《化学工程与工艺专业英语》课文翻译Unit 10 What Is Chemical Engineering

Engineering?什么是化学工程学

In a wider sense, engineering may be defined as a scientific presentationof the techniques and facilities used in a particular industry. For example,mechanical engineering refers to the techniques and facilities employed tomake machines. It is predominantly based on mechanical forces which areused to change the appearance and/or physical properties of the materialsbeing worked, while their chemical properties are left unchanged. Chemicalengineering encompasses the chemical processing of raw materials, based onchemical and physico-chemical phenomena of high complexity.

广义来讲，工程学可以定义为对某种工业所用技术和设备的科学表达。例如，机械工程学涉及的是制造机器的工业所用技术和设备。它优先讨论的是机械力，这种作用力可以改变所加工对象的外表或物理性质而不改变其化学性质。化学工程学包括原材料的化学过程，以更为复杂的化学和物理化学现象为基础。

Thus, chemical engineering is that branch of engineeringwhich is concerned with the study of the design, manufacture,and operation of plant and machinery in industrial chemicalprocesses.

因此，化学工程学是工程学的一个分支，它涉及工业化化学过程中工厂和机器的设计、制造、和操作的研究。

Chemical engineering is above all based on the chemical sciences, suchas physical chemistry, chemical thermodynamics, and chemical kinetics. Indoing so, however, it does not simply copy their findings, but adapts them tobulk chemical processing. The principal objectives that set chemicalengineering apart from chemistry as a pure science, is “to find the mosteconomical route of operation and to design commercial equipment andaccessories that suit it best of all”. Therefore, chemical engineering isinconceivable without close ties with economics, physics, mathematics,cybernetics, applied mechanics, and other technical sciences.

前述化学工程学都是以化学科学为基础的，如物理化学，化学热力学和化学动力学。然而这样做的时候，它并不是仅仅简单地照搬结论，而是要把这些知识运用于大批量生产的化学加工过程。把化学工程学与

纯化学区分开来的首要目的是“找到最经济的生产路线并设计商业化的设备和辅助设备尽可能地适应它。”因此如果没有与经济学，物理学，数学，控制论，应用机械以及其它技术的联系就不能想象化学工程会是什么样的。

In its early days, chemical engineering was largely a descriptive science.Many of the early textbooks and manuals on chemical engineering wereencyclopedias of the commercial production processes known at the time.Progress in science and industry has bought with it an impressive increase inthe number of chemical manufactures. Today, petroleum for example servesas the source material for the production of about 80 thousand chemicals. Theexpansion of the chemical process industries on the one hand and advances inthe chemical and technical sciences on the other have made it possible to laytheoretical foundations for chemical processing.

早期的化学工程学以描述性为主。许多早期的有关化学工程的教科书和手册都是那个时候已知的商品生产过程的百科全书。科学和工业的发展使化学品的制造数量迅速增加。举例来说，今天石油已经成为八万多种化学产品生产的原材料。一方面是化学加工工业扩张的要求，另一方面是化学和技术水平的发展为化学工艺建立理论基础提供了可能。

As the chemical process industries forged ahead, new data, newrelationships and new generalizations were added to the subject-matter ofchemical engineering. Many branches in their own right have separated fromthe main stream of chemical engineering, such as process and plant design,automation, chemical process simulation and modeling, etc.

随着化学加工工业的发展，新的数据，新的关系和新的综论不断添加到化学工程学的目录中。然后又从主干上分出许多的分支，如工艺和工厂设计，自动化，化工工艺模拟和模型，等等。

1. A Brief Historical Outline

Historically, chemical engineering is inseparable from the chemicalprocess industries. In its early days chemical engineering which came intobeing with the advent of early chemical trades was a purely descriptivedivision of applied chemistry.

