大型空分设备经济运行的改造

详细介绍了马钢供气厂在空分设备经济运行方面的技术改造情况,包括空分塔大加温气源的改造、反充液氧缩短空分设备启动时间、氮水预冷系统的改造、氩净化系统的改造、氮气管网系统改造,以及降低氧气放散率等。改造后取得了显著的节能效果。图2。     

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。     

全液体空分设备增加氧气产量的改造

由于瓶装氧气市场需求增大,将3000 m3/h全液体空分设备的液氧汽化后充瓶,以增加氧气产量,但存在汽化充瓶液氧冷量浪费现象,提出对空分设备增设液氧冷量回收系统的改造方案。介绍液氧冷量回收系统的流程和具体实施方案,阐述改造后的操作方法;通过改造前后运行参数的对比,分析改造效果。     

3200m~3/h空分设备的改造

本文介绍3200m3/h空分设备在安装时所进行的增设粗氩塔,以及在运行中边用边改,边修边改所做的膨胀机加热管增设过滤器、增设液史过滤器、改造液氧循环系统、改造仪表气与粗氩送出管、改造切换阀、改造空压机油系统、配制精氩及高纯液氧设备、改造部分管路生产普氮、并联透平压缩机和活塞压缩机、改进仪表气源、改进加热吹除系统、液氮汽化等十多项技术改造、工艺改进。运行结果表明:技改技术可靠,经济效益显著。图4。     

大型化工型内压缩流程空分设备新工艺的研制与发展

针对煤化工装置对气体产品的新要求,从流程选择、优化、节能和安全供气等方面对大型化工型内压缩流程空分设备进行了研究;指出:合理选择单套空分设备规模,发挥多套空分设备联合供气的最大优势;合理、优化改造全精馏无氢制氩系统;设置安全、可靠的液体汽化后备系统;用液体膨胀机代替高压节流阀,是大型化工型内压缩流程空分设备的新特点和发展方向。     

KDON-3500/3200/150型空分设备部分系统的节能改造

为降低KDON-3500/3200/150型空分设备的运行能耗,对氮水预冷系统、液体汽化和贮存系统以及仪表伴热系统进行了技术改造。介绍了相关系统的工艺流程、具体改造方案以及改造效果。     

空分设备试压查漏气源的研究与应用

在53000 m3/h空分设备安装完毕,而空压机不具备提供试压查漏气源的情况下,采用由低温液体贮槽及其配套设施提供气源进行空分系统试压查漏,不仅缩短了工期,而且取得了较好的效益。简介空分设备试压查漏的重要性以及气源选择的方案,介绍由低温液体贮槽及其配套设施提供气源进行试压查漏的具体实施方案,阐述实施过程中的注意事项和产生的效益。     

减少钢铁企业氧气放散量的措施总结

针对钢铁企业空分设备氧气放散量大的情况,从空分设备流程的选择、加装液化装置、向主冷返充液体、变工况操作以及液体直接汽化等方面,分析了减少氧气放散量的措施和可行性,以达到空分设备经济运行的目的。     

6000m~3/h空分设备改造设计与调试

由于6000 m3/h空分设备已服役20多年,运行能耗高,而且已不能满足后续生产装置的氮气需求,所以对空分设备进行了降耗和增产氮气的改造。介绍6000 m3/h空分设备改造前后产品设计参数,分析空分设备改造的流程设计要点、工程设计要点和利旧设备的检测情况,总结改造后空分设备安装和调试过程中出现的问题及解决方法,最后阐述了改造效果。     

KDONAr-6000/13000/120型空分设备扩容改造

介绍了6000m3/h空分设备扩容改造为7300m3/h空分设备的改造内容和改造后的性能指标,详细分析了改造后的经济效益,提出了改造后空分设备尚存在的问题和建议。     

Surface modification of an aramid fibre treated in a low-temperature microwave plasma

The surface modification of an aramid fibre treated in a low-temperature microwave (mw) plasma was investigated. Three different plasma gases, oxygen, argon and ammonia, were used to achieve different surface modifications during fibre treatment. The modification of the fibre surface was analysed with electron spectroscopy and electron microscopy. The influence of the surface modification on the fibre-matrix interaction was inspected by measuring the interlamellar shear strength of the composites and the pull-out strength of a fibre bundle in model composites. The process gas and thus the kind of plasma has no significant influence on the fibre modification resulting from plasma treatment. It was shown that a fibre cleaning with subsequent surface ablation is the dominate modification process during mw plasma treatment, independent of the process gas. The degree of surface cleaning and removal of a contamination layer strongly depended on the treatment range. No incorporation of oxygen or nitrogen containing functional groups was observed. This was explained with the composition of the process gas. The improvements of the composite properties demonstrate the advantage of the mw plasma treatment as a fast, environmentprotected, cost-efficient process for fibre modification.     

氧压机DCS控制系统启动程序改造

14000m3/h空分设备氧压机在试车过程中,因启动程序存在缺陷,启动过程中不能联锁停车。在修改启动程序的过程中发现了控制系统存在的一些新问题,对氧压机的DCS控制系统进行了相应修改,完善控制功能。着重介绍对氧压机在启动过程中因进气压力低而联锁停车功能的修改,达到安全运行的目的。     

浅谈KLN-20Y型液氮装置的优化操作

简介了KLN-20Y型液氮装置的主要技术参数,结合实际生产,就液氮装置的加温吹除、开车、停车与切换以及正常运转中的调整和操作进行了阐述,总结了故障诊断与排除措施。     

液氮温区重力辅助深冷回路热管的实验研究

给出了液氮温区重力辅助深冷回路热管结构设计方案,建立了实验系统,对其启动特性和工作性能进行了实验研究.深冷回路热管以高纯氮作为工作液体,工作温区为90 K～126 K.实验结果表明,深冷回路热管能在重力作用下快速启动,在气体管线高于液体管线20 mm的情况下,最大可传送的功率为11W.     

