CC BY
21
Khudayarov Berdirasul Mirzayevich, Doctor of Science, professor, the Faculty of agricultural mechanization
Tashkent institute of irrigation and agricultural mechanization engineers, Mambetsheripova Ajargul Abduganiyeva, senior teacher, Karakalpak State University named after Berdaq, the Faculty of oil and gas technology
E-mail: majargul@bk.ru
SUBSTANTIATING PARAMETERS OF ADVANCED CENTRIFUGAL APPARATUS
Abstract: In article are brought information about the design, the technological process of new pneumo-centrif-ugal apparatus for application of mineral fertilizers and their mixtures, as well as the results and analysis of theoretical researches, in particular, the radius of fertilizer supply to apparatus.
Keywords: Centrifugal apparatus, mineral fertilizers, construction, technological process, windage, radius.
Based on the findings from pneumo-centrifugal apparatus analysis, pieces of fertilizers with a smaller windage coefficient are farther away and those with a large windage coefficient go to the ground nearer distance. Thus, it is possible to ensure that fertilizer grains, which have high windage coefficient, go farther distance and this way ensuring the closeness or uniqueness of the distance between the various windage fertilizers pieces [1; 2].
a - over-sight seen scheme of the centrifugal apparatus; b - A-A outline diagram of the apparatus; c - the motion scheme of fertilizer grains by the blade; d - attachment scheme. 1 - horizontal disk; 2 - blades; 3 - attachment Figure 1. The scheme of centrifugal fertilizer apparatus
The fertilizer grains, which have high windage coefficient, can only be carried out only under influence of additional airflow. As a technical solution to this problem, a new centrifugal apparatus has been developed (Figure 1). The centrifugal ap-
paratus consists of a flat horizontal disk 1 and an overlay blades 2 attached to it, as well as a device 3 additional airflow generated on the bottom of the disc. Each blades compliance with an attachment is fitted at the bottom of disc (Figure 1 a, b).
The technological process of apparatus is performed following way (Figure 1, c): mineral fertilizers are given to disk 1 which rotates rapidly with w angular velocity. They continue their movements along the crossed line adjacent to the disc 1 and blade 2, while the influence of centrifugal force, and is thrown at its initial vo speed.
During the disc rotation, the air is entering through ABCD duct's entrance, and is come out through absd (figure 1, d). As the surface of outlet hole is A times smaller than the opening, coming out air flow rate is increases approximately by as much.
Thus, proposed centrifugal apparatus shows two functions at the same time, the first one indicates the scattering of fertilizer, the second is to generate additional airflow and to throwing it away after the fertilizer pieces.
It is known that, fertilizer is poured into centrifugal apparatus through special holes of bunker floor which under process of technological operations of fertilizer machines.
The velocity of fertilizers poured into apparatus [3; 4]
=y/2gh (1)
here g - free flow rate, m/s2;
h - pouring height, m.
Given that, h = 0.03-0.05 m the distance between the bunker floor duct's, it can be assumed that the pouring speeds of different sizes and shape are the same.
The location of bunker floor hole relative to disk of fertilizer apparatus will be affected by fertilizer releasing and scattering.
The use of logarithmic blade in direction of rotation of bubble is brought in preliminary study of fertilizer pieces' release from disk at short intervals [5].
Section 10. Technical sciences
Differential equation of fertilizer pieces' motion along logarithmic blade
S = (02T cos^0 - fg + f (02r sin^0 - 2 f G)Sr (2)
here f - angle, between relative velocity and the centrifugal force;
S - distance traveled along the blade, m. Solution of equation (l)
fgyli+a2
S = C1e
Pit
+ C 2eP
(3)
here P,
C2 - initial magnitudes
(a + f )a2 1 and P2 - roots of equations; C conditions of movement, constant s = r, S = 0 determined by the initial conditions of the motion when t = 0.
Outlet angle ft of fertilizer apparatus is a direct indicator that affects the uneven scattering of fertilizers. This indicator depends on fertilizer transmission distance to the disk r, the blade length S and angular velocity w of disk.
The S expresses the total length of the formula (3). However, mineral fertilizers pieces are given away from the center of disk to ro distance, not at the beginning of blade, r1 initial radius of logarithmic spiral shaped blade (Figure 2). As can be seen from picture ro > r1.
Figure 2. A scheme for determining the length of blade fertilizer grains have passed
It can be determined by the following expression oflogarith-mic spiral shaped blade MM1 arc length [6]:
L =1 ^ (4)
cos^
here r1 - initial radius of blade, m;
f - angle, between tangential and radius vectors passing to any point.
It is shown in the line graph, influence to passed length of fertilizer grains over blade indexes in expression (4).
Figure 3. The line graph of change depending on angle 0 to the blade length
The graph shown in (Figure 3 is constructed with radius R = 0.3 m, r = 0.05 m and r = 0.11 m of disc. As shown in
' 1 o
(Figure 3), when the angle f increases, the width of blade is increasing according to with curvature regularities. The length is increasing in return decreasing logarithmic spiral of curvature radius. In this case, increased movement time of fertilizer grains by the blade. This allows the fertilizer grains to be fractionated. In this context, the length of blade is adopted 0.22-0.23 m corresponding to the angle f = 30-35°.
Figure 4 shows a line chart of change depending on blade length ro to fertilization distance.
Figure 4. A line chart of change depending on blade length ra to fertilization distance
The shown line chart in (Figure 4) is constructed at a disc radius R = 0.3 m, r = 0.05 m and f = 30 o. As can be seen in (Figure 4), fertilizer radius increases as fertilizer grains movement of blade length decreases according to the linearity law. Therefore, the radius of fertilizing is enlarged and it is close to length of disc radius.
Based on the results of theoretical and experimental researches, radius of fertilizing was adopted between 0.1000.125 m.
Summary: the proposed centrifugal apparatus is designed to simultaneously scattering the mineral fertilizers, to
generate additional airflow, and redirect them after scattered fertilizing grains, blades in form of logarithmic spirals and fertilization radius will be in the range of 0.1-0.125 m.
References:
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2. Худаяров Б. М., Мамбетшерипова А. А. Пневмоцентробежный рабочий орган для повышения равномерности внесения минеральных удобрения и их смесей. ВЕСТНИК Каракалпакского отделения Академии наук Республики Узбекистан.- Нукус, 2013.- № 1.- С. 19-213.
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4. Мамбетшерипова А. А. Элементы теории рассева минеральных удобрений центробежными аппаратами. ВЕСТНИК Каракалпакского отделения Академии наук Республики Узбекистан.- Нукус, 2017.- № 3.- С. 44-465.
5. Фихтенгольц Г. М. Дифференциал ва интеграл хисоб курси.- Т.: УКувпеддавнашр, 1958.- Б. 225-227.
