Experimental study on oxygen concentrator with wide product flow rate range: individual parametric effect and process improvement strategy

2021 ◽  
pp. 118918
Author(s):  
Quanli Zhang ◽  
Yingshu Liu ◽  
Ziyi Li ◽  
Penny Xiao ◽  
Wenhai Liu ◽  
...  
Keyword(s):  
Experimental Study ◽  
Process Improvement ◽  
Flow Rate ◽  
Improvement Strategy ◽  
Rate Range ◽  
Product Flow ◽  
Parametric Effect ◽  
Oxygen Concentrator ◽  
Flow Rate Range

Improving the Hall Thruster Global Efficiency over a Wide Flow-Rate Range

2021 ◽  
pp. 1-9
Author(s):  
Hao-tian Fan ◽  
Hong Li ◽  
Wei Mao ◽  
Yong-Jie Ding ◽  
Li-Qiu Wei ◽  
...  
Keyword(s):  
Flow Rate ◽  
Hall Thruster ◽  
Rate Range ◽  
Global Efficiency ◽  
Flow Rate Range

Design Optimization of Splitter Blade Impeller in a Centrifugal Pump

2020 ◽  
Author(s):  
Shunya Takao ◽  
Kentarou Hayashi ◽  
Masahiro Miyabe
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Design Method ◽  
General Purpose ◽  
Stable Operation ◽  
Centrifugal Pumps ◽  
Unstable Flow ◽  
Rate Range ◽  
Flow Rate Range ◽  
Suction Performance

Abstract In order to improve suction performance, centrifugal pumps with an inducer are used for rocket pumps, liquid gas transport such as LNG, and general-purpose pumps. Since a higher suction performance than conventional pump is required, a splitter blade that consists of a long blade and a short blade is sometimes adopted. However, the design becomes more difficult due to the increased number of parameters. The stable operation over a wide flow rate range are required in the general-purpose pumps. Therefore it is necessary to design them so that unstable flow phenomena such as surges do not occur. However, the design method to avoid them is not well understood yet. In this study, we focused on the splitter blade impeller in a general-purpose low-speed centrifugal pump with an inducer. Six parameters such as leading edge position and trailing edge position of the short blade for both hub-side and tip-side were set as design ones. A multi-objective optimization method using a commercial software was applied to improve suction performance while maintaining high efficiency. Then obtained optimal shape were analyzed by CFD calculation and extracted the feature. Furthermore, optimized impellers were manufactured and confirmed the performance over a wide flow rate range by experiments. In addition, a optimizing design method that improves pump performance at lower cost was studied.

Research of Wet Gas Experimental Facility with Adjustable and Intermediate Pressure

2012 ◽  
Vol 220-223 ◽  
pp. 875-879
Author(s):  
Ying Xu ◽  
Cun Yin ◽  
Zheng Hai Long
Keyword(s):  
Measurement Uncertainty ◽  
Flow Rate ◽  
Gas Flow ◽  
Uncertainty Assessment ◽  
Experimental Facility ◽  
Rate Range ◽  
Intermediate Pressure ◽  
Loop Design ◽  
Wet Gas ◽  
Flow Rate Range

In order to better simulate the flowing condition of wet gas, Tianjin University has designed and built up a wet gas flow experimental facility with adjustable and intermediate pressure in the flow laboratory. The designed pressure of the facility which used standard meter method and dual closed-loop design is 4MPa. The experiment medium is air and water, and the highest operation pressure is 1.6MPa. The gas flow rate range is 3~1000m3/h, and the liquid flow rate range is 0.05~8 m3/h. This article includes the structure introduction of the facility and the calculation of pressure loss of the system, etc. By the uncertainty assessment for the discussed facility, the conclusion is stated that the facility’s gas measurement uncertainty is 1% and the facility’s liquid measurement uncertainty is 0.35%.

Air/Water Two-Phase Flow Performance of Contra-Rotating Axial Flow Pump and Rotational Speed Control of Rear Rotor

2005 ◽  
Author(s):  
Toru Shigemitsu ◽  
Akinori Furukawa ◽  
Satoshi Watanabe ◽  
Kusuo Okuma
Keyword(s):  
Flow Rate ◽  
Rotational Speed ◽  
Two Phase Flow ◽  
Axial Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Rate Range ◽  
Flow Rate Range ◽  
Axial Flow Pump ◽  
Flow Pump

An application of contra-rotating rotors, consisting of front and rear rotors rotating in the opposite direction from each other, has been proposed against a demand for developing a higher specific speed axial flow pump with a more compact structure, higher efficiency and higher cavitation performance. As axial flow pumps are used for standby operations of air-lock and air/water mixing discharge to prevent floods, air/water two-phase flow performance of the contra-rotating pump has to be also investigated. In the present paper, therefore, experimental results on air/water two-phase flow performance of a test pump with contra-rotating rotors are shown and compared with those of a conventional axial flow pump, consisting of a front rotor and a rear stator. Even under two-phase flow conditions head characteristic curve of the contra-rotating type has a more strongly negative slope than that of the conventional type. The contra-rotating type maintains higher head and higher efficiency even in the low flow rate range and vice versa in the high flow rate range. This result will be discussed by considering the change of outlet flow from front rotor due to two-phase flow with the help of observed air behavior in the rotors. Then effects of changes of rear rotor rotational speed different from front rotor speed, which is an advantage of the contra-rotating axial flow pump, on two-phase flow performance are examined. Under the condition of constant ratio of air to water flow rates, the head rise of the rear rotor linearly increases with rear rotor rotational speed. Air/water two-phase flow performance of the contra-rotating axial flow pump can be improved by this control procedure for the rear rotor rotational speed.

