Doctor of Technical Sciens, Professor Tashkent Institute of Irrigation and Agricultural Mechanization Engineers, Republic of Uzbekistan, Tashkent
THE METHOD OF GENERATING ADDITIONAL AIR POWER IN CENTRIFUGAL APPARATUS AND ITS EFFECT ON WORK QUALITY
The object of research is the process of increasing the initial rate of flat application of mineral fertilizers by throwing them from the pneumomechanical apparatus.
Because the aerodynamic properties of mineral fertilizer grains vary, after they are discharged from the centrifugal apparatus, a process of fractionation is observed according to the properties of the sails during free movement in the air. This process cannot be reversed with an existing decentralized disk apparatus. As a result, the possibility of improving the quality of mineral fertilizers on the field surface is limited.
A new type of pneumomechanical apparatus scheme was developed, developed and field tests were carried out using a method of critical study of the technological processes of centrifugal apparatus in existing and patent information materials and the combination of structural elements in a single working part and the rules of classical mechanics. A mathematical expression was derived and calculated that took into account the formation of additional airflow and the change in the relative velocity of the fertilizer grains relative to it under its influence.
The centrifugal pneumomechanical device is designed to increase the initial speed by simultaneously performing two functions, the first - the throwing of mineral fertilizers, the second - creating an additional air flow and directing it behind the thrown fertilizer grains.
The proposed centrifugal pneumomechanical apparatus ensures that component fertilizers of different sizes, shapes and densities are spread evenly over the field surface.
Объектом исследования является процесс повышения начальной нормы плоского внесения минеральных удобрений путем выброса их из пневмомеханического аппарата.
Поскольку аэродинамические свойства зерен минеральных удобрений различны, после их выгрузки из центробежного аппарата наблюдается процесс фракционирования по свойствам парусов при свободном движении в воздухе. Этот процесс нельзя обратить вспять с помощью существующего децентрализованного дискового устройства. В результате возможности улучшения качества минеральных удобрений на поверхности поля ограничены.
Разработана схема пневмомеханического аппарата нового типа, разработаны и проведены полигонные испытания методом критического изучения технологических процессов центробежного аппарата в существующих и патентных информационных материалах и совмещением конструктивных элементов в единой рабочей части и нормами классической механики. Получено и рассчитано математическое выражение, учитывающее образование дополнительного воздушного потока и изменение относительной скорости движения зерен удобрения относительно него под его воздействием.
Центробежное пневмомеханическое устройство предназначено для увеличения начальной скорости за счет одновременного выполнения двух функций, первая - разбрасывание минеральных удобрений, вторая - создание дополнительного воздушного потока и направление его за выбрасываемыми зернами удобрения.
Предлагаемый центробежный пневмомеханический аппарат обеспечивает равномерное распределение по поверхности поля составных удобрений разной крупности, формы и плотности.
Keywords: mineral fertilizers, centrifugal pneumomechanical apparatus, additional air flow, initial velocity, fertilizer application.
Ключевые слова: минеральные удобрения, центробежный пневмомеханический аппарат, дополнительный поток воздуха, начальная скорость, внесение удобрений.
Taking into account the specific natural climate and soil conditions of the republic, grain is sown mainly in autumn. Feeding it begins in early spring. Taking into account the fertility of the soil and its other physical and mechanical properties, the condition of the grain in the spring, 600-800 kg of ammonia, phosphorus and potassium mineral fertilizers are applied per hectare.
All types of granular and crystalline mineral fertilizers, which are given to feed grain around the world, are made by mass spraying.
The object of the study is to increase the initial velocity of mineral fertilizer grains in the flat distribution on the field surface by throwing them from the pneumomechanical apparatus and to analyze the results obtained.
Typically, the technological process of mass spraying of mineral fertilizers on the field surface with centrifugal devices is divided into three stages, each of which is analyzed separately. Among the processes, the free movement of the fertilizer grains in the air after being thrown from the centrifugal apparatus is more affected by the uneven scattering.
This is because the grains of fertilizer are divided into fractions based on the coefficients of sail. This means that the ability to control the quality of mineral fertilizers is a factor that does not depend on the technological process of the centrifugal disk apparatus. Therefore, the issue of influencing the initial rate of disposal of fertilizer grains from the technological processes of the centrifugal disk apparatus and thereby reducing their uneven scattering is relevant to the study.
60-65% of all mineral fertilizers are applied to the soil by mass fertilization, which requires maintenance of the specified amount (100-1000 kg / ha) and strict adherence to the entire surface of the cultivated area. depending on.
