Sputtering Deposition of VO$lt;inf$gt;2$lt;/inf$gt; Film Using Plasma Emission Monitor as Reactive Gas Flow Rate Feedback Control

2015 ◽  
Vol 30 (11) ◽  
pp. 1228 ◽  
Author(s):  
WANG Xiao ◽  
YAN Lu ◽  
LI Ying ◽  
CAO Yun-Zhen
Author(s):  
B.S. Soroka ◽  
V.V. Horupa

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.


1998 ◽  
Vol 63 (6) ◽  
pp. 881-898
Author(s):  
Otakar Trnka ◽  
Miloslav Hartman

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.


Author(s):  
Pengju Huo ◽  
Xiaohong Li ◽  
Yang Liu ◽  
Haiying Qi

AbstractThe influences of loose gas on gas-solid flows in a large-scale circulating fluidized bed (CFB) gasification reactor were investigated using full-loop numerical simulation. The two-fluid model was coupled with the QC-energy minimization in multi-scale theory (EMMS) gas-solid drag model to simulate the fluidization in the CFB reactor. Effects of the loose gas flow rate, Q, on the solid mass circulation rate and the cyclone separation efficiency were analyzed. The study found different effects depending on Q: First, the particles in the loop seal and the standpipe tended to become more densely packed with decreasing loose gas flow rate, leading to the reduction in the overall circulation rate. The minimum Q that can affect the solid mass circulation rate is about 2.5% of the fluidized gas flow rate. Second, the sealing gas capability of the particles is enhanced as the loose gas flow rate decreases, which reduces the gas leakage into the cyclones and improves their separation efficiency. The best loose gas flow rates are equal to 2.5% of the fluidized gas flow rate at the various supply positions. In addition, the cyclone separation efficiency is correlated with the gas leakage to predict the separation efficiency during industrial operation.


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