Sirvi Autor "Ihnatiev, Ye." järgi

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Assessment of the structural-aggregate composition of podzolized chernozem under various agrogenic impacts and post-agrogenic state
(Estonian University of Life Sciences, 2024) Bulgakov, V.; Gadzalo, I.; Kropivnyi, V.; Demydenko, O.; Holovach, I.; Ihnatiev, Ye.; Trokhaniak, O.; Olt, Jüri; Estonian University of Life Sciences. Institute of Forestry and Engineering
Identify the main patterns of transformation and establish normative parameters of changes in the structural and aggregate composition of low-humus podzolized chernozem (type of soil, known as ‘chernozem’ in Ukrainian, which translates to ‘black soil’) in the Central ForestSteppe of Ukraine in the transition period to the no-till system and minimal tillage in the agrocenosis of 5-field grain generally accepted approaches to assessing soil structure and modern statistical methods of compiling information analysis data. The generally accepted research methods were used: field, laboratory, mathematical methods, comparative and computational. The study uses fractal comparative analysis, which is a sensitive tool for assessing the distribution of structural units and water-stable aggregates in the soil. Over the past 6 years, the experimental plots have been organized with a 5-field grain-row crop rotation using three different primary tillage systems: systematic plowing, surface tillage, and transitional tillage (minimal tillage on the background of systematic plowing six years ago). It was found that the structural-aggregate state of the 0–30 cm layer of Chernozem under surface tillage was in better condition in terms of aggregate water stability over the seasonal cycle and provided better conditions for further transition to the no-till system in crop rotation compared to surface tillage after systematic plowing. According to fractal indicators, the state of water-resistant structure in the spring is assessed as unstable, although the surface treatment of qualitative and quantitative indicators of water resistance is better compared to plowing. In the summer, a fractal assessment of the state of the waterproof structure showed that regardless of the method of tillage, its condition has deteriorated to a greater extent. Thus, the fractal dimension was at the level of D > 2, which indicates the edge of the unstable state of the waterproof structure, but the Hurst index was H ≤ 0, which indicates the process of destruction of waterproof aggregates. Based on the definitions, we can say that from the systematic application of surface tillage agrophysical condition of 0–30 cm layer of chernozem in terms of structural condition and water resistance of the structure was in better condition compared to plowing and transitional tillage, which should be regarded as the end of the transition period (6 years) before the application of the No-till system in unchanged design in 5-field crop rotation.
Development and examination of high-performance fluidised bed vibration drier for processing food production waste
(2020) Kaletnik, H.; Sevostianov, I.; Bulgakov, V.; Holovach, I.; Melnik, V.; Ihnatiev, Ye.; Olt, Jüri; Estonian University of Life Sciences. Institute of Technology
Drying and processing wet particulate food production waste, such as distillery dreg, brewer's grains, beet pulp, spent coffee and barley slurry etc. for their further use as cattle fodder or fuel is an important and topical problem, which needs effective solutions. As a solution of the problem, the authors have developed improved equipment and a fluidised bed vibration drier, which ensures reaching the required output of the work process and final moisture content in the waste at a minimum power and material intensity and features the combination of the high feasibility with the high reliability of design. In order to validate the improved drying work process together with the optimum parameters of the vibration drier, theoretical investigations based on the mathematical model of the process developed by the authors have been carried out. The process of the vibration drier’s frame oscillating together with the waste has been examined, which has resulted in the generation of the differential equation that analytically describes the said process. The work process under consideration has been researched into from the thermophysical point of view using the specific initial data typical for the specific food producer. The research has resulted in obtaining the following design and process parameters of the vibration drier, in particular, for its heating pipes: diameter rt = 0.1 m; length lt = 5 m; number nt = 20, heat-transfer factor Kp = 30 and the final temperature of the dried food production waste to2 = 80 °C. The listed parameters provide for reaching the required final moisture content in the dried food production waste. Also, new relations have been generated for determining the principal process parameters of the improved drier (productive capacity, heat consumption, mass of heat carrier, waste conveyance speed, sizes and masses of the drier’s actuating elements). The obtained relations can be applied in the further theoretical and experimental research on the drier as well as the development of standard methods for its design and calculation.
