Gaedes rotierende Quecksilberluftpumpe

The rotary mercury pump of Gaede Wolfgang Gaedes invention of a quickly acting high vacuum pump was induced by his studies about the Volta effect. The so far known pumps were not able to create sufficient low pressure to optain very clean surfaces. Alfred Schmidt, owner of the E. Leybold’s Nachfolger Company, Cologne, learned from the publication about the demonstration of the pump its importance. He made an agreement with Gaede to develop together the invention during 1906 and 1908 to a product for use in industrial application – first step into industrial high vacuum technology     

Wolfgang Gaede ‐ Wegbereiter der Vakuumtechnik

The inventions of Wolfgang Gaede were the beginning of the extensive industrial application of vacuum technology: the 1905 invented high vacuum mercury pump simplified the production of electric bulbs. From this time Gaede joined the company E. Leybold's Nachfolger research & development activities for 40years. Three of his inventions, the diffusion pump, the (turbo‐) molecular pump and the principle of “gas ballast” are worldwide in use even today. The most important stations of Gaede's biography are reported.     

喷嘴角度对水银扩散泵抽气性能影响的DSMC模拟研究

扩散泵由于其大抽速、连续稳态工作的优点,有望应用于未来聚变堆的偏滤器抽气系统中,以降低目前托卡马克装置中广泛采用的捕集式低温泵所带来的高氚存储量问题。由于氚相容性的限制,目前的商业油扩散泵无法直接应用于聚变堆中,水银将是理想的扩散泵工作介质。为了支持未来聚变堆偏滤器抽气系统的水银扩散泵设计,需要针对水银扩散泵开展设计优化研究。本文采用直接模拟蒙特卡洛方法,基于KT-150扩散泵结构,研究了喷嘴角度对水银扩散泵的抽气速度及水银返流率的影响。结果表明喷嘴角度为45°时能够达到最佳的抽气速度1.53m^3/s,同时返流率没有显著提升。     

何氏系数的定义、表达型式及其应用

本文介绍了1932年何增禄先生为了评价扩散泵各种喷咀结构的抽气效率,在他的论文中首先提出了"抽速系数"(Speed Factor)的定义和表达式.这个系数的提出促进了扩散泵性能有很大的提高,结构也有很大的改进.人们为了表彰他这一贡献,将这个系数定名为"何氏系数"(Ho Coefficient).后来人们以泵口直径为标准来评价泵的抽气效率,将这个系数又分别定义为:"何氏系数"为泵的实际抽速与泵体内径与顶喷咀外径之间的环形抽气面积上按分子泻流计算的理论抽速之比;而"抽速系数"则为泵的实际抽速与泵入口断面积上按分子泻流计算的理论抽速之比.这两个系数之间有一定的换算关系.德国学者Jaeckel(亚开尔)和Nller(缪勒)分别又给何氏系数提出了新的表达型式,便于计算.使何氏系数更加完善,在一些高真空泵的设计和改进上得到了广泛地应用.     

100 Jahre HV‐Pumpe von Wolfgang Gaede. 100th Anniversary of Gaede's High Vacuum Pump

In 1905 Wolfgang Gaede invented a sturdy, quickly operating high vacuum pump, which was easy to use. It was produced and distributed under licence from E. LEYBOLD’s Nachf. This firstly allowed the application of high vacuum technique to industriel production. Gaede continued to work with Leybold just to the end of his life in 1945.     

The use of perfluoropolyether fluids in vapour stream pumps

The performance of a 5 in. diameter diffusion pump (Edwards EO4) has been studied using a distillation cut of the perfluoropolyether fluid with an average mass of 3000 amu. A pumping speed for air of 700 l/s was measured which is similar to the speed obtained when the pump is charged with Silicone 704 fluid. A higher critical backing pressure was obtained, however, for the new fluid viz 1.2 torr compared with 0.8 torr for the conventional fluid. Fragmentation spectra of the vapour molecule obtained by direct injection into the ion source and from backstreaming fluid showed prominent peaks at mass to charge ratios 31 and 69 corresponding to the fragments CF and CF₃. The similarity of the spectra obtained by the two methods suggests that the fragmentation takes place in the ion source and that the fluis is not degraded by use in the pump. An analysis of the pumping mechanism in vapour stream pumps is given.     

油扩散泵抽气速率与被抽气体的关系

通过对油扩散泵抽气速率、气体分子平均热运动速度和分子流态下气体流导的分析，指出油扩散泵对不同气体的抽气速率具有选择性，给出了泵对不同气体和空气抽气速率比值的计算值，同时指出电离规的规管常数与气体种类有关。     

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).     

