化工专业英语练习题 参考答案

练习一参考答案

1将下列句子或段落翻译成英语

1)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)As a chemical engineer,you might be called on to design individual process units (such as reactors,

distillation columns,heat exchangers),supervise the operation of a process,or modify a process design to accommodate a change in the feed or in the desired product characteristics.As a rule,to any of these things you must know the amounts,compositions,and conditions of the materials that enter and leave each process unit,and if you are working with an existing units,you must be able to measure enough of these quantities to verify that the process is doing what it was designed to do.

3)Founded in 1839from 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.2将下列句子或段落翻译成汉语

1）包括的一系列操作，如混合、蒸发、过滤，无论产物是什么，这些操作都基本同，从而导致了单元操作的概念。

2）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。

3）缺乏经验的新手对涉及到的一些错综复杂的问题可能知之甚少，如混合不完全、径向温度梯度的

增加、传热面积对产热速比值的降低等。

4）

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。练习二参考答案1将下列句子或段落翻译成英语1)

New-product R&D is directed toward developing new products that may or may not fit within the company’s current markets.These are usually high-risk,high-return projects.Estimates vary,but usually the success rate of new-product RD is about 5%or less.The projects that do hit can big,however.2)Figure 7shows 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 D o c u C o m P D F T r i a l w w w .p d f w i z a r d .c o m

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将下列句子或段落翻译成汉语

1）略

3)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）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。

练习三参考答案

1将下列句子或段落翻译成英语

1）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 customers 2）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将下列句子或段落翻译成汉语1)

略2)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。D o c u

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1将下列句子或段落翻译成英语

1）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.

3)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.

2将下列句子或段落翻译成汉语

1）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。

2）略

练习五参考答案1将下列句子或段落翻译成英语

1)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 40000kg/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将下列句子或段落翻译成汉语

1)略

2）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。

3）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。D o c u C o m P D F T r i a l w w w .p d f w i z a r d .c o m

1将下列句子或段落翻译成英语

1)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)Carbon disulfide,a key component in the manufacture of rayon fibers,is produced in the reaction

between methane and sulfur vapor over a metal oxide catalyst.Methane and molten sulfur,each at 150,are ℃fed to a heat exchanger in stoichiometric proportion.Heat is exchanged between the reactor feed and product streams,and the sulfur in the feed is vaporized.The gaseous methane and sulfur leave the exchanger and pass through a second preheater in which they enter the reactor.Heat is transferred from at a rate of 41kg/mol of feed.The reaction products emerge from the reactor at 800℃,pass through the heat exchanger,and emerge at 200℃with sulfur as a liquid.

2将下列句子或段落翻译成汉语

1)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）化工设备分为两类：定制设备或定型设备。例如，定制设备（如精馏塔、容器、换热器）的尺寸

及性能是工艺工程师根据已有原理和数据确定的，当然有些机械方面的细节应符合安全操作规程及具体的制造规程。

练习七参考答案1将下列句子或段落翻译成英语1）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.1summarizes some of the chemical derivatives that can be produced from the two basic intermediate products.

2)Nitric acid is used extensively for the production of inorganic and organic nitrates,for metal

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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 NO 2in water.A side reaction that lowers the product yield is the oxidation of ammonia to nitrogen and water vapor.

2将下列句子或段落翻译成汉语

1）略

2）略

3）为了理解化学家和化学工程师在过程开发活动中做出的既可行又合乎需要的贡献，必须了解他们各自的知识基础、思考问题的方法及兴趣所在。简言之，化学家的贡献在于寻找化学物、催化剂和反应条件的组合，以达到生产所需产品的最优转化率，而工程师的贡献在于确定实用、经济、安全的设备构型，使这些条件得以实现。

练习八参考答案

1将下列句子或段落翻译成英语

1)All large chemical plants use a great deal of steam for heating,power generation,and process

applications.The cost of fuel required to generate this stream in a power-plant boiler can be extremely high,and in many cases can make the difference between profit and loss for the plant.A common way to reduce the fuel costs associated with steam production is to pass hot gas streams produced in the plant through waste heat boilers to produce steam.

2)An important parameter in the design of gas absorbers is the ratio of flow rate of the feed liquid to that of

the feed gas.The lower the value this ratio,the lower the cost of solvent required to a given quantities of

gas.2将下列句子或段落翻译成汉语

1）通过吸收将气体混合物中一个或多个组分脱除到合适的液体中去，是第二大基于扩散速率控制的

相际传质的化工操作。

2)化学需氧量（COD ）氧化水样品中还原物质所需重铬酸钾量的一种亮度，化学需氧量浓度

为ppm ，化学当量等于消耗的重铬酸盐总量。化学需氧量通常大于生物耗氧量，因为有些物质（如纤维素）在生物条件下可与重铬酸盐反应而不与氧反应。

2)本文旨在综述进行中试的各种目的，并阐明在各种场合应用化学工程专业知识的益处，表明（深

刻）理解中试结果的内涵而用于最终生产装置设计和将来的小试得益更多。D o c u C o m P D F T r i a l w w w .p d f w i z a r d .c o m