蒸餾設(shè)備外文翻譯

1、<p><b>　　附錄1</b></p><p>　　Distilling Equipment</p><p>　　Distillation is a separation process based on the relative volatility of the materials to be separated and on a change in

2、 phase of the original mixture. In the simplest example, a volatile component as a liquid residue. With slight exception, distillation differs from evaporation and drying in the means provided for saving the volatile co

3、mponent, in the degree of difficulty of separation, and in the complexity of the operation when more than one volatile component is to be separated, each from </p><p>　　The modern science of chemical enginee

4、ring treats distillation as a unit operation to which several principles and design methods can be applied, regardless of the materials to be handled or the industry involved. The trend in equipment is away from special

5、or peculiar designs for different industries and toward designs fitted to the needs of the process.</p><p>　　Distillation equipment is built in many typed, arrangements, and sizes to meet the conditions of t

6、he particular mixture to be handled and the products to be made. Selection of the type to be used is based on the physical properties of the material to be distilled, the degree of the separation to be effected, and the

7、 magnitude of the operation. The size of the component parts of the distillation system that is chosen is a matter of engineering design based on well-developed methods as given in h</p><p>　　Distillation ca

8、lculations for determining the degree of separation and the size of equipment are based on vapor-liquid equilibrium data , heat and material balances , allowable vapor velocities, disengaging rates. The calculations are

9、simplest for batch distillation of one volatile constituent from a nonvolatile residue. They become increasingly complicated as the number of constituents becomes greater whether a batch or a continuous process is used.

10、</p><p>　　Although it is assumed that the reader is not seeking detailed instruction in design of equipment , it is well that he be aware of the information required to make a complete over the range of temp

11、erature and pressure of the operation as follows:</p><p>　　1.Specific gravity of liquid.</p><p>　　2.Specific volume of vapors.</p><p>　　3.Solubility of each component in the other a

12、nd in water if open steam is used .</p><p>　　4.Specific heat of liquid and vapor.</p><p>　　5.Latent heat of liquid.</p><p>　　6.Viscosity of liquid and vapor.</p><p>　　7

13、.Surface tension (at least approximate values for estimating entrainment).</p><p>　　8.Thermal conductivity of liquid and vapor(for heat transfer calculations ).</p><p>　　9.Foaming characteristic

14、s.</p><p>　　10.Corrosion rate on probable materials of construction.</p><p>　　In comparison with tray towers, packed towers are suited to small diameters (24 in. or less), whenever low pressure

15、is desirable, whenever low holdup is necessary, and whenever plastic or ceramic construction is required. Applications unfavorable to packings are large diameter towers, especially those with low liquid and high vapor ra

16、tes, because of problems with liquid distribution, and whenever high turndown is required. In large towers, random packing may cost more than twice as sieve or valv</p><p>　　Depth of packing without intermed

17、iate supports is limited by its deformability; metal construction is limited to depths of 20~25ft, and plastic to 10~15ft. Intermediate supports and liquid redistributors are supplied for deeper beds and at sidestream wi

18、thdrawal or feed points. Liquid redistributors usually are needed every 2.5~3 tower diameters for Raschig rings and every 5~10 diameters for Pall rings, but at least every 20ft.</p><p>　　The various kinds of

19、 internals of packed towers are represented whose individual parts may be described one-by-one:</p><p>　　1.Is an example column showing the inlet and outlet connections and some of the kinds of internals in

20、place.</p><p>　　2.Is a combination packing support and redistributors that can also serve as a sump for withdrawal of the liquid from the tower.</p><p>　　3.Is a trough-type distributor that is s

21、uitable for liquid rates in excess of 2 gpm/sqft in towers feet and more in diameter. They can be made in ceramics or plastics.</p><p>　　4.Is an example of a perforated pipe distributor which is available in

22、 a variety of shapes, and is the most efficient critical, they are fitted with nozzles instead of perforations.</p><p>　　5.Is a redistribution device，the rosette, that provides adequate redistribution in sma

23、ll diameter towers; it diverts the wall towards which it tend to go.</p><p>　　6.Is a hold-down plate to keep low density packings in place and to prevent fragile packings such as those made of carbon, from d

24、isintegrating because of mechanical disturbances at the top of the bed.</p><p>　　The broad classes of packings for vapor-liquid contacting are either random or structured. The former are small, hollow struct

25、ures with large surface per unit volume that are loaded at random into the vessel. Structured packings may be layers of large rings or grids, but are most commonly made of expanded metal or woven wire screen that are sta

26、cked in layers or as spiral windings.</p><p>　　There are several kinds of packings. The first of the widely used random packings were Raschig rings which are hollow cylinders of ceramics, plastics, or metal.

