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1.
N. Jongen M. Donnet P. Bowen J. Lemaître H. Hofmann R. Schenk C. Hofmann M. Aoun‐Habbache S. Guillemet‐Fritsch J. Sarrias A. Rousset M. Viviani M.T. Buscaglia V. Buscaglia P. Nanni A. Testino J.R. Herguijuela 《化学工程与技术》2003,26(3):303-305
The synthesis of powders with controlled shape and narrow particle size distributions is still a major challenge for many industries. A continuous Segmented Flow Tubular Reactor (SFTR) has been developed to overcome homogeneity and scale‐up problems encountered when using batch reactors. Supersaturation is created by mixing the co‐reactants in a micromixer inducing precipitation; the suspension is then segmented into identical micro‐volumes by a non‐miscible fluid and sent through a tube. These micro‐volumes are more homogeneous when compared to large batch reactors leading to narrower size distributions, better particle morphology, polymorph selectivity and stoichiometry. All these features have been demonstrated on single tube SFTR for different chemical systems. To increase productivity for commercial application the SFTR is being “scaled‐out” by multiplying the number of tubes running in parallel instead of scaling‐up by increasing their size. The versatility of the multi‐tube unit will allow changes in type of precipitate with a minimum of new investment as new chemistry can be researched, developed and optimised in a single tube SFTR and then transferred to the multi‐tube unit for powder production. 相似文献
2.
测定钠中杂质的手动阻塞计的研究 总被引:1,自引:1,他引:0
文章介绍了测定钠中杂质浓度的手动阻塞计的原理、装置和实验结果。为了减少测量误差,我们研究了影响准确测定阻塞温度的因素,并且找到了减少测量误差的办法。在同样的杂质饱和温度下,该阻塞计测得的高、低阻塞温度所对应的杂质浓度差是很接近的。对氧其差值为1.03ppm;对氢为0.0763ppm。 相似文献
3.
简单回顾了国内外在火电机组运行优化领域的研究历程,列举了目前国内外市场上针对火电机组的各种主流运行优化产品的功能特点和应用情况,分析了国外引进产品和国内自主研发产品在中国当前市场环境下各自的优势和劣势。介绍了当前运行优化系统在国内电站机组的应用现状,阐述了国内外运行优化系统在实际应用中存在的问题,并提出了相应的改进意见。对机组运行优化系统的未来发展进行了展望,指出机组运行优化系统将利用先进技术设备和信息平台,与电站管理紧密结合,在日益规范的市场中不断发展完善,为提高电站经济性发挥更大的作用。 相似文献
4.
Hydrolysis of Milk Fat with Lipase in Reversed Micelles 总被引:5,自引:0,他引:5
Enzymatic hydrolysis of milk fat was studied in a reversed-micelle system consisting of lecithin, water (1% total volume) and butteroil. Candida cylindracea lipase entrapped in the water pools of reversed micelles hydrolyzed surrounding triglycerides. The optimum temperature for enzyme activity was 55°C with an activation energy of 15.4 kcal/mole, while maximum enzyme activity was observed between pH 4 to 6. The molar ratio of water to surfactant (R value) in the system influenced enzyme activity with maximum activity at R = 10. Enzyme activity also increased with increasing surfactant or enzyme concentration. 相似文献
5.
蒸汽喷射器射流场流动模型研究综述 总被引:1,自引:1,他引:0
综述了3种不同维数的喷射器射流场流动模型的研究工作,分析了3种模型各自的特点后指出,一维模型的建立主要基于定压混合理论或定常面积混合理论;二维偏微分方程模型建立后基于差分法等数值算法进行求解.随着网格技术和计算方法的提高,三维粘性射流场中激波和湍流的数值模拟发展迅速. 相似文献
6.
Yodel: A Yield Stress Model for Suspensions 总被引:1,自引:0,他引:1
A model for the yield stress of particulate suspensions is presented that incorporates microstructural parameters taking into account volume fraction of solids, particle size, particle size distribution, maximum packing, percolation threshold, and interparticle forces. The model relates the interparticle forces between particles of dissimilar size and the statistical distribution of particle pairs expected for measured or log-normal size distributions. The model is tested on published data of sub-micron ceramic suspensions and represents the measured data very well, over a wide range of volume fractions of solids. The model shows the variation of the yield stress of particulate suspensions to be inversely proportional to the particle diameter. Not all the parameters in the model could be directly evaluated; thus, two were used as adjustable variables: the maximum packing fraction and the minimum interparticle separation distance. The values for these two adjustable variables provided by the model are in good agreement with separate determinations of these parameters. This indicates that the model and the approximations used in its derivation capture the main parameters that influence the yield stress of particulate suspensions and should help us to better predict changes in the rheological properties of complex suspensions. The model predicts the variation of the yield stress of particulate suspensions to be inversely proportional to the particle diameter, but the experimental results do not show a clear dependence on diameter. This result is consistent with previous evaluations, which have shown significant variations in this dependence, and the reasons behind the yield stress dependence on particle size are discussed in the context of the radius of curvature of particles at contact. 相似文献
7.
8.
高精度智能转速测量模板的设计 总被引:1,自引:1,他引:0
介绍了一种利用高性能的16位单片机80C196KC进行转速实时高精度的测量方法,阐述了如何通过CAN总线实现与微机通讯;详细描述了硬件电路的设计,并给出了软件程序框图。 相似文献
9.
根据7号高炉中控室供电状况,进行了供电平衡分析。调整两段负荷,使供电平衡安全。 相似文献
10.
Matrix expression and reachability analysis of finite automata 总被引:1,自引:1,他引:0
In this paper,we propose a matrix-based approach for finite automata and then study the reachability conditions.Both the deterministic and nordeterministic automata are expressed in matrix forms,and th... 相似文献