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The design of chemical reactors is probably the one activity which is unique to chemical engineering, and it is probably this function more than anything else which justifies the existence of chemical engineering as a distinct branch of engineering.
Physical treatment Steps
Produces

Recycle
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The raw materials undergo a number of physical treatment steps to put them in the form in which they can be reacted chemically. They then pass through the reactor.The products of the reaction must then undergo further physical treatment- separations, purifications, etc. - for the final desired product to be obtained. 原料进行了一些物理处理的步骤，使它们能够发 生化学反应。然后让他们通过反应器。产物要经 历进一步的物理处理——分离，净化提纯等等， 以获得期望的最终产品。
只有……才有的 化学反应器的设计也许是一种只有化学工程领域才涉及 的工作。并且可能正是因为这种功能才奠定了化学工程 作为工程领域的一个特殊分支而存在的合理性
English
Thermodynamics
热力学
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Thermodynamics gives two important pieces of information needed in design, the heat liberated or absorbed during reaction and the maximum possible extent of reaction. 热力学给出设计中需要的两条重要的信息，在反应中 会放出和吸收热量，而且最大值可能表示反应的程度。
物理处理步骤设备的设计在单元操作中研究。在这里我们关心的 是一个过程的化学处理步骤。
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Economically this may be in inconsequential unit, say a simple mixing tank .More often than not, however, the chemical treatment step is the heart of the process, the thing that makes or breaks the process economically. 从经济的角度说，这可能是个 不重要的单元，比如说一个简 单的搅拌槽。然而通常，化学 处理步骤是一个过程的核心， 它决定这个过程经济的成败。
“to produce”为动词不定式作目的状语 “a succession of”意为“一系列”
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Fig. 3.1shows a typical situation. 图 3.1展示了一个典型的情况。
Raw
materials
Physical treatment Steps
Chemical treatment Steps
化学关注的是这种 反应的研究。它研 究反应的模式和机 制，反应中涉及的 物质和能量的变化， 及产品形成的速 率。.
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It is the last-mentioned area of interest, chemical kinetics, which is of primary concern to us.Chemical kinetics searches for the factors that influence the rate of reaction.It measures this rate and proposes explanations for the values found.
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Chemical reactions are invariably accompanied by the liberation or absorption of heat, the magnitude of which must be known for proper design. Consider the reaction 化学反应总是伴随着热量的释放或吸收，为了合理的 设计，必须知道它的大小，考虑下面的反应： aA→rR+sS ,Δ Hr positive, endothermic ; negative , exothermic
适当的条件下， 供给的材料可 能转变为新的 不同的材料， 形成不同的化 学物质。
If this occurs only by rearrangement or redistribution of the constituent atoms to form new molecules, we say that a chemical reaction has occurred..
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The heat of reaction at temperature T is the heat transferred from surroundings to the reacting system when a moles of A disappear to form r moles of R and s moles of S, with the system measured at the same temperature and pressure before and after reaction. With heats of reaction known or estimable from thermochemical data, the magnitude of the heat effects during reaction can be calculated.
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Design of the reactor is no routine matter, and many alternatives can be proposed for a process . In searching for the optimum it is not just the cost of reactor that must be minimized. One design may have low reactor cost, but the materials leaving the unit may be such that their treatment requires much higher cost than alternative designs. Hence, the economics of the over-all process must be considered.
如果发生这种 情况只是由于 构成原子的重 排或再分配， 形成新的分子， 我们就说一个 化学反应已经 发生了。
Chemistry is concerned with the study of such reactions.It studies the mode and mechanism of reactions, the physical and energy changes involved and the rate of formation of produces.
热力学也可以从反应物的标准自由能来计算平衡常数。 由于平衡常数已知，可以估算出反应中可以得到的预期产品的最 大产量。
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English
化学动力学
Chemical Kinetics
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Under appropriate conditions feed materials may be transformed into new and different materials which constitute different chemical species
Process Equipment and Control Engineering
Unit 15
Chemical Reaction Engineering
化学反应
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Every industrial chemical process is designed to produce economically a desired product from a variety of starting materials through a succession of treatment steps. 每一个工业化工过程的设计都是从各种原材料出发， 经过一系列的生产加工步骤，来经济地生产出期望 的产品。
温度为T时， a mol的A消失生成了r mol的R和s mol的S，反应 的热量是环境传递给反应体系的，这是在反应前后相同的温度和 压力下对体系测量的结果。从热化学数据中可以得到或估算反应 的热量，反应中产生的热量大小可以计算。
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Thermodynamics also allows calculation of the equilibrium constant K from the standard free energies of the reacting materials. With the equilibrium constant known, the expected maximum attainable yield of the products of reaction can be estimated.