【作者】 毕超；

【导师】 江波；

【作者基本信息】 北京化工大学 ， 机械设计及理论， 2008， 博士

【摘要】 近年来,往复式单螺杆销钉挤出机以其独特的混炼性能越来越多地应用于聚合物混炼加工领域。本文以WXJ-140往复式单螺杆销钉挤出机的研制开发为主线,对往复式单螺杆销钉挤出机的设计原理、挤压系统和传动系统运动仿真、混炼机理、螺纹元件内物料三维动态流动过程以及停留时间分布测量和建模等方面进行探索和研究。运用系统工程设计原理,全面剖析了往复式单螺杆销钉挤出机的结构特点,构建了挤压系统销钉-螺棱复合运动数学物理模型,通过运动仿真模拟,对其加工过程进行了全程、实时、动态和全方位观察和研究,完善了往复式单螺杆销钉挤出机挤压系统和传动系统的设计原理,并对WXJ系列往复式单螺杆销钉挤出机系列化开发理论进行研究和实践。采用有限元数值方法对往复式单螺杆销钉挤出机三种典型螺纹元件内物料流动及混合进行三维动态模拟,分析了工艺条件、物料特性以及销钉布置对挤出机分布、分散混合性能的影响。在数值模拟理论指导下,开发了国际上最先进的具有超高混合性能的四排销钉四条螺棱的新型混炼元件。在验证数字图像处理方法测量塑化挤出机停留时间分布可行性的基础上,对往复式单螺杆销钉挤出机的停留时间分布进行了实验研究。为了预测和控制挤出机的时间分布情况,分别应用化学反应工程和流体力学方法,根据机器的结构组成和螺杆的组合形式,建立了预测往复式单螺杆销钉挤压造粒机组停留时间分布的数学模型。目前,往复式单螺杆销钉挤出机的技术和市场基本上被瑞士Buss公司独家垄断,本研究取得的阶段性成果不仅可为该机型的系列化开发和推广应用提供理论依据,还可为我国高分子材料科学和技术的进步提供新的设备平台。更多还原

【Abstract】 In the resent years,because of the unique kneading characters,more and more reciprocating single screw pin-barrel extruder were used in the polymer mixing process.Based on the development of the WXJ-140 reciprocating single screw pin-barrel extruder,the design principle,dynamic simulation of the plasticating system and driving system,mixing mechanism,fluid flow and mix inside the screw elements,and the experimental measurement and modeling of the residence time distribution in the extruder were studied herein.The structures and functions of the reciprocating single screw pin-barrel extruder were analyzed using the systematic engineering design principle.In order to improve the design principle of this kind of the extruder,the dynamic simulation of the plasticating and driving systems was carried out,which was helpful to give a direct,comprehensive,real-time and dynamic observation of the extrusion process.Meanwhile,the mathematic model on the multiple motions of the pins mounted on the barrels and the flights of the screw elements was also founded.Furthermore,the application of the scale-up theories in the serialization development of the WXJ extruders was also studied.The flow and mixing characters of the common screw elements in the reciprocating single screw pin-barrel extruder were studied using a polyflow finite element software package.Base on the statistical treatment of the flow trajectories,the dynamic mixing process and the effects of the operating conditions,material viscosity and the pins on the mixing performances of the extruder was studied.At the same time,a novel mixing screw element named NKE with four flights was developed and compared with the traditional mixing element(KE element).After validating the feasibility of the digital image processing method in measuring the residence time distribution(RTD)of the plasticating extruder,a experimental study on the RTD in the reciprocating single screw pin-barrel extruder was done.For the sake of the control and forecast of the RTD,based on the assembly of the equipment and the component of the screw,two mathematical models on the RTD in the extruder were built by the chemical reaction engineering method and computing fluid dynamics method, respectively.At present,the technologies and markets of this kind of equipment are all controlled by a few of foreign manufacturers basically.Some domestic enterprises and institutes including Beijing University of chemical technology have developed small-and medium-sized reciprocating single screw pin-barrel extruder,but there is no enough dependable and systemic theory for the development of the lager-sized equipment.Generally speaking,all the preliminary investigations can provide not only the theoretical basis for application and serial development of this kind of equipment,but also a new scientific research stage for the improvement of the polymer materials science and technology of China.更多还原