An approach based on the graph theory was used to study the Pitzer acentric factor of paraffins. Wiener Number was found to be a good measure of acentric degree of molecular structure. A proportional relationship between Pit-zer acentric factor and Wiener Number for paraffins was established. The relationship can be used to predict Pitzer acentric factor of isomeric alkanes. The predicted results agreed with experimental values satisfactorily.

Hydrodynamic and mass transfer charateristics of a new VST with nozzle-type vapour riser were studied in a circular column of 1.2m with air-water system. The influences of various geometric factors and hydrodynamic conditions upon the tray pressure drop, weeping and the lower limit of gas velocity andentrainment and upper limit of gas velocity were examined. The tray efficiency of the new VST was studied with ethanol-water system and was compared with that of sieve tray. The results are shown as below: 1. The wet pressure drop over the tray is the sum of dry pressure drop and pressure drop caused by gas phase passing through liquid layer. The pressure drops of the new VST with the nozzle-type vapour riser are 40% less than those of conventional VST operating under the same conditions. 2. The amount of weeping can be correlated by the following equation: 3. Entrainment is the upper limit of allowable gas velocity depends on the condition of gas escaping from the slat between cap and tray.

This paper introduces the UNIFAC group contribution approach into Butlers equation. A new method is set up to predict the surface tension of binary and multicomponent non-electrolyte systems, requiring only pure component properties and UNIFAC parameters. With the introduction of the activity coefficients γBi=αBi/xBi, γSi=αSi/xSi, Butlers equation may be transformed to give Here σm represents the surface tension of the mixture and σi the surface tension of pure component i. Ai is the molar surface area of component i and Ai its partial molar surface area in the solution, αBi, γBi and xBi stand for the activity, the activity coefficient and molar fraction of component i in the bulk liquid respectively and αSi, γSi and xSi for those 011 the surface layer of solution. N is the number of components. The value of Ai is set up equal to Ai which is calculated from the equation Ai=Vi2/3N01/3 where Vi is the liquid molar volume of pure component i and N0 Avogadros number. The bulk activity coefficients and surface activity coefficients are calculated with UNIFAC group contribution approach in a similar way. Predictions based on this approach agree well with experimental data for 100 binary, 10 ternary and 2 quaternary systems. The total average relative deviations from experiment are 2.53% and 5.33% for binary and multicomponent systems respectively, within acceptable limit for engineering design.

The unevenness of temperature profile of highly viscous liquid in an agitated vessel was described with a non-dimensional variable Analyzing the non-dimensional differential equation tor the laminar flow of the agitated liquid with helical ribbon impeller yielded the functional relation O = f(Pe,Ec/Re) Regression of the Newtonian and pseudoplastic fluids temperatures measured in the agitated vessel resulted in the correlations for five types of combined impellers such as helical ribbon-anchor, helical ribbon-helical screw-anchor etc. It is found that in -out helical ribbon anchor ( I ) impeller is the best one.

In a general way, chemical engineering system design synthesis via algorithmic methods can be formulated as a Mixed-Integer Nonlinear Programming (MINLP) problem. This work involves developing a general MINLP algorithm for solving the above mentioned problem. The introduced notions of decomposition, projection etc. make it easy to implement this solution procedure. The performance of the proposed algorithm is illustrated with numerical problems. The proposed algorithm is shown to be a promising alternative for solving system design problems.

An algorithmic solution procedure for solving the heat exchanger network synthesis problem is presented in this paper. A superstructure representation of the problem is established, and the addressed problem is formulated as amixed-integer nonlinear programming(MINLP) problem. An example is successfully solved with the MINLP algorithm developed in Part(I) of this paper. The simultaneous structural and parametric optimization is the main advantage of this solution procedure over some published procedures.

A temperature-dependent association model (TDAM) based on the association solution theory was established to describe the excess enthalpy, HE, for the alcohol-containing systems. For a particular system, the system dependent parameters, A and B, were related to HE as follows: The relation between temperature and association heat, ΔH, was expressed as: where only three parameters, A, B, and ΔH, were needed. By interpolating the HE data of two temperatures, the HE data for the other temperatures could be predicted. The results correlated by the TDAM gave better agreement with experimental data than those by the QCSM and WILSON Models. The TDAM model can be used for predicting excess enthalpy and vapor -liquid equilibria with satisfactory results.

The effects of particles projection from a fluidized bed surface on the heat and mass transfer between two isothermal regions was investigated through experiment and mathematical modelling. The amount of particles projection increased with the increase of superficial velocity and the increase of the bed height. The amount of particles projection between the two regions was 50%-65% of the total amount of the mass transfer in the bed. On the basis of the Rong-Fan shallow bed mathematical model and experimental conditions, a dynamic model was proposed. The "On Line Method" derived by R. F. Sincover and N. K. Madson was used to solve the partial differentia] equations. The calculated results were in better agreement with the ex-perimental values.

