端面混炼挤出机的研究

本文研究了一种新型挤出机一端面挤出机,井在各种不同间隙下和不同转速下测得了端面混炼挤出机的产量、压力和功耗等参数,同时加入预混好的具有一定比例的碳酸钙聚乙烯混料,进行取样切片,通过电镜扫描对样片进行混炼效果定性分析。     

混炼装备的研究现状与发展

本文对国内外混炼装备的研究现状和发展趋势进行了评述,详细地介绍了同向双螺杆混炼挤出机、FCM连续混炼机、往复式销钉螺杆挤出机等几种新型混炼设备,然后重点从混炼原理、设计原理及应用等方面对串联式磨盘螺杆挤出机进行了分析,最后对混炼技术与装置的发展趋势进行了展望,提出了几种混炼装置及技术的发展方向。     

销钉机筒挤出机的基本结构与工作原理

<正> 在机筒上装置销钉是近年来挤出机一种新的结构型式,这种挤出机在国外已用于塑料和橡胶的配料、混炼和成型加工。销钉机筒除了具有与销钉螺钉相似的增强塑化与混炼效果的性能外,还具有产量高,对物料适应性强,挤出温度低等特点。     

混炼装备的研究现状和发展

本文对国内外混炼装备的研究现状和发展趋势进行了评述，详细地介绍了同向双螺杆混炼挤出机、FCM连续混炼机、往复式销钉螺杆挤出机等几种新型混炼设备，然后重点从混炼原理、设计原理及应用等方面对串联式磨盘螺杆挤出机进行了分析，最后对混炼技术与装置的发展趋势进行了展望，提出了几种混炼装置及技术的发展方向。     

双螺杆结构改善泡沫胶的预混炼

传统的PE和PS的物理起泡法是在两个前后排列安装的单螺杆挤出机上完成的。但Berstorff公司称ZE/KE Schaumtandex组合具有较高的挤出效率，其第一段混炼和塑化挤出机由双螺杆挤出装置替代。 Berstorff称，这种组合的使用可同时为双螺杆挤出机带来良好混炼能力和单螺杆挤出机极佳的冷却能力。 双螺杆结构满足了因市场原材料不断增加而致的混炼量增加的要求，且更适用于产量在750gk/h以上泡沫胶的混炼。与单螺杆挤出机相比，双螺杆具有较好的进料能力和较高的尺寸/产量比。此外，随着今后产量的增加，双螺杆机筒和螺杆的标准设计可能使其…     

用MCT冷喂料挤出机连续制备混炼胶工艺分析

实例分析采用多流道传递式（ＭＣＴ）混炼冷喂料挤出机连续制备混炼胶的工艺条件及特性。指出低置螺杆传递混合区的温度，提高背压及提高螺杆转速时，机器工艺性能优良，产量大，混炼塑化效果好。     

新型混炼技术应用研究

聚合物改性对混炼设备的性能提出了更高要求。介绍了自主研制的5种新型混炼设备：同向平行双螺杆挤出机、串联式磨盘螺杆挤出机、往复式销钉螺杆挤出机、新型销钉式冷嗖料橡胶混炼挤出机的性能特点、适用范围、结构机理等。并对几种设备的混炼效果作了重点介绍。     

基于动态成型过程的强化分散混炼方法

介绍了基于动态成型过程强化分散混炼的方法以及实现这些方法的动态混炼挤出机的结构及工作原理。这种低能耗强混炼技术包括在单螺杆上增设差动混炼单元、增加物料沿程反馈螺杆以及采用三螺杆劫态混炼挤出机等。     

挤出机螺杆直槽式屏障混炼元件的优化设计

研究挤出机螺杆直槽式屏障混炼元件的优化设计问题。根据粘性流体流动基本方程。以单位产量能耗最小为优化目标,建立简化的挤出机螺杆直槽式屏障混炼元件优化设计的数学模型，并应用复合形法求解，确定剪切长度、剪切问隙、屏障长度和屏障槽数等主要几何参数。本研究优化结果均在文献所建议的最佳取值范围内。     

