Pumping performance analysis on turbomolecular pump

Hsieh, Fan-Chun; Lin, Ping-Hung; Liu, Daren; Chen, Fong-Zhi

doi:10.1016/j.vacuum.2011.02.010

Cited by 14 publications

(4 citation statements)

References 1 publication

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“…Then, the number of molecules that move from one side of the turbine blade to the other side is obtained. Finally, the ratio of the number of molecules that pass the blade to the total number of molecules, which is the transmission probability, is obtained [20,21]. The relationship between the transmission probability and turbine blade parameters can be obtained by changing the blade inclination, pitch chord ratio and speed ratio [22,23].…”

Section: Turbine Stage Pumping Performance Calculation Modelmentioning

confidence: 99%

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The Pumping Performance of a Multiport Hybrid Molecular Pump and Its Effect on the Inspection Performance of a Helium Mass Spectrometer Leak Detector

Wang

Hou

et al. 2022

Applied Sciences

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The multiport hybrid molecular pump is a new type of molecular pump that was specifically designed for use in helium mass spectrometer leak detectors. This pump enables the instrument to detect both downstream and counter-current leaks. Access to different extraction ports can fulfill various leak detection requirements, which broadens the application range of these detectors and improves their detection efficiency. This paper establishes a model for the calculation of the parameters of a helium mass spectrometer leak detector under fine inspection conditions, studies the influence of different turbine blade parameters and fine inspection port positions on pumping performance and leak detection, discusses a method to determine turbine blade parameters and fine inspection port positions under fine inspection conditions, and provides a theoretical basis for the development of helium mass spectrometer leak detection technology and the optimization of multiport hybrid molecular pump structures. The results show that reducing the blade inclination and increasing the number and height of blades can improve the detection sensitivity. Provided that the hybrid molecular pump has good pumping capacity, the helium mass spectrometer leak detector can obtain high detection sensitivity when the single blade inclination angle is 25°, the number of turbine blades is 25 to 30, the blade height is 3 mm, and the blade thickness is 0.6 mm to 0.8 mm. To determine the position of the inspection port, it is necessary to consider the actual requirements of the leak detector, such as the working pressure of the inspected parts, the leakage rate and the minimum detectable leakage rate. When the inspection port is between the 7th- and 8th-stage blade rows, optimum working pressure of the mass spectrometer chamber for better leak detection performance and large pressure detection range are guaranteed.

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Section: Turbine Stage Pumping Performance Calculation Modelmentioning

confidence: 99%

“…molecules, which is the transmission probability, is obtained [20,21]. The relationship between the transmission probability and turbine blade parameters can be obtained by changing the blade inclination, pitch chord ratio and speed ratio [22,23].…”

Section: Turbine Stage Pumping Performance Calculation Modelmentioning

confidence: 99%

The Pumping Performance of a Multiport Hybrid Molecular Pump and Its Effect on the Inspection Performance of a Helium Mass Spectrometer Leak Detector

Wang

Hou

et al. 2022

Applied Sciences

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“…A selection method of pre-pump was proposed to improve pumping performance. Hsieh et al [ 21 ] pointed out that the starting pressure of the molecular pump had a significant impact on the compression ratio and pumping rate. The excessive pressure in the front stage would lead to unstable operation of the molecular pump.…”

Section: Introductionmentioning

confidence: 99%

Study on the Pumping Performance and Structure Parameters Optimization of High-Speed Small Compound Molecular Pump

Chen,

Zhang,

et al. 2024

Micromachines

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A molecular pump is the core component of vacuum systems in portable mass spectrometers and other analytical instruments. The forms of the existing molecular pumps mainly are the combinations of vertical bleed and compression channel, which have the shortcomings of heavy mass and large volume, which seriously restricts the application and development of portable mass spectrometers. Aiming at the problems of low strength and insufficient pumping performance under the miniaturization constraints (mass of 1.8 kg; exhaust diameter of 25 mm) of molecular pumps, a compound pump consisting of a horizontal bleed channel and multi-stage spiral compression channel is proposed. The pumping principle of the compound molecular pump is analyzed to obtain its preliminary structural size parameters. The test particle Monte Carlo method is presented for establishing an aerodynamic model for a high-speed small compound molecular pump, which can be used to investigate the pumping performance of bleed blades and compression channels in a thin air environment. On the basis of the aerodynamic model, the NNIA multi-objective optimization algorithm is presented to optimize the structural parameters of the compound molecular pump. After structural parameter optimization, the maximum flow rate and compression ratio of the compound molecular pump are increased by 13.6% and 41.6%, respectively. The experimental results of the pumping performance show that the predicted data of the aerodynamic model are in good agreement with the experimental data, with an error of 12–27%. Namely, the established aerodynamic model has high accuracy and the optimized structural parameters of the compound molecular pump can provide basic conditions for the large-scale application and promotion of portable mass spectrometers.

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“…Turbo-molecular pumps (TMPs), as an important type of industrial equipment, have been widely used in process, which needs an ultra-clean environment such as chemical vapor deposition, etching processes, and so on [7].Therefore, in order to obtain an ultra-clean vacuum environment, the oilfree AMBs (Active Magnetic Bearings) technology were widely employed in the TMP system [8][9][10]. The object studied in this paper is a radial magnetic bearing(RMB) used in a TMP.…”

Section: Introductionmentioning

confidence: 99%

Influence of Processing Location Hole on a Radial Magnetic Bearing Performance

Ren¹,

Le²

2017

dtetr

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Abstract.As an electromechanical product, the performance of a magnetic bearing (MB) is determined not only by the original design, but also by the process and the assembly process. The location hole is a necessary part of the machining and assembly. In this paper, the influence of the location hole on the performance of the magnetic bearing is analyzed by the combination of equivalent magnetic circuit method and finite element method. The main performance with and without location hole are compared in detail, including magnetic field distribution, bearing capacity, current stiffness and displacement stiffness. Through the analysis, the sufficient margin for installation process should be fully guaranteed at design stage.

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Pumping performance analysis on turbomolecular pump

Cited by 14 publications

References 1 publication

The Pumping Performance of a Multiport Hybrid Molecular Pump and Its Effect on the Inspection Performance of a Helium Mass Spectrometer Leak Detector

The Pumping Performance of a Multiport Hybrid Molecular Pump and Its Effect on the Inspection Performance of a Helium Mass Spectrometer Leak Detector

Study on the Pumping Performance and Structure Parameters Optimization of High-Speed Small Compound Molecular Pump

Influence of Processing Location Hole on a Radial Magnetic Bearing Performance

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