An inner tube was inserted respectively into the boiling section and condensing section to form a new type of configuration of a two phase closed ther-mosypon. Visual observation and heat transfer experiments on the new two phase closed thermosyphon showed not only a better stability in operation, but also a higher heat transfer coefficient. A fluid flow physical model was proposed. On the basis of the Soliman condensing heat transfer model, a condensing model with vapor and liquid flowing corurrently in annulus was proposed and the mean deviation between the calculated values and the experimental values was 19.4%.

The growth rate data of HCOONH4 crystal faces as a function of supersat-uration at 313.15K were measured. Bennemas modification of BCF surface diffusion model was applied to crystal growth from solution, and the values of growth parameters were calculated. The influence of volume diffusion on the growth rate of HCOONH4 crystal was discussed in light of the coupling model Gilmer, Ghez, and Cabrera.

Condensation heat transfer from the external surface of horizontally pla red wired elliptical tubes was studied both theoretically and experimentally. The numerical solutions for local and average condensation Nusselt numbers Nu () and Nu were presented for a number of the values of parameters , e. A and were compared with classical solutions in a special case (circular smooth tube: e=0, A=0). The general non-dimensional formulae for condensation heat transfer were obtained and the empirical constants and optimum wiring parameters were proposed.

The exchange energy parameter Xu of Flory new polymer solution theory could be evaluated from thermodynamic interaction parameter X which was determined by inverse gas-liquid chromatography. By using this value of X12 together with S1/S2, the ratio of contact surface area per unit characteristic volume (hard core volume) for polymer and solvent, the interaction parameters X, for polydimethylsiloxane, polyisobutylene, natural rubber and polystyrene with solvents were calculated, and plotted as X vs.2, the segment fraction of polymer. The values of X thus calculated were in good agreement with the experimental values. Moreover, the volume change in mixing VE/V0 and enthalpy of mixing corrected to infinitely dilute solution oi polymer ΔHM∞ were calculated with these parameters, and agreed with the observed values.

The physical and chemical characteristics of a sulfur-tolerant semi-water gas methanation catalyst, developed by the authors are described. The range of reaction temperature is 400-550℃. The pressure is no smaller than 0.6MPa. The sulfur content in the raw gas is in the range of 500-5000ppm(mol). The space velocity is about 1000h-1. The conversion of carbon monooxide is about 40%. The intrinsic kinetics equations are as follows:

An actual multi-cycle complex process was simulated and analyzed on microcomputer by solving simultaneous equations, and a new algorithm, the modified Newtons method, was presented. The Newtons method was modified in three aspects: partly removing the coupling items in the Jacobi matrix to ensure its convergence; reducing the number of conditions of the Jacobi to make the variables vary in step with each other; and iterating enough times after each inversion of the Jacobi to reduce the total times of inversion. Simulation of 150 groups of data show that the algorithm proposed is simple and efficient.

Electrical flocculation was investigated* for separation and extraction of α-amylase BF7658 from a bearing solution, prepared from its crude powder products via leaching. The factors related to the effectiveness of electrical flocculation such as pH value, strength of electrical field (E) and its duration time (t), the initial concentration of a-amylase (c0) and the dosage of flocculant (W) were studied systematically: 1. Under optimum conditions, i.e. E=8V/cm, t= 15min, pH=6.5, c0 = 2600u/ml, W = 200ppm, the activity of amylase can be recovered no less than 90%, the loss of activity can be reduced to no more than 5%, the activity of flocproduct can be no less than 250000u/g. 2. The selectivity of electrical flocculation depends on the difference of pH values between the enzyme to be separated and other proteins involved, the specific affinity between the flocculant and the enzyme to be separated. 3. Although the electrical field can increase the recovery of a-amylase and decrease the loss of activity obviously, electrical flocculation can not take place, without flocculant in the solution.

An ebulliometer was used to measure the vapor-liquid equilibria of etha-nol-ethyl acetate with calcium chloride(4%mass), (10%mass), (12%mass), magnesium perchlorate and copper (II) chloride under atmospheric pressure. The experimental data were correlated with the solvation method presented by the author and the calculated vapor compositions and boiling points were in good agreement with the experimental data.

Four kinds of modified copper surfaces Were obtained with ion-implantation technique. Fine dropwise condensation of steam could be obtained on these surfaces. The effect of steam temperature on dropwise condensation was studied experimentally. The results indicated that the heat transfer coefficient of dropwise condensation increased with the increase of steam temperature near atmospheric pressure. The properties of the condensing surface strongly affect the heat transfer of dropwise condensation. A discussion on the results was given from drop nucleation theory and surface energy effects.

This paper presents a study of the effect of inorganic electrolytes on the rate of coalescence of organic droplets in an aqueous continuous phase. It was found that the addition of ionizing salts to the aqueous phase resulted in an increase in coalescence time at a flat interface with droplets of polar organic liquids, such as butyl acetate. In contrast, no change in coalescence time was observed for non-polar droplets such as heptane. These results are discussed in relation to existing theories of drop coalescence, and a qualitative explanation of the phenomenon is proposed in terms oi an increase in the intertacial viscosity.