The common behavior of three sets of residual oil gasifier with twin - fluid nozzle at 8. 53MPa,was commercial-scale studied and an experiment of cold model was performed. The residence time distribution for three models of gasifier at six jet velocities and the velocity profile for seven models of gasifier at two jet velocities were measured. The equations of the density function of residence time distribution, the axial growth of the velocity half - radius, the axial decay of radial maximum jet velocity and radial profile of jet velocity were obtained.

The zone model of gasification reaction of residual oil in gasifier with twin - fluid atomizer has been developed according to the test and measurement results of flow field in cold model gasifier. In this model, the components of recoil current: hydrogen, carbon monoxide and so on, take part in the combustion reaction and a reverse shift reaction takes place in the exit of the gasifier. The commercial - scale behavior for example, gas composition , life of the refractory and quench ring, is given reasonable explanation.

A fuzzy multicriteria modelling method of defining a structural parameter for representing the grade of welding defect damage is presented. The methodology for safety assessment of process equipment and piping containing welding defects in fatigue loading based on the theory of fuzzy set for treatment of imprecisions and uncertainties is proposed, and the related expert system has been built.

Coal char gasification with CO2 was studied in the 900-1500℃ temperature range of ash fusion under normal pressure. It was found that the activation energy changed with the gasification process. Except for the initial stage of reaction, gasification was affected seriously by internal diffusion. There was a characteristic temperature in coal char gasification at a high temperature, where the gasification rate was significantly reduced in the intermediate and final stages of reaction. Its effect covered about 200-300℃ around the characteristic temperature, its value was related to many factors, such as the kind of coal, the properties of ash etc., generally lower than the ash softening temperature.

The pore structure of Datong, Newlands (NL), and Blair Athol (BA) coal chars, and the rate of gasification of these chars with CO2 were measured at 1000-1500℃ and under normal pressure. The relationship of the change of pore structure and inner surface area during gasification with gasification rate was studied. Char gasification was shown to be carried out on the inner surface area of microporosity at high temperature, so the microporosity plays an important role in gasification.

A differential mathematical model for hollow fiber membrane gas separator including a gas pressure drop equation in hollow fibers was established and reduced to an algebraic one in order to simplify the calculations. The two models were tested experimentally and compared with the models in references. The models in this paper give better results than those in references when the pressure drop in hollow fiber can not be neglected. The models in this paper are very useful in design,calculation and development of hollow fiber membrane gas separator. The influences of inside diameter and length of hollow fiber and operating pressure on the separation process were studied. The optimum pressure of permeated gas in hydrogen and nitrogen separation process was about 0.4-1.0MPa.

A perturbation model for electrolyte solution has been developed. A mixture of charged hard spheres and neutral hard spheres is used as the reference system of perturbation expansion and the interactions between various particles including repulsion force, dispersion, induction and electrostatic force are taken as the perturbation terms. The expressions of Helmholtz free energy and internal energy are deduced. Comparing with the methods in the literature, the reference system and expansion of perturbation terms of our model are more reasonable. The long - range term is simpler and the effect of the size difference between particles can be partly shown. The internal energy results calculated with our perturbation model are close to MC data.

The efffects of mixing characteristics and chemical characteristics on the precipitation process conducted in a semi-batch stirred tank were investigated and analysed. It was found that there existed critical points of stirrer speed Nc, viscosity μc and feed time tfc, at which the mean size and the variance of particle size distribution (PSD) were minimal. This fact could be attributed to the interaction of micromixing and macromixing and was vital to industries such as the manufacturing of ultra-fine particles and catalysts. Experimental results also showed that the feed location possessed great effects on PSD and critical stirring speed Nc. Generally, smaller values of Nc would be achieved when the feed location was put nearer to the impeller.

On the basis of turbulent theory and the results observed by high speed strobo-scopic microscopic photography for meso-and micro-mixing processes, a mixing mechanism was proposed and then a new mixing - precipitation model including micromixing, turbulent dispersion(meso-mixing)and backmixing(macro-mixing)was established to predict the par-ticls size distribution (PSD). By this model the values relevant to the critical points on the curves of the effects of mixing factors, i. e. ,stirrer speed and feed time on PSD were first quantitatively predicted. The results agreed well with those of experiments. This fact denotes that the model is quite reasonable, practical and capable of prediction.

The chemical equilibrium compositions and equilibrium constants of methanol synthesis reaction, starting from carbon monoxide, carbon dioxide and hydrogen, were studied experimentally at p=4. 0-6. 6MPa and t=220-260℃. Meanwhile, based on the experimental data of Kp measured in this paper, the thermodynamic prediction of Kp from Kf and equation of state was studied and it was found that the chemical equilibrium of methanol synthesis can be described well by using Cherednichenkos Kf Ⅰ and Bissetts Kf, Ⅲ relationship and a modified SKR equation.

