HYSYS过程模拟软件在空分设备操作中的应用

描述了HYSYS过程模拟软件在空分设备操作中的应用,并介绍了软件应用过程中的体会。     

KDON-4000/3000型空分设备的技术改造

介绍了KDON-4000/3000型空分设备主塔及前序设备、液氩汽化及氮气供应系统以及制氩系统存在的待改造的方面,改造方案和改造效果。     

Kinetics and Mechanism of High-Temperature Oxidation in Air of Au - Cu Alloy

We have used thermogravimetry to study the kinetics of high-temperature (up to 800 °C) oxidation of the alloy 58.3 mass% Au - 41.7 mass% Cu with isothermal heating of the specimens. Using petrographic analysis of the oxide layers, we determined the reaction products. We have shown that up to 200 °C, the indicated alloy is not oxidized at all. More rapid oxidation of the alloy is observed at temperatures above 400 °C. Up to 500 °C, an inner layer consisting of Cu₂O predominates in the two-layer scale on the alloy, while the outer CuO layer has a significantly smaller thickness. At 600 °C, the upper layer of scale contains Cu₂O while the lower layer contains Cu₂O and gold. At higher temperatures, all the way up to 800 °C, the scale is two-layer as before but its upper layer contains CuO while its lower layer contains Cu₂O and small gold rods distributed in that oxide. Thus we have established three oxidation regions characterized by different scale phase compositions and different mechanisms for the process, mainly due to transition from an ordered state of the alloy (intermetallic AuCu₃) to a completely disordered solid solution of gold in copper. We used the Arrhenius equation to calculate the apparent activation energy for oxidation: E₁ = 20.4 kJ/mole for the temperature range 400–500 °C and E₂ = 9.5 kJ/mole for 600–800 °C. __________ Translated from Poroshkovaya Metallurgiya, Nos. 7–8(444), pp. 85–91, July–August, 2005.     

高炉炉料结构的优化和探索

在世界铁矿石资源状况日趋紧张的环境下,对宝钢高炉的用矿结构变化进行了探讨。多年来,宝钢高炉不断优化炉料结构,逐步降低球团矿比例,增加烧结矿比例,并针对不同高炉的情况制定了适宜的炉料结构,这对降低生铁成本起到了积极的作用。     

超声波在线防垢、除垢与强化传热的实验研究

超声波防垢除垢与强化传热的机理是超声波的空化效应与机械效应.根据这一机理并由水力学计算,首次设计出了较完善的超声波防垢除垢及强化传热实验台,并确定防垢除垢与强化传热实验中所要控制的主要物理参数为:超声波频率、功率、反应体系温度.实验表明:适当提高超声波频率、功率和反应体系温度有利于提高清洗效率.     

防治管式降膜蒸发器结垢的生产实践

针对用于烧结法碳分母液蒸发的管式降膜蒸发器加热管结垢形成的原因,采取了相应的改进措施。改进后蒸发器的蒸发效率显著提高,蒸汽消耗明显降低。     

Physical Modelling of Transport Phenomena in a Delta‐shaped,Four‐strand Tundish with Flow Modifiers

Experiments were conducted in a full‐scale physical model of a delta‐shaped, four‐strand tundish to study the effect of flow modifiers on tundish performance. Two different types of flow modifiers were studied; an existing flow‐modifier and a turbulence‐inhibitor. Their effects were quantified by measuring residence times of fluid in the tundish and residual ratios of inclusions. Although the Turbulence‐Inhibitor appeared to be more effective in guiding flows than the flow‐modifier, the latter gave the longer average residence times and smaller residence time differences between the inner and outer nozzles, which resulted in a higher residual ratio of inclusions.     

大对象流式处理方法在数字影像管理技术上的应用

随着数字影像技术的迅猛发展,数字影像数据得到快速累积,数字影像管理技术越来越受到重视;本文针对当前数字影像管理技术面临的问题,系统研究了对象-关系数据库大对象(LOB)流式处理方法在数字影像管理技术上的应用,并结合实例,介绍了具体实现方法。     

Universal plasma electron source

The construction of universal plasma electron sources that allows to generate both focused electron beams and large cross-section beams within stationary and pulse mode of operation is proposed, without any essential change in the construction of the source. The special feature of the source is the stability of electron beam parameters over a wide range of pressure (up to 10⁻² mbar), which makes it possible to use it in difficult vacuum conditions caused by intensive gas emission from the treated surface. High stability of the focused electron beam parameters is achieved due to a special configuration of electric and magnetic fields in the region of electron extraction. Generating large cross-section beams, a weak dependence of beam parameters of gas pressure, is achieved by using the method of double-grid stabilization of the emitting plasma surface. Physical processes causing an increase in parameter stability are discussed.     

Efficient and accurate multilayer solid‐shell element: non‐linear materials at finite strain

We present in this paper an efficient and accurate low‐order solid‐shell element formulation for analyses of large deformable multilayer shell structures with non‐linear materials. The element has only displacement degrees of freedom (dofs), and an optimal number of enhancing assumed strain (EAS) parameters to pass the patch tests (both membrane and out‐of‐plane bending) and to remedy volumetric locking. Based on the mixed Fraeijs de Veubeke‐Hu‐Washizu (FHW) variational principle, the in‐plane and out‐of‐plane bending behaviours are improved and the locking associated with (nearly) incompressible materials is avoided via a new efficient enhancement of strain tensor. Shear locking and curvature thickness locking are resolved effectively by using the assumed natural strain (ANS) method. Two non‐linear 3‐D constitutive models (Mooney–Rivlin material and hyperelastoplastic material at finite strain) are applied directly without requiring the enforcement of the plane‐stress assumption. In particular, we give a simple derivation for the hyperelastoplastic model using spectral representations. In addition, the present element has a well‐defined lumped mass matrix, and provides double‐side contact surfaces for shell contact problems. With the dynamics referred to a fixed inertial frame, the present element can be used to analyse multilayer shell structures undergoing large overall motion. Numerical examples involving static analyses and implicit/explicit dynamic analyses of multilayer shell structures with both material and geometric non‐linearities are presented, and compared with existing results obtained from other shell elements and from a meshless method. It is shown that elements that did not pass the out‐of‐plane bending patch test could not provide accurate results, as compared to the present element formulation, which passed the out‐of‐plane bending patch test. The present element proves to be versatile and efficient in the modelling and analyses of general non‐linear composite multilayer shell structures. Copyright © 2005 John Wiley & Sons, Ltd.