scholarly journals Study on the Calculation Method for Pumping Process in as Vacuum System

2021 ◽  
Vol 2097 (1) ◽  
pp. 012026
Author(s):  
Si Huang ◽  
Jiawei Guo ◽  
Tiankun Yi ◽  
Songfeng Li ◽  
Taizhong Wu
Keyword(s):  
Calculation Method ◽  
Theoretical Models ◽  
Vacuum System ◽  
Flow State ◽  
Actual Measurement ◽  
Vacuum Chambers ◽  
High Pressure Stage ◽  
Time Calculation ◽  
Measured System ◽  
Vacuum Systems

Abstract The calculation methods for vacuum system pumping were usually based on some simple theoretical models, the corresponding results had significant deviations from actual situations. In this study, medium and low vacuum systems (including vacuum chambers, pipes and pumps) were taken as research objects. With a measured vacuum system, and relationship between pump’s suction flowrate and inlet pressure, a new calculation method for vacuum pumping time was proposed, in which laminar or turbulent model was selected according to the pipeline’s flow state. New and traditional laminar method were used to calculate the pumping process of the measured system, which found that in the middle and high pressure stage, the pipeline flow was in turbulent state and the resistance was non-negligible. If the influence of turbulence was ignored, the calculated pressure drop would be faster than actual situation. The calculation result was verified by actual measurement result, indicating that new method is practical for vacuum pumping time calculation.

Design, Manufacturing and Pump-down Curve Simulation of High Vacuum Systems

2012 ◽  
Vol 220-223 ◽  
pp. 575-579
Author(s):  
Tien Tung Chung ◽  
Chih Kang Lu ◽  
Yi Ting Tu
Keyword(s):  
Vacuum Chamber ◽  
Extreme Ultraviolet ◽  
High Vacuum ◽  
Vacuum Pressure ◽  
Vacuum System ◽  
Extreme Ultraviolet Lithography ◽  
Ultraviolet Lithography ◽  
Vacuum Chambers ◽  
Equivalent Length ◽  
Vacuum Systems

This paper presents a vacuum system design for extreme ultraviolet lithography (EUV) and studies the prediction of pump-down curves for vacuum chambers. Related basic theories include gas laws, conductance for several kinds of flow regimes, equivalent length for pipes, outgassing, diffusion, and permeation etc. The simulation program consists of a MFC module and a MATLAB module. The MFC module is used to input necessary parameters, including start and target pressure for pumping, volume and inner surface area of vacuum chambers, configuration of pumping lines, performance of vacuum pumps, and gas loads. The MATLAB module deals with the pump-down curve calculation based on related theories. The governing equation of the conservation of mass in a pumped vacuum chamber is derived from extended Temkin isotherm. The pump-down curve of vacuum chamber is predicted by four steps, including calculation of equivalent length for pipes, conductance of pipes, and effective pumping speed of pumps, and pump-down time. An empty vacuum chamber is used to test the developed program. The pump-down curve reaches 6.5E-8 torr with 42 hours pump-down time in experiment measurement, and the simulated curve reaches 5.79E-8 torr at the same time point. The developed program can predict pump-down curve with a good accuracy in the range from low vacuum pressure to high vacuum pressure.

Real-Time Calculation Method for Single-Phase Cascaded H-Bridge Inverters Based on Phase-Shifted Carrier Pulsewidth Modulation

2020 ◽  
Vol 35 (1) ◽  
pp. 977-987 ◽  
Author(s):  
Junpeng Ma ◽  
Xiongfei Wang ◽  
Frede Blaabjerg ◽  
Wensheng Song ◽  
Shunliang Wang ◽  
...  
Keyword(s):  
Real Time ◽  
Calculation Method ◽  
Single Phase ◽  
Pulsewidth Modulation ◽  
Time Calculation

scholarly journals Buried Depth of a Submarine Pipeline Based on Anchor Penetration

2019 ◽  
Vol 7 (8) ◽  
pp. 257
Author(s):  
Xueyuan Zhu ◽  
Qinglong Hao ◽  
Jie Zhang
Keyword(s):  
Numerical Simulation ◽  
Penetration Depth ◽  
Water Depth ◽  
Calculation Method ◽  
Water Surface ◽  
Submarine Pipeline ◽  
Projected Area ◽  
Actual Measurement ◽  
Calculation Results ◽  
The Relationship