By distinguishing the induction period of scaling (IPS)and that of crystallization, a mathematical model was established for IPS of CaCO3 which heterogeneously nucleated on heated surfaces. The relationships between IPS and surface wall supersaturation, surface wall temperature, fluid flow velocity and surface properties were obtained through computation. The surface treatment technique of ion implant nitrogen was used to prepare new surfaces with low surface energy and without additional thermal resistance of metal substrates. The effects of these improved surfaces on IPS were experimentally investigated. It was found that IPS on treated surfaces was 0. 5-1 times longer than that on untreated surfaces.

Multicomponent multifluid heat exchangers with phase change have wide application in gas liquification and separation and petrochemical industry. The heat transfer calculation is much more complicated than general heat exchangers. Some problems of heat transfer are studied in this paper,they are dew point ,boiling point,density,equilibrium constant, thermophysical properties and heat transfer calculation method.

A conducting oxidation-resistant carbide alloy layer can be formed on the surface of graphite electrode by means of the surface alloying method in a molden mixture. This compact layer can effectively reduce the consumption of graphite electrode due to carbon oxidation during arc furnace steelmaking. The process of alloy layer growth is found to be controlled by the non-steady state solid phase diffusion of carbon atom. A kinetic model was established thereupon. The model prediction is in good agreement with experimental data.

The identification of chemical reaction models with the use of eigenfunction expenditure was investigated through the forced ocsillation experiment method. Numerical simulation results revealed that the eigenfunction distribution of rival reaction models raried greatly under some operation conditions. With the experimentation under that operation conditions, the reaction model of true mechanism can be identified

The vapor - liquid phase equilibrium data for the binary systems of benzene - water and m-xylene-water under 0. 1013MPa were determined by using an improved Partt equilibrium cell. Thermodynamic consistency test indicated that the experimental data were reliable.

A unique phosphor tracer technique was used to allow experimental measurement of residence time distribution (RTD) of solids in the circulating fluidized bed. The instantaneous input of light impulse and the detection of the light emission by the excited phosphor particles permit on-line continuous determination of solids tracer concentration with time at different radial and axial positions within the riser and downer. The measured RTD curves in the downer show that less axial solids mixing takes place in the downer than that in the riser. The two-peak distribution of RTD curves in the riser is clearly seen in the experiment.

The least squares method is the simple form of the method of weighted residuals (MWR). The main feature of this method is transforming a boundary problem of partial dif- ferential equation into an equivalent problem of optimization. To illustrate the calculating procedure calculations for two isothermal and two isobaric quaternary systems were made. It showed the advantages of this method in an identical computational form for any dimensional problems and the need for the intrinsic condition only in solving the equation . So the calculation for quaternary system can be easily done on personal computer and takes less calculating time.

Pressure drop, dynamic and static liquid holdup were determined by U-tube pressure manometer,volumetric and gravimetric method for fiber - packed trickle - bed reactors operated at room temperature and atmospheric pressure with gas and liquid mass flowrate varying from 0. 052 to 0. 25kg/(m2·s) and 0. 32 to 2. 56kg/(m2 · s) respectively. The ef- fects of fluid flowrate, bed voidage,fiber property and packing method on pressure drop and liquid holdup were discussed. Correlations for pressure drop and liquid holdup were presented as follows: pressure drop fig=14. 120Ret0.252Reg-1.471 where fig= δlgDeσg/(2Gg2), De = 4ε/C[(1-ε)aP] dynamic liquid holdup Hd = 0. 303Ret0.506Reg-0.141(Gagε)-0.128 static liquid holdup Hs = 0. 512ε-1.46

The intrinsic kinetic model for oxidative dehydrogenation of butene to butadiene over B02 catalyst was studied in an internal recirculation gradientless reactor by the sequential experiment design method, Hook -Jeeve and maximum likelihood method. Among 28 possible models based on a consecutive - parallel reaction network a model with the best fit was obtained as follows Where Dependence of selectivity with respect to butadiene on the partial pressures of oxygen, butene, butadiene and reaction temperature is as follows significance test indicated that reaction temperature was the main factor.

Experimental investigation of heat transfer enhancement of lubricating - oil flowing through the annular space with petal - form fin tube is reported in this paper. Eight kinds of petal - form fin tube are investigated, and the mechanism of heat transfer enhancement with petal - form fins disturbing oil flow is analysed. The results of evaluation of the efficiency of heat transfer enhancement of eight petal - form fin tubes have also been reported.