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.     

串联分子泵获得10-9 Pa真空的实验研究

介绍了采用两级分子泵串联系统获得10^-9Pa真空度的实验研究。实验证明，通过串联一台分子泵，可以有效地提高系统对氢气的压缩比，显著提高系统的极限压强。     

低温水泵和分子泵组合替代低温泵的新设备

本文介绍了一种新型超高真空辅助设备－低温水泵，用之和分子泵组合，可以获得１０＾－８Ｐａ的清洁超高真空，用在半导体集成电路生产过程中，可以使产品质量以及生产效率均得到改善和提高，抽气机理以及设计要点均在文中有所论述。     

全玻璃太阳集热管烘烤排气工艺采用复合分子泵抽高真空

采用复合分子泵替代油扩散泵进行全玻璃真空太阳集热管排气烘烤抽高真空试验。选用了三种型号分子泵,在集热管自动连续烘烤排气线上进行实验。经过约一年较长时间生产运行试验后,分子泵经受了190次以上的集热管管口破裂引起的大气冲击,没有损坏,抽真空性能无明显变化。采用分子泵烘烤排气工艺制备的集热管,按国标在温度350℃,48 h高温老化试验后,吸气剂镜面消失率约为5%,仅为国标规定值的10%。     

涡轮分子泵电源制动单元的研究

研究了涡轮分子泵电源制动单元的设计、制动功率和制动电阻的计算方法。为涡轮分子泵选用理想制动电阻提供依据。根据此设计和计算方法为我公司生产的FD系列涡轮分子泵电源选用了最佳的制动电阻,使涡轮分子泵的停车减速时间大为缩短,该泵的性能和效率显著提高。     

变截面矩形槽牵引分子泵二维抽气理论的研究

本文对牵引分子泵抽气机理进行了深入分析，考虑了通道返流和工作间隙泄漏对泵抽气性能的影响。采用有限差分法对通道内气体分子宏观运动速度分布进行了计算，提 出了牵引分子泵二维抽气理论。     

如何选择和使用涡轮分子泵

本文首先介绍了涡轮分子泵的工作原理,结构型式及其优缺点。为了利用涡轮分子泵,获得清洁真空,国外多利用干式机械泵作其前级泵,构成无油的真空系统。然而,目前国内涡轮分子泵多以油封机械泵为其前级泵,构成了有油真空系统,如果操作不当,很难避免油蒸汽返流,对真空系统的污染。利用有油系统获得清洁真空,国内外都有一些有效防止返流的措施和成功的操作经验。这些对用户正确选择和使用涡轮分子泵有油系统获得清洁真空,有一定的参考价值。     

短叶片涡轮分子泵—一种复合分子泵

本文分析了涡轮分子泵和拖动分子泵抽气机理的不同物理图象，并论证了短叶片涡轮分子泵的抽气作用是这二种分子泵抽气机理同时作用的结果，从而，这种泵具有涡轮分子泵和拖动分子泵的共同优点。     

分子泵的世纪回顾与展望

分子泵自1912年诞生以来,至今已快近一个世纪了,它在初期进展较缓慢,在1970年以前,分子泵的应用还仅限于核物理,电真空,表面科学等领域,但近20年来由于半导体产业的兴起和薄膜工业的发展,分子泵才被人们所重视,并得到了兴旺和发达,现代的分子泵已发展到实用和普及的阶段,本文回顾了分子泵分析近百年的发展历史,详细地介绍了分子泵在各个时期的发展状况,对初期的分子泵,涡轮分子泵,磁悬浮轴承和气体静压静轴式涡轮分子泵,复合式分子泵,低温型涡轮分子泵,新型牵引分子泵,陶瓷涡轮分子泵,轴反应生成物的涡轮分子泵和极高真空涡分子泵等做了重点的分析,最后指出分子泵的发展前景。     

