化工传质与分离

化工传质与分离

一．短语

1.molal fracting 摩尔分数

2.Withdraw continuous 连续获得

3.Materal-balance 物料平衡

4.Volatile component 易挥发组分

5.Binary/ternary mixtures 双/三组分混合物

6.Equilibrium curve 平衡曲线

7.Residual liquid 残液

8.Overhead vapor 塔顶蒸汽

9.Interchange apparatus 交换器

10.Combination rectification and stripping 精馏与提馏相结合

11.Admit the feed to a plate in central part of column把物料引到中间的塔板上

12.Central portion of the column 塔中间部分

13.Reboiler 再沸器

14.Equipped with the necessary auxiliaries 必要的辅助设备

15.Draw a diagram of rectification and stripping 画出精馏与提馏的示意图

16.Flash distillation 闪蒸

17.Differential distillation 微分蒸馏

18.Reflux 回流

19.Rectification 精馏

20.Steady-state distillation 稳态蒸馏

21.Condensing the vapor 冷凝蒸汽

22.valve 阀

23.Mass-transfer equilibrium 平衡态传质

24.Stripping section 提馏部分

25.Level of liquid maintain 维持一定液位

26.Liquid flows by gravity to reboiler 液体由于重力流向再沸器

27.Reflux pump 回流泵

28.Accumulator 储罐

29.Azeotrope 共沸物

30.Heating coil 加热盘

31.Phase equilibria 相平衡

32.Enthalpy balance 焓平衡

33.Distributing space 分布空间

34.Eliminate 消除

35.By inspection of the two equations 观察两个方程

36.Plot the operating line 画出操作线

37.Internal streams with concentration is known 已知浓度的内部流体

38.The slope of the line 直线的斜率

39.The net flow rate 净流率

40.Reflux ratio 回流比

41.Constant molal overflow 恒摩尔溢流

42.Terminus of the operating line 操作线终点

43.The McCabe-Thiele step-by-step construction 法

44.Triangle 三角形

45.Partial vaporization 部分气化

46.Partial condensation 部分冷凝

47.Numbered serially 连续标号

48.Comparable volatility 挥发度相近的

49.Bubble point 泡点

50.Dew point 露点

逐板计算 McCabe-Thiele

51.Diagonal 对角线

52.Abscissa or X-coordinate 横坐标

53.Y-axis or Y-coordinate 纵坐标

54.Numerator and denominator 分子与分母

55.The intersection of the two equations 两个方程的交点

56.Coordinate of two points 两点的坐标

57.The intersection of two curve lines 两个曲线的交点

58.Packed/packing tower 填料塔

59.Single total condenser 单一总冷凝器

60.Dropping the subscripts 去掉下标

61.Flow down/up 向下/上流

62.Chemical operations 化工操作

63.Batch process 间歇过程

64.Continuous process 连续过程

65.A large scale 大规模

66.The condensated vapor 冷凝蒸汽

67.Principle of rectification 精馏的原理

68.Product cooler 产品冷却器

69.Overhead/bottom product 塔顶/底产品

70.In accordance with 与……一致

71.A material balance around the condenser 冷凝器附近的物料平衡

72.In a downward direction 方向向下

73.Ideal plate 理论板

74.Tie line 带状线

75.Flow quantities 流量

76.Latent heat 潜热

77.The absorbing liquid 吸收液

78.Inert gas 惰性气体

79.Inlet 入口

80.Outlet 出口

81.Interstices 孔隙

82.Countercurrent 逆流

83.Strong liquid 富液

84.dephlegmator 分流器

85.Stacked packing 填料

86.Stagnant film of liquid 液膜滞留

87.Channeling 沟流 沟槽效应

88.Nonideal mixtures 非理想混合物

89.isthermal surface 等温面

90.wetted fraction 部分湿润

91.intimate/good contact with 充分接触

92.distribute over 分布

93.flow in thin films 以薄膜形式流动94.packing surface 填料表面

95.flash distillation tin 闪蒸罐

96.petroleum refining 石油炼制

97.internal streams with concentration 98.Leaching 过滤

99.Filtration 筛选

100.located precisely 精确定位

101、 an additional theoretical stage 二、翻译

已知浓度的内部流体

额外的理论板

1、In practice, distillation may be carried out by either of two principal methods.The first method is based on the production of a vapor by boiling the liquid to return to be separated and condensing the vapors without allowing any liquid to return to the still in contact with the vapors.The second method is based on the return of part of the condensate to the still under such conditions that this returning liquid is brought into intimate contact with the vapors on their way to the condenser. Either of these methods may be conducted as a continuous process or as a batch process.实际上，蒸馏可以通过两种基本方法进行。第一种方法是通过加热待分离的液体混合物产生蒸汽，并在没有回流的情况下冷凝蒸汽，实现混合物的分离。第二种方法是在这种情况下将部分冷凝物回流，这部分回流液与在上升至冷凝器途中的蒸汽充分接触。

