This paper describes an imperfect pulse injection stimulus-response technique to study the axial mixing in the extraction column. The comparison among various methods of parameter estimation shows that the least-squares fitting method in the time domain is more accurate one. The uncertainty are discussed. Effects of pulse amplitude and frequency were studied in the standard sieve plate pulsed column.

The exact expressions of concentration and local or average Sherwood number, Sh or Sh for non-Newtonian power law fluids when the flow index n takes any positive rational value, have been obtained by solving the differential equation of diffusion together with the velocity distribution in the falling film. The use of Fourth-order Runge-Kutta method and Wegstiens iteration method in the computer yields results which are a series of values of dimen-sionless concentration 0 local and average Sherwood number for n equal to 1/4, 1/3, 1/2, 1/1.4, 1/1.2, 1, 1.25, 2.5, and GO. When the flow index n=1, i. e. for Newtonian fluids, the result agrees well with the data from the literature. In the above equations, if we substitute thermal diffusivity a for the diffusivity D, local and average Nusselt number Nu, Nu for Sh, Sh, dimens-ionless temperature T=(Ts-T)/(Ts-T1) for , then, they may be used to evaluate the problem of heat transfer in film flow. All the results of calculation may be used for engineering design, but they must be applied within the limits of laminar flow or non-wavy film flow.

The mass-transfer coefficient k is an important parameter for predicting the concentration polarization of reverse osmosis and other membrane separation processes. In order to determine the k value precisely, a diffusion current method with special porous electrodes has been developed. This method can be used to determine the k values for both one dimensional and two dimensional flow. It seems that the actual situation of membrane process is closely approached, so the dimensionless empirical equations obtained have a greater practical value. The equations of pre?ent work are compared with the data of previous authors. Many results seem to be in good agreement. Therefore this paper offers useful reference for research and design of diversified membrane separation systems in future.

Luus random search algorithm[1] does not converge to the optimal solution when the selected initial value X(0) and initial search region R(0) are not proper. This paper has found out a reason of the fact that the above-mentioned algorithm took a systematic reduction of the size of search region under the constant factor. The modified random search, algorithm has been proposed by the author. The idea of this algorithm lies in that the search region is expanded when the search is proceeding with big strides, vice versa. Thus the search region was reduced from the overall situation, but, on the contrary, it was expanded occasionally from the partial situation. The modified algorithm is noted as below:whether X(0) or R(0) was selected has no influence over the reliability 5 theorically it goes a way towards solving the problem of rather high dimension in theory; it is suitable not only to solving the problem of constrained nonlinear programming but also to that of unconstrained; the feasible region is not necessarily limited on convex region. The application of the modified random search algorithm has been described with illustrations and the comparsion between modified and Luus random search algorithm has made.

The results of adsorption equilibrium measurements show that the saturation adsorbed amounts(x/m)M of some organic acids increase in the following order:Acetic

To purify synthetic gases, the technique of pressure swing adsorption process is used. Three kinds of zeolite, type 13X, 5A, NaY and active carbon were used to determine the adsorption equilibrium of CO2 and CO by static(weighing)and flowing method respectively. The amounts of CO2 adsorbed with 13X zeolite and active carbon are larger than others. The representation of adsorption isotherms of CO2 can be done with Langmuir or Freundlich equation. The amounts of CO adsorbed with all the four kinds of adsorbent are small. The adsorption and desorption breakthrough curves of CO2 with type 13X zeolite and active carbon in COa-N2 binary system were investigated.

An experimental study of the hydraulic performance and oxygen desorp-tion efficiency of a vertical sieve tray and T-arrangement rectangular valve tray has been made with water-air system in a 300mm test tower and preliminary correlations were obtained between the tray pressure drop, leakage, entrainment, pressure drop of the gas passing through the liquid layer, and the clear liquid height in the downcomer. On the basis of analysing and comparing the data of the two types of trays with those of F1-type circular valve tray, it is found, under the same experimental conditions, that the fractionation efficiency and tray pressure drop of VST and RVT are approximately equal to those of F1-type circular valve tray but the operating range is much wider than that of the latter type.

In order to apply the gas-rotation-plate (GRP) droplet separator to dust separation, the following experiments were carried out: a GRP separator was installed near the top of a 300 fluidized bed, the dust used was PVCR and Al2O3 powders and Fe2O3 dust collected from an electric precipitator. The efficiency of dust separation was higher than 99% for the dust through 200 mesh, while the pressure drop was lower than 10 mm H2O, at air velocities ranging from 0.4 to 1.7m/s. It was also good for the separation of Fe2O3 dust through 200 mesh. Sealing device was unnecessary for the dipleg for dust returning to the lean phase or dense phase of the bed, owing to the low pressure drop and structural characteristics of the separator. The GRP separator has been used for the flue gas from the furnace of a 6.5-ton boiler. About 1 ton of coal dust was recovered per day. The relationship between the critical particle diameter and the structure parameters was derived under some assumptions.

Measurement of thermal expansion coefficients of solid materials with the thermal dilatometric attachment of Shimadzu DT-2A differential thermal analyser was described. The dilatometer was calibrated with pure copper (99.95%) in the temperature range of RT-900℃ in order to get the instrumental constant. By checking with Fe and Ni samples of known thermal expansion coefficients, the results obtained are found to be in agreement with those from the literature and the differences are less than ±2.5%. Volume expansion ratio of two composites, graphite and glass fibre reinforced plastics, can be calculated through the linear expansion measurements. Approximate equations for calculating volume expansion ratio by curve fitting method were also obtained.

Hydrodynamic behavior of HY-Contact valve tray has been studied on a 1000×150 mm2 rectangular laboratory tray model by using air and water. The primary experimemtal results about dry tray pressure drop, wet tray total pressure drop, entrainment and weeping are reported. Empirical correlations are proposed. Some new phenomena have been observed and interpreted.