In the world practice, centrifugal disk, centrifugal pendulum, centrifugal rotor, centrifugal circular apparatus are used for mass application of mineral fertilizers.
In world practice, for the mass application of mineral fertilizers on the field surface, various types of centrifugal disk workpieces of different types have been developed [1,3,6,7,8,9,10,11,12,13,14]. However, they are designed to sprinkle granular simple or complex fertilizers. It is recognized that this type of workpiece does not meet the agro-technical requirements when spraying mixtures consisting of several simple mineral fertilizers, the granules of which vary in shape, density and size [1,2,3,13,14].
Based on the above, the aim of the study was to improve the quality of work by spraying mineral fertilizers of different grain sizes with a centrifugal apparatus, affecting their initial velocity at the disc.
The task of the study was to improve the technological process of the centrifugal apparatus by creating an additional air flow and to ensure a smooth application of fertilizers on the field surface.
2.Bipolar transistor radiation degradation model
Conducted on the basis of 30 years of research and analysis of patent information and methods of analysis of the results and the rules of classical mechanics, devoted to the design and technological process of all types of centrifugal disk apparatus for spraying mineral fertilizers and their mixtures around the world.
In this case, the shape of the blades in the centrifugal apparatus for high-quality spraying of mineral fertilizers and their mixtures of different shapes, sizes and densities and their placement on the disk, important elements in the design of additional air generating devices were selected and combined into one working part.
3.Comparative analysis of radiation hardness of the current mirrors on bipolar transistors
Many years of scientific, theoretical and experimental research have shown that the main reason for uneven application of mineral fertilizers of different shapes, sizes and densities across the field surface is that mineral fertilizer grains break down into fractions during their movement in the air after being thrown from the apparatus. As a result, fertilizer grains with a low volatility coefficient fall to the ground at a longer distance, while those with a high volatility coefficient fall to the ground at a shorter distance. As a result, small aggregates and large-sized fertilizers are sorted in the middle of the working width of the unit.
This means that if the mixture contains a large amount of large-scale fertilizer, the amount of fertilizer at the edge of the aggregate working width is denser than at the middle, creating a basis for uneven spraying of the mixture on the components. It follows that it is possible to solve the scientific and technical problem by ensuring the long-distance fall of fertilizer grains with high volatility coefficients and by this method ensuring the proximity or uniformity of the landing distance of different volatile fertilizer grains in the fertilizer [1,2,3, 14].
According to the research conducted by the authors, in order to increase the initial velocity of fertilizer grains with a large volatility (sailing) coefficient from the disk, it is possible to direct additional air flow and ensure their disposal over longer distances [2,3,14].
This requires that the technological work of the centrifugal apparatus is not limited to the application of mineral fertilizers, but also has the ability to generate additional air flow at once, as well as theoretically and experimentally based. As a technical solution to these problems, a centrifugal apparatus was developed with improved technological work process and corresponding design (Fig. 1), [2,3,14].
The proposed centrifugal pneumomechanical apparatus consists of a flat horizontal disc 1, logarithmic coil-shaped blades 2 fixed to the upper side, and devices for generating additional airflow 3 mounted on the lower side (Figure 1).
Figure 1. a - diagram of the top view of the centrifugal pneumomechanical apparatus; b - computer graphics view of the proposed centrifugal pneumomechanical fertilizer. 1-flat disc; 2 shovels; 3.4 Air inlet and outlet holes of the device in accordance with Figure 1. Schematic of the proposed pneumomechanical fertilizer apparatus
Flat disc with a diameter of 600 mm 1. The height of the paddles is 50 mm. At the bottom of the disc 1, on each paddle 2, is placed a device that generates one additional air, respectively (Fig. 1 a, b).
From the moment when the mineral fertilizer grains are thrown from the pneumomechanical apparatus at the initial speed under the influence of centrifugal force, the second phase of their movement, i.e. free movement in the air, begins. During this period, they begin to be affected by additional airflow.
