20100909 化工专业英语练习题 题目 1-8.doc

1) 过程指引起一种物质和(多种)物质的混合物发生物理变化或化学变化的操作或一系列操作。进入过程的 物料称之为对该过程的输入或进料，而离开的物料称之为输出或产品。A process is any operation or series of operations that causes a physical or chemical change in a substance or a mixture of substances . The material that enters a process is referred to as input or feed the process, and that which leaves is called output or product.2) B.Braun 成立于 1839 年，从一个生产医药产品的小生产厂家不断发展，以成为一个跨国公司，现经营医药产品、医疗技术、药物及生物技术Founded in 1839 from a small production firm for pharmaceutical products, B. Braun has grown steadily into a multinational company dealing with medical products, medical technology, pharmaceutical and biotechnology.1） In the same way that a complex plant can be divided into basic unit operations, so chemical reactions involved in the process industries can be classified into certain groups, or unit processes (e.g., polymerizations, etherifications, and nitrations), have common characteristics.复杂的工厂可划分为基本的操作单元一样，过程工业中涉及的化学反应也可划分为一定的单元过程（如聚合、酯化、和硝化），它们具有共同的特性。2） The notion of a processing plant encompassing a number of operations, such as mixing, evaporation, and filtration, and of these operations being essentially similar, whatever the product, led to the concept of unit operations.包括的一系列操作，如混合、蒸发、过滤，无论产物是什么，这些操作都基本相同，从而导致了单元操作的概念。3）The chemical engineer must work closely with the chemist in order to understand thoroughly the chemistry involved in the process and to make sure that the chemist gets the reaction kinetic data and the physical property data needed to design, operate, and optimize the process 化学工程师必须与化学家紧密合作，以完全了解过程中涉及的化学知识，并要弄清化学家是否得到了过程设计、操作及优化所需的化学动力学数据及物性数据。4） All fluids are compressible - even water - their density will change as pressure changes. Under steady conditions, and provided that the changes in pressure are small, it is usually possible to simplify analysis of the flow by assuming it is incompressible and has constant density.所有的液体是可压缩的甚至水他们的密度变化是压力的变化。稳定的条件下的变化,并给出在压力很小,通常可以简化假设流量分析是不可压缩的和有一定的密度。5） In a region such as outer space, which is virtually void of gases, the pressure is essentially zero. Such a condition can be approached very nearly in a laboratory when a vacuum pump is used to evacuate a bottle. The pressure in a vacuum is called absolute zero, and all pressures referenced with respect to this zero pressure are termed absolute pressures. 在某一区域内如太空,这几乎是无用的气体,压力本质上是零。这样的条件下,能够到达几乎在实验室里当真空泵是用来撤离一个瓶子里。在真空压力称为绝对零,所有的压力参考关于这个零压称为绝对压力。Many pressure-measuring devices like the manometer measure not absolute pressure but only difference in pressure. The reference pressure is actually the atmospheric pressure. Whenever atmospheric pressure is used as a reference, the possibility exists that the pressure thus measured can be either positive or negative. When this difference is positive, this type of pressure reading is called gage pressure.许多压力的测量设备,如压力,但是不是绝对压力唯一的不同。参考压力实际上是大气压力。每当气压作为参考,有可能存在着压力从而测量可以积极还是消极的。当这种差异是积极的,这类型的压力阅读被称为规的压力。1) 图 7 所示的一个基本实例，是石油化工某部分的一个完整设计（主要是单元操作，换热网络和控制回路）。系统包括反应和分离部分。反应属于催化反应，由于催化剂的失活（deactivation），其转化率在几个月的操作周期内是变化的。当催化剂活性较低时，反应转化率下降，相应地精馏塔的进料发生变化。精馏塔有自己的控制系统（未画出），以保证塔底产物(bottom product)组成保持稳定。塔顶组分（循环）组成是可变的，以抵消（to accommodate）催化剂失活的影响。Figure 7 shows the base case, a complete design (main unit operations, heat exchanger network, and control loops) for part of a petrochemicals process. The system involves reaction and separation. The reaction is catalytic and conversion is variable over periods of several months due to catalyst deactivation. During times od low catalyst activity, conversion falls off and consequently the composition of the distillation feed stream changes. The distillation column has its own control system (not shown), which is used to ensure that the composition of the bottom product is kept constant. The top product composition (recycle) is variable to accommodate the effect of catalyst deactivation.2) 化学工程是处理那些原材料变化或分离成有用产品的工业过程。