Anchor penetration is an important issue involved in the study of submarine pipeline damage accidents. To explore the penetration of a ship’s anchor under certain conditions, this study investigated the motion and force of an anchor and formulated a calculation method for the bottoming speed of an anchor. Meanwhile, the depth of anchor penetration was calculated under different conditions according to bottoming speed through programming. Finally, the reliability of the calculation method for the penetration depth was verified by comparing the actual measurement and the numerical simulation. On the basis of the findings, the calculation results were further analyzed, and conclusions were derived regarding the relationship between anchor mass, the horizontal projected area of the anchor, the anchor height on the water surface, and water depth. The conclusions provide suggestions for the application of anchor penetration in terms of seabed depth with certain reference values.

Effect of Composition and Wall Thickness on Mechanical Properties of High Pressure Die Castings

2014 ◽  
Vol 790-791 ◽  
pp. 241-246
Author(s):  
Jenő Dúl ◽  
Zsolt Leskó
Keyword(s):  
Mechanical Properties ◽  
Computer Simulation ◽  
High Pressure ◽  
Wall Thickness ◽  
Vacuum System ◽  
Die Geometry ◽  
Experimental Tool ◽  
Preparation Phase ◽  
Die Castings ◽  
Vacuum Systems

In this paper we present two types of currently used vacuum systems on the HPDC and the preparation phase of an experimental tool. To investigate the properties of HPD castings we have designed a die geometry that complies with requirements of vacuum and non-vacuum systems. We used computer simulation to shape up the runner-and overflow-system. In the course of our work we examined specimens with differing thickness and alloys with different compositions to check the changes of mechanical properties and the effect of vacuum system.

Particle Behavior in Vacuum Systems: Implications for In-Situ Particle Monitoring in Semiconductor Processing Equipment.

1996 ◽  
Vol 39 (6) ◽  
pp. 40-48
Author(s):  
Patrick Kinney ◽  
Gwi-Nam Bae ◽  
David Pui ◽  
Benjamin Liu
Keyword(s):  
Semiconductor Industry ◽  
Simple Solution ◽  
Vacuum System ◽  
Spatial Distributions ◽  
Semiconductor Processing ◽  
Deposition Pattern ◽  
System Components ◽  
Vacuum Systems ◽  
Particle Monitoring

The flow of aerosol in vacuum conditions representative of many semiconductor processes (100 sccm, 1 Torr). was investigated. The study was performed using aerosols with highly nonuniform spatial distributions. An ideally nonuniform aerosol was produced by generating an aerosol beam using an aerodynamic lens. The flow containing the aerosol beam was drawn through vacuum system components. The size of the beam was measured upstream and downstream of these components by collecting the aerosol on a filter and observing the deposition pattern. Very little mixing phenomenon was observed. These results point to a potential limitation in the methods employed by the semiconductor industry for in-situ particle monitoring in vacuum systems. A simple solution to this flaw is suggested.

Residual Gas Phase Contamination of Al-Cu Alloy Films and its Effect on Electromigration Behavior

1996 ◽  
Vol 428 ◽  
Author(s):  
Imran Hashim ◽  
Ivo J. Raaijmakers ◽  
Glen Adler ◽  
Ardy Sidhwa ◽  
Sudhir Chopra
Keyword(s):  
Gas Phase ◽  
Physical Vapor Deposition ◽  
Target Material ◽  
Vacuum System ◽  
Al Alloy ◽  
Alloy Films ◽  
Cu Alloy ◽  
Effect Of Impurities ◽  
Residual Gas ◽  
Vacuum Systems

AbstractThe major sources of impurities in sputtered Al alloy films for interconnects, prepared by physical vapor deposition include those originating from the target material, residual gases present in the vacuum system, and those introduced through the gas delivery system. In this study, we report the effect of impurities incorporated from residual gases present in vacuum systems on the electromigration performance of 0.6 μm wide Al-l%Cu lines. Controlled leaks of isotope gases H2O18, N215, O218, and C13H4, in 10−6 10−9 Torr range, were introduced into a PVD tool during the sputtering process. Using these isotope gases, the impurities originating from residual gases were distinguished from those originating from other sources of impurities. The sputtering target was found to be the major source of H and O impurities in the film, whereas N atoms are introduced in the film mainly through the gas phase. Furthermore, N atoms in the film were found to affect its electromigration behaviour to a larger extent than O and H.

