scholarly journals Collecting of finely dispersed particles by means of a separator with the arc-shaped elements

2019 ◽  
Vol 126 ◽  
pp. 00007 ◽  
Author(s):  
Andrey V. Dmitriev ◽  
Vadim E. Zinurov ◽  
Oksana S. Dmitrieva

This paper includes the description of a separator, developed by the authors for the gas flow purification from the finely dispersed particles. The authors also studied the influence of the separator dimensions and the dusty gas flow rate on the degree of its purification from the finely dispersed particles, as well as on the change in the hydraulic resistance of this apparatus. This paper also shows that the main forces that make the greatest contribution to the purification of the gas flow from the finely dispersed particles are centrifugal and inertial. Moreover, the dependencies of the purification efficiency on the Stokes numbers are shown in this paper. The authors studied the change in the hydraulic resistance coefficient of this apparatus from the Reynolds numbers as well.

2020 ◽  
Vol 329 ◽  
pp. 03035
Author(s):  
Vadim E. Zinurov ◽  
Andrey V. Dmitriev ◽  
Guzel R. Badretdinova ◽  
Rustem Ya. Bikkulov ◽  
Ilnur N. Madyshev

In order to increase the efficiency of gas purification from the particles of up to 20 microns and to increase the service life of bag and electrostatic filters, the authors propose to use a centrifugal separation device with coaxially arranged pipes to be installed before the fine purification devices. The numerical studies of gas dynamics in a separation device were conducted in ANSYS Fluent software package. As a result of conducted numerical studies, it was found that the pressure loss in the centrifugal separation device is not more than 70 Pa at the inlet gas flow rate from 1 to 15 m/s and the width of rectangular hole within the range from 10 to 15 mm. The low pressure losses are caused by the design features; in particular, the resulting vortices in the inter-cylindrical space practically do not contact the wall surfaces of device. The equations of pressure loss depending on the width of rectangular holes and the hydraulic resistance coefficient of separation device depending on the inlet gas flow rate were obtained. The design coefficient of hydraulic resistance of separation device was equal to 0.45.


2021 ◽  
Vol 25 (2) ◽  
pp. 196-206
Author(s):  
V. E. Zinurov ◽  
A. V. Dmitriev ◽  
G. R. Badretdinova ◽  
R. Ya. Bikkulov ◽  
I. N. Madyshev

This article sets out to estimate power consumption when trapping finely-dispersed particles of silicon dioxide using a separator with coaxially-arranged pipes, as well as the efficiency of such an installation. To this end, a numerical simulation of the movement of a gas flow with finely-dispersed particles of silicon dioxide through a separator with coaxial pipes was carried out in the ANSYS Fluent software. During the experiments, the inlet gas flow rate varied from 5 to 10 m/s, while the width and height of the rectangular slit ranged 2.1-8.7 and 10-30 mm, respectively. It was shown that the maximum efficiency of collecting finely-dispersed silicon dioxide particles and the minimum power consumption required for pumping the gas flow through the installation largely depends on the formation of a stable vortex structure in the interpipe space. The research showed that the optimal inlet gas flow rate equals 7.5 m/s. At this rate, the efficiency of particle collection corresponds to higher rates with a devia tion of ± 6%. In this case, the pressure loss is 1.74 times lower than that at higher rates. In order to achieve an efficiency of at least 90% with the height of the rectangular slit from 10 to 30 mm, the Stokes numbers must correspond to values of more than 50. The power consumption required for pumping a gas containing silicon dioxide particles through a separator equipped with coaxial pipes comprises from 1.9 to 31.2 W at the inlet gas flow rate of 7.5 m/s. In this case, the parameters of the rectangular slit are as follows: width - from 2.1 to 8.7 mm, height - from 10 to 30 mm. The use of separators with coaxially-arranged pipes in technological lines based on plasma technologies can become an alternative to installations for fine gas purification.


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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