This paper makes a systematic study of flooding in vertical tubes with liquid flowing downward and gas flowing upward and defines clearly two types of flooding mechanism of climbing film flooding and liquid bridging flooding. If the velocity of gas is not high enough to cause reverse movement of liquid film, liquid is entrained by gas and forms a liquid slug, i. e., liquid bridge. As the gas stream carries the slug upward, flooding appears. We studied flooding in sharp edged tubes and put forward a semi-theoretical relation. Observation and measurement were done in reflux condensers. The experimental investigation agreed well with the mechanisms mentioned above. An experimental correlation for flooding in tapered tubes was proposed and the flooding mechanism was analyzed briefly. The experiments proved that the flooding velocity could be raised by eliminating entrance disturbance. A new type of tubes with some holes on its ends was developed,

Based on the group additivity method of Rihani and Doraiswamy, a computer program for automatically analyzing structures and computing heat capacities has been set up. The method was verified by using literature data of 356 organic compounds. The assessment of its computing precision and applicability was made and some new group parameters were recommended in this paper.

Hydrodynamic behaviors of rotating perforated disk column(RPDC) were studied with an emulsion-water system. The emulsion was dispersed in water and its holdup was measured. The effects of column dimensions and operating conditions on holdup and characteristic velocity were studied. By using dimensional analysis, the authors obtained two experimental correlations for estimating holdup and characteristic velocity respectively. Drop size distributions were studied photographically. The experimental results showed that drop size distributions could be described by upper limit log-nomal distribution.

In this paper the uniformity within and among the wafers in LPCVD reactors is analyzed by means of mathematical models, which describe the diffusion-reaction process between two adjacent wafers and mass, heat transport in the annular flow region. Results indicate that the uniformity h and effectiveness factorη within each wafer can be represented as function of volume change modulus ε and diffusion modulus φ; approprately installing heating device out of reactor tube can improve the uniformity from wafer to wafer or increase the conversion of reactant, These conclusions can serve as guidance tor design of LPCVD reactors and selection of operation parameters.

Very small particles of catalyst have been used in industry te enhance the effectiveness of catalyst. In such case, the capillary force caused by surface tension of liquid phase rapidly increases and a great number of liquid-phase bridges between particles is built. It is considered that hydro-dynamic performance and mass transfer for small particles greatly differ from those for large particles. This investigation studies the effect of flow condition and physical properties of liquid on gas-liquid interfacial area"a", when gas and liquid flow cocurrently downward through trickle bed of small particles. Correlations of"a"in trickle-flow and pulse-flow regimes were obtained by regression analysis.

A new theory of thermal conduction, the reaction rate theory has been established. By using the model of statistical thermodynamics and the idea of local composition, a new equation of thermal conductivity was given in the form ofThis equation was applied to 87 binary systems for correlation and 5 ternary systems for prediction. The results showed that the equation was of good applicability and reliability.

The permeability resistance model and equations which describe the permeation resistance of Zn2+ through HFSLM(Hollow Fiber Supported Liquid Membranes)are presented. In this paper, the equations describing the behavior of HFSLM modules of once-through mode at low metal concentration was derived. It was proposed that the thickness of the aqueous boundary-la yer of metal concentration in the incompressible viscous parallel flow teed phase was directly proportional to minus one half power of average feed velocity. Results showed that this hypothesis was in good agreement with the data of experiments. The total resistance of mass transfer in this chemical system consists of the aqueous resistance of the boundary-layer of metal concentration in the feed phase and the organic resistance of the diffusion-layer ot the metal-complex concentration in the membrane phase.

A new laboratory gas liquid mass transfer equipment, sphero-cylindrical column, has been developed and its mass transfer behavior has been studied. The authors proposed a modified surface renewal mass transfer model, with which the mass transfer charateristies of sphero-cylindrical column could be better explained. The calculated results of the modified model and experimental data were in fair agreement.

A new mathematical model for predicting the Murphree tray efficiency in the presence of liquid weeping is proposed by taking account of the uneven distribution of liquid velocity and unequal eddy diffusivities in Z and W direction on a tray.Typical calculation results indicate that the Murphree tray efficiency in the presence of liquid weeping depends on the following factors: weeping fraction ε, Pe, E_(OG), λE_(OG) and K = D_w/D_l. The discussions are useful for scale up design and commercial production.

