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排序方式: 共有1377条查询结果,搜索用时 15 毫秒
1.
ABSTRACTA mathematical model has been developed by coupling genetic algorithm (GA) with heat and material balance equations to estimate rate parameters and solid-phase evolution related to the reduction of iron ore-coal composite pellets in a multi-layer bed Rotary hearth Furnace (RHF). The present process involves treating iron ore-coal composite pellets in a crucible over the hearth in RHF. The various solid phases evolved at the end of the process are estimated experimentally, and are used in conjunction with the model to estimate rate parameters. The predicted apparent activation energy for the wustite reduction step is found to be lower than those of the reduction of higher oxides. The thermal efficiency is found to decrease significantly with an increase in the carbon content of the pellet. Thermal efficiency was also found to increase mildly up to three layers. Multilayer bed remains as a potential design parameter to increase thermal efficiency. 相似文献
2.
利用TRIZ理论,采用因果分析现有结构中缺陷与不足产生的原因。在分析了整个集装箱吊具旋锁机构的系统组件模型后,利用因果分析寻找产生的原因。针对不同的问题采用不同的TRIZ解题工具分别运用技术矛盾、物质—场分析、进化分析对旋锁机构进行创新方案的设计。 相似文献
3.
In most used rotary valves in GM-type pulse-tube refrigerators the rotor makes heavy mechanical contact with the stator, so the valve is liable to wear, and large torques are needed. In this paper we will describe two types of valves, which have balanced forces on the rotor. In the first valve the rotor and the stator make no mechanical contact. The second type is a contact valve, like the classical valves, but the forces on the rotor are balanced in a different way. Therefore, these valves are less liable to wear, and the torques needed to rotate the valves are small. 相似文献
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Abstract— In response to the increasing structural applications in duplex steels for welded structures, fatigue behaviour of a SAF 2304 grade duplex stainless steel was investigated, considering both the base metal and GTAW welded joints. Fatigue curves and fatigue limits under rotary bending fatigue were obtained. The study focused attention on the microstructural features of fatigue crack propagation of the two series of experiments, thereby permitting an evaluation of the tortuous crack path of welded joints and the mechanisms related to threshold microstructural barriers. 相似文献
6.
转子-轴承系统启动过程瞬态不平衡响应的有限元分析 总被引:1,自引:0,他引:1
转子系统在启动的瞬态过程中通过共振区时常常会产生很大的振动。利用有限元法对多自由度的某转子-轴承系统的,临界转速和启动过程的瞬态不平衡响应进行了分析,研究了该系统的瞬态振动特性,讨论了启动加速度对转子系统振动的影响。计算结果为降低旋转机械系统启动过程的振动影响提供了一定的理论参考。 相似文献
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Design improvements on rotary valve particle feeders used for obtaining suspended airflows 总被引:2,自引:0,他引:2
Mehmet Yasar Gundogdu 《Powder Technology》2004,139(1):76-80
The back repulsion of low density particles, sticking of particles in feeder valve and interlocking and cohesive archs of particles in feeder hopper have been widely observed problems of a conventional rotary valve feeder used for feeding of granular particles into an airflow line. In this study, these problems of the rotary valve feeders were isolated by means of novel modifications to its conventional design. Results of the modifications showed that the modified feeder can be sensitively used to feed granular particles with mass feeding rates ranging between 5±0.15 and 85±0.85 g/s without encountering problems experienced with conventional rotary valves. 相似文献
9.
环形转底炉海绵铁生产方法 总被引:7,自引:0,他引:7
介绍了国内外环形转炉生产海绵铁方法(Fastmet法,Inmetco法和COF-R)发展状况。分析了此种工艺的工艺特点和热工特点,指出了这种方法与回转窑法,遂道窑法比较具有强大的市场竞争力。 相似文献
10.
Ultrasonic-assisted drilling of Inconel 738-LC 总被引:4,自引:0,他引:4
B. Azarhoushang J. Akbari 《International Journal of Machine Tools and Manufacture》2007,47(7-8):1027-1033
Generally in the drilling of modern aviation materials such as nickel and titanium base super alloys, problems frequently occur in terms of burr formation at the cutter exit, tool stress, high heat generation on tool surface as well as low process reliability. A recent and promising method to overcome these technological constraints is the use of ultrasonic assistance, where high-frequency and low-amplitude vibrations are superimposed on the movement of cutting tools. This paper presents the design of an ultrasonically vibrated tool holder and the experimental investigation of ultrasonically assisted drilling of Inconel 738-LC. The circularity, cylindricity, surface roughness and hole oversize of the ultrasonically and conventionally drilled workpieces were measured and compared. The obtained results show that the application of ultrasonic vibration can improve the hole quality considerably. Improvements of up to 60% have been achieved. 相似文献