BEPC储存环真空系统

本文描述了ＢＥＰＣ储存环真空系统的设计、制造和运行。为了使储存环中正负电子的寿命达到８—１０小时，要求真空系统的动态压强低于３×１０－９Ｔｏｒｒ。储存环真空系统的主要气载是由同步辐射光与真空盒壁相互作用产生的。由于弯转的铝真空盒具有容易加工、高的热导性和低的放气率等特性，被广泛应用于真空系统。１１０Ｌ／ｓ的涡轮分子泵机组把系统预抽到１０—６Ｔｏｒｒ左右，主抽泵是工作在弯转磁场中的分布式溅射离子泵。５００Ｌ／ｓ的溅射离子泵安装在特殊的部位，如高频腔，静电分离器以及物理实验区等．１００Ｌ／ｓ离子泵每隔６．５米安装一台，当分市泵不工作时用来维持系统真空．八个全金属闸板阀把真空系统分成八个部份。为了减少由于高次模造成的束流能量损失，要求真空系统光滑过渡。     

Renaissance einer Hundertjährigen. Die Molekularpumpe von Wolfgang Gaede

New Success after 100 years: the ?Molecular Pump”? of Gaede The molecular drag pump was invented by W. Gaede in 1908. The design of the prototyp needed two years, and another two years later the first molecular pumps were 1912 ready for selling. But the sophisticated design and handling and the war 1914 limited the world wide application of the pump. Now at the end of the 20^th century the invention was successfully used as final compression stage in turbomolecular pumps.     

Weitbereich-Turbomolekularpumpen und Membranvorvakuumpumpen als trockene HV- und UHV-Pumpsysteme

The development of new turbomolecular pumps with increased critical backing pressures up to 30 mbar made it possible to use oilfree diaphragm pumps as backing pumps. The combination of a wide-range turbomolecular pump with a diaphragm pump represents an inexpensive, compact and technical dry vacuum pumping system for high and ultrahigh vacuum applications. The interaction of wide-range turbomolecular pumps with diaphragm pumps is discussed in terms of gas throughput, compression ratio, ultimate pressure and power consumption of the turbomolecular pump and selection criteria for the diaphragm backing pump are shown.     

Engineering aspects of turbomolecular pump design

The development of modern (thin-bladed) turbomolecular high-vacuum pumps began in 1957 with the demonstration of the possibility of obtaining high compression ratios with axial flow compressors in the molecular flow regime. Thirty years later, such pumps had become the major method for high vacuum pumping. It had been apparent from the beginning that pneumatic compressors can be useful at any pressure provided a proper number of suitable impellers were used. However, theoretical studies, initially by Prof. A. Shapiro's group at MIT (Massachusetts Institute of Technology) dealt primarily with the pumping mechanism in molecular flow rather than with an optimum practical pump design. Some observations in such studies were misunderstood and the first pump designs were not optimized. Later, compound or hybrid pumps were introduced, which incorporated molecular drag pumping stages. In more recent years, pumps have been made which can exhaust directly to the atmosphere by means of added centrifugal-regenerative impellers. The use of different impeller types provides freedom to the designer to create pumps that match any reasonable desired performance.This paper will attempt to explore some of the engineering aspects of design, especially relationships of volume and mass flows, permissible pressure ratios in various density domains, and their relevance to power consumption.     

Sind Trockenläufer wirklich die Lösung aller Probleme?

With this article the author intents to generate the awareness, that dry pumps due to its pump principle, performance characteristic and physical limitations not always to be seen as the solution to all challenges in vacuum technology out there. Monitoring and protective measures are resulting in more sensitivity to failures and operational errors, higher operating and maintenance cost as well as a certain knowledge about safe operation of dry pumps for system manufacturers and users is required in comparison to the classical rotary vane pumps. The requirement for oil free process chambers and apparatus were the major push to develop and improve dry pump technology but despite this trend the rotary vane pumps is for certain applications the pump of choice will be still around for quite some time.     

Correction: Sind Trockenläufer wirklich die Lösung aller Probleme?

