建立了内径140 mm、锥角60的可视化锥柱喷动整床和半床实验系统,研究了液含量、颗粒粒径、形状等对床内湿颗粒聚团的影响规律。实验表明:湿颗粒喷动床内有块喷动、死床和非均匀结块三种聚团类型,聚团的出现类型与粒径dp有很大的关系;当dp〉1 mm,液体饱和度S〉0.2时,容易出现块喷动;当dp〈1 mm,S〉0.05时,容易出现死床、非均匀结块。在此基础上,从微观颗粒受力分析出发,提出了一种预测湿喷动床内聚团倾向的方法。
The experimental system containing a conical-cylindrical spouted bed and a same dimension semi-spouted bed is established in this study.The internal diameter of the cylindrical column is 140 mm.The conical base of internal angle 60° is located at the bottom of cylindrical column.The effects of liquid contents,particle size and particle shape on the agglomerate in the bed are studied.The results show that there are three kinds of agglomerate in the wet spouted bed,i.e.agglomerate spouting,defluidization and non uniform agglomerate.The agglomerate behavior is strongly reliant on particle size.When particle size dp 1 mm and the liquid saturation S 0.2,the agglomerate spouting is easy to take place.When dp 1 mm and S 0.05,the defluidization and non uniform agglomerate is easy to take place.Based on the analysis of forces acted on particles,a new method for predicting the tendency of the agglomerate in the wet spouted bed is proposed.