The rigorous critical state criteria based on Helmholtz free energy is used with equations of state fordirect calculation of critical properties(T_c,P_c and V_c)of 44 binary and 5 ternary systems.Special at-tention is paid to systems containing polar component(s)and the improvement in critical volume prediction.For extending this method to polar systems,the recently developed Cubic Chain-of-Rotators equation ofstate has been applied.As compared with SRK and PR equations of state,the improvement in V_c pre-diction is most impressive.

A stochastic approach,namely,Monte Carlo method with“tree structure pattern”has been adopted tosimulate the random backrnixing,residence time,reaction and dynamics of solid particles with size distribu-tion and with complex reaction in a complex flow system.Turbulence of particles in reactor system is simu-lated by stochastic tree pattern which is shown by pseudo-random number series picked from a uniformlydistributed set of numbers between zero and one.A Monte Carlo procedure is employed to model the par-ticles’ stochastic residence time,random flow and reaction with fluid.A large number of discrete bundlesof particles have been simulated and followed.Statistic results of all particles in the last information representthe solution to the problem under steady state of flow.The approach has a simple physical concept and simulation procedure.All calculation has been carriedout easily with a computer.For simple reaction system,results are in good agreement with those obtainedfrom the known approach and experiments.The method could provide a new kind of technique for simu-lating the behavior of particles in a continuous flow reactor.

This paper presents a two-stage method for the optimal heat exchanger network synthesis.In the firststage based on the study of the pinch point properties,a network minimizing the utility consumption and thenumber of exchangers is developed.Usually,this network is close to the optimal.In the second stage,anonlinear programming formulation is developed,and its solution with features of minimum capital andannual operating costs provides an improvement on the network obtained in the first stage.An integratedsoftware package for heat exchanger network synthesis has been developed.This package consists of a sp-readsheet,a graphics program,a data base management system,a menu program,an application networksynthesis program,a network simulation program and a data base of standard size exchangers.The appli-cation of this method is illustrated with several examples which include a complex crude oil preheating heatexchanger network.

A general unsteady state solution is obtained by means of Green’s functions for a dispersion-typetubular reactor model with an immobile zone.Arbitrary initial concentration profiles along the reactorfor the flowing zone and the immobile zone are allowed and the feed concentration is time-varying.Firsta self-adjoint operator is defined and then the Green’s function is determined.The solution is finally con-structed from the Green’s function.

Electrostatic pseudo liquid membrane(ESPLIM)separation process,developed recently in this laboratory,is a novel chemical separation technology.ESPLIM is an interdisciplinary technology evolved from thecombination of solvent extraction,liquid membrane and electrostatic techniques.It can be used to separate,purify and concentrate specific solutes from aqueous solutions.Therefore,it is suitable for the recovery ofvaluable metals from aqueous solutions in the field of hydrometallurgy(including nuclear fuel cycles)and forthe processes of waste water treatment.This paper discusses the basic principles of this new technology.Taking the extraction of Co~(2+)by D2EHPA as an example,effects on metal extraction of electrical fieldstrength,extractant concentration and the flow ratio of feed to stripping solution have been studied.Exper-iments show that the once through extraction efficiency of Co~(2+)can reach 99% while Co~(2+)can be concen-trated up to 40—50g/L in the stripping solution.

The characteristics of two-phase flow and heat transfer in an internal thermosyphon boiling device withchannels of different geometrical shapes and dimensions including straight and helical channels have beeninvestigated.The swirl-flow boiling device has more stable performance,higher heat transfer coefficientand higher rate of fouling removal than those of straight flow and has been successfully used in severalkinds of vaporizing equipment,such as reboiler,evaporator and closed thermosyphon.

A new metallic-diaphragm cell for liquid diffusion has been examined and successfully applied to thedetermination of diffusion coefficients for five binary systems containing long-chain molecules for which theparameter values of the empirical polynomial correlating diffusion coefficient with concentration have beenobtained.A new equation correlating diffusion coefficient with concentration

In this paper a new model of the drop breakage in a vibrating plate tank has been developed by a me-chanism based on the shearing stress in the neighborhood of the holes in the plates as a breakage force,andthe coalescence of drops may be dealt with by the process of gas molecule collision.Based on the theoreticalanalyses,simulation of drop breakage and coalescence which are random processes has been carried out byMonte-Carlo simulation technique.The parameters of breakage and coalescence rate have been obtained.

A numerical method for calculating the rheological behavior of polymeric liquids from their molecularmodels is presented,and several dumbbell models are then calculated in terms of this method.Answers aregiven to some problems which could not be solved theoretically.

It is found that the reactor has four types of flow regimes:a,b,c,and d,of which b is desirable inoperation.Therefore it is essential to find the criteria for flow regime transitions.On the basis of momen-tum,energy and mass balance principles,theoretical criteria are obtained and agree well with the experi-mental results,which can be expressed ascri1

The Markov process with discrete state and time is used to simulate the distribution of liquid flow in apacked column.The theoretical prediction agrees well with the experimental data.

Experiments have been carried out to investigate the effects of operating temperature(50 to 500℃)andpressure(1×10~5 to 8×10~5 Pa)on the transition from bubbling to turbulent fluidization by computer analysisof the pressure fluctuation in dense phase.In order to reveal the influence of particle properties on the tran-sition process,eight kinds of particles were employed.A empirical correlaton which takes into accountthe effects of temperature and pressure is recommended for the prediction of transition velocity