scholarly journals Advances in Plasma Ion Nitriding

2019 ◽  
Author(s):  
Ralph Poor
Keyword(s):  
Glow Discharge ◽  
High Voltage ◽  
High Speed ◽  
Gas Flow ◽  
Plasma Nitriding ◽  
Ion Nitriding ◽  
High Voltage Power Supply ◽  
Process Gas ◽  
Detection Technology ◽  
Control Electronics

Abstract The ion or plasma nitriding process has been around for many decades. Developed in the late 1930s, the process was used extensively in Europe. During the 1980s, the process became more popular in the U.S., and many systems were purchased. Early on, the process was not widely understood, and some applications were not a good fit. As plasma nitriding advantages and limitations became realized, the process found its niche in many different industries. Very demanding applications proved to be good applications for ion over gas nitriding. In general, plasma nitriding uses high voltage power operating in the 500–100VDC range, often conducting hundreds of amps to power the process by activating the glow discharge. The glow discharge is not only capable of heating the parts but also ionizes the atmosphere to allow the process to operate. This paper provides insight into plasma nitriding and discusses new advances, widening the range of applications for the process. Many of the advances are in the form of advanced process control electronics, mass flow controllers for process gas flow, and, most importantly, newer high voltage power supply designs with high speed microprocessor arc detection technology.

Experimental Inverstigations On the Pressure Fluctuations in the Sealing Gap of Dry Gas Seals with Embedded Pressure Sensors

2021 ◽  
Author(s):  
Jingjing Luo ◽  
Dieter Brillert
Keyword(s):  
High Speed ◽  
Gas Flow ◽  
Static Pressure ◽  
Pressure Sensors ◽  
Operating Conditions ◽  
Test Facility ◽  
Experimental Investigations ◽  
Mechanical Seals ◽  
Process Gas ◽  
Sealing Gap

Abstract Dry gas lubricated non-contacting mechanical seals (DGS), most commonly found in centrifugal compressors, prevent the process gas flow into the atmosphere. Especially when high speed is combined with high pressure, DGS is the preferred choice over other sealing alternatives. In order to investigate the flow field in the sealing gap and to facilitate the numerical prediction of the seal performance, a dedicated test facility is developed to carry out the measurement of key parameters in the gas film. Gas in the sealing film varies according to the seal inlet pressure, and the thickness of gas film depends on this fluctuated pressure. In this paper, the test facility, measurement methods and the first results of static pressure measurements in the sealing gap of the DGS obtained in the described test facility are presented. An industry DGS with three-dimensional grooves on the surface of the rotating ring, where experimental investigations take place, is used. The static pressure in the gas film is measured, up to 20 bar and 8,100 rpm, by several high frequency ultraminiature pressure transducers embedded into the stationary ring. The experimental results are discussed and compared with the numerical model programmed in MATLAB, the characteristic and magnitude of which have a good agreement with the numerical simulations. It suggests the feasibility of measuring pressure profiles of the standard industry DGS under pressurized dynamic operating conditions without altering the key components of the seal and thereby affecting the seal performance.

Control of the Process Gas in Plasma Conditions

2003 ◽  
pp. 139-151
Keyword(s):  
Mass Spectrometry ◽  
Plasma Nitriding ◽  
Gas Analysis ◽  
Control Analysis ◽  
Ion Nitriding ◽  
Zone Formation ◽  
Process Gas ◽  
Gas Control ◽  
Kinetics Of

Abstract Process gas control for plasma (ion) nitriding is a matter of estimating the flows necessary to accomplish the required surface metallurgy. This chapter reviews several studies aimed at better understanding process gas control in plasma nitriding and its influence on compound zone formation. Emphasis is placed on the effect of sputtering on the kinetics of compound zone formation. The discussion covers the processes involved in process gas control analysis by photo spectrometry and mass spectrometry and the difficulties associated with gas analysis.