化学工程师必须能对全流程以及所用的设备进行开发、设计和操作；选择合适的原料；高效、安全、经济地操作工厂，同时确保生产的产品能满足顾客的要求Chemical engineer has to deal with industrial processes in which raw materials are changed or separated into useful products. Chemical engineers must develop, design, and engineer both the complete process and the equipment used; choose the proper raw materials, operate the plants efficiently, safely, and economically; and see to it that products meet the requirements set by customers1) The above examples teach us an important lesson, although it is the chemists who make and discover the new chemicals which may have special properties, a considerable input from engineers and technologists may be required before the chemical can be processed and converted into a suitable form in which it can be used.上述这些实例给我们一个主要的启示：虽然化学家制备并开发了具有特性性质的新的化学物质，但是要将这些化学物质加工并转化为可实用的合适形态， 还需要工程师和技术人员投入大量的工作。2) “Unit operations” evolved in meeting the need of economic large-scale manufacture of commodity products. The concept of unit operations held that any chemical manufacturing process could be resolved into a coordinated series of operations such as pulverizing, drying, roasting, crystallizing, filtering, evaporating, distilling, electrolyzing, and so on.单元操作已发展成为满足商品大规模生产的需要，其概念认为：任何化学生产过程可分解为一系列同等的操作，如粉碎、干燥、焙烧、结晶、过滤、蒸发、蒸馏、电解等。3) The term “chemical engineer” implies that the person is primarily an engineer whose first professional concern is with manufacturing processes making something, or making some process work. The adjective “chemical”implies a particular interest in processes which involve chemical changes.术语“化学工程师”意味着人主要是一个工程师的第一个专业的关心的是制造过程做活儿,或做一些过程的工作。这个形容词“化学”意味着一个特定的兴趣涉及的化学变化过程。1） 除对恒定平均值(mean values)可能的微小涨落外，如果一个过程的所有变量(variables)（即：所有温度、压力、体积、流速等）的值都不随时间变化，该过程可认为是处于稳定操作。如有任何过程变量随时间变化，则可称为处于过度态或非稳态。将其本质而言，间歇过程和半间歇过程是非稳定态，而连续过程是稳态或过度态。If the values of all the variables in a process (e.g. all temperatures, pressures, volumes, flow rates, etc.) do not change with time, except possibly for minor fluctuations about constant mean values, the process is said to be operating at steady state. If any of the process variables change with time, transient or unsteady-state operation is said to exist. By their nature, batch and semi batch process are unsteady-state operations, whereas continuous processes may be either steady state or transient 2）合成有机化合物可定义为从天然存在的原料（如石油、天然气、煤）中衍生出的产品，这些原料至少要经过一种化学反应过程（如氧化反应、加氢反应、卤化反应 halogenations、磺化反应 sulfonation,或烷基化反应）。Synthetic organic chemicals can be defined as derivative products of naturally occurring materials (petroleum, natural gas and coal), which have undergone at least one chemical reaction, such as oxidation, hydrogenation, halogenation, sulfonation, or alkylation.1） A pilot plant is a collection of equipment designed and constructed to investigate some critical aspects of a process operation or perform basic research. It is a tool rather than an in itself. A pilot plant can range in size from a laboratory bench-top unit to a facility only marginally smaller than a commercial unit. The purposes for its construction and operation can vary widely: confirming feasibility of a proposed process; providing design data; determining the economic feasibility of a new process; determining optimum materials of construction; testing operability of a control scheme; determining the extent of plant maintenance; producing sufficient qualities of product for market evaluation; obtaining kinetic data; screening catalysts; providing areas of advanced technology; providing data for solutions to scale-up problems; providing technical support to an existing process or product assessing process hazards; determining operating costs; optimizing an existing process; and performing basic process research.