27、 They were an economical replacement for the crushed rock often used then. Because of their simplicity and their early introduction, Raschig rings have been investigated thoroughly and many data of their early introducti

28、on, Raschig rings have been investigated thoroughly and many data of their performance have been obtained which are stil</p><p>　　Structured packings are employed particularly in vacuum service where pressur

29、e drops must be kept low. Because of their open structure and large specific surface, their mass transfer efficiency is high when proper distribution of liquid over the cross section can be maintained.</p><p&g

30、t;<b>　　附錄2</b></p><p><b>　　蒸餾設(shè)備</b></p><p>　　蒸餾分離過程是在基于原始混合物材料的相對(duì)揮發(fā)度的不同。舉一個(gè)簡(jiǎn)單的例子，一個(gè)揮發(fā)性成分的液體殘留物。略有例外，蒸餾不同于蒸發(fā)和干燥在提取揮發(fā)性成分所以運(yùn)用的手段，在較困難的分離過程，并且在復(fù)雜的操作時(shí)，不止一個(gè)揮發(fā)性成分從其他組分中分離時(shí)，一般說來，

31、蒸餾適用于液體混合物，但也有例外，典型的就是木材與煤的干餾，它是從固體中分離液體組分。、</p><p>　　現(xiàn)代科學(xué)的化學(xué)工程將蒸餾作為一個(gè)單位運(yùn)作的若干原則和設(shè)計(jì)方法是可取的，無論是材料的處理或相關(guān)行業(yè)的參與。設(shè)備的發(fā)展趨勢(shì)是遠(yuǎn)離特殊或獨(dú)特的設(shè)計(jì)，對(duì)不同的行業(yè)和對(duì)設(shè)計(jì)的都需要的加工方法。</p><p>　　為了滿足特定的條件加以處理混合物和得到所需產(chǎn)品，蒸餾設(shè)備是建立在許多類型，布局

32、，和大小。設(shè)備類型的選取是基于物料的物理性能，產(chǎn)品的分離效果和產(chǎn)品的產(chǎn)量。蒸餾設(shè)備各部件的選取的是各種手冊(cè)和教科書上面工程設(shè)計(jì)的基礎(chǔ)上發(fā)展完善的方法，僅僅豐富的制酚醛蒸餾設(shè)備的經(jīng)驗(yàn)。本章旨在指導(dǎo)選擇設(shè)備的型號(hào)和安排，但故意略去了詳細(xì)設(shè)計(jì)里面的冗長(zhǎng)的論文。</p><p>　　精餾計(jì)算確定分離的程度和設(shè)備類型是基于汽液平衡數(shù)據(jù)，熱量和物料平衡，允許汽速度，脫離率。簡(jiǎn)單的間歇精餾是從非揮發(fā)性物系分離出揮發(fā)性物系。它們

33、的復(fù)雜程度取決于物系增加了或連續(xù)精餾。</p><p>　　假設(shè)讀者不尋求設(shè)備詳細(xì)的說明，知道下列操作時(shí)溫度和壓力的波動(dòng)范圍是必須的：</p><p><b>　　1.液體比重</b></p><p><b>　　2.蒸汽比體積</b></p><p>　　3.在常壓下，一個(gè)成分在另一個(gè)重的溶解度，

34、以及在水中的溶解度</p><p>　　4.液體和氣體狀態(tài)下的比熱</p><p><b>　　5.液體的潛熱</b></p><p>　　6.液體和蒸汽的粘度</p><p>　　7.表面張力（至少近似估計(jì)值夾帶）</p><p>　　8.液體和蒸汽的導(dǎo)熱系數(shù)（傳熱計(jì)算）</p>

35、<p><b>　　9.泡點(diǎn)</b></p><p>　　10.建造材料可能腐蝕速率</p><p>　　相對(duì)于板式塔，填料塔適合小直徑（二點(diǎn)四英寸或以下），壓力低，小塔儲(chǔ)量, 塑料或陶瓷結(jié)構(gòu)。這些不適合大直徑塔，尤其是那些低液體和高氣體組成，由于液體分布問題，和需要較高調(diào)節(jié)。在大直徑情況下，任意填料塔的造價(jià)將是篩板塔或浮閥塔的兩倍。</p>

36、<p>　　深度填料塔有沒有中間支撐取決于自身的變形量，金屬結(jié)構(gòu)僅限于縱深為20 ?25英尺，塑料為10 ? 15英尺。中間支撐和液體再分布器為下面塔盤提供回流或再分布。每個(gè)填料塔都需要液體再分布器，至少每隔20英尺需要2.5~3個(gè)塔直徑大小的拉西環(huán)，5~10個(gè)塔直徑的鮑爾環(huán)。</p><p>　　現(xiàn)在介紹逐一下填料塔中個(gè)別部件的結(jié)構(gòu)：</p><p>　　1.與內(nèi)部連接的入口和

37、進(jìn)口部件</p><p>　　2.填料支撐板和再分布器可以作為集液盤收集塔內(nèi)液體</p><p>　　3.槽式液體分布器適合于液體流率超過2加侖/平方英尺直徑為2英尺或更大的塔內(nèi)，它的材料可以是陶瓷或塑料</p><p>　　4.穿孔管分布器有不同的形狀，最有效的是裝有噴嘴而不是穿孔</p><p>　　5.花環(huán)型在分布器適用于小直徑塔，&l

38、t;/p><p>　　6.擱置式鋼板保持低密度填料到位，以防止脆弱的填料，如碳制成的，因?yàn)閺谋澜鈾C(jī)械擾動(dòng)上方的塔盤</p><p>　　塔板上層填料是汽液接觸界面，它們可以使規(guī)整填料也可以是不規(guī)則的。中空結(jié)構(gòu)可以提供較大的接觸面積。但最常用的彎折延展的金屬或金屬編織的絲網(wǎng)，層層堆疊，或螺旋繞組。</p><p>　　這有幾種類型的填料。首先是廣泛使用的不規(guī)整空心圓柱陶瓷