规整填料层压降的计算及与散装填料的比较

根据文献[6]导出的规整填料层压降关联式,由实验数据计算出9种规整填料本文关联式的压降常数,用空气-水物系和非水物系的实验数据进行了验证,并与Billet关联式计算值和实验值进行了比较;对规整填料层与散装填料的泛点和压降进行了比较。结果表明:该关联式与实验数据吻合较好,压降计算误差在±15％;规整填料力学性能优于散装填料。     

散装填料层泛点和压降的新关联

在理论分析的基础上 ,导出了散装填料层泛点气体速度和压降的新关联式 ,由实验数据计算了常用填料新关联式的液泛填料因子和压降常数。新泛点关联式对 8种填料泛点气速的计算值与实验数据的总平均计算误差为 3.5 2 % ;新压降关联式对各种填料的压降平均计算误差一般在 10 %以下。关联值与实验数据吻合很好 ,计算准确性优于文献公式 ,且比文献公式计算简便。     

计算散装填料层泛点的新方法

在半理论分析的基础上，导出了散装填料层泛点气体速度的关联式，由实验数据计算了常用填料本文关联式的液泛填料因子。本文泛点关联式对8种填料泛点气速的计算值与实验数据的总平均计算误差为3.52%，新关联方法与实验数据吻合很好，计算准确性优于文献公式，且比文献公式计算简便。     

波纹填料层泛点的新关联

本文在半理论分析的基础上，导出了波纹填料图泛点气体速度的关联式和关联图，得出了可以用空气－水物系的泛点实验数据求出其它物系泛点气速的结论。新关联方法与实验数据吻合很好，计算准确性优于文献公式。     

填料塔泛点/压降模型计算比较

以文献报道的实验数据及关联式为基础 ,比较了Billet模型、S -B -F模型及常用泛点 /压降计算模型在国产散堆和规整填料的泛点 /压降上的计算偏差 ,并对国产散堆和规整填料的泛点 /压降计算模型进行了总结     

板网填料液泛研究

将用于在管两相流动的Wallis'方程根据规整填料的结构特征加以改进,周末关联规整填料的泛点数据,计算结果与板网填料的泛点实验数据相差很小。将该方程重新整理可以反映规整填料泛点能力参数和流动参数的关系,计算结果与实验值相当。因此该方程大一种比常用的Bian－Hoagen关联式更好的关联规整填料泛点的方法。     

关联填料层泛点的新方法

将用于直管两相流动的Ｗａｌｌｉｓ′方程根据规整填料的结构特征加以改进, 用来关联规整填料的泛点数据, 计算结果与板网填料的泛点实验数据相差很小。将该方程重新整理可以反映规整填料泛点能力参数和流动参数的关系, 计算结果与实验值相当接近。因此用该方程来关联规整填料泛点比常用的Ｂｉａｎ Ｈｏａｇｅｎ 关联式更好     

规整填料层压降的研究

根据实验数据研究了规整填料层压降的关联，导出了规整填料层压降的关联式，计算表明，与实验数据相吻合。各种规整填料在不同空塔气速下的压降计算误差一般在±１５％以下，准确性优于文献公式，计算简便，为规整填料层压降的计算提供了可靠的方法。     

波纹填料层压降的新关联

导出了计算波纹填料层压降的半经验关联式，在包括泛点气速的多种气速下关联式对于波纹填料层压降的计算值与实验数据吻合较好，计算准确性优于文献公式。     

泡沫铝规整填料的实验研究

为了考察新型多孔金属填料的性能,对泡沫铝填料进行流体力学和传质实验研究,获得了该填料的填料压降、泛点气速、持液量等流体力学性能数据及填料层压降和液泛气速的关联式,传质实验结果显示:泡沫铝规整填料的理论板数可以达到10块以上,说明泡沫铝填料是一种新型高效规整填料。     

Determination of flooding gas velocity and liquid hold-up at flooding in packed columns for gas/liquid systems

A new model of suspended bed of droplets for describing the vaour or gas the vapour or gas velocity at the flooding point in packed of columns for rectification and absorption under vacuum and normal pressure is presented metallic, ceramic and plastic packings with diameters of 8–90 mm as well on sheet metal and gauze packings, in a wide range of liquid and vapour loads. Approximately 650 literature measurements and own data were evaluated. The mean relative error in determining the gas velocity at flooding point is less than ±5%. On the basis of the double layer model, a new equation was derived for the hold-up at flooding point, which is needed for the calculation of the flooding gas velocity. An example of calculations for sample applications is also included.     

