A surface equation of state for nonionic surfactant aqueous solutions is developed by using perturbation theory and two - dimensional gaseous theory. A surface equation of state for ionic surfactant aqueous solutions is also developed by combining perturbation theory and pressure equation . The surface pressures of six polyoxyethylene n - alkanol - water systems, polyoxyethylene n - octylphenol - water system and sodium dodecyl sulphate - water system are accurately correlated . By using the adjustable parameters obtained, the surface pressures of other polyoxyethylene n - alkanol - water systems , polyoxyethylene n - octylphenol - water system and sodium dodecyl sulphate - water system at different temperatures are predicted. Both the correlated values and the predicted values are satisfactory.

A practical system for fault diagnosis should have the following three functions: one with which fault diagnosis can be done very quickly so that the system can find use for fault diagnosis in real time production processes; one with which the training (or learning) of the system and diagnosis for the processes can be carried out simultaneously; and one with which knowledge learned about faults can be accumulated when learning is going on.We focus on how to construct a fault diagnosis system, which is based on neural network. We discuss a new type of neural network, named a linear classifying-reforming neural network and how to train it for fault diagnosis.The linear classifying-reforming neural network system is based on linear learning algorithm. The system consists of classifying sub-network and reforming sub-network. The classifying sub-network does a classification for inputting patterns to be recognized, and at the same time the output results from the network are inputted the reforming sub-network. The reforming sub-network can treat the information from the classifying sub-network and output some reforming patterns related to the recognized patterns. A simple recurrent linear algorithm is adopted for training the system. Because the training is done recurrently and only weights needed to change are adjusted in training, the training can be done very quickly, and the system is able to classify and learn simultaneously. Moreover, the weights of the sub-networks could not be destroyed when training, so that knowledge learned can be accumulated. The use of the linear classifying-reforming neural network is illustrated in incipient fault diagnosis of a chemical reactor.

This paper gives a general method to calculate solid and liquid equilibrium (SLE) stage by identifying the number of phases and the species of crystals existing at equilibrium automatically. An effective and rapid algorithm is proposed to obtain the result at equilibrium. Meanwhile this algorithm also gives the sequence of each crystal being precipitated and the composition of each phase at the time of crystal precipitation. This is important for the need of process simulation for solid - liquid separation. Especially, the method proposed does not depend on the phase diagram. On the contrary, the phase diagram of solid and liquid equilibrium could be obtained-by this method. Several examples are given to show that this method is capable of predicting the composition of SLE for systems with hydrate, multi -ion and complex salts.

The existence of concentration shocks due to nonlinearity of the adsorption isotherm is the feature of simultaneous adsorption and reaction processes in a fixed bed. A new approach to the shock is suggested in this paper. The shocks are regarded as moving boundaries which cut the spatial domain into separate "smooth" subregions, and the consistency equations on the shocks are taken as boundary conditions or connection ones that link the adjacent subregions. Then, a moving coordinate following the movement of the shocks is introduced and the shock discontinuities are transformed into fixed boundaries in the coordinate. Finally, simple trial functions are used to approximate concentration profiles in the smooth region , and the integral form of the governing equations provide a close set of first order ordinary differential equations. By the method, the problem of migration of two components with Langmuirian adsorption and reversible reactions is greatly simplified to that of four ODEs. A complete solution for the problem is obtained , and the characteristics of the shock movement under various conditions are discussed. It is found that when the weakly adsorptive reactant A is initially dominant, a maximum of distance between the two shocks exists there, and for irreversible reactions, the A - rich region does not disapear even when A is depleted, it becomes a constant thin layer between two shocks in the end of the movement.

The separation performance of an innovative liquid - liquid hydrocyclone proposed by the authors was studied experimentally by using the Coulter counter technique. The number, size and concentration of oil droplets were measured, and the grade efficiency curves were determined for different oil contents, flow rates and overflow ratios. The results show that the separation performance of the hydrocyclone is improved with the increase of flow rate and overflow ratio. The performance of the proposed innovative hydrocyclone is obviously better than that of the F - type hydrocyclone proposed by Southampton University. The best separation performance is obtained at the flow rate of 10 m3·h -1 and overflow ratio of 3% - 5%, and the critical diameter of oil droplet to be separated is as small as 30 μm. Meanwhile, this diameter is about 60μm in the F - type hydrocyclone under the same test condition.

The enhancement of gas - liquid mass transport by fine adsorbent particles (less then 10μm) and its mechanism were studied. Based on the analysis of enhancement of gas - liquid mass transfer by physical adsorption, and the effect of fine adsorbent particles on fluid viscosity and component diffusion coefficient, the enhancement mechanism model is proposed in this paper with the aid of penetration theory and segmental linearization of adsorption isotherm and is used for performance calculation.

The effect of fine adsorbent particles on gas - liquid mass transfer under distillation condition was studied in a bubble column, by using4A and 13X (in micron) as molecular sieve. It was found that the fine adsorbent particles cannot enhance gas - liquid mass transport unless adsorbents have strong adsorption on the less volatile components. The enhancement, however, has a limit up to a certain percentage of solids content, for example, about 10% in our experiment. Our experimental study confirms the predicted values from the model calculation.