Target voltage measurements during DC sputtering of silver in a nitrogen/argon plasma

During reactive sputtering, addition of the reactive gas results in a target voltage change. This effect finds its origin in the modification of the gas composition but also in the change of the target condition. In this paper, we focus on the target voltage changes during magnetron sputtering of silver in an argon/nitrogen plasma. In the first second during the nitrogen addition, we notice a decrease of the target voltage followed by an increase in target voltage. The target voltage decrease can be easily explained from the increased volume ionisation. The change of the target condition seems to be responsible for the target voltage increase. However, this effect cannot be explained from the formation of a silver nitride phase on the target surface as generally accepted during reactive sputtering of metal nitrides. Indeed, silver is a poor nitride former. To explain the target voltage increase, we have studied in this paper the influence of ion implantation of N₂⁺ ions on the target voltage during magnetron sputtering. The ions were implanted in situ in a silver target and the target voltage of this modified target was registered under the same conditions as during the sputtering experiments. The implantation of the N₂⁺ ions results in a target voltage increase. Hence, during sputtering of a silver target in an argon/nitrogen plasma, the target voltage increases by the presence of non-reacted N atoms in the target top surface layers.     

Use of a Laser/TIG Combination for Surface Modification of Ti-6Al-4V Alloy

The surface modification of materials such as Ti-6Al-4V is necessary to improve their wear resistant properties for use in tribological applications, in this paper it is shown that a laser with low power and tungsten inert gas (TIG) can be combined together for surface modification of Ti-6Al-4V alloy, and when performed in a controlled atmosphere of pure nitrogen or a mixture of nitrogen and argon, can produce a wear-resistant surface alloy. Compared with laser processing, a cheaper surface modification process has been developed involving a shorter processing time, which is free of stringent requirements such as a vacuum system.     

Multivariate monitoring of batch process startup

A batch process is finite in duration and can be separated into two stages: startup and production. We develop a methodology to monitor a batch process during the startup stage to reduce the length of the startup stage. We focus on processes that are characterized by multiple process parameters and product characteristics. Because of the complex interdependencies characterizing the process parameters and product characteristics, it is more effective to evaluate them simultaneously. To address the multivariate nature of the process we use a multivariate statistical model: PLS (Projection to Latent Structures). PLS has been applied to several applications in statistical process monitoring. We present a new application of PLS to the startup stage of a batch process. Iterative adjustments made during startup in search of an acceptable production zone consume considerable amounts of material, labor and equipment time. We develop a monitoring procedure to reduce the time as well as the number of iterations and adjustments needed for startup. A PLS model is constructed, using baseline data, to characterize the relationship among process parameters during good production. The startup stage is monitored using the PLS characterization to determine if the process is consistent with good production. We illustrate the improved startup operations with an example from a batch process in filament extrusion, the application that motivates this work. Copyright © 2001 John Wiley & Sons, Ltd.     

活塞用近共晶铝硅合金熔体变质精炼复合处理技术的应用

铝合金熔体处理的主要目的是提高熔体的变质效果及纯净度,本文论述了当前国内广泛使用的几种铝合金熔体变质处理及净化处理技术,重点介绍了活塞用近共晶铝硅合金熔体P变质处理及氮气--氯气混合气体＋精炼剂复合净化处理技术在活塞铸造领域的应用。     

Presence and detection of anaerobic ammonium-oxidizing (anammox) bacteria and appraisal of anammox process for high-strength nitrogenous wastewater treatment: a review

Until now, anaerobic ammonium oxidation (anammox) has been widely applied as an alternative method to the conventional nitrification–denitrification pathway for biological nitrogen removal from wastewater. Since their discovery in a denitrifying fluidized bed reactor in the Netherlands in the early 1990s, anammox bacteria have also been detected in natural environments. Anammox is one of the newly found drivers known to contribute to the biogeochemical nitrogen cycle. In the marine environment, more than 50% of nitrogenous compounds are reportedly converted into nitrogen gas via the anammox pathway. These observations were made using state-of-the-art techniques for detecting anammox bacteria based on their lipids, small-subunit ribosomal RNA genes, functional genes, and unique reaction pathways. The research objectives for anammox bacteria are quite diverse, ranging from the application of anammox processes to various wastewater types, to anammox biochemistry and phylogeny, to elucidating how anammox bacteria have evolved. Since the genome of the anammox bacterium Kuenenia stuttgaritiensis was deciphered, anammox bacteria have proved to be quite versatile. The next challenge is to enrich knowledge of anammox bacterial physiology and phylogeny to improve their use in engineered and natural environmental systems and minimize nitrogen loads to downstream water bodies. Furthermore, rapid startup of the anammox process for engineered systems is required to broadly harness the benefits of anammox bacteria. This review article summarizes the physiology and phylogeny of anammox bacteria, detection methods of anammox bacteria and reactions, the behavior of anammox bacteria in natural environments, and recent developments in their use for engineered systems.     

小型空分设备优化操作

针对小型空分设备启动时间长、能耗高等问题,采取了外部补充冷量和连通膨胀机轴承气等措施,有效缩短空分设备的启动时间、延长其安全运行周期。