2、Consider a single plate in a column or cascade of ideal plates. Assume that the plates are numbered serially from the top down and that the plate under consideration is the nth plate from the top. Then the plate immediately above this plate i5 plate n-l, and that immediately below it is plate n+1. 考虑塔中只有单层塔板或多层理想塔板的蒸馏情况，假设这些塔板被从顶部往下连续的编号，所研究的板为第n块板，那么他上面紧挨的那块板为n-1，下方紧挨的为n+1。

3、By definition of an ideal plate, the vapor and liquid leaving plate n are in equilibrium, so xn and yn represent equilibrium concentrations.通过定义一块理想塔板上离开第n块板的气体和液体达到平衡的，所以xn 和yn代表平衡浓度

4、Since the liquid streams are at their bubble points and the vapor streams at their dew points, the heat necessary to vaporize component A must be supplied by

the heat released in the condensation of component B. 由于液体流在它们的泡点，而气体在它们的露点，组分A蒸发的能量必须来自组分B被冷凝时释放的能量

5、All plates above the feed plate constitute the rectifying section, and all plates below the feed, including the feed plate itself, constitute the stripping section. The feed flows down the stripping section to the bottom of the column, in which a definite level of liquid is maintained. Liquid flows by gravity to reboiler B. This is a steam-heated vaporizer which generates vapor and returns it to the bottom of the column. The vapor passes up the entire column. At one end of the reboiler is a weir. The bottom product is withdrawn from the pool of liquid on the downstream side of the weir, and flows through the cooler G. This cooler also preheats the feed by heat exchange with the hot bottoms.所有进料板以上的塔板组成精馏段，所有进料板以下的塔板（包括进料板本身在内）组成提馏段。进料液体流向塔底，在底部可以获得一定浓度的液体，液体在重力作用下流到再沸器，这是一个蒸汽加热的蒸馏器，他能够产生蒸汽并返回塔底部，部分蒸汽穿过塔板到达顶部。在再沸器的一端是一个堰，底部产品通过堰下降流动吗，然后经过冷却器G，这个冷却器通过与较热的底部产品热交换实现对进料预热。

6、The vapors rising through the rectifying section are completely condensed in condenser C, and the condensate is collected in accumulator D,in which a definite liquid level is maintained. Reflux pumb F takes liquid from the accumulator and delivers it to the top plate of the tower.This liquid stream is called reflux, it provides the downflowing liquid in the rectifying section that is needed to act on the upflowing vapor. Without the reflux no rectification would occur in the rectifying section and the concentration of the overhead product would be no

greater than that of the vapor rising from the feed plate.从精馏段蒸发的气体被完全冷凝在冷凝器C中，冷凝液被收集在储罐D中.回流泵F从储罐中抽出液体并送至塔的顶部板。这股流体成为回流，在精馏段它主要提供向下的液体，这种液体是上升气体需要的，没有回流，精馏段就不能进行精馏操作，且塔顶产品的浓度将不会比进料板上升的蒸汽高。

7、Condensate not picked up by the reflux pump is cooled in heat exchanger E, called the product cooler, and withdrawn as the overhead product.没有被回流泵取走的冷凝液在称之为产品冷却器的热交换E中被进一步冷却，然后作为塔顶产品出料。

8、Important factors in the design and operation of plate columns are the number of plates required to obtain the desired separation, the diameter of the column, the heat input to the reboiler and the heat output from the condenser, the spacing between the plates, the choice of type of plate, and the details of construction of the plates.板式塔的设计和操作过程中重要的因素是获得理想的分离效果所需要的塔板数，塔的直径，进入再沸器的热量和冷凝器中释放的热量，板间距大小，塔板类型的选择，以及塔板构造的详细资料。

9、In accordance with general principles, the analysis of the performance of plate columns is based on material balances, energy balances, and phase equilibria. 和一般性的原理一致，分析板式塔性能是基于（物质）质量平衡，能量平衡和相平衡进行计算的。

10、In gas absorption a soluble vapor is absorbed, by means of a

liquid in which the solute gas is more or less soluble, from its mixture with an

inert gas. The washing of ammonia from a mixture of ammonia and air by means of liquid water is a typical example. The solute is subsequently recovered from the liquid by distillation, and the absorbing liquid can be either discarded or reused. Sometimes a solute is removed from a liquid by bringing the liquid into contact with an inert gas，such an operation, the reverse of gas absorption, is desorption or gas stripping. 气体吸收是指一种可溶性的气体被吸收（的过程），在这种液体中溶质气体或多或少有些溶解。气体混合物中含有惰性气体。利用水从氨气与空气的混合物中将氨气洗涤出来就是一个典型的吸收的例子。溶质通常通过蒸馏的方法得到再生，而吸收的液体可以抛弃掉或重新利用，有时一种溶质是通过将液体与惰性气体接触得以回收的，这个操作为气体吸收的逆过程，称为脱附或气体的提馏。

11、The inlet liquid, which may be pure solvent or a dilute solution of solute in the solvent and which is called the weak liquor, is distributed over the top of the packing by the distributor and, in ideal operation, uniformly wets the surfaces of the packing. 进入的液体，它可以是纯的溶剂或者是溶液，它被称为“稀释液”，稀释液通过分布器被分布在填料表面被均匀的淋湿。

