Modeling the Absorption of Acidic Gases by Alkanolamine Solutions Incorporating Several Reactions

A general model, based on double film theory, is developed to study absorption with chemical reactions. In the liquid film region, the model is a set of differential equations that describe the mass transfer accompanying several chemical reactions; the resolution of the system is achieved by the finite difference method using an implicit scheme combined with Newton's method. Continuity equations and equilibrium coefficients are exploited in the treatment of the bulk region, which is based on the Newton‐Raphson method; the results are used directly as boundary conditions in the liquid film equations. Maxwell‐Stefan equations have been used as a rigorous approach in this model.     

Engineering Model of a Nonisobaric Heavily Laden Gas‐Particle Jet

An axisymmetrical model of a rapid nonisobaric heavily laden gas‐particle jet is developed. The model is based on the general functions for both axial and radial pressure distributions, which were discovered by a numerical study of rapid gas‐particle jets by the CFD code. The model equations were solved analytically. The results obtained by the model developed are in good agreement with those computed by the CFD code for a wide range of flow parameters.     

Belgian Experiences in the Ozonization of Water

After reviewing the uses of ozone in the preparation of drinking water, high purity water for Pharmaceuticals industries, and swimming pools throughout Belgium, a discussion of technological developments made at the Tailfer plant (serving Brussels) concerning the uses of ozone is presented. These subjects include analytical and monitoring techniques developed for ozone, procedures for ozone contacting employed at this plant, treatment of ozone contactor off–gases, and the use of oxygen–enriched process gas to produce supplemental amounts of ozone required periodically. Capital and operating cost data are presented.     

惰性气体保护熔炼--国外精铸技术进展述评(8)

惰性气体保护熔炼的基本原理是将低温液态惰性气体滴在熔池表面或直接将惰性气体覆盖在熔池上方，驱赶熔池上方的空气，降低熔池上方气体中的氧含量，从而避免合金液氧化和吸气。使用该技术后，熔炼过程无须熔剂覆盖和脱氧，不仅非金属夹杂物、气体夹渣等铸造缺陷大为减少，而且由于合金液纯净度提高，流动性也有所改善，浇不足、冷隔等缺陷随之减少：     

Structure–fracture relationships in gas-filled gelatin gels

Food aeration has become one of the fastest growing unit operations practiced in the food industry. Dispersed air (or other gases) provides an additional phase within the gel that may accommodate new textural and functional demands. This paper addresses the relationships between structural characteristics and fracture properties of gas-filled gelatin gels (GGG), and compare these properties with those of control gelatin gels (CGG). Three gases were used in the fabrication of GGG: air, nitrogen and helium. Experimental methods to determine density, gas hold-up, bubble sizes and bubble size distributions as well as fracture properties of GGG are presented. Increasing protein concentration produced higher density, lower gas hold-up and decreased polydispersity of bubbles due to its effect on increased solution viscosity. Type of gas affected density and gas hold-up due to the different diffusivities of gases and structures (bubble size, size distribution and number of bubbles per area) formed in GGG. Fracture values increased for both GGG and CGG with increasing protein concentration for the three gases used. GGG were weaker and less ductile than CGG, the decrease in stress and strain at fracture being between 70 and 80%, and 40 and 65%, respectively. A power law relationship (σ_f = 2.73 × 10⁻¹²ρ_G^4.76) was found between the fracture stress and gel density for the three gases studied. This study shows that the presence of bubbles in gel-based food products results in unique textural properties conferred by the additional gaseous phase.     

Computational fluid dynamic analyses of catalytic combustors for 100 kW-class molten carbonate fuel cell

The asymmetric inner structure of a catalytic combustor causes wall cracking because of regional overheating. Thus, a symmetric shape is proposed in the present work and analyses of the computational fluid dynamics of the existing combustor and the proposed type have been performed. A simulation of the revised combustor without a swirl device revealed that the flow of gases is concentrated on the center of the combustor and only catalysts around the center are used. In the revised combustor with a swirl device, the overall temperatures were estimated to be uniform. However, near the swirl device, high temperature exceeding 1,700 K was measured. Therefore, a heatproof surface coating on the swirl device is necessary for protection of the material. At the initial start-up of the catalytic combustor, hydrogen and natural gas are used. When only natural gas is used, the simulation indicated that the gas does not burn in the revised combustor without a swirl device. However, in the combustor with the swirl device, methane of 34.8% volume burns in the simulation. On the other hand, when hydrogen and natural gas are burned together, methane of 91.7% volume burns in the simulation.     

页岩气开发水资源影响及温室气体排放研究评述

环境问题是影响页岩气中长期、可持续开发的关键因素之一,而对页岩气开发环境影响的研究则是相关环境政策制定的基础。文章以国际学术期刊上刊登的相关研究为分析对象,首先梳理了页岩气开发环境影响研究的兴起过程,并指出了页岩气开发过程中水资源消耗、水质污染和温室气体排放是国际学术界页岩气开发环境影响研究的三个主要方面。然后,系统评述了当前国际学术界对此三方面环境影响的研究现状、得到的基本结论、结论之间的差异以及差异背后的原因,以期对中国开展此类研究,特别是量化研究提供借鉴。     

Estimation of optimum experimental parameters in chlorination of UO2 with Cl2 gas and carbon for UCl4

For the preparation of uranium tetrachloride, the chlorination of UO₂ was carried out and an appropriate reaction system was confirmed. The effects of reaction temperature, time, injection ratio of N₂ gas and appropriate amount of carbon using a reductant on the conversion ratio and volatilization were evaluated. The optimum reaction time and temperature in chlorination of UO₂ for the preparation of UCl₄ were 2 h and 500–700°C, respectively. Also 50% of N₂ gas in chlorine gas proved to be the appropriate injection ratio.     

电解二氧化锰生产中粉尘和酸雾废气净化的探讨

介绍了生产电解二氧化锰的制液过程中,产生含有粉尘、酸雾废气的特点.并对这种废气的治理提出了采用湿式除尘器与气液吸收设备相组合的装置——文丘里除尘器及改进的玻璃钢酸雾净化塔净化方案。通过分析、比较,提出了研制、生产既能除尘,又能吸收酸雾的高效气液吸收设备的设想。