An experimental investigation is carried out on friction and heat transfer characteristics of four spirally corrugated tubes with various geometrical parameters for the turbulent flow of single - phase water and oil. The correlations of momentum transfer roughness function ( R - function) and heat transfer roughness function ( G - function) are developed on the basis of momentum and heat transfer analogy from the present data and are compared with the results of previous investigators. A modified procedure is proposed to evaluate the performance of enhanced heat transfer concerning the large variation of oil Pr with temperature, and it is used for the performance evaluation of tube 1 and 2. Tne investigation results can be applied to heat exchanger design and optimization of geometrical parameters of spirally corrugated tubes.

In order to predict the changes in magnetically fluidized bed from aggregate fluidization to par-ticulate fluidizaion, or vice versa, the criteria of magnetically stabilized fluidized bed are formulated, which are different from Rosensweig s criteria and avoid some difficulties from Rosensweig s method. The criteria are based on Foscolo s "particle bed model", which is derived from a fluid dynamic mechanism for particle - particle force transmission and hypothesizes particles chained with each other in the fluidized bed. This hypothesis is very well adapted to particles in magnetically fluidized bed. By following Foscolos model and considering magnetic field on particles, the criteria can describe the stability of magnetically fluidized bed. The stability diagrams from the criteria agree with Cocker s experimental data. The results prove that Foscolo s "particle bed model" is also applicable magnetically fluidized bed. According to the criteria, the effect of magnetic field is analysed on the stability of magnetically fluidized bed in both the laminar and turbulent flow regime. Comparing the criteria we proposed with Fos-coles criteria of fluidized bed, we fined that magnetic field is conducive to increasing the stability of magnetically fluidized bed.

By reducing intermittency to periodicity, the very complex slug flow structure is simplified to an equivalent unit consisting of a liquid slug, one adjacent Taylor bubble and an aerated liquid film. A region with high local concentration of dispersed bubbles is formed in the front of the liquid slug, because the liquid film entrains gas penetrating the liquid slug. In the current paper, a hydrodynamic model is constructed for gas - liquid two - phase slug flow in vertical tubes, which considers the gas exchange between the Taylor bubble and its following liquid slug. It can predict the flow characteristics of this complex flow pattern. A detailed experimental investigation was carried out in air/water system. An EKTAPRO 1000 high speed motion analyzer and the optical probes were used as measuring instruments. The results predicted by this model are in better agreement with the available experimental data.

The characteristics of differential pressure fluctuations in vertical upward steam - water two ?phase flow under the condition of high temperature and high pressure are studied by using the signal process technique. The fluctuations are analyzed by using the methods of time domain and frequency domain, which is a power spectrum density (PSD) function.The features of the curves of the power spectrum versus frequency are categorized as two kinds. The feature of the power spectrum density function is extracted by means of the Root Mean Square (RMS), from which an objective flow regime indicator is developed. The experimental result agrees well with the flow regime map proposed by McQuillan & Whal-ley under the pressure of 3.0 MPa. Future studies are required to improve the accuracy of identification.

Two - phase flow instability in parallel boiling channels are often encountered in a wide range of engineering systems, such as nuclear reactor, steam power plant, special heat exchanger, steam generator, process equipment and so on.Most authors have done experimental studies and theoretical analysis for two - phase flow instability. The research work almost focuses on single tube. There are much less for parallel channels. Based on the experimental results for high pressure steam - water two - phase flow instability, the non - linear mathematical model of two - phase flow instability in parallel channels are proposed in this paper. The calculation results show that system stability is independent of magnitude and nature of initial disturbance but is dependent on the operating condition. The calculated results agree well with the experimental data.

In this paper, the correlation structure model of pressure fluctuations in a gas - solid fluidized bed is established. The self- similar parameter H and the intensity parameter σw of Gaussian white noise in the model are determined by the help with wavelet transform. Consequently, it is proved that the pressure fluctuations can be decomposed into the addition of Fractal Brownian Motion (FBM) and Gaussian White Noise (GWN), and the content proportion of the GWN in the signal is figured out. Finally, the changes of H and σw in different operating conditions are studied and physical interpretation is given.

Adsorption cooling attracts large attention because it uses waste heat, non - CFC refrigerants, and has no moving parts. The traditional heat and mass transfer model for the adsorbent bed does not take into account the internal mass transfer resistance inside an adsorbent particle. Therefore, the mass transfer mechanism in the bed can not be expressed accurately. In this work, the mathematical model for the heat and mass transfers in the adsorbent of a waste heat adsorption cooling system is developed , by taking into account both the internal and the external resistance. The model includes four parts: heat transfers in heating/cooling fluids, heat transfers in the metal tube, heat transfers in the fins, and heat and mass transfers in the adsorbent. The model for the heat and mass transfers in the adsorbent is a three-dimensional non - equilibrium model that takes into account both the internal and the external mass transfer resistance in the adsorbent. In the analysis, the Darcy s law is used to express the external mass transfer, while an empirical adsorption rate equation is used to analyze the internal mass diffusion . The model is solved with QUDS (quadratic upstream differencing scheme) and ADI (alternating direction implicit) methods, In the end, an experiment is done to validate the model.

