为了更好地评估和优化正向除渣器的结构性能,了解纤维在其内部纸浆悬浮液流场中的运动特征和收集效率。基于纤维的吸水膨胀性,结合球形纤维粒子的概念,笔者利用FLUENT软件对正向除渣器内部纸浆悬浮液流场进行了数值模拟。结果表明:模拟实验所取的两种纤维中,从正向除渣器良浆出口流出的湿纤维a的颗粒轨迹数要高于湿纤维b的颗粒轨迹数,同时计算得到湿纤维a和湿纤维b的收集效率分别约为58%和55%; 纤维的收集效率随着纤维颗粒的密度、直径和长度的增大而降低,其中纤维收集效率对纤维长度的敏感度较小,当纤维长度从1 mm增大到5 mm时,两种湿纤维收集效率的最大差值约为6%; 而纤维收集效率对纤维直径的敏感度相对较大,当纤维的直径在10～70 μm之间时,两种湿纤维的收集效率最大差值约为40%。
Abstract
In order to analyze the flow characteristics and collection efficiency of fiber in the internal pulp suspension field of forward cleaner,the internal pulp suspension field was numerically simulated with FLUENT software according to the swelling performance of fiber between dry and wet fiber, and combined with the concept of spherical fiber particle. The results showed that the particles track number of wet fiber a was higher than that of wet fiber b, while the two kinds of fibers from the accept outlet of forward cleaner, and according to the calculation that the collection efficiencies of fiber a and fiber b were 58% and 55%, respectively. The collection efficiency of fiber gradually decrease along with the increas of density, diameter, length of fiber, and the collection efficiency of fiber was not sensitive to the length of fiber. When the fiber length increased from 1 to 5 mm, the biggest drop value of collection efficiency of fiber was about 6%. The collection efficiency of fiber was sensitive to the density of fiber, and the biggest drop value of collection efficiencies on the two kinds of fibers was about 40% when fiber diameter changes from 10 μm to 70 μm.
中图分类号：
TS733+.4
TQ019
TQ028.5
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参考文献
[1] Park S, Venditti R A, Jameel H, et al. The effect of fibre properties on fibre fractionation using a hydrocyclone[J]. Journal of Pulp and Paper Science, 2005, 31(3):132-137.
[2] Derksen J J. Direct meso-scale simulations of fibres in turbulent liquid flow[J]. Canadian Journal of Chemical Engineering, 2010, 88(4):677-681.
[3] Yashiro S, Sasaki H, Sakaida Y. Particle simulation for predicting fiber motion in injection molding of short fiber reinforced composites[J]. Composites Part A:Applied Science and Manufacturing, 2012, 43(10):1754-1764.
[4] 赖艳萍,赖维,卢晓江,等.圆柱形水力旋流器筛分纸浆纤维的数值模拟和实验研究[J].中国造纸学报,2009,24(1):108-111.Lai Y P, Lai W, Lu X J, et al. Numerical simulation and experimentation for fiber fractionation in the cylinder hydrocyclone[J]. Transactions of China Pulp and Paper, 2009, 24(1):108-111.
[5] Cullivan J C, Williams R A, Dyakowski T, et al. New understanding of a hydrocyclone flow field and separation mechanism from computer fluid dynamics[J]. Minerals Engineering, 2004, 17(5):651-660.
[6] Bliss T, Hagemeyer R W, Manson D W. Centrifugal Cleaning[G]//Pulp and Paper Manufacture. Vol. 6. 3rd ed. Paptac, 1992.
[7] Staie E, Salcudean M, Gartshore I, et al. A Computational study of particle separation in hydrocyclones [J]. Pulp and Paper Science, 2002, 28(3):84-92.
[8] 付平乐,陈克复,刘焕彬.纸浆悬浮液的多相流动分析及其物理模型[J].广东造纸,1998(2):12-14.
[9] Khodadadi Y M, Ramazani S A, Kamyabi A, et al. Simulation of flow of short fiber suspensions through a planar contraction[J]. Scientia Iranica, 2012, 19(3):579-584.
[10] 孙加龙,陈克复,周春晖.纸浆纤维悬浮液物性参数对流动特性的影响[J].力学与实践,2003,25(1):16-19.Sun J L, Chen K F, Zhou C H. Turbulence study of the influence of material parameters upon the pulp fiber suspension[J]. Mechanics in Engineering, 2003, 25(1):16-19.
[11] 杨福成.现代除渣器的理论与实践(续一)[J].黑龙江造纸,2003(2):24-25.
[12] Ho S L. Synthetic fibre fractionation in hydrocyclone[D]. Vancouver:University of British Columbia, 2001.
[13] Sommerfeld M, Ho C A. Numerical calculation of particle transport in turbulent wall bounded flows [J]. Powder Technology, 2003, 131(1):1-6.
[14] 赵立新,崔福义,蒋明虎,等.基于雷诺应力模型的脱油旋流器流场特性研究[J].化学工程,2007, 35(5):32-35.Zhao L X, Cui F Y, Jiang M H, et al. Study on the characteristics of flow field inside de-oiling hydrocyclone based on Reynolds stress model[J]. Chemical Engineering, 2007, 35(5):32-35.
[15] Elsayed K, Lacor C. The effect of vortex finder diameter on cyclone separator performance and flow field[C]. Fifth European Conference on Computational Fluid Dynamics. Portugal, 2010.
[16] 李进良,胡仁喜.精通FLUENT6.3流场分析[M].北京:化学工业出版社,2009.
基金
收稿日期:2013-01-10 修回日期:2013-04-02
基金项目:“十一五”国家科技支撑计划(2011BAC11B01); 江苏高校优势学科建设工程资助项目(PAPD)
第一作者:张健,男,硕士生。*通信作者:张辉,教授。E-mail: hgzh@njfu.edu.cn。
引文格式:张健,沙九龙,杨帅,等. 正向除渣器中纤维流动性与收集效率的模拟分析[J]. 南京林业大学学报:自然科学版,2014,38(1):130-134.
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