串联密炼机一次法低温混炼工艺生产乘用轮胎胎面胶

采用串联密炼机一次法低温混炼工艺生产乘用轮胎胎面胶,并与传统密炼机混炼工艺进行对比。结果表明:与传统混炼工艺相比,采用串联密炼机一次法低温混炼工艺生产的混炼胶F_(max)提高,焦烧时间t_5延长,胶料的加工安全性提高;硫化胶定伸应力、拉伸强度和回弹值提高,耐磨性能改善;炭黑分散性和硫黄分散程度明显改善;胶料混炼能耗降低,生产效率提高,胶料质量更加稳定。     

XLH-150型连续混炼工业化机台的混炼工艺参数 对胶料性能的影响

研究XLH-150型双转子连续混炼机的混炼工艺参数与胶料性能间的关系,确定XLH-150型连续混炼工业化机台的最佳混炼工艺,并与传统密炼机三段混炼工艺进行对比。结果表明：XLH-150型连续混炼工业化机台的最佳混炼工艺为初炼采用GK-45E型啮合型密炼机,转子转速为50 r·min^-1,温度为40℃,混炼时间为270 s,填充因数为0.6;补充混炼采用XLH-150型双转子连续混炼机,转子转速为40 r·min^-1,过2遍连续混炼机,各段温度分别为70,65,60和55℃。采用连续混炼工艺的胶料性能优于采用传统三段混炼工艺的胶料性能,即胶料的Payne效应降低11%,滚动阻力降低15%,拉伸强度和撕裂强度略有提高;同时生产效率提高44%以上,总单位能耗降低39%。     

低温一次法炼胶工艺与传统法炼胶工艺在高结构炭黑配方中的应用

在胎面胶配方中采用高结构 N134炭黑进行大料对比实验,结果表明：一次法炼胶工艺较传统多段炼胶工艺的混炼胶流动性更好,利于后序半成品部件的加工;一次法生产的混炼胶物性及磨耗均优于传统多段混炼胶;同时,低温一次法减少了混炼段数,提高了生产效率;而且一次法也适用于多白炭黑配方胶料的混炼。因此,低温一次法炼胶工艺更能突出其必然优势     

低温一次法炼胶工艺的研究开发和应用进展

简述国外新型连续混炼工艺,重点总结和介绍国内低温一次法炼胶工艺的研究开发和应用进展。低温一次法炼胶工艺是将传统的多段混炼改为一次混炼,即胶料通过密炼机高温密炼后,先经过第一台开炼机进行冷却,然后通过中央输送系统对称地分配到周围多台开炼机进行连续低温混炼,直接得到终炼胶,整个过程强化了下辅机的混炼作用,且全过程实现自动化控制,取消了胶料中间传递和反复升降温过程,从而大幅度减少占用场地,降低能耗,缩短混炼时间。橡胶混炼技术未来的发展方向是利用物联网设计理念和可视化监控方式、高度集成成套智能装备的智能化炼胶车间总体设计。     

低温一次法混炼工艺在高结构炭黑胎面胶生产中的应用

研究低温一次法混炼工艺在高结构炭黑胎面胶生产中的应用,并与传统多段混炼工艺进行对比。结果表明:与传统多段混炼工艺相比,采用低温一次法混炼工艺的混炼胶流动性更好,有利于半成品部件的加工;硫化胶的物理性能更好;混炼段数减少,生产效率提高。     

使用串联密炼机一次法低温混炼工艺生产PCR胎面胶

白炭黑是实现绿色轮胎生产的关键材料,而传统炼胶方式对于高填充白炭黑的胶料混炼是非常困难的。为更好地解决白炭黑混炼的工艺难题,采用串联式密炼机一次法低温混炼工艺。研究得出,串联式密炼机与传统的密炼机混炼工艺相比具有更为优异的炼胶性能,胶料混炼能耗降低,生产效率提高,胶料质量更加稳定。     

全自动开炼机与传统开炼机的对比实验研究

基于全自动开炼机实验机台的最佳工艺参数,对开炼机炼胶效果进行了对比实验研究。实验采用低温一步法混炼工艺流程,密炼机初混后的胶料分成2份,分别在传统开炼机和全自动开炼机上进行低温炼胶,最后比较2种机台的炼胶效果。实验结果表明,全自动开炼机保证了良好的塑炼效果,提高了终炼胶的物理机械性能(拉伸强度和撕裂强度分别提高了8.3%和10.4%),提高了炼胶质量稳定性和均一性。     

