双组分颗粒声场流态化的实验研究

在内径为56 mm的玻璃声场流化床中,以5~10 nm未改性和有机改性的SiO2为实验物料主体颗粒,Fe3O4(粒径小于0.053 mm)为客体颗粒,在声压级为90~105 dB时系统考察了声场频率、声场强度和主客体颗粒不同配比关系对超细颗粒流化行为和聚团尺寸的影响。结果表明,当声场频率处于50 Hz,声压级大于100 dB时,声波可以有效地消除节涌、抑制沟流、降低临界流化速度,减小聚团尺寸,显著改善超细颗粒的流化质量。声场频率一定,声场强度越大,颗粒团聚体的直径越小。客体颗粒的添加比例存在一适宜范围。

Sound-Assisted Fluidization of SiO2 and Fe3O4 Particle Mixtures

The fluidization behavior of 5-10 nm SiO2 and Fe3O4 particle mixtures was investigated in a fluidized bed of 56 mm diameter under different sound pressure levels and sound frequencies.The effects of different proportion of Fe3O4 on fluidization behaviors were also studied.The sound wave generated by a loudspeaker located above the bed,whose sound pressure level varied from 90 to 105 dB and sound frequency varied from 30 to 500 Hz.It was found that the acoustic field could restrain channels,reduced minimum fluidization velocities,and improved dramatically the fluidization quality as the sound pressure level exceeded 100 dB and the sound frequency was 50 Hz.At a given sound frequency,the diameter of particle mixtures agglomerate was decreased with an increase in sound pressure levels.The optimized proportion of Fe3O4 was presented.