13、Stacked packings, with open channels running uninterruptedly

through the packed bed, give lower pressure drops than dumped packings, in which the gas must frequently change in velocity and direction. This advantage is offset, how-ever, by the poorer contact between the fluids in stacked packings.有规律填装的填料（人工装填的填料）具备开放式通道，流体通过填料床时能够顺利通过，与随意填装的填料相比，压力降较小，在这种填料中必须，运动的气体必须经常地改变速率和方向。然而在填料接触不充分的流体，这种优势就会被抵消掉

14、The requirement of good contact between liquid and gas is the hardest to meet, especially in large towers.液体和气体的充分接触的要求是最难达到的，尤其在大的塔中

15、Actually the films tend to grow thicker in some places and thinner in others, so that the liquid collects into small rivulets and flows along localized paths through the packing. Especially at low liquid rates much of the packing surface may be dry or, at best, covered by a stagnant film of liquid. This effect is known as

channeling; it is the chief reason for the poor performance of large packed towers.

实际上，这一层膜有某些区域会变厚，在某些区域又会变薄，以至于液体汇集成小溪流而遍及填料存在的路径上。尤其是在较低的液体流速下，填料表面的大部分是干的，或者是表面停滞了一层液体的膜。这种作用称为沟槽效应，它也是大的填料塔的性能较差的主要原因。

16、The pressure drop therefore increases with the l.8th power of the velocity, which is consistent with the usual law of friction loss in turbulent flow. At low and moderate velocities, the pressure drop is proportional to the l.8th power of the flow rate but is greater than that in dry packing at the same gas velocity.压力降是随速度的1.8次幂增加的。这与在湍流中的摩擦损失定律相一致。在中低速条件下，压力降与流速的1.8次幂成正比。但比相同气速下通过干填料的压力降大。

17、At point e, the flooding point, the top of the packing is covered with a layer of liquid through which bubbles of gas issue. The liquid can no longer flow down through the packing, and the layer grows until liquid is blown out of the top of the tower with the gas.在泛点e，塔顶的填料被液层覆盖，气泡从中流出，液体层不再经由

填料向下流动，而且，液层会不断增厚直到液体被上升气体吹离塔顶。

18、The device consists of a cylindrical column, or tower, equipped with a gas inlet and distributing space at the bottom; a liquid inlet and distributor at the top; liquid and gas outlets at the bottom and top, respectively; and a supported mass of inert solid shapes, called tower packing or tower filling.

这个设备由一个圆柱形的塔组成，在底部配有气体进口和气体分布空间。顶部没有液体进口，液体分布器，液体和气体的出口和进口分别设在底部和顶部。塔内支撑着固体形状的物质，我们称它为塔的填料或塔内填充物。

19、Without the reflux no rectification would occur in the rectifying section and the concentration of the overhead product would be no greater than that of the vapor rising from the feed plate.没有回流，精馏段就不能够进行精馏操作，且塔顶产品的浓度不会比进料板上的上升蒸汽的浓度高。

20、The condenser is often placed above the top of the column and the reflux pump and accumulator omitted Reflux then returns to the top plate by gravity. A special valve, called a reflux splitter, may be used to control the rate of reflux return. The remainder of the condensate forms the overhead product.

冷凝器经常被放置在塔的顶部，而回流泵和储罐省略，这样回流的液体在重力作用下回流带到塔顶部的塔板上，一种特殊的阀门叫做回流阀，用来控制回流速率

，剩下的冷凝液形成了塔底产品

21、This limitation is removed by admitting the feed to a plate in the central portion of the column. Then the liquid feed flows down the column to the still, which in this type of plant is called the reboiler, and is subjected to rectification by the vapor rising from the reboiler. Since the liquid reaching the reboiler is stripped of component A, the bottom product can be nearly pure B.如果让液体塔中间部分进料，则这种限制可以被避免，液体进料流向塔底部，这种类型的设备叫做再沸器。通过再沸器蒸发出来的蒸汽经行精馏，这样液体到达再沸器提溜A组分，塔底产品几乎接近纯组分B。

三、简答

1、精馏过程

A mixture composed of the components with different volatility conduct repeatedly partial evaporation and condensation in a rectification column at the same time for separating it into nearly pure productions.将挥发度不同的组分多组成

的混合物在精馏塔中同时多次进行部分气化和部分冷凝，使其分离成几乎纯态组分的过程。

2、进料要求

The principal requirements of a tower packing are:

1 It must be chemically inert to the fluids in the tower.它对于塔中的液体必须是惰性的

2 It must be strong without excessive weight.必须在没有多大重量的情况下强度很大

3 It must contain adequate passages for both streams without excessive liquid holdup or pressure drop.在保证没有太多的液体滞留或压力降不大的情况下，必须具有足够的通道

4 it must provide good contact between liquid and gas.必须能够让气体和液体充分接触

5 It must be reasonable in cost.合理的价格