With this article the author intents to generate the awareness, that dry pumps due to its pump principle, performance characteristic and physical limitations not always to be seen as the solution to all challenges in vacuum technology out there. Monitoring and protective measures are resulting in more sensitivity to failures and operational errors, higher operating and maintenance cost as well as a certain knowledge about safe operation of dry pumps for system manufacturers and users is required in comparison to the classical rotary vane pumps. The requirement for oil free process chambers and apparatus were the major push to develop and improve dry pump technology but despite this trend the rotary vane pumps is for certain applications the pump of choice will be still around for quite some time.     

CXS chemical dry vacuum pump brings smart vacuum to the process industry

The chemical sector as a whole has been quick to recognise the clear advantages of dry vacuum pumps over traditional wet technologies, and dry vacuum pumps are now well established around the world as an efficient, reliable option. A new trend is now emerging: for vacuum to be seen as a ‘utility’. In response, dry vacuum technology is being developed by manufacturers to be available on demand in a ‘plug and pump’ system that requires minimum set‐up and maintenance. The most advanced chemical dry vacuum pumps, such as the new CXS pump from Edwards, deliver exceptional energy efficiency and performance, are cost‐effective to run, and are environmentally sound.     

HYDRAULIC TRANSPORT OF ABRASIVE SOLIDS: THE AIR-LIFT PUMP

Although the air-lift pump has been superseded by submersible pumps in raising water from wells and mines, it still provides an attractive means of lifting abrasive slurries because, unlike mechanical pumps, it has no moving parts to wear. However, current design of air-lift pumps must rely on empirical equations, or, at best, incremental computer solutions. Design is complicated by the fact that relative velocities of the phases change over the whole pump length. A new design equation is developed to predict the lift of an air-lift pump, given the flowrates of air, liquid and solid in the pump, and the dimensions of the air-lift tube. The new equation is baaed on well-established multiphase flow theory, and offers significant advantages over current design techniques. In combination with an equation for the overall pump efficiency, the new equation provides a method for optimizing the design parameters for the air-lift pump.     

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.     

A Simplified Model to Estimate the Size Distribution Change of Polydispersed Aerosol for Cyclone Separator

ABSTRACT

Although the air-lift pump has been superseded by submersible pumps in raising water from wells and mines, it still provides an attractive means of lifting abrasive slurries because, unlike mechanical pumps, it has no moving parts to wear. However, current design of air-lift pumps must rely on empirical equations, or, at best, incremental computer solutions. Design is complicated by the fact that relative velocities of the phases change over the whole pump length. A new design equation is developed to predict the lift of an air-lift pump, given the flowrates of air, liquid and solid in the pump, and the dimensions of the air-lift tube. The new equation is baaed on well-established multiphase flow theory, and offers significant advantages over current design techniques. In combination with an equation for the overall pump efficiency, the new equation provides a method for optimizing the design parameters for the air-lift pump.     

Kennfeldanalyse einer Schraubenvakuumpumpe

Operating Performance of Screw Vacuum Pumps This paper presents detailed analyses of the operating performance of a dry‐running screw vacuum pump. The characteristic parameters, suction speed and final attainable pressure ‐ which primarily define the operating performance of screw vacuum pumps ‐ are explored in experimental and theoretical investigations. Experiment and simulation in combination are used to show the correlation between the main physical and technical characteristics and the operating performance of screw vacuum pumps. This basic knowledge is essential for understanding the specific machine physics of positive displacement vacuum pumps, especially for screw vacuum pumps, and is useful in view of further design and optimization processes. The experiment covers measurements of the operating performance of the investigated isochoric screw vacuum pump working against ambient pressure. As operating parameters intake pressure (1000mbar to 10^‐3mbar) and rotor speed are varied over a wide range. The theoretical analysis of the operating performance contains simplifying models as well as simulations of the thermodynamic processing. The impact of external leakages, clearance vacuum flows and further losses on operating performance are described in detail.