A mathematical model for predicting tray efficiency of a new vertical sieve tray tower was proposed, considering the characteristics of the gas-liquid cocurrent up-flow in the caps and the liquid mixing between the caps on the tray. The behavior of the tray was represented by a model of dual cell, a mass transfer cell and a liquid mixing cell. The numerical results were summarized in graphs relating the Murphree tray efficiency to the point efficiency, the stripping factor, the degree of liquid circulation and the row number of the caps.The liquid circulation rate was measured in an air-water simulator. Tray absorption efficiency and point efficiency were determined with an air-ammonia-water system in the same simulator.The tray efficiencies calculated from the mathematical model using tha correlations for the liquid circulation rate and the point efficiency were consistent with the experimental results.

Power consumption, mixing time, velocity distribution and How patterns in agitated vessel of 0.286m in diameter with various types of helical ribbon impellers were measured with syrup, CMC solution and Boger fluid as test fluids. The effects of rheological properties of the fluids on axial velocity, tangentical velocity and radial velocity in the vessel with the presence of secondary flow were quantitatively described. It was also indicated that flow patterns of high viscoelastic fluid were quite different from those of high viscous fluid. Interpretations of power consumption and mixing time data were given on the basis of flow pattern observations.

Reactions leading to losses of current efficiency have been analysed in electrochemical production of chlorate. According to this analysis and Faradays Stoichiometry, an equation of material balance pf active chlorint was developed to relate losses of current efficiency to the operational parameters of the process including pH of electrolyte, current density, etc. This relationship was also been experimentally tested in chlorate cell with dissolving oxygen cathode.

The aqueous dispersions of C. I. Disperse Blue 79 of different concentrations were prepared in the presence of anionic or nonionic surfactants in this research. The influences of simple inorganic electrolyte on the stability and the electrokinetic properties of the dispersions were studied by using the settlement value as the stability parameter, and the electrokinetic potential as the parameter of the electric double layer of the particles. Good agreement was obtained between the two parameters. The results showed that the simple inorganic electrolyte might initially increase the stabilities of the dispersions at low concentration by assisting the building-up of the electric double layer, but decrease the stabilties by compressing this double layer when its concentration went beyond a critical value. Although the increase of the adsorption of surfactants on the dye particles caused by the increasing concentration of the electrolyte might increase the absolute value of the electrokinetic potential and there are increase the stabilities of the dispersions, the direct influence of the electrolyte on the electrie double layer was always dominant.

This paper presents a study on synthesis of a hydrogel material hy high dose rate electron beam produced by accelerator. The main results are as follows:1. The polymerization system produces the gel when the conversion attains approximately 20%.The radiation doae which completes this kinetic process is only 0.5-2.0Mrad, in other words, the radition time requires only 1-4min.2. The relationship between the initial rate of polymerization (V) and dose rate (I) are as follows:HEMA+EGDMA system: V_0∞I~(0.53) HEMA +EHMA+EGDMA system: V_0∞I~(0.48) HEMA+ EHMA+ EGDMA + RH system: V-0∞I~(0.5)3. When the compounding includes the hydrophobie monomer such as butyl acrylate, the mechanical strength of soft lens made from the hydrogel material is increased while the water absorption is decreased.4. The hydrogel material have been used for the manufacture of the soft contact lenses.

The power consumption for agitating viscoelastic fluids including Boger fluids and Newtonian fluids in the laminar regime were compared for the inner-and-outer helical ribbon-anchor and the four helical ribbon-anchor impellers. The influence of elasticity on power consumption is significant. For Boger fluids the power consumption could be up to 1.5 times of that fro Newtonian fluids.The power consumption correlations:for agitating Newtonian, pseudoplastic and viscoelastic fluids was developed by means of a second-order elastic fluid rheological model. The parameters f_v,f_s and F~*_(1av) were determined experimentally. The predicted results agree with experimental data.

A rotating packed device for intensifying mass transfer by centrifugal force was investigated. The apparatus was proved to be of larger capacity, higher efficiency, smaller volume and smaller weight as compared with ordinary separation devices. The rotor dimension was 300 mm in diameter and 40 mm in height, and packed with packings. Distillation test was made with ethanol-water binary mixture in a single rotor device. The data was obtained at 6.9t/(m2·h) reflux rate based on the inner surface and at 900 rpm. The packing thickness inradial direction equivalent to a theoretical plate was 3.93 cm for the φ6×6×0.1 ring packing, i.e, packings one meter in thickness was equivalent to 25 theoretical plates in terms of separation efficiency.

This paper presents the method for measuring the hydrodynamic and mass transfer performance of tower packings with a computer aided system which consists of pressure differential transducer and oxygen probe.