多粒级加重质流化特性的实验研究

为拓宽加重质的粒级分布范围，保证流化床床层稳定，根据颗粒的性质及级配原则，对窄粒级加重质进行配比，分析其粒度组成及流化特性，并进行分选实验。结果表明，在一定粒度范围内，具有细粒级宽分布的颗粒有利于改善流化质量；以不同粒度分布的两种加重质进行配比，粗颗粒中细颗粒的质量分数不宜超过50％，且30％为最佳；较宽粒级范围的加重质具有良好的分选特性，在分选气速适合的范围内，能形成均匀稳定的床层并取得较好的分选效果；气速为5．67cm／s，分选时间为90s时，流化床的分选精度较高，且Ep值为0．030。该研究为提高气一固流化床的分选性能提供了借鉴。

Experiment on fluidization characteristics of multi-size fraction dense medium

Aimed at extending the scope of size fraction distribution and ensuring the stability of flu- idized bed, this paper relies on the property of the particles and grading principle, achieves the ration of single size dense medium, analyzes the size distribution and fluidization characteristics, and features sep- aration experiment. The experimental results show that , given a certain particle size range, particles with fine grained wide distribution facilitate an improved quality of fluidization; matching different particle size distribution of two dense medium entails adding fine particle content of less than 50%, or rather, opti- mum 30% , into coarse particle; dense medium with a wide size range exhibits a good separation property and, given the suitable scope of separation of gas velocity, produces uniform stability bed and good sepa- ration effect ; and the velocity of 5.67 cm/s and separation time of 90 s results in a higher separation pre- cision, with the consequent Ep value of 0. 030. This research may provide the reference for improving the separation performance of gas-solid fluidized bed.