In this study, a dynamic method was developed to determine the local mass transfer coefficients of the air-lift loop reactor. In investigating local mass transfer coefficients, we found that the circulation ratio of gas phase was an important parameter affecting the mass transfer behaviours in the downcomer. The larger the ratio, the larger would be the effective mass transfer coefficient. Based on momentum balance, the following equation was derived: where ub∞ was determined as 0.16m/s for air-water system.

The reduction kinetics of the U3O8 via AUC( Ammonium Uranyl Carbonate) has been investigated. The results showed that the reaction rate was independent of particle size and the conversion had a linear relationship with time. It suggested chat the particle was highly porous and was composed of plate-like "grains". This analysis was confirmed by observing the surface and cross section of the particles with SEM. It provides the physical basis for establishing the reaction models of highly reactive powders and their pellets. The calculated curves from the models by using parameters determined independently were in good agreement with the experimental results.

In this paper, a complex turbulent flow with reaction in the combustion chamber of a cylindrical furnace is studied by "vorticity-stream function" method, together with the popular k-ε two-equation turbulent model. The Monte Carlo method is used to model the radiative heat transfer. The combustion model postulates a physically controlled, one step reaction with fuel and oxygen not coexisting at the same location. Calculated results are compared with the measured data of a petroleum atomospheric heater whose diameter is φ2.29m. The average error of the temperature field of flue gas is 8.89%. The calculated flow pattern is similar with the result by using jetted model.

By separation of variables, the model equation of mass transfer of moving drops can be converted into two-variable Liouville equation. Calculus of variations and Ritz method are used to obtain eigenvalues λ2 and eigenfunctions BnZn(x, y) of the Liouville equation. The mass transfer coefficient F then can be obtained by linear superposition Experiments were carried out in a column of 76mm in diameter. Water and n-butanol were used as continuous phase and disperse phase respectively. Succinic acid as the solute was transferred from water to butanol drops. The model developed matched the experiment data quite well.

A new equation of state for electrolyte solutions is presented based on perturbation theory. Molecule-molecule, ion-molecule and ion-ion interactions are incorporated into the equation of state. The equation covers the entire fluid density range from zero to liquid-like densities. Therefore, it can be used for both phases in vapor-liquid equilibrium calculations.For mixtures without elec-trolytes the equation resembles the equation developed by Hu et al. (1984). The equation was used to correlate the vapor-liquid equilibrium for ammonia-carbon dioxide-water system with fewer parameters than other existing models. Satisfactory results were obtained, and they were equivalent to, or better than those from other models.

In the paper, fuzzy optimization selecting method is presented for chemical engineering projects. It includes the fuzzy optimum selecting model, membership formulas and weight calculation. It is shown that the proposed theoretical model is clear in physical concept and convenient in calculation.It provides a new way of optimum selecting chemical engineering projects.

Based on the momentum differential equation for a stream with varying mass, a mathematical model describing the distribution of the gas stream along the axis of a radial flow reactor has been given. It is a boundary problem of a special dimensionless differential equation of the second order: for n-shaped flow Au"u + Bu u + Cu2 = 0 for Z-shaped flow Au"u + Buu + Cu + Eu2 + F(1 -u)2 = 0 with the boundary conditions y =0, u =1; y =1, u = 0 The values of coefficients A. B. C. E and F depend on the factors, such as, geometric parameters and resistance coefficients of the side flow through the hole for the divided flow channel, the combined flow channel and the porosity of the radial catalyst bed. To simplify the solution of the above boundary problem for n-shaped radial flow reactor, an analytical solution of the dimensionless differential equation is proposed. In practice, the results of the simulation of the oxidation of ammonia and the synthesis of ammonia in the reactor revealed the fluid dynamics characteristic of a radial flow reactor.

Extensive experimental investigation of C6H6-C7H8 and C6H6-CCl4 systems using Intalox Metal Tower Packing (IMTP) and modified IMTP was performed in a packed column of 300mm inside diameter. A new HETP model with a lower safety factor in practical design is obtained from theoretical analysis together with commercial scale mass transfer data.