In the second phase of the study, the following was accepted: - the force of the additional air flow is directed horizontally; - the velocity and direction of the air flow are the same on the cross-sectional surface of the outlet; - The initial velocities and directions of all fertilizer grains thrown from the shovels are the same. The additional air flow coming out of the outlet of the device, the movement
during which it expands in proportion to the distance to the hole, pushing the fertilizer grains in the air with it. Taking into account the distance-dependent decrease of the additional air flow rate [4,5] and the relative movement of the fertilizer grains relative to it, as well as the change in velocity, the authors obtained the following expression,
where the distance traveled by the additional air stream along the axis, m;
axial velocity of additional air flow, m / s;
k - coefficient of air resistance;
Vx - initial velocity of additional air flow, m / s;
coefficient of turbulence of the α-flow, a = 0.07-0.14;
x is the distance from the air outlet of the device, m;
d is the diameter of the outlet, d = 0.043 m2.
(1) the “+” sign in the expression; The "-" sign is used in cases.
(1) is an expression of the second order differential equation, which was calculated by the following values in the Runge-Kutta-Felberg automatic step numerical method: k = 0.184-0.265, Vx = 50.0-110.0 m / s; the initial throwing velocity of the fertilizer grain is V0 = 25 m / s, the free fall acceleration is g = 9.8 m / s [1.14].
Under the influence of additional air flow, the initial velocity of the fertilizer grains at the outlet changes. This is because the value of the additional air flow velocity is on average 3-4 times higher than the velocity at the time of application of mineral fertilizers from the apparatus, and the directions of movement are also parallel. Based on the results of the calculations, Figure 2 shows the change in the velocity of the fertilizer grains under the influence of the additional air flow.
As can be seen from Figures 2 a, b, the initial velocity of the fertilizer grain was 25 m / s, while after additional air flow, its velocity was 42 m / s (Fig. 2 a), 53 m / s (Fig. 2 b) and 70 m. / s (Fig. 2 c). This can be explained by the fact that the force of the additional air flow gives impetus to the fertilizer grains. From the analysis of the graphs, it can be seen that over time the rate of additional air flow decreases rapidly, while that of the fertilizer grain is relatively slow. However, the fertilizer grain had a significantly higher velocity than the initial velocity at the time of discharge from the pneumomechanical apparatus. This is why their throwing distance is large, which allows the machine to increase the working width.
Figure 2. Additional air flow and fertilizer grain
1, 2- additional air flow and fertilizer grain velocities respectively Figure 2. Graphs of change of fertilizer grain initial velocity at additional air flow rate 50 (a), 75 (b) and 100 m / s (c)
Once the mineral fertilizer grains are released from the effect of the additional airflow generated in the apparatus, the third phase of their movement begins.
In the third phase, it was assumed that the wind speed in the environment was less than 5 m / s.
Resistance of the medium to the fertilizer grain [4,5,6].
where m is the mass of fertilizer grain, kg; kp-fertilizer grain sailing coefficient, 1 / m; u is the relative velocity of the fertilizer grain, m / s. The equation of motion of fertilizer grains in the XOU coordinate system in a resistive environment is as follows [1,9,14].
where x is the distance traveled by the fertilizer grains along the axis, m;
y = h - distance traveled by fertilizer grains along the ou axis, m.
Vu is the volatile velocity of the fertilizer grain, m / s.
Solve equation (5) with respect to time t and put it in equation (2). For this
Given that, the following expression was formed,
(7) by performing mathematical operations on the expression,
(8) Substituting the value of t into (3),
(9) The initial velocities of the expression fertilizer grains were calculated from the values v0 = 18–30 m / s, vu = 12 m / s, and g = 9.8 m / s2, and the connection graphs shown in Figures 3 and 4 were constructed.
Figure 3 shows a graph of the change in the distance traveled by the fertilizer grain depending on the volatile (critical) velocities.
Figure 3. Dependence of the distance traveled by the grain of fertilizer on the critical velocity
From Figure 3 it can be seen that the distance traveled increases with the increase in the critical velocity of the fertilizer grain along the bubble curve.
This situation can be explained by the fact that the higher the volatility rate of the fertilizer grain, the less the effect of the environment that resists it. Considering that the volatile velocity of fertilizer grains varies in a large 1.5–15.5 m / s depending on their size, when the volatile velocity is 8–10 m / s, the distance covered by them is in the range of 8.6–11.2 m.
Figure 4 shows a graph of the change in the distance traveled by the fertilizer grain depending on the initial velocity.
Figure 4. Graph of the change in the distance traveled by the grain of fertilizer depending on the initial velocity
It can be seen from Figure 4 that as the rate at which the fertilizer grain enters the resisting medium increases, it is observed that the distance covered by them increases in a view close to the bubble curve. This situation is explained by the fact that the initial speed of the fertilizer grain is large, it can overcome the resistance force exerted by the environment at a certain distance.
