一种基于深冷混合工质节流制冷机的高真空水汽捕集器

详细介绍了一种新型的高真空深冷水汽捕集器.该深冷水汽捕集器采用单压缩机驱动的混合工质节流制冷机冷却,制冷系统采用商用单级油润滑压缩机驱动,在配套600 L涡轮分子泵时,压缩机的额定输入功率450 W,捕集器表面温度最低为110 K.在相同真空测试条件下,开启低温捕集器可使系统极限真空度和抽速均提高一个数量级.该新型深冷捕集器具有优异的性能、低廉的造价及高可靠性等特点,与其他高真空获得设备如涡轮分子泵结合可成为一种优异的洁净高真空获得系统.     

Experimental Study of Oil‐Free Claw Vacuum Pump Characteristics

Experimental study of pumping characteristics of a pilot model of a claw single‐stage vacuum pump with identical rotors was carried out. The curves of pumping speed vs. pressure at different rotary speed and the ultimate pressure at different rotors speed were determined on a test unit. Indicator pressure diagrams in working chambers of claw vacuum pump were obtained with the help of special sensors. Thus, an experimental data bank concerning the pumping characteristics of claw vacuum pump was created. It may be used for estimation of mathematical model adequacy and further development of the pump design.     

New Turbomolecular Pump with Central Opening for Free Axial Access. Eine neue Turbomolekularpumpe mit zentraler Öffnung für freien axialen Zugang

Standard turbomolecular pumps show typically one annular active intake area on the high vacuum flange side (single‐flow pumps). The central circular part of the inlet of the compressor turbine is blind for pumping. The new design proposes a central opening of a turbomolecular pump all along the axis. This central bore can be used e.g. for mounting of feed throughs, manipulators, windows or for coupling to further vacuum devices, in particular also for enclosing tube‐like vacuum systems. This design allows a multi‐use of a pumping port at a vacuum vessel without reducing there the pumping speed. Moreover, the new design is ideal for axial or radial differential pumping arrangements as e.g. needed for all gas jet like set‐ups or other pressure reduction stages.     

新颖的4000吨亚磷酸-二甲酯真空抽气系统

叙述在亚磷酸－二甲酯真空抽气系统中采用气冷罗茨真空泵机组代替过去一般采用的多台W型往复式真空泵并联组合，可以大大降低功率消耗、提高抽气效率及其节约维修费用。     

油气混和状态真空抽气系统试验初步研究

根据系统抽真空要求,完成管路设计选型与抽空能力计算.针对混和型介质及系统防火防爆的特点,优先选用干式真空泵.通过搭建真空管路系统,针对不同抽速真空泵、不同管路长度、不同抽空容器、不同混和介质开展多组试验.试验结果分析表明,干式真空泵能够满足抽空要求:管路中最小管径的管路长度对抽真空时间有较大影响;在本次试验条件下,环境温度变化对抽空时间有一定影响.     

火电站凝气器用水环真空泵的选型计算

我国火电站凝气器抽真空设备，８０年代中期开始选用水环真空泵。由于凝气器内复杂的热力学特性，使得水环真空泵的选型计算，不同于一般用途的选型计算，就此问题作扼要叙述。     

钢包真空脱气处理工艺及设备

随着炼钢技术的飞速发展,真空脱气处理技术成为减少钢中气体和非金属杂质的有效措施,其关键在于如何获得真空。本文以某厂利用蒸汽喷射泵的钢水炉外真空处理为例,介绍了真空系统的设备组成,阐述了真空泵的抽气理论,利用边试验边改进的方法来优化蒸汽喷射泵的抽气性能。最后,给出了钢水的真空脱气处理工艺及其效果。     

场发射透射电镜真空系统的并行自动抽气控制

真空系统是场发射枪透射电镜的重要组成部分.按照场发射枪透射电镜对真空提出的要求,规划了真空系统的构成,设计了抽真空的流程.采用真空泵并行抽气的工作方式,缩短真空抽气时间,提高真空泵的利用率.通过隔离阀的通断实现了真空泵抽气对象的切换,通过计算机程序控制PLC实现了真空的自动抽气.通过测试,能够达到预定的真空度要求.     

关于真空除气使用的真空泵情况分析与讨论

为使真空泵的抽气能力能最大程度适应除气过程,在选用真空泵时需考虑到搅拌气体数量、设备表面放气和设备的漏气率.随着钢液真空处理技术的发展,能保证高效率、有效地脱除钢液中的气体成为迫切的问题.由于抽出气体有灰尘,维修次数多等综合因素,应采用抽气能力大、运转可靠性强、结构简单的蒸汽喷射泵而非机械泵.但近年来,钢液真空处理真空...     

罗茨真空机组预抽阶段的抽气特性比较研究

针对罗茨泵真空机组在启动预抽阶段的三种工作模式——旁通式、直通式和变频式,分别建立了简化计算模型,推导得出罗茨泵进入正常稳态工作之前罗茨机组的有效抽速计算公式,以及被抽容器的抽气时间计算方法.通过一个计算示例,对比得出了三种不同启动预抽方式的压力-时间曲线,结果表明,直通式、旁通式、变频式工作模式下容器的抽气时间依次减...     

Verhinderung von Ölrückströmungen in Wälzkolbenpumpen

Prevention of oil backflow in Roots pumps - Residual gas analysis by quadrupole mass spectrometry In industrial vacuum applications too, there is a growing trend towards dry, oil-free, pump systems. But what does oil-free mean? All bearings and gearboxes used in roots and screw pumps require lubrication with oil or grease. While constructive measures are implemented to avoid contamination of the process gas by back-flowing lubricants from the pumps, no tests have yet been carried out on complete pumping stations to confirm their effectiveness. With the help of this report it is possible for the first time to make qualitative statements about the oil-free nature of dry pumping stations.     

