外文翻譯--攪拌設備

- 1 - 附錄 1 攪拌設備在工業(yè)生產(chǎn)中應用范圍很廣，尤其是化學工業(yè)中，很多的生產(chǎn)都或多或少地應用著攪拌操作?；瘜W工藝過程的種種化學變化，是以參加反應物質的充分混合為前提的。對于加熱、冷卻和液體萃取以氣體吸收等物理變化過程，也往往要采用攪拌操作才能得到很好的效果。攪拌設備在許多場合是作為反應器來應用的。例如在三大合成材料的生產(chǎn)中，攪拌設備作為反應器約占反應器總數(shù)的 90%。其他如染料、醫(yī)藥、農(nóng)藥、油漆等行業(yè)，攪拌設備的使用亦很廣泛。有色冶金部門對全國有色冶金行業(yè)中的攪拌設備做了調查及功率測定，結果是許多濕法車間的動力消耗 50%以上是用在攪拌作業(yè)上。攪拌設備的應用范圍之所以這樣廣泛，還因攪拌設備操作條件（如溫度、濃度、停留時間等）的可控范圍較廣。能適應多樣化的生產(chǎn)。 攪拌設備的作用如下： 1）使物料混合均勻； 2）使氣體在液相中很好地分散； 3）使固體粒子（如催化劑）在液相中均勻地懸??； 4）使不相溶的另一液相均勻懸浮后充分乳化； 5）強化相同的傳質（如吸收等）； 6）強化傳熱。對于均相反應，主要是 1）、 6）兩點。混合的快慢、均勻程度和傳熱情況好壞，都會影響反應結果。至于非均相系統(tǒng)，則還影響到相界面的大小和相間的傳質速度，情況就更復雜。 所以攪拌情況的改變，常常很敏感地影響到產(chǎn)品的質量和產(chǎn)量，生產(chǎn)中的這種例子非常普遍。在溶液聚合和本體聚合的液相反應裝置中，攪拌的主要作用是：促進釜內物料流動。使反應器內物料均勻分布，增大傳質和傳熱系數(shù)。在聚合反應過程中，往往隨著轉化率的增加，聚合液的黏度也增加。如果攪拌情況不好，就會造成傳熱系數(shù)下降或局部過熱，物料和催化劑分散不均勻，影響聚合產(chǎn)品的質量，也容易導致聚合物粘壁，使聚合反應操作不能很好地進行下去。 在互不相溶的液體之間或液體與固體之間相互作用時，攪拌在加速反應的進行方面起著非常重要的作用。因為增加 一物相混入另一物相的速度，接觸面就會增大，物質就以較大速度相互作用。在某些情況下，攪拌是在反應過程中創(chuàng)造良好條件的一個重要因素。例如，使傳熱作用加強，減少局部過熱，以及加熱過程中物質焦化等。如高壓聚乙烯生產(chǎn)中，由于攪拌的作用，使物質在反應器內有一定的停留時間，更重要的是使催化劑 - 2 - 在器內分布均勻，以防止局部猛烈的聚合作用而造成爆炸。因此攪拌設備在工業(yè)生產(chǎn)中起著非常重要的作用。 攪拌設備在石油化工生產(chǎn)中被用于物料混合、溶解、傳熱、制備懸浮物、聚合反應、制備催化劑等。例如石油工業(yè)中，異種原油的混合調整和精制，汽油中 添加四乙基鉛添加物而進行混合使原料液或產(chǎn)品均勻化。化工生產(chǎn)中，制造苯乙烯，苯胺染料和油漆顏料等工藝過程，都裝備著各種型式的攪拌設備。 在石油工業(yè)中因為大量應用催化劑、添加劑，所以對攪拌設備的需要量很大。由于物料操作條件的復雜性、多樣性，對攪拌設備的要求也復雜化了。如化工行業(yè)用到的硅鋁反應器、打漿罐、鋇化反應器、硫磷反應釜、烴化反應釜、白泥攪拌槽等都是裝有各種不同型式攪拌器的攪拌設備。在造紙行業(yè)中，攪拌設備應用及其廣泛，在制漿，堿回收等工藝過程都用到攪拌設備。 攪拌設備使用歷史悠久，應用廣泛但對攪拌操作的科學 研究卻很不夠。攪拌操作看來似乎簡單，但實際上，他所涉及的因素卻極為復雜。對于攪拌器型式的選擇。從工藝的觀點以及力學觀點來說，迄今都研究得不夠。隨著社會的進步，科學技術的發(fā)展，對于攪拌設備的改進和新型的設計會有很大的提高。在近幾年來設備有大型化的發(fā)展趨勢，也要求攪拌設備大型化。如國外聚合釜的容積已由最初的 840m擴大到 60100m,最大的已達到 200m。采用大型聚合釜可大大減少操作和檢修人員，有利于自動化，減少投資，提高生產(chǎn)率，穩(wěn)定產(chǎn)品質量。隨著容積的大型化，釜型逐漸由細長型向矮胖型發(fā)展，而且采用底 部攪拌的方式越來越多。多用三葉后掠式攪拌器，三葉后掠式攪拌器是目前大型聚合釜采用的一種較好攪拌器。因排出量大，釜內液相循環(huán)充分，每分鐘可達 510 次，能促釜內反應均勻一致。另外，經(jīng)實踐證明此槳葉必須配合擋板使用，以提高剪切力功能，才能更好地發(fā)揮作用。 攪拌也可以在管路中進行，采用在管路中安裝裝置的辦法對氣 液系和液 液系進行混合。例如采用噴射泵對水及醋酸丁酯進行混合。在石油精制中，也采用使液體設置在管路中的銳孔板或擋板，以便使兩種液體進行接觸。還有在管路中放入攪拌器的，即所謂管道攪拌。 管道攪拌設備能連續(xù)輸 送一切流體，也能輸送含有固體的流動化的半流體。此種攪拌型式，相當于攪拌設備的筒體部分，容積較小，液體在此停留時間極短的情況比較多。在其內部為了充分進行混合分散或傳熱等需 - 3 - 要極強的攪拌，由于管道攪拌設備空間很小，裝置小，可使攪拌力均勻作用，可減少過剩的攪拌，所以對整個液體減少了功率消耗。對于連續(xù)化、自動化。特別是對成本有嚴格要求的，要求特別小的形狀和高性能時，使用管道攪拌設備是很有效的。正因為管道攪拌設備有這些優(yōu)點，所以在石油精制、石油化工，化學纖維、食品等工業(yè)和水處理技術中廣泛被用于液 液混合、濃度調整、液 液萃取、油脂乳化、液 液稀釋溶解、固 液溶解、液 液和氣 液反應等場合。 - 4 - 附錄 2 Mixing equipment in the industrial production of a wide range of applications, especially in the chemical industry, many production are more or less application of mixing operation. A variety of chemical changes in chemical process, is fully mixed in the reaction material premise. For the heating, cooling and liquid extraction with gas absorption physical process,also often used for mixing operation in order to get good results. Mixing equipment is used as reactor application on many occasions. For example,in the three major synthetic materials production, mixing equipment as the reactor accounted for about 90% of the total number of reactor. Other such as dyestuff, medicine, pesticide, paint and other industries, the use of mixing equipment is also very widely. Nonferrous Metallurgy Department of mixing equipment nationwide in non-ferrous metal metallurgy industry to do an investigation and determination of the power, is the result of power consumption of many wet workshop more than 50% is used in mixing operation. The scope of application of mixing equipment is so widely, but also because of the operating conditions (such as temperature,concentration of mixing equipment, the residence time of the controllablerange). To adapt to the diversification of production. The following mixing equipment: 1) the raw materials are mixed evenly； 2)to make the gas well dispersed in the liquid phase； 3) the solid particles(such as catalyst) evenly suspended in liquid phase； 4) the other liquidimmiscible