste.