This paper modifies a mathematical model for distillation with two liquid phases so as to suit for thermally coupleddistillation with two liquid phases and advances an algorithm based upon the modified Naphtali-Sandholm method.Thestructures of Jacobi matrix and its submatrices of all types are given.The multiple phase flash method combined with acomparison of free energies for determination of the liquid phase split in stage is used.Seperation of butanol-water-propanol ternary system is employed to justify the method mentioned above.Satisfactory results are obtained.

The separation of fungal suspension Trichoderma reesei was studied by using cross-flow filtration(CFF)with re-versed-flow cleaning(RFC)technique.The advantage of this technique is demonstrated in comparison with other filtra-tion techniques.The filtration rate is influenced by different frequencies of RFC.For optimum combination of CFF andRFC,both experimental and theoretical considerations are necessary and are discussed.An expression has been derivedfor the optimum filtration time needed to maximize the flux for a given RFC period assuming that the filtration stage canbe approximated by Ruth’s equation.The practical usefulness of this calculation is demonstrated on a batch thickening op-eration.

It has been studied that the residence time distribution(RTD)function in a screw extruder in relation to that in thescrew and that in the die.For a complex flow field such as that between screw and die,it was supposed that the RTDfunction in the screw and that in the die were almost independent on each other.Therefore,a probabilistic method wasused to predict the RTD function in a complete extruder from that in the screw and that in the die.The experiments fordetermining the RTD were based on a stimulus-response technique.The results predicted,both in single-screw extruderand in twin-screw extruder,were in good agreement with those experimentally obtained.

Two heat transfer parameters in the fixed bed,radial effective conductiviw k_(er),and wall heat transfer coefficient h_ware estimated by using the method of orthogonal collocation and non-linear least square.The temperatures at forty collo-cation points distributed along the radial direction are measured simultaneously by means of multiehannel data logger.Theeffects of bed height,Re_p,d_t/d_p,gas inlet temperature and wall temperature on k_(er)and h_w are studied.The results indicatethat the effect of gas inlet temperature and wall temperature is negligible.Bed height will only influence the parameter es-timations in shallow bed and at low Re_p.Both k_(er)and h_w tend to reach a limit with increasing bed height.The asymptoticbed height which is independent of d_p is about 0.5 m,while the asymptotic values of k_(er)and h_w increase with d_p.The pa-rameters obtained with the wall being heated are about 10% lower than those with the wall being cooled.k_(er),h_w and stag-nant contribution terms k_(er)and h_w are all related to dp·k_(er)and h_w estimated at the asymptotic bed height are correlated bythe following equations:k_(er)=0.199+0.015 d_t/d_p+0.0020/(1+14.15(d_p/d_t)~2)Re_ph_w=33.4+4.23d_t/d_p+0.333/(1+8.54(d_p/d_t)~2)Re_p(5.5

The molecular structures of the products of the cyanation of 2,6-bromo-4-nitro-4′-(N,N-diethy1)-azo dye withCuCN were analyzed and identified.Mechanism of the formation of the by-products was also discussed.

In this paper a study of the system CaSO_4-PbSO_4 has been made using a high temperature microscope to determinethe solidus and liquidus temperature of mixtures of CaSO_4 and PbSO_4,and the phase diagram for the system constructed.Solid state reactions of mixtures of CaSO_4 and PbSO_4 at temperatures below the solidus temperature have been performedand a new compound,3CaSO_4·PbSO_4,has been found and subjected to differential thermal analysis to check for its re-versible transitions.

A new mathematical model,designated as stochastic state pool model,is proposed for simulating the liquid flow andmass transfer behaviour,including the concentration profiles of liquid and gas phascs in a packed column.Application ofthe new model is demonstrated by an example of the desorption of CO_2 in a packed column.

Fluidization under the action of external forces has recently received much attention at home and abroad.Funda-mental study in this novel field has led to the creation of new techniques and equipment in chemical and biochemical pro-cesses,such as reactors for catalytic and pseudo liquid-solid reactions as well as contaetors for gas-liquid-solid systems.In conventional fluidization,solid particles acquire fluidity under the action of a gas or liquid passing at a sufficientvelocity.Under the action of external forces,fluidization can take place at fluid velocities higher than that for particleelutriation or lower than that for incipient fluidization under normal conditions.These external forces can often help toavoid bubbling or suppress backmixing,thus improving mass and heat transfer.Studies on fluidization under various ex-ternal force fields,such as magnetic,oscillating,centrifugal,and ultrasonic,will be reported in a series of papers.

This paper presents an experimental study on the axial and radial distributions of heat transfer coefficients in a fastfluidized bed operated at ambient temperature.The following formula is recommended to correlate the local heat transfer coefficients in fast fluidized beds:where a,n_1 and n_2 are functions of radial positions.

New correlations based on group-contribution method for estimating critical properties have been proposed with con-tribution values of 67 groups.The new correlations have been examined by extensive comparison of the values calculatedwith the experimental data of 275 substanees.The average percent deviations of estimation of T_c,P_c and V_c are respective-ly 0.76,2.73 and 2.50 which are lower than those estimated by the Lydersen method and the Ambrose method chosenfor eomparision.

The concept of effective concentration of surfaetant in membrane phase has been proposed,considering the high ad-sorption density of the surfactant at the droplet interfaces in LSM system.The effective concentration of surfactant,C_2,can be estimated by Eq.(7)—(9).The swelling caused by emulsification during the initial dispersion process was investigated.The swelling rate wasmeasured by a density method.A model for estimating the“Emulsification”swelling rate,F_(se),has been proposed,basedon a mechanism of swelling due to the entrainment of water resulted from the interracial turbulence and emulsification inthe initial dispersion process.It has been found that Eq.(26)gives excellent fit to the experimental data of Fujinawa,etal.and of the authors.

Water transfer through the organic phase of kerosene containing surfactant Span 80,L113B and certain carrier wasstudied theoretically and experimentally in(W/O)/W liquid surfactant membranes.The process of swelling owing to os-motic pressure can be pictured as solubilization of water in membrane phase caused by surfactant and certain carriers andthen diffusion of it through the membrane between the two aqueous phases due to the gradient of chemical potential.Amathematical model for estimating the permeation-swelling rate has been developed.This mathematical model does notcontain any adjustable parameters and the predicted values agree well with the experimental data of Fujinawa et al.,Xinsheng Ma and Yajun Shi and the authors.Using an apparatus developed for measuring the solubility of water in membrane phase,data for solubilization ofwater in oil caused by some surfactants and carrier were measured.

The adsorption equilibria of N_2,Ar,CH_4,CO_2,and N_2O on H-Mordenite were studied with a constant volume appa-ratus under pressure from 3.04×10~3 to 1.43×10~7 Pa at—196°,0°,25°,50°and 75℃.The amount of adsorption ofN_2,Ar and CH_4 increases with pressure until approaching saturation at about 6.08×10~6 Pa.A maximum exists on theadsorption isotherm of CO_2 and N_2O,and their isotherms at different temperatures cross each other.All the data obtainedin this work can be correlated by the extended adsorption potential theory quite well.All experimental points can be repre-sented by the generalized characteristic curve.

The concept of local fluidity is proposed and applied to the derivation of a new three-parameter correlation for liquidviscosity with temperature,φ=1/μ=B_o[(V—V_o)/V_o]exp(—C/VRT)which is fitted separately to the experimental data of each of the eighty-three polar and nonpolar,organic and inorganicsubstance of various types with totally 1044 data points.The parameter values determined for each substance are present-ed.The overall average deviation of viscosities predicted is 1.30% against 4.38% for the Makhija and Stairs correla-tion.The correlation presented is applicable to a wide range of substances for the whole range of temperature from freez-ing point to critical point.