高分子专业英语选讲课文翻译资料

PART B 聚合反应工程 UNIT 11 Reactor types 第十一单元 反应器类型

Reactors may be categorized in a variety of ways, each appropriate to a particular perspective. For example, Henglein (1969) chooses a breakdown based on the source of energy used to initiate the reaction (i.e., thermal, electrochemical, photochemical, nuclear). More common breakdowns are according to the types of vessels and flows that exist.

反应器可以用许多方法分类，各自适用于特定的目的。例如，Henglein（1969）基于用于产生反应的能量来源，即，热量，电化学，光化学，原子核，选择了一种细目分类。更多普通的细目分类是按照所存在的容器和流量的类型。 Batch Reactors 1. 间歇反应器

The batch reactor (BR) is the almost universal choice in the chemist’s laboratory where most chemical processes originate. The reason is the simplicity and versatility of the batch reactor, whether it be a test tube, a three-neck flask, an autoclave, or a cell in a spectroscopic instrument. Regardless of the rate of the reaction, these are clearly low production rate devices. As scale up is desired, the most straightforward approach is to move to a larger batch reactor such as a large vat or tank.

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间歇反应器在化学实验室几乎是一般的选择，大多数的化学过程在那里产生。间歇反应器的原理具简单性和通用性，不管它是一支试管，一个三颈瓶，一个高压釜，还是一个光谱仪器的比色皿。不管反应比例，很清楚这些是低产率设备。当要求放大反应器时，大多直截了当的途径是移至一个较大的间歇反应器如一个较大的大桶或罐。

Commercial batch reactors can be huge, 100 000 gal or more. The cycle time, often a day or more, typically becomes longer as reactor volume increases in order to achieve a substantial production rate with an inherently slow reaction. Fabrication, shipping, or other factors place a limit the size of a batch reactor. For example, transportation capacity can limit the size of a batch reactor for which shop, as opposed to on-site, fabrication of the heat exchange surface is required. This limits the production rates for which batch reactors may be economically utilized. Also, batch reactors must be filled, emptied, and cleaned. For fast reactions these unproductive operations consume far more time than the reaction itself and continuous processes can become more attractive.

商业化的间歇反应器是庞大的，10万加仑或更大。对于慢化学反应，为提高生产率必须增加反应器体积，而这往往导致反应器的循环周期变长，常常以天计算。制造、运输以及其他因素限制了反应器的规模，如热传递能力会限制间歇反应器的尺寸，热交换器必须在制造厂而不是在现场加工。这限制了产率由于这间歇反应器可以被经济地利用。间歇反应器也必须装料、卸料和清洗。为了加快反应这些非生产性的操作消耗了多于反应本身的时间，连续化过程可能更有吸引力。 2. Semibatch Reactors (SBR) 2.半间歇反应器

Some reactions may yield a product in a different phase from the reaction mixture. Examples would be liberation of a gas from a liquid-phase reaction or the formation of a precipitate in a fluid-phase reaction. To drive the reaction to completion, it may be desirable to continuously separate the raw product phase. A semibatch operation may result as well from differing modes of feeding the individual reactants. For reasons we will discuss later, it may be desirable to charge one reactant to the reactor at the outset and bleed a second reactant in continuously over time. Such reactors have both a batch and a flow character and, like batch reactors, are useful for slow reactions and low production rates.

一些反应器可以从反应混合物的不同相态中生产出某种产品。例如液相反应中气体的释放，或流动相反应中沉淀的生成。为了驱使反应完全，希望继续分离粗产物相。个别反应物的不同加入方式也导致半连续操作。原因我们以后讨论，可希望一开始加入一种反应物以后连续加入第二种反应物。这类反应器同时具有一个间歇和一个流动的特征，像间歇反应器，适用于慢反应和低产率。

3. Continuous Stirred Tank Reactors (CSTR) 3. 连续流动搅拌反应器

It is a small step from the batch reactor to the CSTR. The same stirred vessel

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高分子专业英语选讲课文翻译资料

may be used with only the addition of piping and storage tanks to provide for the continuous in-and outflow. Faster reactions can be accommodated and larger production rates can be achieved because of the uninterrupted operation. CSTRs are most often used for liquid-phase reactions, such as nitration and hydrolysis, and multiphase reactions involving liquid with gases and/or solids. Examples would be chlorination and hydrogenation.

从间歇反应器到连续流动搅拌反应器是小小的一步。同样的搅拌式容器的使用可仅仅添加管道和储罐以提供连续进料和出料。因为连续操作可加快反应并提高产率。通常大多数连续流动搅拌反应器用于液相反应，例如硝化和水解，多相反应器涉及液-气和/或液-固。例如氯化和加氢。 4. CSTR in Series

4.多级串联连续流动搅拌反应器

It was shown that considerable gains in production rate and economics can be achieved by passing the reacting mixture through a series of CSTRs. Again, we see how easy it is to achieve a gradual scale up, say for a specialty chemical for which is increasing. CSTRs in series are usually used for liquid-phase reactions. 事实证明通过一系列多级串联连续流动搅拌反应器的混合能够获得高产率和重大的经济效益。再者，这种反应器容易放大，例如某种化学品的需求逐步增加时常这样做。多级串联连续流动搅拌反应器通常用于液相反应。 5.Tubular Reactors 5.管式反应器

As the production rate requirement increases, batteries of CSTRs become increasingly complex and tubular reactors become attractive. With the transition to tubular reactors, some versatility is lost and more process integration is required. Nevertheless, tubular reactors find extensive application in liquid-phase reactions, for example, polymerization, and are almost always the continuous reactor of choice for gas-phase reactions, for example, pyrolysis. Exceedingly high production rates can be achieved with tubular reactors either by increasing the diameter of the tube or more commonly by using a sufficient number of tubes in parallel.

