scholarly journals Mechanism and Effect of the Dilution Gas Flow Rate on Various Fe–Si/SiO2 Soft Magnetic Composites during Fluidised Bed Chemical Vapour Deposition

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 963
Author(s):  
Zhaoyang Wu ◽  
Zihan Gao ◽  
Qian Zhao ◽  
Hui Kong ◽  
Mingyang Li ◽  
...  
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Sio2 Film ◽  
Fluidised Bed ◽  
Gas Flow Rate ◽  
Soft Magnetic ◽  
Magnetic Composites ◽  
Soft Magnetic Composites

The effect of the dilution gas flow rate on inorganic oxide insulating layers can improve fluidised bed chemical vapour deposition (FBCVD) in Fe–Si/inorganic-oxide soft magnetic composites and obtain excellent magnetic properties. Herein, Fe–Si/SiO2 composite particles coated via FBCVD and deposited at a 125–350 mL/min Ar-dilution gas flow rate were prepared and sintered into soft magnetic composites. Results demonstrate that SiO2 deposited on the Fe–Si substrate particle surface changed from submicron SiO2 clusters (125 mL/min) to an incomplete SiO2 film, then to a complete SiO2 film, and finally to a porous SiO2 film as the Ar-dilution gas flow rate increased. SiO2 layers began to transform from the amorphous to the beta-cristobalite state with a hexagonal crystal structure between 1149.45 K and 1280.75 K. However, the SiO2 amorphous layers’ crystallisation did not affect the Fe–Si substrate particles’ crystal structure. With the increasing Ar-dilution gas flow rate, the saturation magnetisation of Fe–Si/SiO2 soft magnetic composites initially decreased and then increased. The electrical resistivity increased before 150 mL/min, followed by an increase between 150 and 250 mL/min and then decreased, whereas the total core loss exhibited the opposite trend. These results show that magnetic performance can be promoted by selecting a suitable dilution flow rate.

Relationship between Precursor Gas Flow Rate with the Structural and Morphology Properties of Diamond like Carbon Films

2014 ◽  
Vol 970 ◽  
pp. 128-131
Author(s):  
Ong Wai Kit ◽  
Karim bin Deraman ◽  
Wan Nurulhuda Wan Shamsuri ◽  
Jackie Chen Keng Yik
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Chemical Vapour ◽  
Carbon Films ◽  
Diamond Like Carbon ◽  
Gas Flow Rate ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Atomic Force ◽  
Direct Current Plasma

Diamond like carbon (DLC) thin films were grown onto glass substrates by using direct current plasma enhance chemical vapour deposition (DC-PECVD) system. Films were deposited under fixed deposition pressure (4 x 10-1 Torr), substrate temperature (500°C) and deposition time (3 hours) but with different flow rate of precursor gas (methane, hydrogen and argon). The fabricated films were characterized by using x-ray diffraction (XRD) and atomic force microscopy (AFM). XRD has revealed that the DLC films were having amorphous phase as the XRD spectrum did not show any obvious sharp peak. From AFM, it was discovered that the precursor gas flow rate has inversely relationship with the grain size and surface roughness of films.

SCIENTIFIC AND ENGINEERING PRINCIPLES OF EFFICIENT FUEL USE AND ENVIRONMENTALLY FRIENDLY GAS COMBUSTION IN STOVE PLATES. PART 1. MODERN STATE-OF-THE-ART AND DIRECTIONS FOR IMPROVEMENT THE GAS BURNING IN DOMESTIC GAS COOKERS

2017 ◽  
pp. 3-18 ◽  
Author(s):  
B.S. Soroka ◽  
V.V. Horupa
Keyword(s):  
Natural Gas ◽  
Flow Rate ◽  
Gas Flow ◽  
Renewable Energy Sources ◽  
Combustion Process ◽  
Orifice Diameter ◽  
Firing Process ◽  
Gas Flow Rate ◽  
Gas Combustion ◽  
Gas Stoves

Natural gas NG consumption in industry and energy of Ukraine, in recent years falls down as a result of the crisis in the country’s economy, to a certain extent due to the introduction of renewable energy sources along with alternative technologies, while in the utility sector the consumption of fuel gas flow rate enhancing because of an increase the number of consumers. The natural gas is mostly using by domestic purpose for heating of premises and for cooking. These items of the gas utilization in Ukraine are already exceeding the NG consumption in industry. Cooking is proceeding directly in the living quarters, those usually do not meet the requirements of the Ukrainian norms DBN for the ventilation procedures. NG use in household gas stoves is of great importance from the standpoint of controlling the emissions of harmful components of combustion products along with maintenance the satisfactory energy efficiency characteristics of NG using. The main environment pollutants when burning the natural gas in gas stoves are including the nitrogen oxides NOx (to a greater extent — highly toxic NO2 component), carbon oxide CO, formaldehyde CH2O as well as hydrocarbons (unburned UHC and polyaromatic PAH). An overview of environmental documents to control CO and NOx emissions in comparison with the proper norms by USA, EU, Russian Federation, Australia and China, has been completed. The modern designs of the burners for gas stoves are considered along with defining the main characteristics: heat power, the natural gas flow rate, diameter of gas orifice, diameter and spacing the firing openings and other parameters. The modern physical and chemical principles of gas combustion by means of atmospheric ejection burners of gas cookers have been analyzed from the standpoints of combustion process stabilization and of ensuring the stability of flares. Among the factors of the firing process destabilization within the framework of analysis above mentioned, the following forms of unstable combustion/flame unstabilities have been considered: flashback, blow out or flame lifting, and the appearance of flame yellow tips. Bibl. 37, Fig. 11, Tab. 7.

Preparing Soft Magnetic Composites for Structural and Micromechanical Investigations

2017 ◽  
Vol 54 (6) ◽  
pp. 366-387
Author(s):  
T. Schwark ◽  
M. Müller ◽  
Y. Mine ◽  
T. Kreuter ◽  
O. Kraft ◽  
...  
Keyword(s):  
Soft Magnetic ◽  
Magnetic Composites ◽  
Soft Magnetic Composites

On the Influence of Fluctuating Flow Rate Upon the Performance and Behaviour of Isothermal Reacting Systems

1998 ◽  
Vol 63 (6) ◽  
pp. 881-898
Author(s):  
Otakar Trnka ◽  
Miloslav Hartman
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Fluidized Bed Reactor ◽  
Computational Techniques ◽  
Continuous Stirred Tank Reactor ◽  
Gas Flow Rate ◽  
Solid Reaction ◽  
Continuous Stirred Tank ◽  
And Performance ◽  
Reacting Systems

Three simple computational techniques are proposed and employed to demonstrate the effect of fluctuating flow rate of feed on the behaviour and performance of an isothermal, continuous stirred tank reactor (CSTR). A fluidized bed reactor (FBR), in which a non-catalytic gas-solid reaction occurs, is also considered. The influence of amplitude and frequency of gas flow rate fluctuations on reactant concentrations at the exit of the CSTR is shown in four different situations.

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