1． 简要的历史轮廓

从历史上来说，化学工程学与化学加工工业密不可分。在早期，化学工程学随着早期化学产品交易的发展而出现，是应用化学的纯描述性的分

支。

The manufacture of basic chemical products on Europe appears to have begun in the 15th century when small, specialized businesses were first set up to turn out acids, alkalis, salts, pharmaceutical preparations, and some organic compounds.

在欧洲，基础化学产品的制造出现在15世纪。一些小的、专门的企业开始创立，生产酸、碱、盐、药物中间体和一些有机化合物。

For all the rhetoric of nineteenth-century academic chemists in Britainurging the priority of the study of pure chemistry over applied, their studentswho became works chemists were little more than qualitative and quantitativeanalysts. Before the 1880s this was equally true of German chemical firms,who remained content to retain academic consultants who pursued researchwithin the university and who would occasionally provide the material formanufacturing innovation. By the 1880s, however, industrialists werebeginning to recognize that the scaling up of consultants’ laboratorypreparations, and syntheses was a distinctly different activity from laboratoryinvestigation. They began to refer to this scaling problem and its solution as“chemical engineering”—possibly because the mechanical engineers whohad already been introduced into works to who seemed best able tounderstand the process involved. The academic dichotomy of head and handdied slowly.

由于十九世纪英国的学院化学家强调纯化学的研究高于应用化学，他们的要成为工业化学家的学生也只是定性和定量分析者。在19世纪80年代以前，德国的化学公司也是这样。他们愿意聘请那些在大学里进行研究的人作顾问，这些人偶尔为制造的革新提供一些意见。然而到了80年代，工业家们开始认识到要把顾问们在实验室的准备和合成工作进行放大是一个与实验室研究截然不同的活动。他们开始把这个放大的问题以及解决的方法交给“化学工程师”—这可能是受到已经进入工厂的机械工程师的表现的启发。由于机械工程师熟悉所涉及的加工工艺，是维修日益复杂化的工业生产中的蒸气机和高压泵的最合适的人选。学院研究中头和手两分的现象逐渐消亡。

Unit operation. In Britain when in 1881 there was an attempt to namethe new Society of Chemical industry as the “Society of Chemicalengineers”, the suggestion was turned down. On the other hand, as a result ofgrowing pressure from the industrial sector the curricula of technical

institutions began to reflect, at last, the need for chemical engineers ratherthan competent analysts. No longer was mere description of existingindustrial processes to suffice. Instead the expectation was that the processesgeneric to various specific industries would be analyzed, thus making roomfor the introduction of thermodynamic perspectives, as well as those beingopened up buy the new physical chemistry of kinetics, solutions and phases.

单元操作。1881年英国曾经准备把化学工业的一个新的协会命名为“化学工程师协会”，这个建议遭到了拒绝。另一方面，由于受到来自工业界日益加重的压力，大学的课程开始体现出除了培养分析工作者还要培养化学工程师的要求。现在仅仅对现有工业过程进行描述已经不够了，需要对各种特殊工业进行工艺属性的分析。这就为引入热力学及动力学、溶液和相等物理化学新思想提供了空间。

A key figure in this transformation was the chemical consultant, GeorgeDavis (1850-1907), the first secretary of the Society of Chemical Industry. In1887 Davis, then a lecture at the Manchester Technical School, gave a seriesof lectures on chemical engineering, which he defined as the study of “theapplication of machinery and plant to the utilization of chemical action on thelarge scale”. The course, which revolved around the type of plant involved inlarge-scale industrial operations such as drying, crashing, distillation,fermentation, evaporation and crystallization, slowly became recognized as amodel for courses elsewhere, not only in Britain, but overseas. The first fullyfledged course in chemical engineering in Britain was not introduced until1909;though in America, Lewis Norton (1855-13) of MIT pioneered aDavis-type course as early as 1888.