聚合物共混改性混炼挤出设备的探讨

探讨了聚合物共混改性的基本理论和聚合物混炼挤出设备的发展历程。重点从结构原理、性能及应用等方面对单螺杆挤出机、双螺杆挤出机以及电磁动态混炼挤出机进行了分析，并探讨了聚合物混炼挤出设备的发展方向。     

Discrete element method simulation of binary blend mixing of cohesive particles in a high-intensity vibration system

The effects of processing intensity, time, and particle surface energy on mixing of binary cohesive powder blends in high-intensity vibration system were investigated via discrete element method simulations. The mixedness was quantified by the coefficient of variation, C_v; lower being better. The mixing rate, which is the speed at which homogeneity was achieved, was inversely proportional to the mixing Bond number, defined as the ratio of particle cohesion to the shear force resulting from the mixing intensity. Results show that both increasing processing intensity and reducing surface energy led to a faster mixing rate. However, the mixedness improved initially as mixing action (the product of mixing rate and mixing time) increased, but later deteriorated upon its further increase. Thus, both mixing rate and mixing intensity need to be tuned for optimum mixing performance depending on the cohesion level of particles; too high or too low mixing action should be avoided.     

考虑非等温混合的能量集成水网络设计方法

讨论了能量集成水网络中非等温混合对系统能量目标的影响,提出了分割温度的概念。对于同性混合,系统的公用工程需求量不会减少。对于异性混合,通过确定分割温度并比较分割温度以上区间混合流股的热量之和与低温区间所需的热量,可以准确确定系统公用工程会增加、减少或者保持不变。基于以上思想,得到了非等温混合规则。它能判断是否存在能量惩罚,以及如何通过设计混合温度来避免能量惩罚。结合改进的"分离系统"法,提出了一种系统化的能量集成水网络设计方法。     

仿柳叶形静态混合器的流动及混合特性

对仿柳叶形静态混合器内混合气流进行了速度场与浓度场的试验研究,结果表明该混合器内速度场与浓度场偏差均达到了非常理想的效果（优于国家标准偏差值）。同时采用CFD软件对该静态混合器内的流场进行了数值模拟,试验与模拟的数值结果以及两者的浓度云图分布都有着较好的一致性。随后的研究结果表明：在混合元件尾迹区域出现了纵向涡和发卡涡来促进混合;在经过混合元件区域时因为湍流动能耗散率增加形成的高湍流动能耗散率区能够使物质交换更加频繁;整个静态混合器的流动阻力也主要发生在该区域,随之出现的返混现象也在一定程度上加强了混合效果。     

Numerical investigation of granular mixing in an intensive mixer:Effect of process and structural parameters on mixing performance and power consumption

Discrete element method (DEM) simulations of particle mixing process in an intensive mixer were con-ducted to study the influence of structural and process parameters on the mixing performance and power consumption. The DEM model was verified by comparing the impeller torque obtained from simulation with that from experiment. Impeller and vessel torque, coordination number (CN) and mixing index (Relative standard deviation) were adopted to qualify the particle dynamics and mixing performance with different parameters. A method based on cubic polynomial fitting was proposed to determine the critical mixing time and critical specific input work during the mixing process. It is found that the mixing performance and energy efficiency increases with the decrease of impeller offset. The mixing perfor-mance is improved slightly with the increase of blade number and the impeller with 3 blades has the highest energy efficiency due to its low input torque. Results indicate that the energy efficiency and the mixing performance increase with the decrease of filling level when the height of granular bed is higher than that of blade.     

