Effect of Multilpe Jets on Attrition in a Fluidized bed

• Main Authors: Juang Chung-Jer, 莊忠哲
• Other Authors: Shu-Yii Wu
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/21376759744934993034

碩士 === 逢甲大學 === 化學工程學系 === 87 === Within the processes of fluidized bed combustor and catalyst regenerator, attrition and elutriation of fine particles from jetting to take bed-materials be losing. The main reason of the carryover is the distributor poor design in a fluidized bed as the orifice obstructed by the particle agglutination to cause local over high velocity. Cause industrial catalyst are expensive that increase the operation capital from catalyst quantity to lose. Two factors of effect the particle size distribution are attrition and elutriation of fine particle. The relation of attrition and elutriation were discussed in our previous work, in this investigation we focus on the multiple jets effect on the attrition in a fluidized bed. Experimental work was carried out in a batch gas fluidized bed with 6.62cm inner diameter and 2.5 height and perforated distributor. There are various sizes of silica sand and multi-jets with various geometry arrangements. The multi-jets velocities are handled from 208m/s~38m/s with inner diameters of 5, 4, and 3mm individually and pitch of 2, 3, and 4cm to simulate behavior of jetting area in a fluidized bed. The experimental results show that the attrition is function of particle size distribution, materials nature, multiple jets velocity and orifice diameter of jets, the empirical attrition rates have been developed by two models; one is from the energy (model 1), the other is from particle motion (model 2).