白炭黑补强胶料的开炼机混炼工艺研究（Ⅱ）——溶聚丁苯橡胶

试验设计一种白炭黑补强溶聚丁苯橡胶的开炼机混炼工艺。相对于传统三段混炼工艺中的二段在高温开炼机上进行,将一段胶的热处理（硅烷化反应）放在老化箱中进行,重点考察热处理时间对胶料性能的影响。结果表明,该混炼工艺安全易行,二段热处理温度和时间控制精准,避免了高温混炼对胶料的剪切破坏,所得胶料的性能与密炼机混炼效果相当。     

低温一次法混炼和传统混炼工艺的对比

对比采用传统混炼工艺和低温一次法混炼工艺的天然橡胶(NR)/顺丁橡胶(BR)并用胶性能,并运用"壳层滑动模型"对其原因进行分析。低温一次法混炼是轮胎行业在胶料混炼工艺方面的重大变革,采用一次法混炼工艺的胶料具有炭黑分散好,硫黄和促进剂均匀程度高,热损失小的特点。     

白炭黑补强胶料的开炼机混炼工艺研究（Ⅰ）——天然橡胶

试验设计一种白炭黑补强天然橡胶的开炼机混炼工艺.相对于传统三段混炼工艺中的二段在高温开炼机上进行,将一段胶的热处理（硅烷化反应）放在老化箱中进行,重点考察热处理时间对胶料性能的影响.结果表明,该混炼工艺安全易行,二段热处理温度和时间控制精准,避免了高温混炼对胶料的剪切破坏,所得胶料的性能与密炼机混炼效果相当.     

强化密炼机下辅机的剪切分散和混炼作用

通过比较强化下辅机与现有密炼机的混炼技术,论述现有密炼机生产线混炼技术的优缺点,提出在现有混炼技术基础上,采用新型开炼机来强化密炼机下辅机的剪切分散和混炼作用,使胶料混炼过程能够一次性完成,并起到提高胶料质量及节约能量和作业场地面积等作用。     

AC Electrokinetic Fast Mixing in Non-Parallel Microchannels

A novel ultra-fast micromixer of a quasi T-channel with electrically conductive sidewalls is presented here and some new phenomena in its mixing process are observed and reported. The mixing is about 10²–10³ times faster than that by purely molecular diffusion, and about 10² times faster than that in existing micromixers, which are based on the electrokinetic instability (EKI). Both parallel and non-parallel channel are investigated and compared by evaluating their mixing. Mixing behaviors in the microchannels are studied in terms of scalar concentration distributions. It is found that with a small angle (about 5° in this case) between the two electrodes sidewalls, mixing can be enhanced rapidly at even low AC voltage. The influence of the applied AC voltage phase shift between the two electrodes on the mixing process is also explored. The result reveals that the mixing is the strongest under a 180° signal phase shift. Fast mixing is also achieved under high AC frequency in this micromixer. Fluorescent micro particles are used to visualize the flow pattern for better understanding of the mixing enhancement mechanism. The design of this micromixer could provide new opportunity for applications where fast mixing is demanded.     

Coiled flow inverter as an inline mixer

Helical coils are widely used in the process industries to improve the mixing efficiency under laminar flow conditions. It was further observed that in the regular helical coils, there exists a confined region in the tube cross-section where fluids are entrapped and can escape only by diffusion. In the present work, an attempt has been made to further enhance the mixing in the coiled tube at low Dean number using the phenomenon of flow inversion. The study is performed in coiled flow inverter (CFI) [Saxena, A.K., Nigam, K.D.P., 1984. Coiled configuration for flow inversion and its effect on residence time distribution. A.I.Ch.E. Journal 30, 363-368] which was developed using the concept of inverting the direction of fluid by 90^°. It comprises coils with equidistant 90^° bends. The scalar mixing of two miscible fluids has been quantified for different process conditions (Dean number, Schmidt number and number of bends) by using scalar transport technique. There was a significant increase in mixing performance of CFI as compared to regular helical coils at low Dean number. The mixing efficiency increased with the increase in Dean number and number of bends. It was also observed that the mixing performance was enhanced with increase in Schmidt number. A new correlation has been proposed for unmixedness coefficient of CFI as a function of Dean number, Schmidt number and number of bends. The proposed correlation has maximum error of ±20% with the numerical predictions.     

Die Herstellung von Kakaoerzeugnissen unter Anwendung von Pflugscharmischern

Manufacture of Cocoa Products Using Plough Share Mixers Various problems arise during mixing and thermal treatment of powdered material in the production and further processing cocoa powder. Means for solving such problems are shown. An effective process of mixing and the plough share mixers used for the same are described; these nearly automatic mixers are widely applicable. A further development of these mixers, the so-called DRUVATHERM-units, enable the combination of several mechnical processes, such as mixing, pulverizing of agglomerates, moistening, coating, tempering, cooling, drying and carrying out reaction processes under pressure or vacuum and at higher temperature. These new type of units can compete with conventional driers and roasters. They open new economical paths in the conventional treatment of products in cocoa industry as well.     

