Development of a Solids Conveying Throughput Model for Grooved Barrel Extruders Based on Discrete Element Simulations
Development of a Solids Conveying Throughput Model for Grooved Barrel Extruders Based on Discrete Element Simulations
复制标题
基于离散元模拟的槽筒挤出机固体输送吞吐量模型的开发
DOI：
10.1007/978-3-662-60809-8_5
复制
发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Brüning
中科院分区：
文献类型：
--
作者：
Schöppner;Brüning
对于单螺杆挤出机的设计，产量的预测需要有较高的精度。物料输送能力的计算对于具有槽形喂料段的挤出机尤为重要。与光滑的筒式挤出机不同，整个装置的产量是在喂料部分决定的。固体输送的分析模型需要进行各种简化，如对输送情况的分类、固体块流的假设和压力各向异性系数的假设，而最近成功地用于描述光管挤出机中固体输送的离散单元法(DEM)在数值模拟中没有考虑上述简化。这里，小球被近似为球形粒子或由球体组成的粒子。基于虚拟重叠、接触模型和牛顿运动方程的解，有可能对颗粒流动进行更复杂的考虑。在模拟的每个迭代步骤中，可以计算颗粒速度、接触力和导出量，例如螺杆通道和沟槽中的质量吞吐量或沿槽筒的径向压力积累。因此，可以通过实验的统计设计来研究DEM模拟模型，以便通过回归将目标值转换为元模型。该方法避免了数值模拟计算时间过长以及解析方法假设过于简单的问题，将影响模拟的参数分为材料参数、几何参数和工艺参数。相关的材料参数包括聚合物-聚合物和聚合物-钢表面的摩擦系数以及恢复系数和颗粒直径。螺杆直径、沟槽深度和螺距、沟槽数量及其宽度、深度和角度的几何形状是不同的。通过改变角度，既考虑了传统的轴向槽，也考虑了螺旋槽。最后，模拟中还考虑了工艺参数速度和背压的影响。为了减少模拟工作量，在初步调查中识别了不相关的参数。
Regarding the design of single screw extruders, the prediction of the throughput needs to be of high accuracy. The calculation of the solids conveying throughput is particularly important for extruders with a grooved feed section. In contrast to smooth barrel extruders the throughput of the entire plant is determined at the feed section. Various simplifications are necessary for an analytical modelling of the solids conveying, e.g. the classification into conveying cases, the assumption of solid block flow and the assumption of pressure anisotropy coefficients.In numerical simulations with the Discrete Element Method (DEM), which has recently been successfully used to describe solids conveying in smooth barrel extruders, the simplifications mentioned above are not taken into account. Here, the pellets are approximated as spherical particles or particles composed of spheres. Based on virtual overlaps, contact models and the solution of Newton’s equations of motion, a more complex consideration of the pellet flow is possible. In each iteration step of the simulation, the particle velocities, contact forces and derived quantities, e.g. the mass throughput in the screw channel and the grooves or the radial pressure build-up along the grooved barrel can be evaluated. Therefore, a DEM simulation model can be investigated by means of statistical design of experiments in order to convert the target values into a metamodel by regression. Long computation times of numerical simulations will be avoided in this matter as well as too simple assumptions of analytical approaches.The influencing parameters to be simulated are divided into material, geometry and process parameters. Relevant material parameters are the coefficients of friction of the polymer-polymer and polymer-steel surface as well as the restitution coefficient and the particle diameter. The geometry is varied in the form of the screw diameter, the channel depth and pitch, the number of grooves and their width, depth and angle. By varying the angle, both conventional axial grooves and helical grooves are taken into account. Finally, the process parameters speed and backpressure are also considered in the simulations. In order to reduce the simulation effort, irrelevant parameters are identified in preliminary investigations.
登录
查看更多内容
影响因子：
4.7
作者：
Moysey, P. A.;Thompson, M. R.
通讯作者：
Thompson, M. R.
Nutbuchsenextrudern 节日素材区域模型
DOI：
--
发表时间：
2003
期刊：
影响因子：
--
作者：
Jürgen Miethlinger
通讯作者：
Jürgen Miethlinger
考虑背压和高螺杆转速的单螺杆光滑机筒挤出机固体输送压力吞吐量行为建模
影响因子：
1.3
作者：
J. Trippe;V. Schöppner
通讯作者：
V. Schöppner
单螺杆挤出机中固体输送的不可压缩模型
DOI：
--
发表时间：
2002
期刊：
影响因子：
--
作者：
Shibo Zhang;Valentinas Sernas
通讯作者：
Valentinas Sernas
Nutbuchsenextrudern 中的Schüttdichte und Massedurchsatz
DOI：
--
发表时间：
1993
期刊：
影响因子：
--
作者：
E. Grünschloss
通讯作者：
E. Grünschloss