在这个转变期，一位关键的人物是化学顾问George Davis，化学工业协会的首任秘书。1887年Davis那时是Manchester专科学校的一名讲师，做了一系列有关化学工程学的讲座。他把化学工程学定义为对“大规模化学生产中所应用的机器和工厂”的研究。这们课程包括了大规模工业化操作的工厂的各种类型，如干燥、破碎、蒸馏、发酵、蒸发和结晶。后来逐渐在别的地方而不仅仅在英国，而是国外，成为许多课程的雏形。英国直到1909年化学工程学才成为一门较为完善的课程，而在美国，MIT的Lewis Norton早在1888年就已率先开出了Davis型课程。

In 1915, Arthur D. Little, in a report on MIT’s programme, referred to itas the study of “unit operations” and this neatly encapsulated the distinctivefeature of chemical engineering in the twentieth century. The reasons for the

success of the Davis movement are clear: it avoided revealing the secrets ofspecific chemical processes protected by patents or by an owner’s reticence—factors that had always seriously inhibited manufacturers from supportingacademic programmes of training in the past. Davis overcame this difficultyby converting chemical industries “into separate phenomena which could bestudied independently” and, indeed, experimented with in pilot plants withina university or technical college workshop.

1915年，Arthur D. little 在一份MIT的计划书中，提出了“单元操作”这个概念，这几乎为二十世纪化学工程学的突出特点做了定性。Davis这一倡议的成功原因是很明显的：它避免了泄露特殊化学过程中受专利权或某个拥有者的保留权所保护的秘密。过去这种泄露已经严重了制造者对学院研究机构训练计划的支持。Davis把化学工业分解为“能进行研究的单个的工序”从而克服了这个困难。并且在大学或专科学校的工厂里用中试车间进行了试验。

In effect he applied the ethics of industrial consultancy by whichexperience was transmitted “from plant to plant and from process to processin such a way which did not compromise the private or specific knowledgewhich contributed to a given plant’s profitability”. The concept of unitoperations held that any chemical manufacturing process could be resolvedinto a coordinated series of operations such as pulverizing, drying, roasting,electrolyzing, and so on. Thus, for example, the academic study of thespecific aspects of turpentine manufacture could be replaced by the genericstudy of distillation, a process common to many other industries. Aquantitative form of the unit operations concept emerged around 1920s, justin time for the nation’s first gasoline crisis. The ability of chemical engineersto quantitatively characterize unit operations such as distillation allowed forthe rational design of the first modern oil refineries. The first boom ofemployment of chemical engineers in the oil industry was on.

他采用了工业顾问公司的理念，经验传递从一个车间到另一个车间，从一个过程到另一个过程。这种方式不包含限于某个给定工厂的利润的私人的或特殊的知识。单元操作的概念使每一个化学制造过程都能分解为一系列的操作步骤，如研末、干燥、烤干、电解等等。例如，学校对松节油制造的特殊性质的研究可以用蒸馏属性研究来代替。这是一个对许多其它工业制造也很普通的工艺过程。单元操作概念的定量形式大概出现在1920年，刚好是在第一次全球石油危机出现的时候。化学工程师能赋予单元操作定量特性的能力使得他们合理地设计了第一座现代

炼油厂。石油工业第一次大量聘请化学工程师的繁荣时始了。

During this period of intensive development of unit operations, otherclassical tools of chemical engineering analysis were introduced or wereextensively developed. These included studies of the material and energybalance of processes and fundamental thermodynamic studies ofmulticomponent systems.

在单元操作密集繁殖的时代，化学工程学另一些经典的分析手段也开始被引入或广泛发展。这包括过程中材料和能量平衡的研究以及多组分体系中基础热力学的研究。

Chemical engineers played a key role in helping the United States and itsallies win World War Ⅱ. They developed routes to synthetic rubber toreplace the sources of natural rubber that were lost to the Japanese early inthe war. They provided the uranium-235 needed to build the atomic bomb,scaling up the manufacturing process in one step from the laboratory to thelargest industrial plant that had ever been built. And they were instrumentalin perfecting the manufacture of penicillin, which saved the lives ofpotentially hundreds of thousands of wounded soldiers.

