挡板数量对多孔陶瓷干法制粉混合过程的影响
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摘要
为探究多孔陶瓷干法制粉挡板数量对粉体混合均匀度影响,建立欧拉空气-粉体双相流模型分析空气与粉体运动状态,简化并构建粉体混合过程物理模型,修正重整规化群(renormalization group,RNG)k-ε湍流模型,分析挡板数量对粉体轴向、径向体积分数与速度云图、矢量图的影响,并改善挡板数量提高粉体混合均匀度。结果表明:当挡板数分别为1、2、3、4时,粉体平均体积分数分别约为0.25、0.22、0.24、0.26,粉体平均速度分别约为0.7、0.6、0.5、0.4 m/s;制粉室内有2个挡板的粉体密度曲线后段约为2 g/cm3,密度曲线波动小,粉体混合均匀度最高。2个挡板制粉室内粉体堆积度最低。
In order to explore the influence of number of baffles on the powder mixing uniformity of porous ceramics, the Euler two phase flow model was established to analyze the movement state of air and powder, simplifying and setting up a physical model for the powder mixing process and modifying RNG k-εturbulence model, the influence of number of baffles on the axial and radial volume fraction, velocity cloud chart and vector diagram was analyzed, which improved the number of baffles to increase the uniformity of powder mixing. The results show that,when the number of baffles is 1, 2, 3, 4 respectively, the average volume fraction of powder is about 0.25, 0.22, 0.24, 0.26 respectively; the average speed of powder is about0.7,0.6,0.5,0.4 m/s respectively; when the granulation chamber contains two baffles, the back section of the powder density curve is about 2 g/cm~3, the fluctuation of density curve is small, and the powder mixing uniformity is higher than the other three. The data shows the accumulation of powder in the two baffles chamber is lowest.
In order to explore the influence of number of baffles on the powder mixing uniformity of porous ceramics, the Euler two phase flow model was established to analyze the movement state of air and powder, simplifying and setting up a physical model for the powder mixing process and modifying RNG k-εturbulence model, the influence of number of baffles on the axial and radial volume fraction, velocity cloud chart and vector diagram was analyzed, which improved the number of baffles to increase the uniformity of powder mixing. The results show that,when the number of baffles is 1, 2, 3, 4 respectively, the average volume fraction of powder is about 0.25, 0.22, 0.24, 0.26 respectively; the average speed of powder is about0.7,0.6,0.5,0.4 m/s respectively; when the granulation chamber contains two baffles, the back section of the powder density curve is about 2 g/cm~3, the fluctuation of density curve is small, and the powder mixing uniformity is higher than the other three. The data shows the accumulation of powder in the two baffles chamber is lowest.
引文
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[14]钟天铖,汤文成,刘碧茜.推进式搅拌器固液混合的计算流体力学模拟[J].东南大学学报(自然科学版),2016,46(4):713-719.
[15]吴嘉,邹世强,吴永文,等.挡板偏心度对振荡流反应器三维流场对称性影响的研究[J].高校化学工程学报,2005,19(6):733-738.
[2]王斌,郑伍魁,李辉,等.我国陶瓷墙地砖制粉工艺的进展[J].硅酸盐通报,2015,34(5):1312-1319.
[3]陈涛,刘玉涛,花拥斌,等.基于CFD的建筑陶瓷干法制粉造粒室倾斜率的分析[J].陶瓷学报,2016,37(6):724-728.
[4]吴南星,廖达海,占甜甜.陶瓷干法制粉机搅拌轴偏心距对颗粒分散性的影响[J].硅酸盐通报,2014,33(12):3300-3303.
[5]施阳和,赵进.两种不同挡板的双层桨搅拌槽三维流场数值模拟[J].化工机械,2014,41(2):211-214.
[6]郭聪聪,赵恒文,许卓,等.搅拌槽内挡板对搅拌效果的数值模拟[J].给水排水,2011(增刊):199-202.
[7]张立栋,韦庆文,王擎,等.回转干馏炉内挡板形状对二元颗粒运动混合的影响[J].浙江大学学报(工学版),2018,52(8):1542-1550.
[8]张文青,李勇,董放,等.开口型挡板在复合除尘器的数值模拟及优化[J].化学工程,2018,46(7):57-62.
[9] TAMBURINI A,CIPOLLINA A,MICALE G,et al. CFD simulations of dense solid-liquid suspensions in baffled stirred tanks:prediction of suspension curves[J]. Chemical Engineering Journal,2013,178(1):324-341.
[10] SHABANI M O, MAZAHERY A, ALIZADEH M, et al.Computational fluid dynamics(CFD)simulation of effect of baffles on separation in mixer settler[J]. International Journal of Mining Science and Technology,2012,22(5):703-706.
[11]沈春银,陈剑佩,张家庭,等.机械搅拌反应器中挡板的结构设计[J].高校化学工程学报,2005,19(2):162-68.
[12] CHUNG C K,WU C Y,SHIH T R. Effect of baffle height and Reynolds number on fluid mixing[J]. Microsystem Technologies,2008,14(9/10/11):1 317-1 323.
[13]孟振亮,刘梦溪,李飞,等.新型气固环流反应器内颗粒流动的CFD模拟[J].化工学报,2016,67(8):3 234-3 243.
[14]钟天铖,汤文成,刘碧茜.推进式搅拌器固液混合的计算流体力学模拟[J].东南大学学报(自然科学版),2016,46(4):713-719.
[15]吴嘉,邹世强,吴永文,等.挡板偏心度对振荡流反应器三维流场对称性影响的研究[J].高校化学工程学报,2005,19(6):733-738.