In this paper, the calculating method which corrects the non-ideality of the vapor phase for systems containing carboxylic acid by the theory of molecular aggregation is proposed. The fugacity coefficient of the vapor phase for the components of these systems deviates seriously from unity owing to association. A modified virial equation is used for the vapor phase and UNIQUAC model is used for the liquid phase. Good results of calculation of vapor-liquid equilibrium data are obtained.

A generalized four-parameter equation of state based on corresponding states principle was proposed in a previous paper by Zhang and Xu (1986).In this work, a new mixing rule was derived by analysing the relationship between molecular parameters and bulk properties of fluids. High-pressure vapor-liquid equilibria of 22 binary systems were calculated using the Zhang and Xu equation with the new mixing rule. The calculated pressures and mole fractions of the vapor phase were compared with the experimental values in the literature and also with the results obtained with the LKP corresponding states method. The comparison indicated that the method described here provided better estimates than the LKP method.

The P-V-T relations for polar substances are studied by using a partition function. The attraction effects are divided into polar and nonpolar term, and a polar partition expression with intermolecular potential function is derived, to modify Van der Waals equation of state and obtain a correlation for attraction parameter"a". Polar substances are correlated with critical compressibility factor as well as reduced dipole moment. The calculated vapor pressure and heat of vaporization of 45 kinds of polar substances are satisfactory. A modified, SRK equation is developed with improved accuracy.

Two heat transfer parameters, the radial effective conductivity ker and the wall heat transfer coefficient hw were estimated by means of non-linear least square. The two-dimensional pseudohomogeneous model was solved by using orthogonal collocation. A fixed bed packed with vanadium-phosphorous catalyst for oxidation of n-butane to maleic anhydride was studied. The temperatures at forty collocation points along the radial direction were measured by a multi-channel potential logger. The effects of bed height, particle Reynolds number, tube diameter to particle diameter ratio, and wall temperature on kei, and hw were investigated, and the following correlations were proposed (5.5

A new kinetic theory of tensile strength for polymer networks has been proposed. It is based on the Eyring chemical activation rate theory and the molecular theory of rubber elasticity at large deformations. The coefficient of overstress of a polymer chain is derived by combining the deformation behavior, stress concentration of a polymer chain and the chain orientation as a united event of polymer failure. A kinetic equation for bond rupture of over-stressed chain is established by taking the coefficient of overstress as a variable. After integration and simplification a new equation of state for ultimate fracture is obtained. It is successful in reating the ultimate strength and extensibility to the parameters of structure, the temperature and the extension rate. The failures of four different polymer networks were studied by uniaxial extension method. These experimental data of ultimate properties were treated with the proposed theory. The results show that the proposed theory can predict the failure behavior of polymer networks and provide a theoretical foundation for the construction of failure envelop.

The heat transfer of enhanced vapor condensation over the surface of an elliptical pipe has been studied theoretically and experimentally. An equation of dimensionless parameters for the condensation of vapor in a static saturated state was derived, and the effects of some major parameters on the heat transfer coefficient of vapor condensation were analyzed and discussed. The heat transfer coefficients over the surface of elliptical pipes with the same perimeter but with different ratios of major and minor axes were measured experimentally to yield some experimental curves. The theoretical analysis was in good agreement with experimental results. The heat transfer of vapor condensation over an elliptical pipe was greater than that over a circular pipe.

Five kinds of copper alloys were made by applying ion-implantation technology. The elements chosen were He, Ar, N, H and O. The dropwise condensation of steam was realized on the five new surfaces. The surface characteristics of the alloy layers were analysed by using XPX, AES and SIMS. The mechanism of dropwise condensation formed on the new surfaces was analysed.

The effect of pH value on the ultrasonic copolymerization of polyvinyl alcohol (PVA) in its aqueous solution with acrylonitrile (AN) was studied. It was found that the reaction might be controlled merely by varying the pH value of the system. The resulted irradiation mixture was a stable water based dispersion. The particle size of the copolymer formed increased with the decrease of pH value. With the decrease of pH value, both the yield of copolymer and AN content in the copolymer would be increased. No homopolymer of AN was found in the reaction products.