Four different used tire samples were pyrolysed in a TG/DTA analyzer under N2. The tire samples showed two distinct weight losses in TG/DTG profiles, representing decomposition at a lower and a higher temperature. The major rubber ingredients of the tires, natural rubber (NR), styrene -butadiene rubber (SBR) and polybutadiene rubber (BR), were pyrolysed separately under the same conditions. NR decomposed mainly at a lower temperature, SBR and BR at a higher temperature. In addition, different heating rates affected the shape of DTG curves in tire samples pyrolysis. It was found that tires and rubber ingredients pyrolysis can be described by 1st order kinetics. The kinetic parameters (pre - exponential factor and apparent activation energy) were determined in Arrhenius plots with two linear regions. Also, tire samples composition was obtained by using TGA, in general, 6% - 9% volatile matters, 55% - 60% rubber, 30% - 33% carbon black, and 3% - 6% ash. The DTA results showed that the pyrolysis of tires is an exothermic process which may result from synthetic rubber depolymerization and natural rubber pyrolysis weight loss.

Forced convective condensation heat transfer characteristics of nonazeotropic mixtures of R32/ R134a in a horizontal tube were experimentally investigated, with six different R32 mass fractions ranged from 0 to 60%. Nearly 2000 local - average heat transfer coefficients were taken. The measured heat transfer coefficients were compared with those of the pure R22 and R134a. When compared on an equal mass flux basis, the R32/R134a mixture with about 20% R32 mass fraction had the lower heat transfer coefficient than those of the other mixtures, and those of pure R22 and R134a. The results also revealed considerable degradation of heat transfer coefficients of R32/R134a mixtures, when compared with the linearly interpolated values between the two pure components.

The reaction of immobilized enzyme in spherical porous support coupled with intraparticle and external mass transfer were studied in a batch reactor. An exact solution for the case of the first order reaction was presented. The orthogonal collocation method was used to simulate the complex systems. The catalytic reaction (the Michaelis - Menten equation as example), enzyme inactivation rate and the intraparticle and external mass transfer resistance of the substrate were taken into account to research the distribution of the substrate concentration in porous support, the changes of the bulk concentration and conversion with time.

The effects of forced periodic oscillation of oxygen concentration on the propylene ammoxida-tion reaction over a Mo - Bi catalyst were investigated in a continuous flow micro - fixed bed reactor at 44℃. The propylene conversion, acrylonitrile selectivity and periodic average yield were studied with various forced oscillation patterns and compared with the results of steady - state operation , which is the condition of industrial operation. The results show that the periodic average yield of acrylonitrile under any forced periodic oscillation of oxygen concentration among this experimental conditions, thus obtained could higher than that under the steady - state condition. A better forced periodic oscillation condition was that the low ratio of oxygen with propylene 9.0, operation time 210 min, and the high ratio 10.5, operation time 60 min. Operating under this condition, the periodic average yield of acrylonitrile reached 80.70% , increased about 2.3% compared with the acrylonitrile yield of steady- state operation.

The design and calculation of the integrated process of distillation and pervaporation for the separation of MTBE/C4/methanol mixture was carried out with the HYSIM modeling system. The component concentration profiles and temperature distributions in the distillation column were obtained. The integrated process for different draw streams taken from the distillation column was also calculated. The results show that the integrated process with side draw stream is much better than that of the stream taken from the top of the distillation column. The methanol mole fraction in the top product was reduced to 9.07 × 10 - 5 for the integrated process. The water scrubbing process was eliminated and much energy could be saved in comparison with the conventional process.

In recent years, the process of carbon dioxide reforming of methane to produce syngas has been invesigated extensively worldwide. The performance of a zirconia supported platinum catalyst is reported in this paper. The experimental results show that the catalyst is very active and stable under atmospheric pressure, while it deactivates very fast under high perssures. Pressure has strong influence on the activity, stability and selectivity of the catalyst.

Physical properties, such as dynamic viscosity, saturated vapor pressure, specific heat capacity, dissolution enthalpy, enthalpy of vaporization and standard gaseous enthalpy of formation for oxyfluorfen and its synthetic intermediates, were determined or calculated. The intermediates include 4 - chlorobenzotriflouride, 3,4- dichlorobenzotriflouride, 1, 3 - bis ( 2 - chloro - 4 - trifluomethyl phenoxy) benzene and 2,4 - bis(2 - chloro - 4 - trifluomethyl phenoxy) nitrobenzene. Tne quantum mechanics molecular models (AMI) and the application of group contribution method based on molecular structure were verified. The results have not been reported in the literature, and could provide chemical engineering design with fundamental data.