The effect of electric fields on the absorption of pure sulfur dioxide by water drops

The effect of an electric field on the absorption of sulfur dioxide by pure water drops is examined experimentally. Field strength is varied up to 8.0 kV/cm, and nozzle Reynolds number is varied between 26 and 78. Drop surface charge density, size, shape, shape oscillation, acceleration and total sulfur dioxide uptake are measured directly. Significant reduction in drop size and increase in acceleration with increasing field strength are the major effects observed, while alteration in drop shape and oscillation are slight. Calculated average mass transfer coefficients increase with both field strength and nozzle velocity, but total sulfur dioxide uptake decreases with field strength due to reductions in drop-gas contact time. The results suggest that the design of scrubbers with electric fields concentrated in the region of drop formation but absent elsewhere show the greatest promise for improved efficiency.     

基于GPGPU的实体表面实时提取

为实时提取三维实体表面,提出一种基于GPGPU并行计算的实体表面实时提取方法。在分析深度剥离算法原理和GPU图形绘制管线的基础上,给出在GPU上利用深度剥离算法实现实时提取三维实体表面的算法;通过OpenGL的高级着色语言GLSL控制GPU的图形绘制管线实现了该算法,给出其伪代码。以龙、叶轮和刀具扫描体的模型为应用实例验证了该算法效果良好,特别是对于刀具扫描体表面的提取,可满足实时性要求。     

Azo disperse dyes with polyfluoroalkyl groups attached to the nitrogen atom of the coupling component

A number of new azo disperse dyes with polyfluoroalkyl groups attached to the nitrogen atom of the coupling component have been prepared. The influence of polyfluoroalkyl groups on the colour and properties of azo dyes has been studied. The replacement of hydrogen atoms of the methyl group of the coupling component by polyfluoroalkyl radicals causes a hypsochromic shift of absorption maximum in a neutral solution and deepening of the dye colour in an acid solution. All tested dyes showed a high lightfastness on acetate and polyamide fibres.     

Experimental observation of temperature gradients occurring in a single zeolite pellet

An experimental study has been made of temperature profiles incident within a zeolite adsorbent particle in the course of adsorption of n-heptan. Using thermocouple wires 0.1 mm in diameter it has been possible to measure simultaneously the temperatures of the surface and in the centre. It was observed that temperature differences between center of the pellet and ambient stagnant gas may be more than 20°C. The results of this work indicate that the overheating of an adsorbent particle is a very rapid process which is followed by a slow cooling of the hot particle. Experimental data are compared with predictions calculated from the theoretical model.     

Flow distribution and pressure drop in plate heat exchangers—II Z-type arrangement

To investigate the flow distribution and the pressure drop in the Z-type arrangement plate heat exchangers, a theoretical analysis has been made including mass and momentum balances for a flow element in both the intake and exhaust conduits. Calculations based on one-dimensional flow equations have been carried out.It is found that the flow distribution and the pressure drop can be determined by a general characteristic parameter (m). Nearly uniform flow distribution may be obtained when m is equal to zero. In the case when m² is positive, the channel flow rates will increase in the direction of the intake stream. If m² is negative the channel flow rates will also increase in the intake stream direction. The analysis also shows that the total pressure drop in plate heat exchangers is practically the same for both U - and Z-type arrangements. The results are applicable to a wide variety of combinations of heat exchanger dimensions, channel goemetries and fluid velocity. They are summarized by charts that permit a designer quickly to estimate the flow patterns.     

Vapour liquid equilibrium with association in both phases: A model with the concentration-dependent liquid phase association constant applied to acetic acid—benzene, -toluene, -p- and -o-xylene

A model employing the correction factors of Marek and Standart, but using a concentration-dependent liquid phase association factor of Jenkins—Robinson, has been used to model vapour—liquid equilibrium data for mixtures of acetic acid with benzene, toluene, o-xylene and p-xylene. With the aim to use systems of acetic acid—benzene and acetic acid—toluene as the test mixtures for distillation columns, the examination of the systems of acetic acid—aromatic hydrocarbons was undertaken. The model promises to be useful in modelling isobaric and isothermal data of acetic acid—benzine, acetic acid—toluene, acetic acid-p-xylene and acetic acid-o-xylene systems. Deviation plots show that the isothermal and isobaric data are represented well.     

A modification of broyden's method for the solution of sparse systems—with application to distillation problems described by nonideal thermodynamic functions

An algorithm that permits Broyden's method to be used for the solution of large systems of algebraic equations with sparse Jacobians is presented. The new procedure is compared to Schubert's modification of Broyden's method and to the Newton-Raphson method by solving an extractive distillation problem. It is demonstrated that the new procedure is competitive with Schubert's method when it is necessary to evaluate Jacobian matrices numerically.     

Exploiting border structure in solving large sparse linear systems in bordered triangular form

An elimination strategy for solving sparse linear systems in bordered triangular form is presented. This strategy is designed to exploit certain common structural properties of the borders of such a system. It may also be interpreted as a recursive application of block elimination. The technique is numerically efficient and provides significant reductions in fill-in compared to routine Gaussian elimination. It is applicable in the iterative solution of the large systems of nonlinear equations that arise in the equation-oriented approach to process simulation and design calculations, as well as in other problems of interest to the chemical engineer.     

双阳煤在PKM气化炉试烧总结

介绍了在PKM气化炉中弱粘结性双阳煤的试烧情况,并给出了主要工艺参数控制范围。试烧结果表明:依兰煤中配入50%双阳煤,汽氧比6.0:1时,气化炉工况良好。     

Metal recovery in a pilot-scale rotating cylindrical wiper-blade electrode system

The performance of an experimental pilot-scale electrochemical reactor using a rotating cylindrical electrode equipped with wiper blades is described. Data obtained from monopolar depositing and bipolar stripping—depositing of copper from dilute aqueous electrolytes are presented and certain economic aspects of metal recovery are discussed.