中试工厂是用于研究过程操作中某些关键问题或进行基础研究的一整套设备。它是研究手段而不是研究目的。中式工厂的规模，可从实验室小型实验设备直 至比工业装置的外形略小一点的装置。建立并进行中试操作的目的很多：检验所设想过程的可行性；提供设计数据；确定新过程在经济上的可行性；确定最佳的施工材料；检验控制系统的可操作性；确定工厂的维护范围；生产足够量的产品以供市场评价；获取动力学数据；为先进技术提供试验基地；提供解决放大问题的数据；为以有过程或产品提供技术支持；评定过程的危险程度；确定操作费用；优化现有工艺；进行基础过程研究。2) A batch reactor is used for small-scale operation, for testing new processes that have not been fully developed, for the manufacture of expensive products, and for processes that are difficult to convert to continuous operations. The reactor can be charged through the holes at the top. The batch reactor has the advantage of high conversions that can be obtained by leaving the reactant in the reactor for long periods of time, but it also has the disadvantages of high labor costs per batch and the difficulty of large-scale production.间歇反应器用于小于小规模生产，用于试验尚未完全开发成功的新过程，还用于生产昂贵的产品，以及那些难于实现连续化操作的过程。间歇反应器可以从顶部加料。延长反应物在反应器的停留时间可以获得较高的转化率，这是间歇反应器的优点，而其缺点在于每个周期的劳动成本高及难以进行大规模生产。1） 异庚烷由丁烯和异丁烷在浓硫酸的乳化液(emulsion)中反应生产。过程的新鲜进料以 40,000kg/h 的速率加入。其中含25.00mole%的异丁烷、25.00mole%丁烯和 50.00mole%的正丁烷，后者在过程中是化学惰性的。部分反应器的出料（effluent）循环至反应器的进口。其余部分流入分层槽（settler）在槽中水相（硫酸）和烃相得以分离。酸循环至反应器，烃则进入精馏塔。塔顶馏出物含正丁烷和异庚烷，而塔底产物全为异丁烷循环至反应器。Isooctane is produced by the reaction of butylenes and isobutene in an emulsion the concentrated sulfuric acid. The fresh feed to the process flows at a rate of 40000 kg/h, and contains 25mole% isobutene, 25% butylenes, and 50% n-butane, which is chemically inert in this process. A portion of the reactor effluent is recycled to the reactor the inlet, and the remainder passes to a settler, in which the aqueous (sulfuric acid) and hydrocarbon phases are allowed to separate. The acid is recycled to the reactor, and the hydrocarbons pass to a distillation column. The overhead from the column contains isooctane and n-butane, and the bottoms product, which is recycled to reactor, contains only isobutene.2) 流化床催化裂化装置（cracker）的典型简图见图 15。装置的特征是有两个巨大的容器（vessel），一个用于使进料在热催化剂上进行反应，另一个用空气烧去碳以使用过的（spent）催化剂再生。新型（newer）分子筛催化剂的活性如此之高，使得物料和催化剂之间的接触时间必须急剧减少，否则石油就会过度裂解(overcrack)而得到不希望得到的气体和焦碳。A typical diagram of a fluid catalytic cracker is shown in Fig. 15. The unit is characterized by two huge vessels, one to read the feed with hot catalyst and the other to regenerate the spent catalyst by burning off carbon with air. The activity of newer molecular-sieve catalysts is to great that the contact time between feed and catalyst is reduced drastically. If not, the oil will overcrack to give unwanted gases and coke.1) While technical advances and efficiency improvements in specific unit operations are occurring the time, the big story is the hybridization of processes. Combining individual unit operations, such as reaction, and heat exchange, into larger, concurrent operations will be major trend om upcoming years. Technologies such as reactive distillation, catalytic membranes, and phase-transfer catalysts all represent examples of hybridized processes where reaction and separation are combined.当技术进步和提升效率发生在特定单元操作,大的故事是有关杂交过程。结合个人单元操作,如反应,与换热,成规模更大、并行操作将主要趋势即将到来的市的年。