基于FLUENT软件,采用雷诺应力模型(RSM)对正向除渣器中3%的纸浆悬浮液流场进行数值模拟,同时采用相间耦合的离散相模型计算浆渣颗粒的运动轨迹和分离效率。结果表明:正向除渣器内部流场具有小幅度的不对称性; 从除渣器壁面到中心轴处的总压最大压降在4 500 Pa左右。根据不同截面上轴向速度的分布特征可以发现,正向除渣器内部纤维浆料流场主要由中心区域的内旋流和外围的外旋流所组成; 粒径在0.02 mm时的重杂质和轻杂质的分离效率都维持在50%左右,粒径大于0.2 mm时的重杂质分离效率随着粒径的增大而提高,而轻杂质分离效率随粒径的增大而降低; 在粒径接近1 mm时,相对密度大于或等于石子的浆渣颗粒的分离效率已达到100%。
Abstract
Based on the FLUENT software, the 3% concentration of pulp suspension flow field was obtained with the Reynolds stress model(RSM). Meanwhile, the motion trail and separation efficiency of pulp impurities were obtained with the coupling of the alternate with discrete phase model. The results of simulation show that there is slightly asymmetric in the internal flow field of forward cleaner. The largest pressure drop of total pressure is about 4 500 Pa from the wall to the central axis of forward cleaner. The axial velocity profile at any section of forward cleaner is composed of two regions, including an internal vortex in the central region and an external vortex in the outer region. The separation efficiency for heavy and light impurities with the particles diameter of 0.02 mm are all maintained at about 50%, when the particles diameter is more than 0.2 mm, separation efficiency of heavy impurities will increase along with the particle diameter increasing, which of light impurities will decrease along with particle diameter increase. When the particles diameter is close to 1mm, the separation efficiency of the particles which the relative densities are greater than or equal to the stones has reached 100%.
中图分类号：
TS733+.4
TQ019
TQ028.5
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基金
收稿日期:2012-03-25 修回日期:2012-06-30
基金项目:南京林业大学江苏省制浆造纸科学与技术重点实验室开放基金(201001); 江苏高校优势学科建设工程资助项目(PAPD)
第一作者:张健,硕士。*通信作者:张辉,教授。E-mail: hgzh@njfu.edu.cn。
引文格式:张健,陈永利,王晨,等. 正向除渣器内部纤维浆料流场的数值模拟[J]. 南京林业大学学报:自然科学版,2013,37(2):141-146.
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