The Control of Power for Efficient Batch Mixing

In the batch mixing of composite solid propellants, small variations in the mixing process can lead to unacceptable variability in the properties and performance of the propellant grain. A new closed-loop mixing strategy is proposed to improve the robustness of the mixing process with respect to these small variations, and thereby to reduce the variability of the finished grain from batch to batch. The new mixing strategy is based on the hypothesis that repeatability of mixing results can be improved by doing the same amount of work on each batch and that mixing efficiency can be improved by continuously controlling power. Justification of the hypothesis is given. The effectiveness of the new mixing strategy is demonstrated through simulations, using a process model based on measurements and analysis of an existing process for the batch mixing of an ammonium nitrate composite solid propellant. Results indicate that the new strategy improves the repeatability of the mixing process by reducing mixing power fluctuations and by eliminating variations in work done on the mixture from batch to batch. The new mixing strategy is shown to be feasible. Because the new mixing strategy is successful with wide robustness margins for this specific difficult mixing process, the strategy should be effective in the batch mixing of a wide range of composite solid propellants.     

固液两相声共振混合数值模拟

声共振混合作为一种解决力/热敏感超细材料均匀分散混合问题的新方法,其技术特点是混合容器工作在共振状态下使用不超过200Hz的振动产生低频声场促进混合。本文采用气固液三相流模型对一种固体、一种液体在声共振混合容器中的混合过程进行建模。固体颗粒与液体之间相互作用系数采用Gidaspow公式。采用固体颗粒体积分数标准偏差作为标准对混合均匀性进行了评价。计算结果表明,在100g振动加速度下容器中出现了体流现象,并初步计算了不同高宽比、不同激振参数条件下的混合特性,对计算结果进行了分析。最后利用自搭建的声共振混合样机,分别在低固含量、高固含量条件下进行实验,记录混合过程中固体颗粒的运动轨迹。实验结果初步验证了仿真模拟的正确性以及声共振样机的混合能力。     

新型双轴组合桨搅拌性能研究

根据聚合反应的特定工艺过程要求,提出了一种新型组合桨,并设计实验对其混合性能进行研究,与常规桨型进行对比。结果表明,该桨在高黏度流体内,混合时间、排液量、混合效率等方面较常规桨型好,不但能在较短的时间内实现全罐的均匀混合,而且还具有节能降耗的优点。此外,还采用PIV系统对其流场的速度分布进行测试,总结得出其在不同转速比下的流场分布规律,从而为今后该新型组合桨的应用和放大奠定了坚实的实验基础。     

A rapid mixing process in continuous operation under periodic forcing

We introduce a simple and powerful new process for mixing two fluid streams introduced into a pipe via a splitter plate. We demonstrate that the fluids can be thoroughly mixed (at least on large scale) within one pipe diameter downstream of the splitter. Mixing is controlled via periodic velocity forcing of one of the input streams, and is due to amplification of the perturbation as described by instability and receptivity theory. The effectiveness of the mixing depends strongly and non-trivially on the perturbation frequency and amplitude, which distinguishes this method from simple mechanical stirring. The method is effective even at relatively low Reynolds numbers, where laminar flow is observed in the absence of the forcing. Fast mixing can be obtained for different initial velocity ratios of the two inlet streams, rendering the mixing process relatively versatile. Here the mixing method is demonstrated, and potential issues for industrial application are discussed.     

Effects of Assistant Solvents and Mixing Intensity on the Bromination Process of Butyl Rubber

A slow bromination process of butyl rubber （IIR） suffers from low efficiency and low selectivity （S） of target-product. To obtain suitable approach to intensify the process, effects of assistant solvents and mixing inten-sity on the bromination process were systemically studied in this paper. The reaction process was found constantly accelerated with the increasing dosage and polarity of assistant solvent. Hexane with 30%（by volume） dichloro-methane was found as the suitable solvent component, where the stable conversion of 1,4-isoprene transferring to target product （xA1s） of 80.2%and the corresponding S of 91.2%were obtained in 5 min. The accelerated reaction process was demonstrated being remarkably affected by mixing intensity until the optimal stirring rate of 1100 r＆#183;min-1 in a stirred tank reactor. With better mixing condition, a further intensification of the process was achieved in a ro-tating packed bed （RPB） reactor, where xA1s of 82.6% and S of 91.9% were obtained in 2 min. The usage of the suitable solvent component and RPB has potential application in the industrial bromination process intensification.     

塑料母粒加工新技术研究进展

介绍国内外近几年来发展起来的一些用于塑料母粒加工的新技术及方法,包括对载体树脂的选择和处理方法、聚合物包裹技术、液相共混法、熔融相共混法、分子自组装技术及一些其它方法,并指出高分散性、高含量、低成本母粒是塑料母粒的发展方向。