技术,如反应蒸馏、催化膜、相转移催化剂的例子都表现化过程中,反应和分离的总和。2) The formulation of the thermodynamic equilibrium problem and the methodologies used for its solution are presented in this chapter. The resulting equations need a number of pure component and mixture equilibrium properties, which, whenever not experimentally available at the conditions of interest, must be estimated.本章给出了对热力学平衡问题的描述及其解决方法。所导出的方程需要大量纯组分的平衡性质及混合物的平衡性质，如果在要求的条件下，以实验方式得不到这些平衡数据，就必须估算这些数据。Most of the problems in chemical engineering, however, are multivariable and nonlinear, with constraints, and often require the use of discrete valued variables. Also, while optimization is a conceptually powerful framework, its impact has been somewhat limited in practice due to the lack of tools that facilitate the formulation and solution of these problems. 然而，化学工程中大多数问题都是多变量、非线性、有约束条件的问题还常常需要利用离散变量。此外，虽然优化概念上很有效的构想，但由于缺乏描述问题和求解问题的简便工具，使得优化的效果在实用上有一定的局限性。1)因为产物氨的分子的体积比反应物的体积小，所以提高压力会提高氨的平衡转化率。提高温度对平衡产生相反的效应，但会明显（greatly）提高反应速率。温度对平衡的负效应又兼具对反应速率很强的正效应，对其他许多反应也是常见的，为此，需要对各种条件精致地权衡以确保得到令人满意（good）的操作条件，获得可能的利润。较快的反应速率意味着减小设备尺寸，因而相应地降低设备成本。Because the product molecule, ammonia, has a lower volume than the reactant molecules, the equilibrium yield of ammonia is increased by increasing pressure. Temperature increase produces the opposite effect on the equilibrium, but increases the rate of reaction greatly. This negative temperature effect on equilibrium combined with a strong positive effect on rate is common to many other reactions and requires a nice balance of assure good operating conditions and to make profits possible. Greater rate means reduced equipment and consequent equipment cost.2)硝酸广泛用于生产无机硝酸盐和有机硝酸酯、用于各种金属处理，以及用于光刻（photoengraving）。硝酸生产是铂-铑（platinum-rhodium）催化剂上将氨氧化成一氧化氮（nitric oxide），一氧化氮氧化成二氧化氮，然后将二氧化氮溶解于水。降低产品速率的副反应是氨氧化成氮气和水蒸气。Nitric acid is used extensively for the production of inorganic and organic nitrates, for metal treatment of various kinds, and for photoengraving. It is produced by oxidizing ammonia to nitric oxide over a platinum-rhodium catalyst, oxidizing the nitric oxide to nitrogen dioxide, and dissolving the NO2 in water. A side reaction that lowers the product yield is the oxidation of ammonia to nitrogen and water vapor.3）许多石油化工产品从木材制得，首先将木材转化为合成气，合成气然后转化为甲醇或者氨，通过进一步的加工就能够获得所需的产品。图 1 归纳了一些能够以甲醇和氨这两种基本中间体生产的化工产品衍生物。A wide variety of petrochemicals can be produced from wood by first converting the wood to synthesis gas, which can then be converted to either methanol or ammonia and further processed to produce the desired chemical products. Fig.1 summarizes some of the chemical derivatives that can be produced from the two basic intermediate products.1) Much equipment for the separation of liquids and finely divided solids was invented independently in a number of industries and is of diverse character. These developments have occurred without benefit of any but the most general theoretical considerations. Even at present, the selection of equipment for specific solid-liquid separation applications is largely a process of scale-up based on direct experimentation with the process material.在许多工业部门独立开发出许多用于分离液体和细微固体颗粒的设备，它们各具特性。这些开发只是依据一些最基本的理论。即使在目前，为特定固-液分离过程的设备选型主要还是一个以工艺物料直接实验结果为基础的放大过程。2）The unit operations are largely used to conduct the primarily physical steps of preparing of reactants, separating and purifying the products, recycling unconverted reactants, and controlling the energy transfer into or out of the chemical reactor. We also can say that, the unit operations deal mainly with the transfer and change of energy and the transfer and change of materials primarily by physical means but also by physical-chemical means.