Das Saugvermögen von Pumpen: Untersuchung verschiedener Meßverfahren im Grobvakuumbereich

The term pumping speed of a vacuum pump denotes the volume flow rate of gas removed by the pump. In a measurement of the pumping speed it has to be taken into account that the volume of a quantity of gas depends on pressure and temperature. The present article presents a critical investigation of two different procedures for measuring the pumping speed in the rough vacuum regime: In the first procedure, gas flows continuously through the test dome and the pump under investigation. The pumping speed is obtained from the stationary values of throughput and pressure in the test dome. This procedure is well established, technical details are described in various standards. In the second procedure, a large vessel with known volume is evacuated by the pump, and the pumping speed is derived from the pressure decrease with time. In order to avoid disturbances by thermal effects, the vessel may be pumped only during short time intervals with intermediate waiting for thermal equilibrium. The second procedure offers instrumental advantages and its practices are described in a new DIN standard. The physical basis and technical aspects of both procedures including disturbing thermal and other effects are investigated. If applied correctly at inlet pressures in the rough vacuum range, both procedures are expected to yield the same values of the pumping speed. Comparative measurements at a diaphragm pump confirm this expected behaviour within the experimental uncertainty of about 3% (2σ).     

罗茨真空泵试车与运行

介绍了干气提浓装置变压吸附工序中抽真空设备罗茨真空泵,通过对罗茨真空泵气密、试车、运行过程中出现问题的讨论,提出一些解决办法和改进措施,确保泵组的安全平稳运行以及装置的长周期运转。     

非蒸散型吸气剂泵在真空计量中的应用研究

本文简要阐述了非蒸散型吸气剂(NEG)泵的吸气机理,着重介绍了NEG泵在超高/极高真空标准、静态膨胀法真空标准等真空计量标准中的最新应用结果。结果表明:利用NEG泵在室温下获得了10-10Pa的XHV;利用NEG泵将超高/极高真空标准校准下限延伸到了10-10Pa量级;利用NEG泵将静态膨胀法真空标准的校准下限延伸到了10-7Pa量级。最后还对用NEG泵延伸固定流导法微流量标准测量下限的可行性进行了分析。     

镀膜设备真空系统主泵的配置

真空系统是真空镀膜设备的主要组成部分,其主泵的选择对真空性能影响很大,真空镀膜设备的发展要求真空性能清洁无油,动态抽速大.传统的以油扩散泵为主泵的设备不能满足要求,本文叙述了油扩散泵、分子泵及低温泵的特点及北京北仪创新真空技术有限责任公司开发以分子泵及低温泵为真空系统主泵的镀膜设备情况.     

水环离心真空泵在氧气充装系统中的应用

为保证气瓶充装的安全性,武钢氧气公司在新建氧气充装站时配置了一套气瓶抽真空装置。介绍选用的水环离心真空泵的工作原理和技术参数以及氧气充装系统的工艺流程。使用效果证明,在氧气充装系统安装气瓶抽真空装置,不仅可以降低氧气瓶发生化学爆炸的危险性,而且可以提高产品合格率。     

12位清洁开关管真空排气系统

这个系统是真空开关管的真空排气系统。由机架、主真空室、１２支预抽管路、超高真空插板阀和ＺＤＢ－２５０型低温泵组成。经过半年的运转系统工作正常。     

Uncertainty analysis of the high vacuum part of the orifice-flow-type pressure standard

The orifice-flow-type pressure standard is commonly accepted as primary standard for vacuum gauge calibration in the high vacuum gas pressure range. It consists of two parts—a high vacuum part and a flowmeter. Practical questions arising at design of the standard have to be answered based on the standard uncertainty analysis.The analysis of the uncertainty sources in the high vacuum part except deviations from the Maxwellian distribution is given in the paper. Uncertainty of a precise flowmeter is taken from references for comparison. It follows from the analysis that uncertainties caused by some sources at routinely achievable parameters are negligibly small and further improvement brings no benefit. The crucial quantities influencing the total uncertainty are the temperature of the chamber and the flowmeter, the outgassing rate from the inner surfaces, the ultimate pressure of the pump and the additional (detrimental) pumping speed. The pumping speed of the main pump has to be “sufficiently higher” than the orifice conductance.     

A novel route to compact,high performance pumping in UHV–XHV vacuum systems

The need to miniaturize and reduce the footprint of vacuum systems is increasing in industrial and research devices, such as portable analyzers, electron microscopes, surface science systems, semiconductor tools or particle accelerators. This poses serious challenges to the pumping groups in term of design, space constraints and weight. In this paper a novel type of combination pump is introduced, which integrates into a single device a Non Evaporable Getter (NEG) element with a small sputter ion pump (SIP). In this design, the NEG element acts as the main vacuum pump to remove hydrogen and the active gases, leaving to the SIP the ancillary task of pumping inert gases, which are not sorbed by the NEG. This approach, which develops large pumping speeds in a compact package, is helpful to achieve appropriate vacuum conditions in laboratory equipment. It can also improve and simplify the design of complex vacuum systems and apparatuses.     

Kryopumpen im Vergleich zu anderen Hochvakuumpumpen

Within the last 10 years, the cryopump was added to the range of the pumps used in the high vacuum and ultra high vacuum fields. The choice of the right pump often turns out to be difficult. One of the reasons could surely be that the user is not often familiar with the properties of the cryopumps. The article is meant to make the reader aware of all possible criteria, which in turn will make it easier for him to make a decision concerning the pump required for the application. The refigerator cryopumps can be used in any application for which hydrocarbonfree vacuum is required as well as a high pumping speed for almost all gases.