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D OI: http://dx.doi.org/10.20534/AJT-16-11.12-78-81
Rahmonov O'ktam Kamolovich, Head of research and preparation of scientific and pedagogical staff of the Tashkent State Technical University E-mail: [email protected] Rakhmonov Toyir Zoyirovich, "Lukoil Uzbekistan Operating Company" E-mail: [email protected]
Study of the process of deposition of fine particles in the apparatus with a movable nozzle
Abstract: Based on the analysis and solutions of the equations of motion the formulas allowing to calculate the trajectory of the particles in the carrier gas stream were obtained. Computer and laboratory experiments were condutet and the efficiency of purification of fine particles in the dust collecting apparatus with movable nozzle were depined. The results obtained demonstrate a proper convergence parameters. The investigated dust unit can be used to trap aerosol submicron particles with high efficiency and low energy consumption.
Keywords: Equation movement, fine particles, dust equimont, cleaning efficiency, movable nozzles, gas velocity, intensification process.
Deposition of dust particles on droplets under the forces of inertia are implemented in de-dusting apparatus of wet type. The essence of inertial particle deposition is that when dusty gas flow around a spherical water droplets diameter dK, current line separated when approaching the drop and closed after its passage. Larger particles under the influence of inertial forces converge with lines and reaching the surface of the droplet deposited on it. Small particles do not have sufficient kinetic energy to overcome resistance to gas and follow the line current, Flex drop and away gas flow. According to the theory of de-dusting [1] likelihood of particle deposition on the drops under the influence of the inertia force increases with increasing mass ofparticles and increased the speed of its movement towards the drop, and decreases with increasing diameter and resistance drops Wednesday.
According to [2] to increase the speed of the gas and, accordingly, the ratio of kinetic and potential energy (EC/EP) changes the State of the gas-liquid system, accompanied by phase inversion, and eventually the emergence of regimes rising could.
In heavily turbulent flows with heavy traffic flows of packed bodies appear active factors influencing liquid droplets capture small inertial particles. These parameters can significantly alter the terms of a potential flow around the spherical particles of the gas flow. In machines with energy-carrying gas flow in pneumatic
transport modes of intense gas-liquid layer influence the turbulence becomes the decisive factor of the deposition of aerosol particles.
Such a mechanism, called inertial-turbulent proposed in [3]. The mechanism opens wide possibilities of theoretical performance analysis of delay aerosols in real liquid systems, which requires however use limiting assumptions do not distort the real picture of the process, which consists in the following: distribution ofparticles in the volume was adopted evenly distributed, turbulent pulsations taken mono-harmonic, intensity turbulent pulsations is determined by turbulent energy carrier flow, particle, whose coordinates are the coordinates of the drops are considered embedded in the drop.
Movement of sub-micron particles relative to the carrier gas flow is pulsed. The influence ofturbulent pulsations on the particles sizes 0.5 4 1 mkm is estimated through the analysis of the equations of motion of the particles.
Differential equations of motion of particles [4] for the longitudinal and transverse speed of gas taking the harmonic dependence of the velocity of turbulent pulsations of time, can be written as follows:
x+px=p \jx + Ux}Sin
y+py = p[j, +U(y)Sin where P — inertia parameter of particles;
(1)
Study of the process of deposition of fine particles in the apparatus with a movable nozzle
P =
18/u
U(x ) — amplitude values of the longitudinal turbulent momentum;
U(y ) — amplitude values of the transverse turbulent momentum;
a — pulse frequency.
On the equations of potential Ux movement are defined by longitudinal and transverse components Uy of the velocity:
U. = U
i+2 f ^ 1' íi - 3 4 ^
21 R Jl R
U =--U R1XL
Uy 3U° f R J R2
R = (x2 + y2 )
(2)
After mathematical transformations get equation, which allows you to calculate the trajectory of particles in the carrier gas stream:
aa>/3
x = A + U t —
y = B + UyT —
4P2+m
bap
y/p2 + C
= Sin (cor +0O ) Sin (cor +0O )
where
Sinfa = -
1 +
a
J
(3)
(4)
When you combine the coordinates of a moving particle coordinates drops a particle is considered settled on drop.
Figure 1. d=2 mkm diameter submicron particle trapping efficiency depencence of gas velocity. Irrigation accurary Lx10-3
Computer experiment conducted for the study of the gas-liquid flow rate changed in the range from 10 m/s
trajectory of the particle size 0,5^2 mkm. Dust collec- to 20 m/s and density of irrigation within 0.00278 ^
tion efficiency dependence is defined from the gas flow 0.0178 m/s. rate and the density of irrigation. In the experiment of a
Figure 2. d=0.5 mkm diameter submicron particle trapping efficiency depencence of gas velocity. Irrigation accurary L
1
Dust collection efficiency dependence of gas flow velocity for particles dr = 2 mkm (fig.1) shows that at speeds above 16 m/s and irrigation density 0.014 ^ 0.08 m/s effectiveness gives 97 100 For particles of size dr=0,5 mkm (fig. 2) the value of the dust collection efficiency reaches 90% at a speed of 18 m/s gas with a density of irrigation of 0.0178 m/s.
To verify the theoretical results of us studies to identify the extent of the capture of fine aerosols in the dust collecting device with the enclosed attachment.