Measurements of Axial and Radial Thrust Forces Working on a Three-Stages Centrifugal Pump Rotor

2015 ◽  
Author(s):  
Tetsuya Yamashita ◽  
Satoshi Watanabe ◽  
Yoshinori Hara ◽  
Hiroyoshi Watanabe ◽  
Kazuyoshi Miyagawa
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Axial Direction ◽  
Low Flow ◽  
Axial Thrust ◽  
Rate Range ◽  
Wide Range ◽  
Flow Rate Range ◽  
Three Stages ◽  
Thrust Forces

In this study, radial and axial thrust forces working on the whole rotor in a three-stages centrifugal pump are measured in a wide range of flow rate. The forces are measured at two floating journal bearings and one floating ball bearing, which are supported by the individual load cells. The effects of the offset of rotor position in the axial direction on the thrust forces are investigated. It is found that the effect of the axial offset is significant for the axial thrust force in the low flow rate range, whereas it has little influence on the head and efficiency performances in the whole flow rate range.

Primary standards for measuring flow rates from 100 nl/min to 1 ml/min – gravimetric principle

2015 ◽  
Vol 60 (4) ◽  
Author(s):  
Hugo Bissig ◽  
Harm Tido Petter ◽  
Peter Lucas ◽  
Elsa Batista ◽  
Eduarda Filipe ◽  
...  
Keyword(s):  
Flow Rate ◽  
High Tech ◽  
Process Technology ◽  
Special Health Care ◽  
Flow Rates ◽  
Rate Range ◽  
Health Care Applications ◽  
Flow Rate Range ◽  
Primary Standards ◽  
Special Health

AbstractMicroflow and nanoflow rate calibrations are important in several applications such as liquid chromatography, (scaled-down) process technology, and special health-care applications. However, traceability in the microflow and nanoflow range does not go below 16 μl/min in Europe. Furthermore, the European metrology organization EURAMET did not yet validate this traceability by means of an intercomparison between different National Metrology Institutes (NMIs). The NMIs METAS, Centre Technique des Industries Aérauliques et Thermiques, IPQ, Danish Technological Institute, and VSL have therefore developed and validated primary standards to cover the flow rate range from 0.1 μl/min to at least 1 ml/min. In this article, we describe the different designs and methods of the primary standards of the gravimetric principle and the results obtained at the intercomparison for the upper flow rate range for the various NMIs and Bronkhorst High-Tech, the manufacturer of the transfer standards used.

Synthesizing Vertically Aligned Zinc Oxide Nanowires on Borosilicate Glass Using Vapor Trapping Approach

2014 ◽  
Vol 1024 ◽  
pp. 87-90 ◽  
Author(s):  
Nurul Hanim Shamsudin ◽  
Kamarul Aizat Abdul Khalid ◽  
Khairudin Mohamed
Keyword(s):  
Zinc Oxide ◽  
Flow Rate ◽  
Borosilicate Glass ◽  
Gas Flow ◽  
Zno Nanowires ◽  
Synthesis Process ◽  
Operating Pressure ◽  
Rate Range ◽  
Flow Rate Range ◽  
Vertically Aligned

We demonstrate the vertically well-aligned zinc oxide (ZnO) nanowires synthesized on amorphous borosilicate glass (BSG) via simple chemical vapor deposition (CVD) process with a vapor trapping approach. During the process, zinc precursor was put inside a glass vial with the vial’s opening was directed towards the BSG substrate, which is being placed downstream from the gas flow and approximately 30-40 mm from the precursor. The BSG substrates were coated with Nichrome (NiCr) and gold (Au) coating prior to the synthesis process. Vertically aligned nanowires with a high aspect ratio was found to be deposited in total operating pressure of 20-25 bar with an Oxygen flow rate range of 5-10 sccm and argon flow rate range of 30-50 sccm. This vapor trapping approach using BSG substrates provided a good alternative towards controllable growth of ZnO NWs on any much cheaper amorphous substrates for future development of low cost energy-converter heat cell devices based on ZnO nanowires.

Effect of Pre-Whirl on Unstable Flow Suppression in a Centrifugal Impeller With Ring Groove Arrangement

2006 ◽  
Author(s):  
Masahiro Ishida ◽  
Daisaku Sakaguchi ◽  
Hironobu Ueki
Keyword(s):  
Flow Rate ◽  
Guide Vane ◽  
Pressure Rise ◽  
Centrifugal Impeller ◽  
Unstable Flow ◽  
Ring Groove ◽  
Rate Range ◽  
Recirculation Flow ◽  
Setting Angle ◽  
Flow Rate Range

In order to obtain a wider operating range in a centrifugal impeller with inducer, the effect of the pre-whirl induced by the inlet recirculation flow on the flow incidence and the impeller characteristics were analyzed numerically and compared with the experimental results. In order to control the swirl intensity of the recirculation flow, guide vanes were installed circumferentially in the annular bypass of the ring groove arrangement, and the setting angle of the guide vane was changed. The fundamental concept for surge suppression is to achieve the flow incidence less than or close to the critical one. A too large-positive flow incidence can be reduced by increasing the recirculation flow rate determined by the pressure difference between the two ring groove positions, on the other hand, a higher pressure rise in the inducer can be obtained at the flow incidence close to the critical one by suppressing the pre-whirl induced by the recirculation flow. It is clearly shown that the better impeller characteristics and the large recirculation flow rate can be achieved by giving a suitable setting angle of the guide vane. The unstable flow rate range of the tested impeller was reduced by about 53% almost without deterioration of the impeller efficiency in the whole flow rate range.

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