Das Vakuumsystem der TOSKA-Spulentestanlage

Plasma confinement in fusion reactors requires large magnetic fields which are generated by superconducting solenoids. The coils of the future reactor ITER have a size of some 18 m × 10 m. Their construction is a technical challenge: the body of the coil suffers from large mechanical forces, originating from the magnetic field, as well as substantial thermal stress resulting from the cooling to 4.2 K. Nevertheless, the coils are required to be absolutely vacuum tight since no loss of the refrigerant helium is permissible. In the Research Center Karlsruhe (FZK) prototype coils are tested in operation under high vacuum conditions. The test chamber has a volume of 170 m³. It is pumped by an oil diffusion pump with a nominal pumping speed of 16 000 l/s. As fore and roughing pumps, a combination of Roots and rotating vane pump are employed. The available effective pumping speed of the oil diffusion pump has been measured by two different procedures: via the resulting equilibrium pressure in case of an injected stationary gas flow, and via the time-dependent decrease of pressure during pump-down. The measurements give an effective pumping speed of some 2 000 l/s. The main reason for the small pumping speed (as compared to the nominal value) is the small conductances of the inserted vacuum components and baffles. When the heating power of the oil diffusion pump is reduced to one half, the pumping speed decreases only slightly, whereas the maximum throughput decreases to one third.     

Comparison of two pumping speed measuring methods of oil diffusion pumps

This paper presents a comparative study of two pumping speed measurement methods recommended for oil diffusion pumps. The methods used are the test dome method and the conductance tube method with an auxiliary pumping system which is used at very low pressures when the throughput is below 10^?5 Nm s^?1 (～ 0.1 μl s^?1). It is found that, in order to obtain the comparative results in the overlapping pressure region on the speed measurement of oil diffusion pumps by these two methods, the conductance tube in the conductance tube method should be located at a height 1.2 D from the pump mouth when the position of the inlet gauge is at a distance D/2 from the pump flange, i.e. at the same position as recommended in the dome method to obtain the intrinsic speed of the pump.     

Using the Edwards 9B3 diffusion pump for circulation in a dilution refrigerator

Problems with the oil cracking have been encountered in using the Edwards 9B3 diffusion pump with Edwards 200 grade pump fluid. These have been solved by using a different fluid, reducing the power to the heater without a loss of pumping speed and by constructing a more effective cold trap.     

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.     

微型溅射离子泵放电模拟与抽气特性研究

为了解溅射离子泵抽气过程中内部放电与抽速的关系,考虑了N2分子的激发、电离及粒子之间的弹性碰撞等过程,利用COMSOL软件对微型溅射离子泵内部气体放电进行了数值模拟研究.得到了电子密度、温度、粒子轨迹、入射角度及入射能量的分布变化,并分析了这些因素对抽速的影响.在搭建的实验平台上对微型溅射离子泵进行了抽速测量,得到了不...     

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.     

溅射镀膜系统的压力控制的一种新设想

通过对一般溅射镀膜装置特点以及镀膜过程中存在问题的分析，指出：由于溅射镀膜时的工作压力处于扩散泵的恒定排气量区（第一级喷口过载区）．扩故泵在这种环境下工作，返流严重，并且由于喷流不稳定现象导致压力难于控制。提出了一种由扩散泵机组作为溅射镀膜油气系统的改进型设计方案。理论分析表明：使用该方案，扩散泵进气口压力维持在恒定抽速区．返流减小，镀膜室工作压力也易于稳定。     

Rotary shaft seal workshop details announced

The technical programme for the workshop ‘High Performance Rotary Shaft Seals’ has been announced by Poitiers University.This is a short news story only. Visit www.worldpumps.com for the latest pump industry news     

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.     

Geschichte der Vakuumtechnik. History of Vacuum Technology

The history of vacuum technology is more than 2000 years old. Over the past 400 years scientists, engineers and inventors such as Torricelli, Pascal, von Guericke and Gaede have been engaged in vacuum technology. Vacuum has become an essential instrument in science and technology and many processes could not exist without it. Furthermore vacuum technology has been developed as an individual industrially applied technology. The article describes the development of vacuum technology from ancient philosophical speculations about the mercurial glass pipe to the modern diffusion pump.     

HL-2A装置中性束注入器高抽速钛泵及其实验运行分析

针对中性束注入等离子体加热过程中的高真空条件要求,借助于国际合作方式,我们为HL-2A 装置中性束注入器设计了一种大吸附面积的高抽速钛泵系统.钛泵系统抽速设计值为30万L/s,由两台大泵和一台小泵组成,两台大钛泵分别置于注入器主真空室左右两侧,小钛泵置于注入器副真空室右侧.运行实验结果表明,钛泵完全满足HL-2A中性束注入实验的要求.本文主要介绍了钛泵的工程设计和实验运行结果,简要分析了HL-2A装置中性束加热系统高抽速钛泵的运行特点.     

新型K-800A高真空油扩散泵的研制

介绍了新研制的高真空油扩散泵在拓宽抽气速率范围、提高临界前级压力、降低返油率方面的创新设计。给出了新研制的K-800A高真空油扩散泵各项技术指标的实测结果。