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选择正丁醇-丁二酸-水作为实验体系,以有机相为分散相,在φ100mm的塔内系统地研究了单降液管、双降液管和三降液管三种塔板的两相流动特性和传质效率,并对其进行了比较。研究结果表明,在相同的操作条件下,多降液管大孔筛板塔比单降液管塔内的动态存留分数大,板下静液层高度小的特点,同时多降液管筛板塔比单降液管筛板塔具有更高的塔效率。 相似文献
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CTST-MD复合型塔板降液管流体力学性能的实验研究 总被引:1,自引:0,他引:1
结合立体传质塔板(CTST)和悬挂式降液管各自的优势,在CTST塔板的基础上组合悬挂式降液管。以此为实验塔板,在直径为570 mm的有机玻璃塔中以空气-水为实验物料进行冷漠实验,对此种塔板的板压降、降液管的液层高度、液流孔孔流系数等流体力学性能进行了实验研究,并与鼓泡型塔板进行了对比。结果表明,复合型立体传质塔板的板压降低于弓形降液管的CTST和悬挂式降液管的筛板(MD筛板)。在高液相负荷下,复合立体传质塔板降液管液层高度远低于MD筛板,具有更大的液体处理能力。悬挂式降液管液流孔的孔流系数主要与开孔的水力半径有关,受开孔率影响较小。得到了复合立体传质塔板降液管几种孔型的孔流系数值。 相似文献
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本文报导了以圆管为栅条元件的管栅塔板(带降液管)的流体力学和传质性能初试结果。试验得出管栅塔板的气液流动工况与筛板相似,但气泡湍动剧烈,管栅塔板的气体通量大,压降小,操作弹性比可达2.8~4,液相板效率比较稳定,其比塔压降和比塔容积均小于筛板。 本文认为管栅塔板适于老厂塔设备改造,也可在伴有热效应的吸收、精馏中应用。 相似文献
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就痕量精馏中塔板传质效率低、需强化气液传质的问题,研究者提出了新型鼓泡破泡一体化高效精馏塔盘,通过在筛板上泡沫层高度范围内设置一层破泡装置,打破大气泡,减小气泡体积,强制界面进行更新,从而提高传质效率。采用双欧拉模型分别对鼓泡破泡一体化塔盘和筛板进行了气液流场的数值模拟,并对模型进行了验证。对比两种塔板的计算结果可以看出:在相同操作条件下,破泡装置将大气泡破裂成无数小气泡,使高气含率区域面积较普通筛板进一步增大,且气含率梯度变化更均匀;增加破泡装置后,在相同气速条件下气泡上升速度下降,气体在液层中的滞留时间延长,使鼓泡层高度增加,可显著提高传质效率,且降低了气体雾沫夹带量;破泡装置还明显改善了气相的纵向分布,气含率由塔板底部向上逐渐增大且存在明显分界;破泡装置附近湍动较剧烈,气泡破碎喷出的气体会进一步撕裂液膜,气体破碎作用会抑制气泡聚并,促进界面的快速更新更有利于传质过程的进行。研究结果可对工业塔板设计和优化提供指导。 相似文献
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开发了一种流场均匀且液相处理能力大的新型多降液管塔板。本文以水和空气为介质,在内径1219mm的有机玻璃塔内,研究了新型多降液管塔板的流体力学性能。结果表明,在相同气液负荷下,相较于弓形降液管塔板,新型多降液管塔板具有湿板压降低、雾沫夹带量小和漏液少等优点。同时新型多降液管塔板继承了多降液管(MD)塔板液相负荷高的特点,在空塔动能因子2.4(m/s)·(kg/m3)0.5的条件下,全塔喷淋密度仍可高达80m3/(m2·h)。对塔板上液相流场的流体流动特性进行了计算流体力学(CFD)分析,并将模拟结果与MD塔板进行对比。结果表明,新型多降液管塔板降液管的结构和排布方式使得塔板上液体流动更加均匀,预期可以获得更高的塔板效率。 相似文献
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在筛板萃取塔中引入气体搅动,既能明显提高装置的传质效率,又能大幅提高装置处理能力。筛板塔的通量随气速的变化规律与填料塔有显著区别,其性能研究有重要意义。利用煤油(苯甲酸)-水-空气体系,考察了气体搅动和筛孔直径对萃取塔流体力学和传质性能的影响。结果表明,随着表观气速的增加,气含率、分散相含率、液泛速率和传质效率均明显增加。但过高的气速也会导致分散相的过于分散和乳化,传质性能下降,直至液泛。不同直径的筛孔相比,较小的筛孔使分散相停留时间延长,分散相含率和传质效率提高,但液泛速率和处理能力降低。 相似文献
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利用Turbulent–Lehr组合模型对装配水平筛板的气升式反应器进行了计算流体力学(CFD)模拟,研究水平筛板对气含率、气泡直径、体积传质系数(kLa)和气液流速的影响。结果表明,筛板对气相的囤积作用和对液相的阻碍作用增加了反应器的整体气含率。筛板对气相的二次均布作用减弱了筛板和液面之间区域的气泡聚并过程,筛板筛孔对气泡的破碎作用产生了大量小于初始直径的气泡,增加了气泡比表面积(a);筛板对液相的阻碍作用提高了筛板附近的气–液相流动速度差,从而提高了该区域的液膜传质系数(kL),强化了反应器内的气液传质效果。 相似文献
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采用双膜理论对酸水萃取正丁醇溶剂中林可霉素B组分的传质过程进行了分析,分析结果表明传质阻力主要集中在滴内。在往复振动筛板萃取塔内,对酸水萃取正丁醇溶剂中林可霉素B组分进行了实验研究,考察了输入能量和通量对总传质系数的影响。研究表明:虽然输入能量可以强化滴外传质,但对总传质系数的影响却较小;而通量的增加使不同液滴间的碰撞、聚合、再分散作用加强,从而强化了液滴内传质,因此通量对总传质系数的影响比较大。所以,对于酸水萃取正丁醇溶剂中林可霉素B组分这类传质阻力主要集中在滴内的物系,在设计往复振动筛板萃取塔时不应将提高输入能量作为强化传质的主要控制手段,而是提高通量。 相似文献
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《溶剂提取与离子交换》2013,31(3):307-317
