共查询到20条相似文献,搜索用时 109 毫秒
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介绍冷换设备的化学清洗、“尿素难溶垢”的清洗、高压蒸汽发生系统的化学清洗、循环冷却水系统不停车化学清洗,高压射流清洗,叙述工业清洗技术在化肥厂的应用和发展。 相似文献
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国内外对多相流管输体系中水合物沉积的研究虽然很多,但水合物沉积机理仍有待进一步研究。本文根据水合物沉积实验开展条件的不同,将多相流管输体系分为气体主导体系、油基体系、部分分散体系、水主导体系,总结了各体系的水合物沉积的主要机理,并提出了未来的发展方向。管输体系中水合物沉积机理包括水润湿沉积表面、水合物颗粒聚并、水合物的管壁膜生长、水合物颗粒的管壁粘附和水合物的颗粒着床沉积等。大多数学者认为:水合物的管壁膜生长是气体主导体系水合物沉积的主要机理;油基体系水合物沉积的主要机理是水合物颗粒的着床沉积;而部分分散体系和水主导体系的水合物沉积机理尚无统一定论,需进一步研究。多相流管输体系中水合物沉积研究未来的发展方向如下。①搭建全透明的流动环路,观测水合物在管路内实际的形成过程及沉积过程,对水合物沉积机理进行深入研究。②量化研究油水分层、油包水(或水包油)乳状液、自由水层对水合物沉积、堵塞的影响。③对于气体主导体系,除环状流和分层流外,有必要对段塞流、气泡流等其他常见的流型下沉积机理进行研究,重点在于开发一个综合模型来描述水合物沉积过程。④对于水主导体系,水合物形成过程出现的油水破乳的具体机理应是未来水合物沉积过程进行定量研究的方向。⑤国内外对垂直管、弯管及管阀件处水合物沉积堵塞理论研究较少,未来应着重这方面。 相似文献
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D. I. McCready 《Aerosol science and technology》2013,47(3):301-312
An inexpensive microsphere dispersion, deposition, and sampling system is described. This system was used to examine the transport and deposition of small particles (? 1 μm diameter) across the aerodynamic boundary layer which developed over a prototype deposition surface (smooth, flat, acrylic plate). Unit density, polystyrene latex microspheres (0.8 and 1.1 μm diameter) were deposited onto both oil-coated and dry, upper and lower surfaces. Observed deposition velocities were significantly larger than those reported in the literature, possibly because low relative humidities increased electrostatic charge on the experimental plate. The experimental results were greater than those predicted by a turbulent flow particle deposition model. 相似文献
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粒状材料熔融沉积成型系统直接应用粒料成型原型件,造价和使用成本低.对粒状材料熔融沉积成型系统进行开发,并研究影响系统出丝过程的因素.试验表明:所开发的系统达到了预期设计目标. 相似文献
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The deposition of submicrometer soot aerosol particles in a miniature pipe bundle heat exchanger system has been investigated under conditions characteristic for combustion exhaust from diesel engines and oil or biomass burning processes. The system has been characterized for a wide range of aerosol inlet temperatures (390–510 K) and flow velocities (1–4 m s?1), and particle deposition efficiencies up to 45% have been achieved over an effective deposition length of 27 cm. Thermophoresis was the dominant deposition mechanism, and its decoupling from isothermal deposition was consistent with the assumption of independently acting processes. The measured deposition efficiencies can be described by simple linear parameterizations based on an approximation formula for thermophoretic plate precipitators. The results of this study support the development of modified heat exchanger systems with enhanced capability for filterless removal of combustion aerosol particles. 相似文献
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酯化反应釜中积垢的分析 总被引:1,自引:0,他引:1
对PET生产系统酯化反应釜所存在的积垢进行了观察和处理。对积垢的组成和形成机理进行分析,指出酯化Ⅱ反应釜中所发现的积垢主要成分是SbPO4,将锑系催化剂与磷酸根类添加剂接触时间缩短可有效减少SbPO4的生成。通过工艺改进,保证生产系统正常运行。 相似文献
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A flow plating system was used to investigate chromium metal deposition from an electrolyte based on Cr(iii) and glycine. The Cr(iii) glycine species suitable for chromium deposition was identified. The chemical reactions occurring during electrolyte preparation and during metal deposition are discussed. Chemical reaction sequences for the predominant reactions are suggested. The influences of the chromium ion concentration, temperature and electrolyte velocity on chromium deposition are considered. The optimum conditions for good quality chromium metal deposition are determined. 相似文献
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Robert J. Reuvekamp Madhumita B. Ray Alex C. Hoffmann 《Chemical Engineering Communications》2002,189(6):849-864
The deposition of a very fine powder in a horizontal, lean-phase pneumatic conveying conduit containing a 90° bend has been studied experimentally. The total deposition and the deposition pattern were studied as a function of superficial gas velocity, solids loading and bend geometry: one sharp and three smooth bends of different radii of curvature were used. Most deposition was seen in the sharp bend, while in the smooth bends the deposition did not vary much with radius of curvature. The deposition decreased significantly with increasing superficial gas velocity. The experimental results were compared with CFD simulations of the flow field. The observations are consistent with the notion of deposition in regions with low near-wall gas velocity, indicating that models for deposition should be sought in considerations of the deposit stability for this type of system. 相似文献