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41.
目的研究不锈钢-气氮板式热沉中,氮气压力、氮气入口流速以及热沉自身流道深度对热沉传热性能的影响。方法利用AnsysFluent软件,对板式热沉壁面温度分布情况以及进出口压力损失进行模拟仿真。结果提高氮气压力和氮气入口速度可以提升热沉的温度均匀性,但热沉进出口压力损失也会增大。对于气氮-板式热沉而言,流道深度的改变对热沉温度均匀性的影响不大,但流道深度较小时,进出口压力损失较大。结论建议在设计气氮-板式热沉时,流道深度选择在8~10 mm,外流程中氮气压力控制在0.3~0.4 MPa,氮气流速控制在20 m/s为宜。 相似文献
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The off-gas handling system is a vital component of a smelter and it is essential that it operates in accordance with environmental regulations. A key feature of the off-gas management system is maintaining a slightly negative system pressure to prevent gas leakage, such as SO2, out into the work and external environments. To enhance sustainable development, there is also growing interest in capturing and reusing the significant amount of heat and CO2 contained within off-gas. The potential incorporation of heat and CO2 recovery systems places importance on enhancing control to minimize the risk of both gas leakage and disturbance of the smelting process. With these requirements in mind, an easily implementable feedforward control enhancement to existing control schemes is proposed to help provide improved performance. 相似文献
44.
Kinetics of enzymatic unhairing by protease in leather industry 总被引:2,自引:0,他引:2
In leather industry, unhairing is a heavy pollution operation. The conventional lime-sulfide process produces a large amount of sulfide which is toxic to health and difficult to dispose. Moreover, conventional lime-sulfide process leads to the destruction of the hair causing increased COD, BOD and TDS loads in the effluent. As an alternative method, enzymatic unhairing is a promising clean technology. The main utilized enzyme preparations are proteases.There are many reports about enzymatic unhairing, most of which are qualitative. The kinetics of enzymatic unhairing by protease was discussed in this article. It will provide useful information to enzymatic unhairing. In our research, by analysis of the concentrations of released total protein in enzyme bath during protease unhairing, the good linearity between released total protein and square root of time (min1/2) was obtained at the initial stage. The good linearity suggests that enzymatic unhairing by protease is a diffusion-controlled process at the initial stage. The analysis of kinetics of released saccharides also confirms the same conclusion. On the other hand, the same characteristics between the kinetics of released saccharides and that of released total protein further confirms that it is the hydrolysis of core protein by protease that leads to the degradation of proteoglycans and the release of protein and saccharides. However, in our tests, the kinetics of released collagen indicates that the injury to skin took place in 3-6 h. Therefore, it’s necessary to control the time of protease unhairing within an appropriate limit. 相似文献
45.
R. AndrewsAuthor VitaeJ.M. PearceAuthor Vitae 《Journal of Cleaner Production》2011,19(13):1446-1454
As the economic costs of energy and the negative externalities associated with the combustion of fossil fuels threaten the economic viability of greenhouses in northern climates there is a renewed interest in the use of waste heat. This paper presents a technical and economic methodology to determine the viability of establishing waste heat greenhouses using the waste heat from industrial processes in northern climates. A case study is presented of an exchange between a tomato greenhouse and a flat glass manufacturing plant, which found the waste heat system is significantly more economic to operate than a purely natural gas system. 相似文献
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《Journal of Manufacturing Processes》2014,16(1):144-148
The 2205 duplex stainless steel (DSS) is of both good properties austenitic steel and ferritic steel, which applies to the shipbuilding industry usually. In this paper, the OM, XRD and microhardness test methods are used to analyze the variation of submerged arc welded (SAW) joints with and without post weld heat treatment (PWHT). The research results show that the σ phase disappear in the fusion edge zone near heat affect zone (HAZ) and an increase in the welded center zone during the follow-up PWHT, while the amount of γ phase is decreased in the welded center zone with PWHT. A segregation distribution of some second phases is also found in the welded center zone after PWHT. There have two pick values of microhardness arise in the fusion edge zone and the welded center zone separately without PWHT. However, a maximum value of microhardness at the fusion edge zone near HAZ is disappeared and the other is still held at the welded center zone during PWHT. It can be attributed to the changes of second phases, element diffusions and particle segregation during PWHT. A developing mechanism is issued to demonstrate the second phases transferring of the 2205 DSS SAW joints by PWHT. 相似文献
49.
《Journal of Manufacturing Processes》2014,16(4):485-493
Tungsten inert gas-metal inert gas (TIG-MIG) hybrid welding process is an effective way to improve welding productivity and quality due to advantages of the two processes. Mathematical analysis is crucial to fundamentally understand this synergetic welding process. In this study, based on experimental visualization of arc behaviors, some assumptions are proposed to deduce adaptive plane and volumetric heat source models separately for each involved welding method first. The influence of torch angles on distribution of temperature and geometry of weld bead are calculated and compared with experimental results. It shows that this developed algorithm of heat source can be employed to accurately predict welding process whether the electrode gun is slanted backward or forward to the direction of welding. Then TIG-MIG hybrid welding process is simulated and analyzed without considering the attractive or repulsive force of two arcs. The characteristic of TIG-MIG welding process is discussed compared to single MIG. It lays the foundation for the further research on the interaction of the two arcs during TIG-MIG hybrid welding. 相似文献
50.
应用Tripod Beta事故模型对某厂触电事故进行了深入分析,得到了事故原因,并提出预防类似事故的建议措施。 相似文献