当产率需要增加时，增加许多套连续搅拌式反应器变得复杂，而管式反应器变得诱人。转化成管式反应器失去了一些通用性并要求综合许多操作。尽管如此，管式反应器在液相反应中起着广泛作用，例如，聚合反应，气-液反应几乎总是选择连续反应器，例如，高温裂解。采用管式反应器能够获得非常高的产率，要么增加管的直径要么通过使用充足数量的并列管提高更大的通用性。 6. Recycle reactors 6. 循环反应器

Recycle reactor can be batch, CSTR, tubular, and so on in nature with the purpose of the recycle varying from one case to the next. Many large-scale

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commercial processes incorporate the recycle of one or more streams back to an earlier point in the process to conserve raw materials. This practice often results in the accumulation of impurities, which in turn requires separation. Usually it is not simply the reactor outlet stream that is recycled back to the reactor inlet, but it can be. For example in a batch reactor the reacting mixture can be recycled, or pumped around, through a heat exchanger to provide thermal control.

循环反应器出于从一种情况到下一种情况循环变化的目的，在种类上可以是间歇反应器、连续流动搅拌反应器、管式反应器等等。回到较早的观点，在节省粗原料的过程中，许多大规模的商业操作合并了一个或多个循环。这一实践通常导致了杂质的累积，它们依次需要分离。通常不是简单地将反应器的出料返回到入口，当然也可以这样做。例如，在间歇反应器中反应混合物可以回收，或用泵打循环，通过热交换器控制热。

Recycle reactor have also found valuable application in the laboratory and pilot plant because of their special characteristics. At one extreme, in which all of the product is recycled (no net flow), the reactor is the exact equivalent of the well-stirred batch reactor. At the other extreme of no recycle, the reactor is simply the tubular variety. If there is some net flow but the recycle rate is high, the overall reactor performs like a CSTR. Yet the reaction tube itself behaves like differential tubular reactor. This versatility of the recycle reactor can be exploited to great advantage in research and development.

循环反应器由于其特殊的特性在实验室和中试车间也发现了应用价值。一个极端是将所有的产物循环（没有净的流出），此时循环反应器严格等效于全混间歇反应器。另一个极端是没有循环，反应器是简单的管式类。假如有一些净的流出但循环率很高，所有的反应器运行类似于连续流动搅拌反应器。然而反应器本身的 类似于不同的管式反应器。在研究和发展中循环反应器的通用性能够开发出更大的优点（势）。

——Bisio A. , Kabel R L. Scaleup of Chemical Processes. New York: John Wiley & Sons

Inc. , 1985. 255~257 T 14 Styrene-Butadiene Copolymer 第十四单元 丁二烯-苯乙烯共聚物

The synthetic rubber industry, based on the free-radical emulsion process, was created almost overnight during World War II. Styrene-butadiene (GR-S) rubber crated at that time gives such good tire treads that natural rubber has never regained this market. 合成橡胶工业，以自由基乳液过程为基础，在第二次世界大战期间几乎很快地形成。那时，丁苯橡胶制造的轮胎性能相当优越，使天然橡胶在市场黯然失色。 The GR-S standard recipe is 丁苯橡胶的标准制法是

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组分 丁二烯 苯乙烯

十二烷基硫醇

重量分数 72 25 0.5

组分 过硫酸钾 肥皂片 水

重量分数 0.3 5.0 180

This mixture is heated with stirring and at 50℃ gives conversions of 5%~6% per hour. Polymerization is terminated at 70%~75% conversion by addition of a “short-stop”, such as hydroquinone (approximately 0.1 part), to quench radicals and prevent excessive branching and microgel formation. Unreacted butadiene is removed by flash distillation, and syrene by steam-stripping in a column. After addition of an antioxidant, such as N-phenyl-β-naphthylamine (PBNA) (1.25 parts), the latex is coagulated by the addition of brine, followed by dilute sulfuric acid or aluminum sulfate. The coagulated crumb is washed, dried, and baled for shipment. 混合物在搅拌下50℃加热，每小时转化5%～6%，在转化率达70%～75%时通过加入“终止剂” 聚合反应终止，例如对苯二酚（大约0.1的重量百分含量），抑制自由基并避免过量支化和微凝胶形成。未反应的丁二烯通过闪蒸去除，苯乙烯在萃取塔中通过蒸汽萃取（剥离）。在加入抗氧剂后，例如N-甲基-β-萘胺（1.25的重量百分含量），加入盐水，其次加入稀释的硫酸或硫酸铝后乳液凝胶。凝胶碎片被洗涤、干燥并包装装运。

Fig.14.1 SBR plant flow diagram Courtesy of Hydrocarbon Processing and Petroleum Refiner.

图14.1 丁苯橡胶厂流程图取自烃类加工和石油产品精制 This procedure is still the basis for emulsion polymerization today. An important

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