化学工程师在帮助美国及其盟国赢得第二次世界大战的胜利中起了关键的作用。他们发展了合成橡胶的方法以代替在战争初期因日本的封锁而失去来源的天然橡胶。他们提供了制造原子弹所需要的铀-235，把制造过程从实验室研究一步放大到当时最大规模的工业化工厂，而他们在完善penicillin的生产工艺中也是功不可没，它挽救了几十万受伤士兵的生命。

The Engineering Science Movement. Dissatisfied with empiricaldescriptions of process equipment performance, chemical engineers began toreexamine unit operations from a more fundamental point of view. Thephenomena that take place in unit operations were resolved into sets ofmolecular events. Quantitative mechanistic models for these events weredeveloped and used to analyze existing equipment. Mathematical models ofprocesses and reactors were developed and applied to capital-intensive U.S.industries such as commodity petrochemicals.

工程动。由于不满意对工艺设备运行的经验描述，化学工程师开始从更基础的角度再审视单元操作。发生在单元操作中的现象可以分解到分子运动水平。这些运动的定量机械模型被建立并用于分析已有的

仪器设备。过程和放应器的数学模型也被建立并被应用于资金密集型的美国工业如石油化学工业。

Parallel to the growth of the engineering science movement was theevolution of the core chemical engineering curriculum in its present form.Perhaps more than any other development, the core curriculum is responsiblefor the confidence with which chemical engineers integrate knowledge frommany disciplines in the solution of complex problems.

与工程学同时发展的是现在的化学工程课程设置的变化。也许与其它发展相比较，核心课程为化学工程师运用综合技能解决复杂问题更加提供了信心。

The core curriculum provides a background in some of the basicsciences, including mathematics, physics, and chemistry. This background isneeded to undertake a rigorous study of the topics central to chemicalengineering, including:

核心课程固定了一些基础科学为背景，包括数学，物理，和化学。这些背景对于从事以化学工程为中心的课题的艰苦研究是必须的，包括：

·Multicomponent thermodynamics and kinetics,·Transport phenomena,·Unit operations,

·Reaction engineering,

·Process design and control, and

·Plant design and systems engineering.·多组分体系热力学及动力学·传输现象·单元操作·反应工程

·过程设计和控制·工厂设计和系统工程

This training has enabled chemical engineers to become leadingcontributors to a number of interdisciplinary areas, including catalysis,colloid science and technology, combustion, electro-chemical engineering,and polymer science and technology.

这种训练使化学工程师们成为了在许多学科领域做出了突出贡献的人，包括在催化学、胶体科学和技术、燃烧、电化学工程、以及聚合物科学和技术方面。

2. Basic Trends In Chemical Engineering

Over the next few years, a confluence of intellectual advances,technologic challenges, and economic driving forces will shape a new modelof what chemical engineering is and what chemical engineering do.

2. 化学工程学的基本发展趋势

未来几年里，科学的进步，技术的竞争以及经济的驱动力将为化学工程是什么以及化学工程能做什么打造一个新的模型。

The focus of chemical engineering has always been industrial processesthat change the physical state or chemical composition of materials. Chemicalengineers engage in the synthesis, design, testing scale-up, operation, controland optimization of these processes. The traditional level of size andcomplexity at which they have worked on these problems might be termedthe mesoscale. Examples of this scale include reactors and equipment forsingle processes (unit operations) and combinations of unit operations inmanufacturing plants. Future research at the mesoscale will be increasinglysupplemented by dimensions—the microscale and the dimensions ofextremely complex systems—the macroscale.