phase homogeneous suspension after fully emulsified； 5)strengthen the same mass transfer (such as absorption)； 6) heat transfer enhancement. For the homogeneous reaction, mainly 1, 6) 2). Mixingspeed, uniformity and heat transfer is good or bad, will affect the reaction results. As for the heterogeneous system, it also affects the mass transfer velocity of phase interface and the size of the phase, the situation is more complex. So the mixing conditions change, often very sensitive to affect the product quality and yield, production is very common in this example. Insolution polymerization and bulk polymerization of liquid phase reactiondevice, the main role is: to promote the stirring reactor - 5 - material flow. The material is uniformly distributed in the reactor, increasing the mass and heat transfer coefficient. In the polymerization process, often with increasing the conversion rate, polymerization liquid viscosity also increased. If the mixing situation is not good, it will cause the drop of the heat transfer coefficient or local overheating, materials and catalysts is unevenly distributed, quality effect of polymerization product, also easily lead to polymer sticking to the wall, so that the polymerization reactionoperation cannot go down well. The interaction between immiscible liquid or liquid and solid, mixing plays a very important role in accelerating reaction. Because the increase of onephase into another phase velocity, the contact surface will be increased,the material with wide speed interaction. In some cases, the mixing is an important factor to create good conditions in the reaction process. For example, the heat transfer effect is strengthening, reduce local overheating, the material and the heating process of coking. Such as high pressure polyethylene production, because the stirring effect, so that thematerial has a certain residence time in the reactor, it is more important that the catalyst are evenly distributed in the reactor, to prevent localviolent polymerization caused by explosion. Therefore, mixing equipmentplays a very important role in industrial production. The stirring device is used in the petrochemical industry productionmaterial mixing, dissolution, heat transfer, preparation of suspensionpolymerization, catalyst preparation, etc. For example, in the oil industry,crude oil and refined xenogeneic mixed adjustment, adding tetraethyl leadin gasoline by mixing additives and raw material or producthomogenization. Production of styrene in chemical production, aniline dyeand paint process, are equipped with various types of mixing equipment. In the oil industry because of the large number of application of catalyst,additive, so the demand for mixing equipment greatly. Because of the complexity of operating conditions, material diversity, the mixing equipment requirements are complex. Such as chemical industry used siliconaluminum reactor, beating tank reactor, barium, phosphorus reactor,alkylation reaction kettle, white mud stirred tanks are equipped withvarious types of mixing equipment. In the paper industry, and its wideapplication in mixing equipment, pulp, alkali recovery process are used inmixing equipment. - 6 - Mixing equipment has a long history, wide application but for scientific research of mixing operation is not enough. Mixing operation appears to besimple, but in fact, he involved are extremely complex. The stirrer typeselection. From the point of view of process views and mechanics, so farinsufficient study. Along with the progress of the society, the development of science and technology, to improve the mixing equipment and newdesign will be greatly improved. The trend in recent years has a large scale equipment, also requires mixing equipment. As the volume of polymerization kettle abroad has expanded from the initial 840m to 60100m , maximum has reached 200m