筛型塔板上两相密度分布及工况转变条件

应用γ射线吸收技术测定了导向筛板和普通筛板上气液两相密度分布;对工况的转变条件作了实验研究;以雾沫夹带率的极值点为工况转变的判据,认为两个极点之间的操作属于混合型的过渡工况;提出了清液深度h_1,平均泡沫密度(?)以及第一工况转变点的数学关联式.     

筛板喷射工况下的雾沫夹带

以空气／水为物系，对筛板上泡沫和喷射两种工况下的雾沫夹带进行了实验测量，依据喷射工况下雾沫夹带量随气液流量变化的规律，提出了喷射强度的概念及其定量表示，发现喷射工况存在一般喷射和强烈喷射两个状态，并对一般喷射状态下的雾沫夹带进行了新法关联。     

导向筛板三相流动操作时的工况转变

在冷模塔内进行了导向筛板上气－液－液三相流动操作工况及其转变的研究,以空气和油、水混合物为介质,测定雾沫夹带率和板压降的变化规律,并以雾沫夹带率及板压降变化的转折点作为三相流动工况的转变点,以此作为导向筛板操作工况转变的判据．研究了操作条件、导向筛板的结构及物系性质对三相流动工况转变点的影响,提出了导向筛板流动工况转变点的雾沫夹带率及板压降的计算式．     

浮阀塔板传质效率与双相流接触状态的关联

浮阀塔板上主要有喷溅、混合泡沫和完全泡沫三种汽液接触状态,塔板上汽液接触状态、雾沫夹带率和清液层高度三者有良好的对应关系。本文得出了状态转变点的规律,推导和提出了预测三种接触状态下液相传质效率和雾沫夹带率的方法,初步考核结果颇为满意。     

浮阀塔板上两相接触状态及相状态转变规律的探讨

本文作者对锥心浮阀塔板上气液两相的接触状态进行了实验研究,认为主要有喷溅、混合泡沫和完全泡沫三种状态.在正常的气液负荷范围内系混合泡沫状态.文中探讨了两相接触状态的转变规律与塔板入口端的清液层高度以及塔板上的雾沫夹带率有良好的对应关系,从而确定了有两个转相点.此外,还对两相接触状态的转变机理作了初步分析,得出了计算相状态转变点的准数关联式.     

喷射工况下筛板流体力学特性研究

利用总板压降在喷射和鼓泡工况下具有不同的变化规律。测定了筛板上流动工况的转相点。分析了气速、液体负荷、孔径、开孔率以及堰高等因素对相转换的影响。测定了喷射工况下筛板流体力学特性,得出塔板压降、持液量、雾沫夹带量等参数的关联式。     

对界定塔板喷射液泛限的另类探讨

准确界定塔板的喷射液泛限是合理设计塔板的关键,通过实验测定和模型核算,分别对小板间距和大液量工况的塔板喷射液泛限作了探讨。发现小板间距塔板的喷射液泛会提前出现,提前幅度已超过10%。塔板在大液量下运行,能较大幅度地推迟喷射液泛。对于工程界常用Hunt关联计算筛板雾沫夹带,实验数据校核结果表明偏差较大,建议慎用。     

汽-液-液三相蒸馏导向筛板的流体力学性能研究

本文以空气—水—煤油为介质,在600×l50矩形冷模塔内进行了气—液—液三相蒸馏导向筛板的流体力学特性的研究.实验就三相蒸馏塔板上的操作工况(Operating Regimes)及塔板上两液相混合状况进行了研究.并就清液高度、雾沫夹带、板压降等主要流体力学参数进行了大量测试,提出适用于混合工况的主要流体力学参数计算关联式.     

液相黏度对筛板塔流体力学性能影响的研究

以空气-水、空气-甘油水溶液为物系,实验研究了黏度对筛板塔流体力学性能的影响.根据板压降、泡沫层高度、泡沫层平均气含率、雾沫夹带随气体流量变化的趋势,得出如下结论在相同的气速下,随着黏度增加,塔板压降降低,泡沫层高度降低;距测试筛板同一高度的雾沫夹带量随气量的增大而增加,随黏度增大而降低;雾沫分离空间相同时,雾沫夹带量随黏度增加而增大.根据实验数据还得出了不同气速下泡沫层平均气含率与气体空塔动能因子F的实验数据关联式.     