Based on the results of theoretical research, the following conclusions were made:
1. Improving the quality and application of mineral fertilizers on the field surface by improving the working process and design of the centrifugal disk apparatus, ie by installing logarithmic shovels on the upper side and a device that creates additional air flow at the bottom.
2. The initial velocity of the generated additional air flow is 3.0-4.5 times greater than the initial velocity of mineral fertilizer grains and the direction is parallel, which allows to increase the initial velocity of fertilizer grains by 1.5-3.0 times.
3. Direct parallel flow of additional air flow in accordance with the trajectories of fertilizer grains in the air, reducing the process of separation into different fractions based on their aerodynamic properties, ensuring that they fall to the same distance and, as a result, evenly sprayed.
- Xudayarov B.M. Increased uniformity of mineral deposits and mixtures of centrifugal-disc apparatus. Dis. k.t.n. avtoref.- Minsk, 1988, -16 p.
- Khudayarov B.M., Mambetsheripova A.A. Substantiating parameters of advanced centrifugal apparatus // European science review.- Austria, 2018 №9-10 p.235-237.
- Khudayarov B.M., Mambetsheripova A.A.Improving the technological process of the fertilizer from centrifugal fertilizer apparatus and setting the parameters // ACTA TTPU.-Tashkent, 2018. №3. R. 63-65.
- Klenin N.I., Sakun V.A. Selskoxozyaystvennыe and meliorativnye mashiny. -M .: Kolos, 1980, -664 p.
- Bronstein I.N., Semendyaev K.A. Reference book on mathematics.M .: -1962, -589 b.
- Vasilenko P.M. Theory of motor frequency on sheroxovatыm poverxnostyam selskoxozyaystvennyx mashin.Kiev .: UASXN., - 1961. 263 b.
- USSR 1055381 A 01S 17/00. Raspredelitelnыy rabochiy organ raz¬brasыvatelya udobreniy. / V.A.Skolzaev; V. A.Chernovolov; V.P.Zabrodin; T.M.Lyashenko / №3463794 / 30-15 Zayavl. 5.07.82. Opubl. 23.11.83 Opening, inventions -1983.- №43.
- USSR 993863 A 01S 17/00. Rabochiy organ razbrasыvatelya udobre¬niy. /N.M.Fedotov; G.N.Grigorchuk; V.I.Polevik; A.I.Dovgan;
- V.G.Nesterovskiy; V.A.shchemelinskiy; V.A.Chernovolov; B.N.Melnikov; Yu.P.Kayushnikov; S.N, Grigorov / № 3352992 / 30-15 Zayavl.16.11.81. Opubl. Opening, invention - 1983.- №5.
- 8 Fixtengolts G.M. Differential and integral calculus. O'quqpeddavnashr.-T. -1958. 225-227 b.
- USSR 460028 A 01 s 17/00. Razbrasыvatel mineral udobreniy bunkernogo type. /V.A.Skolzaev; N.M.Fedotov; V.A.Chernovolov;
- A.P.Jilin; A.P.Kurilov; V.A.Lure; V.I.Polevik; N.D.Gribnyak;
- E.A.Plotnikov; A.A.Dokuchaev; V.A.Tkachenko; E.A.Gotleb / №1657861 / 30-15 Zayavlyu 25.05.71. Opubl. . "Otkrytiya, izobreteniya, promыshlennыe obraztsы, tovarnye znaki", 1975.- №6.
- Sablikov M.V. Selskoxozyaystvennыe mashiny. II-chast.-M .: Kolos, 1968.- 11-112 p.
- RF Patent №2120724. Rabochiy organ razbrasыvatelya mineralnyx udobreniy. /V.A.Chernovolov, V.I.Volkov, I.A.Kazachkov / №96109518 Zayavl. 12.05.96. Registered in the State Register of Inventions of the Russian Federation October 27, 1998.
- Patent 3652019 (SShA), kl.239682,896. -Opubl.v official. Gaz.matlov patentnogo vedomostva SShA.-1973.-№4.6-7s.
- Malonosov N.L., Temofeeva L.N. Physical properties of tukosmesey on the basis of granulometric components // Trudy / NIUIF.-M., 1976.-Vyp.-229s. 18. Mambetsheripova AA Improving the technological process and substantiation of the parameters of the centrifugal apparatus for spraying mineral fertilizers. Diss .... philosophy (PhD) doctor avtoref. -Tashkent, 2019