设备操作在很大程度上是用来进行主要物理步反应物料配比、准备分组分离纯化回收得救产品反应物料配比、和控制能量传递进、出化学反应器。我们也能说,设备操作应对主要是由于转会和改变的能量和转移和改变的材料主要由物理方法还理化手段。1Unlike many products whose structure and reactions were well known before their industrial application, some polymers were produced on an industrial scale long before their chemistry or physics were studied.和许多的产品结构和反应是非常熟悉的在他们的工业应用,一些聚合物工业生产规模生产化学或物理他们之前的很长一段时间进行了研究。2Configurational isomerism is then due to the presence in the molecule of one or more dissymmetric centers, in the simplest case asymmetric carbon atoms each of which can have (R) and (S) absolute configuration; and, or, to the presence of double bonds which can give cis- and trans-geometrical isomers.然后构型正异构由于存在一个或多个分子不对称中心,在最简单的情况下不对称碳原子其中的每一个都可以有(R)和(S)绝对的配置;或者双联系的存在能给顺和转化几何异构体。3The homologes of benzene are those containing an alky group or alkyl groups in place of one or mote hydrogen atoms.那些含有烷基团体或烷基官能团的同分异构体的苯必须代替一个尘粒氢原子构成。4 Objectionable hydrogen sulfide is removed from such a gas or from naturally occurring hydrocarbon gases by washing with various alkaline solutions in which it is absorbed.讨厌的硫化氢将这些气体或自然发生的碳氢化合物气体从用各种碱液中,这是吸收。5Gas absorption is an operation in which a gas mixture is contacted with a liquid for the purposes of preferentially dissolving one or more components of the gas and to provide and to give a solution of these in the liquid.气体吸收的一种操作联系的混合气体与液体溶解优先为目的的一个或多个组件提供的气体,把解决这些处在液体里。6.The continuous process although requiring more carefully designed equipment than the batch process, can ordinarily be handled in less space, fits in with other continuous steps more smoothly, and can be conducted at any prevailing pressure.连续过程虽然需要更多精心设计的设备比批量生产、通常能处理较少的空间,适用于其它连续舞步顺利,可进行任何流行的压力。7Normally, in evaporation the thick liquid is the valuable product and the vapor is condensed and discarded. Mineral-bearing water is often evaporated to give a solid-free product for boiler feed, for special process requirements, or for human consumption. This technique is often called water distillation, but technically it is evaporation. In one specific situation, however, the reverse is true.一般来说,在蒸发浆是有价值的产品和蒸汽被压缩并且丢弃。含矿物质的水是经常蒸发给无固相产品对于锅炉,为特别的工艺的要求,或给人食用。这一技术是经常被称为“水蒸馏,但技术上讲是蒸发。在某一情况下,然而,刚好相反。1） 将甲烷转化成石油化工产品的最重要的工艺路线是借助于氢气，或借助于氢气和一氧化碳的混合气，后者称之为“合成气”(synthesis gas)。以煤来生产氢气和一氧化碳混合物最初实现工业化（to establish industrially）是通过著名的水煤气反应（water-gas reaction）。Will the methane into petrochemical products is the most important process route by hydrogen, or by hydrogen and carbon monoxide richer mixture, the latter called syngas. With coal to produce hydrogen and carbon monoxide mixture first realization industrialization is through the famous serni-water gas reactions.1） When two objects at different temperatures are brought into thermal contact, heat flows from the object at the high temperature to that at the lower temperature. The net flow is always in the direction of the temperature decrease. The mechanisms by which the heat may flow are three: conduction, convention, and radiation.当两个物体在不同的温度被带至接触热,热源自于物体的高温温度较低的物体。网络流的方向一直在温度降低。所采用的机制流热可以有三个:办理、会议展览、和辐射等。2） To understand the contributions which are feasible and desirable from the two understanding of the individual knowledge bases, perspectives and interests. Put simple, the contribution of the chemist is to identify the various combinations of chemicals, catalysts and conditions which will lead to optimal conversions to the desired product or products, the engineers contribution is to identify practical, economic and safe equipment conf