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高炉液压泥炮故障分析与对策 总被引:4,自引:0,他引:4
液压炮是维系高炉生产的重要设备 ,对济南钢铁集团总公司第一炼铁厂液压炮不同故障情况进行分析 ,并制定相应故障解决对策 ,从而有效地保证了液压炮稳定运行 ,保证了高炉的正常生产。 相似文献
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The main purpose of this paper is to use an external recirculation pipe to inhibit geysering phenomenon in cryogenic propellant transfer system. Inhibiting geysering phenomena in the long vertical cryogenic feeding-line is very important to both the system designers and the operators because they may be latent catastrophic failure(s). Separated-flow model has been used in numerical simulation. Considered the numerical simulation results and the experimental conditions, an experimental set-up using liquid nitrogen (LN2) as working fluid has been built to simulate the recirculation in the long vertical cryogenic feeding-line.From the experimental results, it is clear that the natural circulation occurs in the recirculation system utilizing the external recirculation pipe and geysering phenomenon is inhibited. Adding external recirculation pipe to normal feeding-line system can be an effective method to reduce or eliminate geysering in cryogenic propellant transfer system. 相似文献
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固体颗粒表面改性及其在推进剂领域中的应用研究 总被引:2,自引:0,他引:2
对推进剂组分中的氧化剂、燃料等固体颗粒进行表面改性处理,不仅能提高单组分的使用性能,也是提高推进剂力学性能、改善燃烧性能和推进剂工艺条件的重要途径.本文综述了固体颗粒表面改性的方法及表面改性后的表征,分析了包覆颗粒性能变化及其对推进剂性能的影响. 相似文献
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Experimental nanotips have shown significant improvement in the resolution performance of a cold field emission scanning electron microscope (SEM). Nanotip electron sources are very sharp electron emitter tips used as a replacement for the conventional tungsten field emission (FE) electron sources. Nanotips offer higher brightness and smaller electron source size. An electron microscope equipped with a nanotip electron gun can provide images with higher spatial resolution and with better signal-to-noise ratio. This could present a considerable advantage over the current SEM electron gun technology if the tips are sufficiently long-lasting and stable for practical use. In this study, an older field-emission critical dimension (CD) SEM was used as an experimental test platform. Substitution of tungsten nanotips for the regular cathodes required modification of the electron gun circuitry and preparation of nanotips that properly fit the electron gun assembly. In addition, this work contains the results of the modeling and theoretical calculation of the electron gun performance for regular and nanotips, the preparation of the SEM including the design and assembly of a measuring system for essential instrument parameters, design and modification of the electron gun control electronics, development of a procedure for tip exchange, and tests of regular emitter, sharp emitter and nanotips. Nanotip fabrication and characterization procedures were also developed. Using a "sharp" tip as an intermediate to the nanotip clearly demonstrated an improvement in the performance of the test SEM. This and the results of the theoretical assessment gave support for the installation of the nanotips as the next step and pointed to potentially even better performance. Images taken with experimental nanotips showed a minimum two-fold improvement in resolution performance than the specification of the test SEM. The stability of the nanotip electron gun was excellent; the tip stayed useful for high-resolution imaging for several hours during many days of tests. The tip lifetime was found to be several months in light use. This paper summarizes the current state of the work and points to future possibilities that will open when electron guns can be designed to take full advantage of the nanotip electron emitters. 相似文献
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Wooram Kim Younja Kwon Young Min Jo Young Chul Park 《Journal of Energetic Materials》2017,35(1):44-52
Potassium sulfamate (PS) is an efficient starting material for the nitration reaction used in the synthesis of ammonium dinitramide (ADN), which is an environmentally friendly high-energy oxidizer for propellants that does not release chlorine-based compounds. PS is a core structure to form dinitramide, -N(NO2)2, by taking NO2? from nitric acid. In this work, five test batches of PS were prepared using a few solvents including ethanol, methanol, acetone, isopropanol, and their mixtures. The lab-made PSs matched well with the commercial PS in terms of the chemical structure. The use of acetone led to a high recovery of PS up to 97 w/w% and ultimately contributed to the formation of high-purity and (99.2%) and a high yield (57.3%) that are greater than those for commercial PS (87.3% purity and 31.3% yield). Therefore, we proved that the crystallinity and homogeneity of PS influenced the properties of ADN and the synthesis efficiency. 相似文献