Determination of the energy consumption during the production of various concrete recipes

This article presents a report of the mixing of concrete on the laboratory scale in a single-shaft and twin-shaft mixer. For both mixers we selected five concrete recipes that cover a broad spectrum of concrete mixing techniques. The concrete recipes differ from each other amongst other things by virtue of the aggregate-sized distribution curves, water-cement ratio, flow properties, compressive strength and mixing times. The specifically volume-related application of energy - which is necessary for the homogenization of the particular recipe in the mixer - is an essential influencing variable.The comparison of the specifically volume-related application of energy is possible only if the concrete recipes possess the same homogeneity. The time curve of the homogeneity plotted against the necessary mixing time indicates the mixing efficiency, which in turn is determined by an imaging measurement process. Comprehensive mixing experiments show that the resulting application of energy, measured via the current composition, does not provide sufficient information in order to define the actual homogeneity in the mixture. A method was developed for the purpose of comparing concrete mixtures based on various recipes with the same homogeneity in relation to the specifically volume-related application of energy. The particular application of energy can be determined via the required mixing time and the power output process in terms of time.     

密封件用高硬度丁腈橡胶的混炼工艺探讨

探讨了高硬度丁腈橡胶的混炼工艺,如一段混炼法、两段混炼法和逆炼法.实验证明,高硬度丁腈橡胶中的炭黑等填充剂用量较大时,可采用逆炼法混炼工艺;该工艺混炼效果较好,胶料质量稳定,并降低能源消耗.     

煤浆混合槽混合性能的数值模拟

利用计算流体力学(CFD)方法研究煤浆混合槽的混合性能。采用Fluent 6.2计算软件,选用多重参考系法(MRF)、RNGk-ε湍流模型以及混合物多相流模型,对卧式煤浆混合槽的内部流动情况进行数值模拟,得到了湍流强度、湍动能、压力、速度分布以及出口各相分布等混合性能。模拟结果与实验结果进行了初步比较,吻合较好。研究结果表明,混合时在挡板和搅拌浆叶之间产生漩涡,有利于防止物料堆积,使混合更均匀。     

混合顺序对热集成水网络的能耗影响

研究了流股混合顺序对热集成用水网络的能耗影响。首先，根据两流股的混合规则，基于热力学分析的方法研究了多流股的水网络中，不同的混合顺序对系统能耗的影响。然后，根据产生的影响结果，归纳出混合顺序的规则，可用于指导选择适当的流股混合顺序，从而提高系统节能效果。     

销钉单螺杆混炼段分布混合性能的数值研究

用正交设计法设计了9组不同排布的销钉单螺杆。采用混合熵作为评价销钉单螺杆混炼段混合性能的指标,数值研究了不同销钉结构的单螺杆混炼段内聚丙烯熔体的等温流动过程,考察了一个导程内销钉排数、每排销钉个数和销钉高度对销钉单螺杆混炼段混合性能的影响。结果表明,在所设计的正交试验中,沿螺杆挤出方向各截面的混合熵逐渐增大,出口处该值达到最大;在销钉螺杆混炼段一个导程内安装5排,每排5个高度为12 mm的销钉时,其混合性能较优。     

错位桨搅拌槽内污泥与固体颗粒混合过程的数值模拟

以直径1 m的搅拌槽为模型、含水率92%的污泥和粒径0.1 mm的固体颗粒为工作介质,采用Fluent软件对错位六叶螺旋桨搅拌下污泥与固体颗粒的混合过程进行数值模拟,通过与普通六叶螺旋桨对比,分析了2种桨型的浓度场分布、混合时间及单位体积混合能,并将计算的固体颗粒浓度分布与实验结果进行了比较. 结果表明,固体颗粒浓度分布计算结果和实验结果吻合较好,流动场分布对混合过程有一定影响,相同条件下错位桨搅拌的浓度场分布更快趋于稳定. 当转速N=4 r/s时,错位六叶螺旋桨的混合时间为27 s,比六叶螺旋桨的混合时间缩短9 s. 采用错位桨单位体积混合能仅为普通桨的79.6%,节能效果显著.