Experimental Investigations on the Pressure Fluctuations in the Sealing Gap of Dry Gas Seals With Embedded Pressure Sensors

2020 ◽  
Author(s):  
Jingjing Luo ◽  
Dieter Brillert
Keyword(s):  
High Speed ◽  
Gas Flow ◽  
Static Pressure ◽  
Pressure Sensors ◽  
Operating Conditions ◽  
Test Facility ◽  
Experimental Investigations ◽  
Mechanical Seals ◽  
Process Gas ◽  
Sealing Gap

Abstract Dry gas lubricated non-contacting mechanical seals (DGS), most commonly found in centrifugal compressors, prevent the process gas flow into the atmosphere. Especially when high speed is combined with high pressure, DGS is the preferred choice over other sealing alternatives. Even though the non-contacting seal is proved reliable; the ultra-thin gas film can still lead to a host of potential problems due to possible contact. In order to investigate the flow field in the sealing gap and to facilitate the numerical prediction of the seal performance, a dedicated test facility is developed to carry out the measurement of key parameters in the gas film. Gas in the sealing film varies according to the seal inlet pressure, and the thickness of gas film depends on this fluctuated pressure. In this paper, the test facility, measurement methods and the first results of static pressure measurements in the sealing gap of the DGS obtained in the described test facility are presented. An industry DGS with three-dimensional grooves on the surface of the rotating ring, where experimental investigations take place, is used. The static pressure in the gas film is measured, up to 20 bar and 8,100 rpm, by several high frequency ultraminiature pressure transducers embedded into the stationary ring. The experimental results are discussed and compared with the numerical model programmed in MATLAB [1], the characteristic and magnitude of which have a good agreement with the numerical simulations. It suggests the feasibility of measuring pressure profiles of the standard industry DGS under pressurized dynamic operating conditions without altering the key components of the seal and thereby affecting the seal performance.

The Control System of High Voltage Electrostatic Precipitator Based on FPGA

2013 ◽  
Vol 823 ◽  
pp. 528-531 ◽  
Author(s):  
Zi Sheng Zhang ◽  
Peng Bo Ge ◽  
Xiao Dong Shi ◽  
Bo Feng Liu ◽  
Zhi Qiang Liu
Keyword(s):  
Control System ◽  
High Voltage ◽  
Integrated Circuit ◽  
High Speed ◽  
Electrostatic Precipitator ◽  
Logic Device ◽  
High Voltage Power Supply ◽  
Control Module ◽  
Development Platform ◽  
Field Programmable

It is urgent to study a new control system for improving the efficiency of electrostatic precipitator. The System-on-a-Programmable-Chip (SOPC) development board, which belongs to the series of Cyclone of Altera Company, is used as the development platform. Analog Digital (AD) conversion module, voltage control module and overall control module of the electrostatic precipitator are designed and the simulation waveform of the system is analyzed, based on the programmable logic device EP1C12Q240C6 and Very-High-Speed Integrated Circuit Hardware Description Language (VHDL) programming language. The results show that: by using Field Programmable Gate Array (FPGA) as the control, transformation of AD is accurate and fast and high voltage power supply is stable, which leads to a certain value for generalization.

Design Aspects of a High-Speed High-Voltage PMSM for Aerospace Application

2017 ◽  
Vol 10 (3) ◽  
pp. 122
Author(s):  
Flur Ismagilov ◽  
Nikita Uzhegov ◽  
Vyacheslav Vavilov ◽  
Denis Gusakov
Keyword(s):  
High Voltage ◽  
High Speed ◽  
Aerospace Application

A High-Voltage High-Speed AC Switch Based on Controlled Vacuum Surge Arresters

2018 ◽  
Vol 4 (4) ◽  
pp. 4-13
Author(s):  
Vladimir A. SIDOROV ◽  
◽  
Gennady D. DOMASHENKO ◽  
Marat R. AKHMETGAREYEV ◽  
Yurii V. SHCHERBAKOV ◽  
...  
Keyword(s):  
High Voltage ◽  
High Speed ◽  
Surge Arresters
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