新型气液传质三维塔板设计及流体力学性能研究

【作者】 朱爱梅；

【导师】 张旭东； 唐薰；

【作者基本信息】 湖南大学 ， 应用化学， 2002， 硕士

【摘要】 气液传质设备在炼油、石油化工、精细化工、食品、医药及环保等部门均属量大面广的重要单元设备，在精馏、吸收、增湿、减湿等操作中都要用到。其投资一般占总投资的20％左右，有的甚至高达50％。蒸馏(精馏)是其用途最广的分离操作，在化工生产中，具有举足轻重的作用，所以一直是国外学者关注的重要课题。70年代以前，在大型塔器中，板式塔占有绝对优势。但能源危机的出现，突出强调节能问题，填料塔的技术有了长足的进步，冲击了蒸馏设备以板式塔为主的局面。进入90年代后，填料的发展较慢，进入了一个相对稳定期。与此相反的是，板式塔技术又有了明显的进步。我国在塔板的研究方面虽不如国外活跃，但三维塔板号称以板式塔的形式和造价提供填料塔的分离效果，以其优良性能吸引各研究者做了不少这方面的研究工作。 本文在阅读有关文献的基础上，创造性的设计了三种形式的三维塔板，即板1、板2和板3；并对其流体力学性能进行了研究。其具体内容主要包括：对原有设备进行改造；设计新型的三维塔板；塔板的干板压降、操作压降、雾沫夹带量、漏点、底隙液体吹开点的测量及其影响因素的考察。 实验结果及分析表明，开孔率相同时，所设计的三维塔板的干板压降和操作压降比筛板要高，与浮阀塔板相当或略小。这与国内研究者的观点一致，与日本专利的报道有出入。但要增加筛板的开孔率受限很多，在本实验条件的开孔率的基础上要再增加其开孔率几乎是不可能的；对于三维塔板，由于其独特的开孔设计，其开孔率还可以有较大的提高。三维塔板的干板压降基本上与板孔气速的2次方成正比。板孔形式由平板孔改为喷嘴孔，对其板压降的降低是有效的措施，可以降低25％左右。从干板压降的决定因素的考察可知，其主要是由板孔压降决定的。在整个操作过程中，三维塔板的雾沫夹带量都很小，如板2和板3均未达到雾沫夹带严重的程度。在相同条件下，三维塔板的雾沫夹带比筛板要小得多，如板2的雾沫夹带最大的才占筛板的40％不到。相同条件下，三维塔板的漏点气速与筛板基本相当。三维塔板的操作上限不是雾沫夹带决定的，而是底隙液体吹开点决定的；操作下限与筛板相同，是漏点决定的。三维塔板在L=1500l／h操作点的操作弹性比筛板高45.2％。在整个操作过程中，液流量对三维塔板的流体力学性能影响较小，且较高的板上液层对三维塔板有利。因此它适合液相负荷较大的操作。综合可知，三维塔板的处理能力与筛板相比可以提高较大。所设计的三种形式的三维塔板中，以板2和板3的综合性能较好。更多还原

【Abstract】 At the department of the refining oil, petroleum chemical industry, industry of fine chemicals, foodstuff, medicine and environmental protection etc., equipment of gas-liquid is very important unit equipment used widely. It is used in the operations of rectifying, absorbing, humidification, de-humidification etc.. As usual, its investment is about 20 percent of all investment, and even gets 50 percent high.Distillation or rectification is a kind of separating operation. At the chemical industry processing, it plays a decisive role. So it is a very important thesis for study which scholars internal and external pay close attention to. At the before 1970’ s, plate column plays absolute predominance in column plant. When energy crisis occurred, the question on saving energy is high lightly emphasized. The technology of packing column made great process, and charged into the situation that plate column is main equipment in the distillation equipment. Coming into 1990’ s, the developing speed of packing is rather slow, and goes into a comparatively period. On the contrary, the technology of plant column has obvious progress. In the study field of tray deck, in our country, there is less active than other countries. But three-dimensional tray is known that it owns plate shape and provides packing column’ s separating efficiency. Depending on his good performance, it attracts many studies to do many things in this respect.Based on relate to literature reported, the thesis designs the three-dimensional tray that includes three kinds of structure called Tray 1, Tray2, TrayS. There is a research on its hydrodynamic performance. Its particular content mainly includes transforming old equipment, designing new types of three-dimensional tray, and measuring its hydrodynamic performance that includes measuring dry plate pressure, operating pressure, entrainment, leak source, down opening’ s liquid blowout and seeing out their affecting factors.Experiment’ s conclusion and analysis shows that when tray’ s openingrate is same, at the respect of pressure,the designing three-dimensional tray is higher than conventional sieve tray, and is equal or even a littlelower than floating valve tray. It demands that the study’ s viewpoint home is reasonable, and there is different from Japanese patent demanded. But to increase sieve tray’ s opening rate, there are many factors limited. At the experiment’ s situation, that is to say, when the opening rate is 12.8 percent, to increase sieve tray’ s opening rate, it is hardly possible. On the contrary, due to three-dimensional tray’ s opening designing specially, its opening rate may still improve much. Three-dimensional tray’ s dry plate pressure basically is 2 power of tray opening velocity. Transforming flat plate opening to spraying opening is a very effective way to reduce plate pressure, and can reduce about 25 percent. From investigating on determinative factors of dry plate pressure, we know that plate orifice pressure is mainly determinative factor. At the operating process, three-dimensional tray’ s entrainment is very little. For example, the entrainment of Tray 2 and Tray 3 both do not get serious degree. At the same situation, three-dimensional tray’ s entrainment is much less than that of sieve plate. For example, Tray 2 does not get only 40 percent of sieve tray’ s. The velocity of leak source is almost equal to that of the sieve tray at the same situation. Three-dimensional tray’ s operating upper limit is not decided by serious entrainment, but by down opening liquid blowout. And its operating lower limit is at the same as the sieve’ s, this to say , it is decided by leak source. At the L=15001/h operating point, three-dimensional tray’ s turndown ratio is larger than that of sieve tray, and is about 45. 2 percent higher. At the all operating process, fluid-flow has rather little effect on the hydrodynamic performance of three-dimensional tray, and higher liquid thickness at the plate is very good to three-dimensional tray’ s hydrodynamic performance. So i更多还原