A VERSATILE CORRELATION OF LIQUID HOLD-UP IN TWO-PHASE COUNTER-CURRENT TRICKLE BED COLUMN

A new definition of the flooding point in a two-phase counter-current trickle bed column has been proposed. Based on this point a versatile correlation of liquid hold-up has been formulated. The coefficients of this correlation are invariant to the change of physical properties of liquid, type and size of the packing forming the bed and gas velocity. This conclusion has been reached from the analysis of experiments with four different liquids irrigating the bed and three types of packing of various size. The versatile correlation can be used also re-currently to calculate flooding hold-up and flooding liquid rate from two known values of liquid hold-up for a given gas rate.     

垂直管中的液泛

本文较系统地研究了垂直管中的液泛现象,从液泛机理出发,明确定义两种不同的液泛——爬膜液泛和架桥液泛。并侧重研究了管子直径、管口几何形状对液泛的影响。提出平切口管,斜切口管的液泛关联式。指出提高液泛速度的途径。通过实验对所提论点及关联式进行了验证。     

两相/三相翼形浆搅拌反应器的泛点研究(英文)

The flooding characteristics of hydrofoil impeller were systematically investigated in a two-and three-phase 383 mm i.d. stirred tank operated on air, water and spherical glass beads. The volumetric solid concen-tration Cs was varied from 0 to 25%. And the superficial gas velocity Ug was at the range of 0-0.096 m·s-1. A fast and objective method for identifying flooding point NF is developed based on the statistical analysis of the pressure fluctuation signals. It is found, the effect of solid concentration on the flooding point NF depends on the gas velocity. At the lower gas velocity (Ug = 0.010 m·s-1), the solid concentration has only a minor effect. However, it displays a very significant effect on the flooding point NF at the medium and high gas velocity. The flooding point NF linearly increases with the gas velocity Ug, at lower solid concentration (Cs = 0, 10%). When Cs = 20%, the behavior of NF versus Ug becomes more complex. The correlations of the flooding characteristics in the slurry stirred tank are proposed by considering the solid concentration effect.     

同心圈式超重力旋转床液泛模型

同心圈式超重力旋转床是一种新型超重力旋转床。液泛是超重力旋转床流体力学的重要特征。同心圈式超重力旋转床液体分布器和转子内缘之间的环形空间内的液滴被气体夹带,液滴受到离心力和气体曳力的作用,通过建立微分方程可获得液滴径向速度为零时的液滴运动径向距离。当该径向距离小于环形空间的径向距离,此时产生雾沫夹带液泛。由此建立同心圈式超重力旋转床雾沫夹带液泛模型。实验以空气和水为物系,测定了转子直径为1000 mm、高度为100 mm的同心圈式超重力旋转床在不同转速和表观液速下气体进口和出口之间的气相压降随表观气速的变化。气相压降随表观气速的增大先缓慢增大后快速增大。用表观气速对气相压降求导和目测旋转床中心气体出口处出现大量液体被气体夹带来确定液泛点气速。通过液泛点气速求得雾沫夹带液泛模型的系数k,并对该系数k进行关联。该雾沫夹带液泛模型的计算值和实验值吻合很好,平均偏差为3.1%。该模型优于Sherwood液泛模型,对同心圈式超重力旋转床的工业应用提供了必要的设计依据。     

Estimation of phase velocities at flooding point in packed columns for any gas/liquid system

A method for the estimation of gas velocity at the flooding point of various packings, based on such fundamental parameters as the porosity and specific surface of the packing itself, has been developed and introduced herein. The proposed relationships can be applied to the computation of rectification and absorption towers alike, within a wide range of physical/chemical properties of the gas and liquid phases. The method presented in this paper should be particularly useful for estimating the flooding-point gas velocity of new packing elements, mostly, because it needs no empirical constants to be determined.     

几种D_g50乱堆塔填料流体力学性能的测定和关联

本研究中对D_g50mm的十一种乱堆填料以空气-水系统在不同喷淋密度下测定了不同气速的压降 值及泛点值。 在已取得的大量数据的基础上,分析了Eckert通用关联图法,认为这种方法存在一些缺点。本文提出了改进的计算方法:采用下式以计算泛点气速 采用下式以计算压降 △P=mY/（1-nY）式中 本文成功地关联了取得的数据,对十一种填料整理出特征值——形体常数α及压降常数m、n。     

Liquid holdup in wire-mesh pads

The holdup distribution and pressure drop of five different wire-mesh pads have been investigated experimentally. The wire-mesh pad porosities ranged from 93.4 to 98.4 vol% and were tested at 1 bar with air as gas phase and water as the liquid phase. The liquid holdup in the mesh pads was measured at three locations. The results show variations in the holdup profile of the pads depending on geometry, surface area, gas velocity and measuring height. The results show that the Souders–Brown equation is a poor correlation for low pressure mesh pad design and identifies several mechanisms relevant for wire-mesh pad design. The data show that there is a strong correlation between surface area of the mesh pad and the flooding point.