A new mathematical model of mixing pool type is proposed to simulated the fluid flow and mass transfer behavior in a large tray. In the proposed model, the whole tray deck is divided into a number of square (or rectangular) compartments or mixing pools, each of which is assigned to have adjustable flow and backmixing in both z (along the main flow path) and w (perpendicular to the main flow path) directions. The chief features of present model are: (1)It is a two dimensional model instead of usual one dimensional so that more complicated actual flowing condition obtained from hydrodynamic study in a large tray can be closely simulated by adjusting the flow among mixing pools in both z and w directions. (2)Since backmixing is taken into account, the number of mixing pools in a tray can be fixed instead of varied as in conventional mixing pool model;thus, the application of matrix computation is possible. (3) The present model can be reduced to other tray models depending on the number of mixing pools to be chosen in each direction. The application of present model to predict the liquid phase concentration profiles and Murphree efficiencies in a tray with complicated flow pattern and velocity distribution as we observe in our experimental study are demonstrated. The effects of liquid flow rate, non-uniform velocity field, directional splashing and subsidiary flow are also investigated and discussed.

A stimulus-response technique is used to determine gas-particle heat transfer coefficient in packed bed. The input signal is a one-shot temperature impulse of arbitrary shape and at a distance downstream from the input point the temperature response is measured. The mathematical model adopted for the packed bed is one-dimensional heterogeneous Dispersion-Concentric model. Laplace transform method is used in the solution of the partial differential equations of the model. As the resulting transfer function is too complicated, a Fourier analysis method is applied. The input and response signals are both expanded in Fourier series form. The Fourier coefficients of the response signal can be predicted directly from those of the input signal and the transfer function and thus the calculated response signal function is obtained, which can then be fitted with the measured one to carry out the parameter estimation. In the procedure of curve fitting the mean square deviation between calculated and measured response functions in the whole time domain is minimized. It is found that the result of this work can be put into an expression assuming the same form of a known correlation of mass transfer Nu=2+l.lPr1/3Re0.6 in which the Nusselt number Nu contains the gas-particle heat transfer coefficient determined. The result also shows that in the laminar flow regime the Nusselt number of gas-particle heat transfer does not decrease appreciably with the decrease in Reynolds number. The exprimental equipment is also described in the paper.

This paper discusses the investigation on the effect of reactive activity of quadruply promoted ammonia synthesis catalyst A110 by using synthesis gas containing <5-~30ppm water vapor under high pressure. The experimental data were treated with the modified T- equation. We have found that the poisoning factor POIS=k/kTO is approximately in inverse proportion to VH2O and proportional to 6th power of absolute temperature, and minimal relation with pressure. The catalysts appeared to be inflicted by poison when water vapor reached PH2O/PH2 =10×10-6. The intrinsic apparent energy of activation raised from 38000 kcal/kg-mol to 40000 kcal/kg-mol or higher as the amounts of water vapor poisons increased. In comparison with the catalysts original intrinsic activities, appreciable change of kinetic performance under poisoning conditions, especially in the lower temperature region, has been acquired. After 15 days repeated poisoning experiments it is discovered that most of the catalytic activity has been recovered but a certain degree of its activity has been permanently destroyed by poison. Calculation of the empirical correlations of the poisoning factor of trace water vapor has been procured.

A new composite PbO2/Ti anode with an interlayer of Sb-doped SnO2 was prepared. The resistivity and components of the interlayer were determined by four-probe method and X-ray diffraction respectively. Comparisons of the contact resistance and operating life of the PbO2 electrodes with and without the interlayer showed that the composite PbO2/Sb-SnO2/Ti electrode was good in performance and can be used for practical purposes.

The effect of radiation conditions on the polymerization progress and none-strength temperature (NST) in the radiationinduced bulk polymerization of chloro-trifluoroethylene is presented in order to bring to light the regularity by which high quality products may be prepared. On changing the dose(D), dose rate(I)and radiation temperature (T), the kinetic progress remains smooth. One of the principal factors of controlling the product quality, i. e. NST, has been especially discussed and a relation between the factors which affect NST is obtained. This relation provides the basis for the selection of conditions for preparing products with various properties: when t≤20℃, NST = 1.75.l0-2.T0.9.I-0.39.D0.39; when t≥20℃, NST = 4.108.T-3.3.I-0.36.D0.39. The test results testify that the products from the bench-scale experiment have good thermal stability, excellent mechanical properties, reproducible quality, and high purity. The technological process is simple.

This packing is a new, high efficiency and regular packing. The use of two layers of stainless steel gauze gives good wettability and uniform liquid distribution over the entire packing surface, so that the separation efficiency is increased sensibly even with liquids of high surface tension like water and under low liquid load. Vacuum rectification tests on D2O/H2O system have been performed with a column of 10cm inside diameter, the packing hight of 200cm, and column top pressure about 125 torr. By the use of the measured data, satifactory correlations for pressure drop and mass transfer of this packing were obtained in the article.

In this research, the pressure drop data at different gas velocities and flooding point data have measured with the air-water system at different irrigating rates for eleven random tower packing of Dg50mm. We found some disadvantages in J. S. Eckerts method and think that it is not suitable to be used as the foundation for further modification, On the basis of the researches done by our predecessors, we have in this article, suggested two new equations, one for calculating the flooding velocity the other for calculating the pressure drop

In this work, a pair of group interaction parameters, aCCOH, CHO and aCHO, CCOH, used in the UNIFAC group contribution method, has been supplemented from experimental vapor-liquid equilibrium data of iso-butanol iso-butaldehyde system available from literature[5]. The UNIFAC method has heen used in phase equilibrium calculations for systems of n-and iso-butanol purification process with accuracy approaching or attaining that of results calculated by NRTL and other correlations. In view of the fact that the UNIFAC method is based upon the assumption of additive property of group properties, it is necessary to check the calculating results with a few experimental data and to make appropriate choice of the available group parameters.

The three laws of similitude theory are the essence and centre of the whole theory. This paper presents the second law of similitude theory, or the theorem a machematical proof. The method and steps, adopted here for proof, fit well both to theorem in function analysis and in dimensional analysis.

High-speed magnifying photography is an economical non-intrusive measurement method. It can be used to measure the droplet size in flight. This paper describes the measurement theory, experimental devices and the measurement results of this technique used for the determination of droplets atomized by an industrial burner. For this test, the sauter Mean diameters measured by the industrial burner are 58 micron at 400mm section and 62 micron at 500mm section respectively. The test results are satisfactory with relative error less than 8%.The mi-nimun measurable droplet size is 12μ