化学工程学的焦点一直是改变物体的物理状态或化学性质的工业过程。化学工程师致力于这些过程的合成、设计、测试放大、操作、控制和优选。他们从事于解决的这些问题，传统的规模水平和复杂程度可称之为中等的，这种规模的例子包括有单个过程（单元操作）所使用的反应器和设备以及制造厂里单元操作的组合，未来的研究将在规模上逐渐进行补充。除了中等规模，还有微型的以及更为复杂的系统----巨型的规模。

Chemical engineers of the future will be integrating a wider range ofscales than any other branch of engineering. For example, some may work torelate the macroscale of the environment to the mesoscale of combustionsystems and the microscale of molecular reactions and transport. Other maywork to relate the macroscale performance of a composite aircraft to themesoscale chemical reactor in which the wing was formed, the design of thereactor perhaps having been influenced by studies of the microscale

dynamics of complex liquids.

未来的化学工程师将比任何其他分支的工程师在更为宽广的规模范围紧密协作。例如，有些人可能从事于了解大范围的环境与中等规模的燃烧系统以及微型的分子水平的反应和传递之间的关系。另一些人则从事了解合成的飞机的的性能与机翼所用化学反应器及反应器的设计和对此有影响的复杂流体动力学的研究工作。

Thus, future chemical and engineers will conceive and rigorously solveproblems on a continuum of scales ranging from microscale. They will bringnew tools and insights to research and practice from other disciplines:molecular biology, chemistry, solid-state physics, materials science, andelectrical engineering. And they will make increasing use of computers,artificial intelligence, and expert system in problem solving, in product andprocess design, and in manufacturing.

因此，未来的化学工程师们要准备好解决从微型的到巨型的规模范围内出现的问题。他们要用来自其它学科的新的工具和理念来研究和实践：分子生物学，化学，固体物理学，材料学和电子工程学。他们还将越来越多地使用计算机、人工智能以及专家系统来解决问题，进行产品和过程设计，生产制造。

Two important development will be part of this unfolding picture of thediscipline.

Chemical engineers will become more heavily involved in productdesign as a complement to process design. As the properties of a product inperformance become increasingly linked to the way in which it is processed,the traditional distinction between product and process design will becomeblurred. There will be a special design challenge in established and emergingindustries that produce proprietary, differentiated products tailored toexacting performance specifications. These products are characterized by theneed for rapid innovatory ad they are quickly superseded in the marketplaceby newer products.

在这个学科中还有两个重要的发展是我们前面没有提到的：化学工程师将越来越多地涉及到对过程设计进行补充的产品设计中。因为产品所表现出来的性能将逐渐与它被加工的途径挂钩。传统概念上产品设计与过程设计之间的区别将变得模糊，不再那么明显。在已有的和新兴的工业中将出现一个特殊的设计竞争，那就是生产有专利权的、有特点的产品以适应严格的性能指标。这些产品的特征是服从快速

革新的需要，因而他们将在市场上很快地被更新的产品所取代。

Chemical engineers will be frequent participants in multidisciplinaryresearch efforts. Chemical engineering has a long history of fruitfulinterdisciplinary research with the chemical sciences, particularly industry.The position of chemical engineering as the engineering discipline with thestrongest tie to the molecular sciences is an asset, since such sciences aschemistry, molecular biology, biomedicine, and solid-state physics areproviding the seeds for tomorrow’s technologies. Chemical engineering has abright future as the “interfacial discipline”, that will bridge science andengineering in the multidisciplinary environments where these newtechnologies will be brought into being.

化学工程师将经常性地介入到多学科领域的研究工程。化学工程师参与跨学科研究与化学科学、特种工业进行合作具有悠久的历史。随着工程学与分子科学最紧密地联系在一起，化学工程学的地位也越来越崇高。因为如化学、分子生物学、生物医学以及固体物理这样的科学都是为明天的科学技术提供种子，作为“界面科学”，化学工程学具有光明的未来，它将在多学科领域中搭建科学和工程学之间的桥梁，而在这里将出现新的工业技术。