In the process of research have been measured by definition, fluid and gas flow, gas flow and dispersion of dust of dust.
To determine the dust gas stream external filtering method used on filters AFA.
In so doing, to create iso-kinetic in the selection of sample measurements were done beforehand the speed of movement of the gas piping using a gauge metric tube MIOT. Essence of the method is to achieve equality in line with the flow velocity of the sampling tube and a tract in the sample gas movement.
Figure 3. Submicron particle trapping efficiency depencence of fractional composition. Gas velocity U, m/s
Research each filter weighed before and after measurement using the analytical balance. Knowing the difference between scales, cleaning efficiency was determined by the following formula:
n = AC\-AG .100% (5)
AG,
To determine particulate emission composition used the method of the internal filter cascade impacting factors, design by NIIOGaz. To identify studies capture sub-micron particles in the device with the enclosed attachment (HV) pilot plant was installed. Installation consists of operations 80 mm diameter HV apparatus,
consisting of 200 mm diameter separator, gas blower, running on vacuum. Gas consumption was measured using gas turbine TURGAZ counter-3.
Water consumption by using rotameter. When conducting studies for obtaining fine-dispersed aerosol modeling used arc cutting metals, burning dry leaves and rubber. The results of fine composition shows that the proportion of sub-micron particles in aerosols generated changes within 55 ^ 72%. For effective cleaning aerosols with such fractional composition of scrubbing machines, used only high pressure Venturi tubes [5], hydraulic resistance which are 20 ^ 50 kPa.
Figure 4. Submicron particle trapping efficiency various finely dispersed aerosols dependence of gas velocity. Irrigation accurary L=40m3/m4h
The study of the structural characteristics of polycaproamide-silica nanocomposite material obtained by the sol-gel method
Study to determine the effectiveness of the cleaning unit sub-micron particles with a Movable nozzle were conducted in a wide range of gas flow velocity and the flow rate of the fluid. In studies of gas flow rate in the working area changed in the range from 10 m/s to 20 m/s at constant values of the density of irrigation. The dependence of the efficiency capture of sub-micron particles from the gas flow rate obtained in irrigation density 40 m 3/m 2 h, as described in Figure 2.
As you can see from the chart, increase gas flow rate, as can be seen from the theory of dust deposition [1], leads to an increase in the efficiency of dust collecting system. Studies on determination of the efficiency of dust collecting system ofgas flow rate, can be divided into two series. At speeds of10 4 15 m/s cleaning efficiency is growing slowly,
and at a speed of15 m/s and density of30 irrigation m 3/m 2 h reached 60%. Nozzle elements were used, the size of 6 x 6 mm and weighs 0.6 oz. At speeds over 15 m/s, monitored the UPDF this attachment to the upper restrictive Grill.
In the field of speeds 15^20 m/s used cylindrical body size 6 x 6 mm nozzle and weight « 1 g, which gave an opportunity to raise the speed of up to 20 m/s. Increase speed of 15 m/s to 20 m/s has been accompanied by a sharp increase in the efficiency of the capture of fine aerosols and collection efficiency reaches 90% value. While hydraulic resistance amounted to 4.4 kPa. Thus, the results obtained show that precipitation apparatus with a Movable nozzle can be used for the capture of submicron aerosol particles with high efficiency and low energy consumption.
References:
1. Rakhmonov T. Z., Levsh V. I., Vagapov I. H. Centrifugal effect in gas-liquid separators/Scientific -technical «Uzbek Journal of oil and gas», - Tashkent, - 1999. - No 4. - P. 25-28.
2. Boyko S. I., Litvinenko A. V., Adzhiev A. Y., Gritsay M. A., Morozov B. M., Prusachenko S. N. Separation systems for units of oil gas treatment//Gas industry. - Moscow, - 2009. - No 7. - P. 32-36.
3. Ujov V. N., Valdberg A. Y., Myagkov B. I., Reshidov I. K. Purification of industrial gases from dust. - M: «Chemistry», -1981.
4. Symposium on Separation Science and Technology for Energy Applications, Gatlinburg, Tenn., Oct. 18-22, -2009.//Separ. Sci. and Technol. - V. 45, - No 2. - P. 1167-1181.
DOI: http://dx.doi.org/10.20534/AJT-16-11.12-81-85
Yunusov Furkat Umarovich, PhD, National University of Uzbekistan, Tashkent, Uzbekistan, E-mail: [email protected] Kabulov Bahodir Jabborovich, Professor, Tashkent State Technical University, State unitary enterprise "Science end progress", Tashkent, Uzbekistan, Akbarov Khamdam Ikramovich, Professor, National University of Uzbekistan, Uzbekistan, Tashkent, Makhmudov Ravshankhon Yunuskhonovich, Senior researcher, Tashkent State Technical University, State unitary enterprise "Science end progress", Tashkent, Uzbekistan
The study of the structural characteristics of polycaproamide-silica nanocomposite material obtained by the sol-gel method
Abstract: This article provides the structural-morphological studies of the polycaproamide-silica nanocomposite materials, obtained by the sol-gel method based on tetraethoxysilane, polycaproamide and glycerol, by the nitrogen porometry. A significant effect of glycerol on the final structure of the hybrid polycap-roamide-silica nanocomposite materials is shown. The values of the surface fractal dimension were defined on the basis of the results.