Short-Time Calculation Method of Passenger Flows on Urban Rail Transit Island Platform

2014 ◽  
Vol 644-650 ◽  
pp. 2133-2136
Author(s):  
Tian Shi Li
Keyword(s):  
Probability Theory ◽  
Calculation Method ◽  
Urban Rail Transit ◽  
Rail Transit ◽  
Numerical Examples ◽  
Passenger Flow ◽  
Urban Rail ◽  
Time Calculation ◽  
Passenger Flows ◽  
Short Time

Because urban tail transit becomes the preferred way to travel for more travelers, the passenger flow of rail transit is increasing fast. Due to the increased passenger, the congestion on platform reduces the comfort and puts passengers in danger. This article analyses the model of island platform short-time arrivals based on the probability theory and historical statistics. The calculation method is studied and the Feasibility and algorithm is testified by setting numerical examples.

Application of Long-Short-Pile Composite Foundation of High-Rise Building in Soft Soil

2012 ◽  
Vol 256-259 ◽  
pp. 57-60
Author(s):  
Rong Fang Song ◽  
Ling Yun Lang ◽  
Jing Wang
Keyword(s):  
Bearing Capacity ◽  
Calculation Method ◽  
Design Method ◽  
Soft Soil ◽  
Composite Foundation ◽  
Soft Ground ◽  
Design Calculation ◽  
Actual Measurement ◽  
High Rise ◽  
High Rise Building

A case of the long-short-pile composite foundation in liquefied soft soil under a 30-storey high-rise building is presented, in which the long and short piles are made of cement-flyash-gravel (CFG) and lime. A new design calculation method of bearing capacity and settlement of composite foundation is introduced, and the calculated value is compared with the actual measurement. The results show that the liquefaction of soft ground is eliminated and the demand of load and settlement for upper building is met. At the same time, it is proved that the design method is feasible.

Study on the Calculation Method of Gas Flow in Vacuum System Based on the Fluent Software

2010 ◽  
Vol 29-32 ◽  
pp. 1425-1429
Author(s):  
Shi Wei Zhang ◽  
Jin Ce Liu ◽  
Guang Zhe Song ◽  
Zhi Jun Zhang
Keyword(s):  
Laminar Flow ◽  
Calculation Method ◽  
Gas Flow ◽  
Volume Flow Rate ◽  
Fluid Velocity ◽  
Vacuum Field ◽  
Transitional Flow ◽  
Vacuum System ◽  
Continuity Hypothesis ◽  
Fluent Software

In order to improve the calculation method of the vacuum system design, the research focus on the way applying the Fluent software to calculation of gas flow in vacuum system in this paper. It is proved that the permission pressure lower limit is 1Pa for meeting the continuity hypothesis. The applicable flow patterns include turbulent flow, laminar flow and transitional flow between turbulent and laminar flow, which are totally defined as the viscous flow in the traditional vacuum field. By means of user define function (UDF), a layer mesh cell of negative quality source is defined to simulate the constant volume flow rate at the inlet of positive displacement vacuum pump, which makes up for the lack of compressible fluid velocity outlet boundary conditions in Fluent. The usability of Fluent in vacuum system is confirmed by a successful calculating example of gas flow in an ice condenser of vacuum freeze dryer.

Eine Methode zur Messung geringster Ölbedeckungen in Vakuumsystemen

1967 ◽  
Vol 22 (4) ◽  
pp. 549-553 ◽  
Author(s):  
R. Dobrozemsky ◽  
W. K. Huber ◽  
F. Viehböck
Keyword(s):  
High Vacuum ◽  
High Sensitivity ◽  
Radioactive Tracer ◽  
Operating Conditions ◽  
Ultra High Vacuum ◽  
Vacuum System ◽  
First Results ◽  
Tracer Isotope ◽  
Radioactive Tracer Method ◽  
Vacuum Systems

To get information on extremely small organic deposits in ultra high vacuum systems the sensitivity of most of the conventional methods for thickness measurements is not high enough. On the other hand the radioactive tracer method has shown its high sensitivity and wide versatility in many fields. Tritium with a half life of 12.3 γ and a mean β-energy of 5.4 keV was choosen as tracer isotope. A method is described for Tritium-labelling diffusion pump oils with specific activities up to 100 mC/g. Using the liquid scintillation counting technique one can detect deposits down to below 1010 molecules/cm2. First results with this Tritium labelled pump fluid are given under different operating conditions in an all metal ultra high vacuum system.

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