HTV船型浮阀塔板两相流动操作状态及其相互转变规律

用雾沫夹带速率法将ＨＴＶ船型浮阀塔板上的两相流动状态划分为喷溅、混合泡沫和泡沫状态。并根据气液负荷、塔板几何结构参数以及物性参数关联了这些两相流动状态间的相互转变规律。     

THE VERTICAL DENSITY PROFILES OF TWOPHASE MIXTURE AND THE FLOW REGIME TRANSITION ON SIEVE TRAYS

The vertical density profiles of the gas-liquid mixture on the flow-guide sieve tray and conventional sieve tray have been studied by gamma-ray absorption technique. It has been found that the inflection points of entrainment rates can be regarded as the criterion of transition of flow regimes and that the operating range between two inflection points is the transition regime. The relationships have been established for the lqiuid hold-up (or clear liquid height), the average dispersion density and the transition of flow regime.     

筛板由泡沫态到喷射态工况转变点的测定和模拟

The transition from froth to spray regime on sieve trays was experimentally studied in an air/water simulator with 300 mm diameter. It has been found that the regime transition occurs as the cleax liquid height is equal to the residual pressure drop on the trays. A convenient and accurate technique was proposed for determination of the regime transition point. ]Based on analysis of the transition process at a sieve hole, a new formula which can be used to correlate the experimental results was provided.     

INSIGHT INTO DISTILLATION/ABSORPTION COLUMNS AND FCC RISERS USING GAMMA SCANNING TECHNIQUE

This paper presents the application of gamma ray scanning technique to distillation/absorption columns and FCC risers.The flow regime transition.clear liquid height,froth height.crestliquid height over the exit weir on a V-1 type valve tray and downcomer hydraulics were investigatedusing the scanning device previously developed.The solid distribution and coke deposition were experi-mentally simulated in a FCC riser simulator by employing a three dimensional scanning device devel-oped for the present investigation.The success of this investigation should shed a light forquantifying two-phase contact phenomena in various gas liquid and gas solid two phase flow system.     

Nye Tray Versus Sieve Tray: Experimental Study on Hydrodynamic Parameters

The hydrodynamic parameters of a Nye tray were investigated by performing experiments in a tower with a diameter of 1.22 m. Air was used as the gas phase and water was used as the liquid phase. A number of parameters such as the dry pressure drop, the total pressure drop, the clear liquid height, the froth height, and the entrainment were measured. A tray stability factor was obtained using the amount of weeping, the clear liquid height, the dry pressure drop, and the Froude number. All experiments were repeated for the matching sieve tray under the same conditions. Ultimately, advantages and disadvantages were compared, and the results demonstrated that the Nye tray has a couple of advantages over the sieve tray, except that the sieve tray is slightly more stable.     

筛型塔板在喷射及混合状态操作下三相传质性能

以空气-水-油(煤油及白油)为介质在600mm×150mm矩形冷模塔内测试了筛型塔板气液液三相传质性能。研究喷射及混合状态下,气速、液流强度、油水比等操作条件和塔板结构参数(孔径、开孔率)对塔板效率的影响。气膜和液膜控制的2种物系的实验表明,三相传质的板效率在喷射状态下明显高于混合状态。对测试数据进行关联,获得适用于喷射及混合状态下三相传质板效率的估算式。     

Sieve trays: A view on the state of the art

Sieve tray performance is reviewed with reference to flow regimes and recently released commercial scale experimental data. Correlations are presented for regime transitions, pressure drop, axial mixing, entrainment, capacity, weeping and tray efficiency. The flow regimes, i.e. spray regime and emulsion flow regime, appear to have a dominant effect on nearly all of these performance variables.     

Hydrodynamic Characteristics in the Counter‐Flow Total Spray Tray

The capacity of a column is limited by the distribution of gas and liquid, especially in case of large‐diameter cross‐flow trays. In order to solve the bottleneck, a new counter‐flow tray named total spray tray (TST) was put forward. Taking air/water as medium, the hydrodynamic behavior, including the pressure drop, weeping, entrainment, and clear liquid height, was investigated, in comparison with the CTST, which had a higher capacity. Based on experimental data, the correlations of the TST pressure drop were established by regression analysis method. The experimental results show that the TST has a lower wet pressure drop and less weeping. More interestingly, its clear liquid height can be self‐adjusting with the variation of the gas kinetic energy factor, which is beneficial to improving the capacity.