Abstract The hydrodynamic and mass‐transfer performance of a 75 mm diameter pulsed disc and doughnut column (PDD) and a pulsed sieve‐plate column (PSP) are presented and compared for a toluene–acetone–water system under similar operating conditions. It was found that the pulsed disc and doughnut column flooded earlier than the pulsed sieve‐plate column, indicating that the total throughput per unit cross‐sectional area through the pulsed disc and doughnut column was less. At similar operating conditions (i.e., flowrates, pulse frequency, and amplitude), the mass‐transfer performance of the pulsed disc and doughnut column was higher, and its holdup higher. The mass‐transfer performance of the PSP column, when compared at similar holdup to the PDD, was found to be higher, and so it is concluded that it is a more efficient column for this system. 相似文献
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The extraction of hydrogen peroxide by means of deionized water from anthraquinone working solution via anthraquinone process was carried out in a gas‐agitated sieve plate extraction column. The effects of the superficial velocity of air, dispersed phase and continuous phase on the overall plate extraction efficiency have been investigated. The corrections for the prediction of the overall plate extraction efficiency were presented. The correction proposed to predict the overall plate extraction efficiency in the air, water, anthraquinone working solution three‐phase system agreed satisfactory with experimental data with a maximum absolute deviation of 5.6 %. A new design method for gas‐liquid‐liquid three‐phase extractors is developed based on the multistage countercurrent extraction model. The calculated data by the model agreed well with experimental data and the average relative deviation was less than 10 %. Moreover, the model was used to predict a gas‐agitated sieve plate extraction column for industrial production of hydrogen peroxide. The results show that the plate numbers of gas‐agitated sieve plate extraction column are 30–40 % less than that of liquid‐liquid sieve plate column. 相似文献
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宝塔罩型塔板性能研究 总被引:7,自引:0,他引:7
开发了一种宝塔罩型塔板。该塔板是在塔板上设置数个由板孔、升气筒、塔型罩、进液孔所构成的豆塔罩单元,在单元内气液呈喷射状态接触,实现两相传热传质。流体力学性能和传质性能研究证明:该塔板压降、氧解析效率、漏液等性能与新型垂直筛板相当,但雾沫夹带要比新型垂直筛板低。因而该塔板具有较大的生产处理能力和较宽的稳定操作范围。 相似文献
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The steady‐state method by measuring the concentration profile along the column height is an effective way, but it is a time and material consumption method for large extraction columns. In order to investigate the axial‐mixing and mass transfer performances in a large pulsed‐sieve‐plate extraction column with the diameter of 150mm, a two‐point dynamic method with mass transfer based on the diffusion model has been developed. The results proved that the two‐point dynamic method has the advantages of good accuracy, simple boundary equations and flexible sampling position over the traditional single‐point dynamic method. It is a reliable tool for studying the axial‐mixing and the mass transfer performances. 相似文献