Experimental study of an improved root crop cleaner from admixtures
(2018) Bulgakov, V.; Ivanovs, S.; Nowak, J.; Bandura, V.; Nesvidomin, A.; Ihnatiev, Ye.
One of the ways to raise the quality of sugar beet harvesting is the use of improved digging tools that are able to dig out root crops from the soil without any loss and considerable damage, as well as cleaners of the heap from admixtures. Perspective are the root crop harvesting machines, built according to the modular principle, where, depending on the state of the beet plantation, the composition of the cleaning tools, and the kinematic and technological modes of their operat ion are determined. To carry out experimental studies, experimental equipment was made which, under laboratory and field conditions, made it possible to obtain qualitative separation indicators of the heaps of sugar beet roots with wide variation in the ra nge of kinematic and design parameters of the improved cleaner. As the results of the laboratory and field experimental studies showed, in each of the two stages of cleaning the beet heap, a sufficiently high degree of removal of the soil admixtures and pl ant residues is ensured. Thus, at the first, preliminary stage of cleaning, the removal of admixtures amounted to 65.5 – 75.8%. After the second, basic stage of cleaning, the transported heap contained no more than 1.9% of admixtures. The results of the laboratory and field tests indicate that the proposed design of an improved sugar beet root cleaner from admixtures is prospective.
Justification of parameters for novel rotary potato harvesting machine
(2021) Bulgakov, V.; Bonchik, V.; Holovach, I.; Fedosiy, I.; Volskiy, V.; Melnik, V.; Ihnatiev, Ye.; Olt, Jüri; Estonian University of Life Sciences. Institute of Technology
The authors have set an aim in relation to the development of a novel rotary potato harvesting machine design and the substantiation of rational design and process parameters for the clod crushing tools in the machine in order to improve its separation capacity. A novel design solution has been suggested for the process of crushing the two adjacent potato rows with the vanes of the vertical rotor and the expediency of using the methods of crushing clods in the two adjacent potato rows in advance has been justified. Also, the more rational placement of the clod crushing tools in the potato harvesting machine has been suggested. Following the completed research, the geometrical parameters of the vertical rotor have been substantiated, in particular, its diameter dр = 0.65–1.0 m and height hzag = 0.27 m. Additionally, the process parameters have been substantiated for some other tools crushing the clods, in particular, the angle of inclination of the share’s working face, which has to be equal to 10°, the elevator belt width bel = 1.05 m, the linear velocity of the belt Vp = 1.95 m s –1 , the belt agitation amplitude Аst = 18 mm. If the soil moisture content is equal to W = 18.4%, the soil separation rate rises insignificantly, when the rotor diameter increases within the range of 0.65–1.0 m, moreover, at Vm = 1.0 m s –1 it varies within the range of 85.3–87.2%, at Vm = 1.5 m s –1 – within the range of 87.0–92.7%, at Vm = 2.0 m s –1 – within the range of 86.0–89.1%. The best performance is achieved at a rotor rotation frequency of nр = 100 min–1 and a translational velocity of Vm = 1.5 m s –1 , in which case the soil separation rate S is equal to 93.5%. The tuber damage rate Pb decreases from 4.2% to 1.5%, as the rotor diameter dр increases from 0.65 m to 1.0 m, the translational velocity of the machine Vm – from 0.8 to 2.2 m s –1 at the rotor rotation frequency nр = 50–100 min–1.
A mathematical model of the rear-trailed top harvester and an evaluation of its motion stability
(Estonian University of Life Sciences, 2022) Olt, Jüri; Bulgakov, V.; Beloev, H.; Nadykto, V.; Ihnatiev, Ye.; Dubrovina, O.; Arak, Margus; Bondar, M.; Kutsenko, A.; Estonian University of Life Sciences. Institute of Technology
Improving the quality of sugar beet harvesting to a great extent depends on the first operation in the process, which involves cutting and harvesting sugar beet tops. This technological process is performed with the use of either the haulm harvesting modules of beet harvesters or top harvesting machines as separate agricultural implements, which are aggregated with a tractor. At the same time, front-mounted harvesters are as widely used as trailed asymmetric implements, in which case the aggregating tractor moves on the already harvested area of the field. The purpose of this work is to determine the optimal design and kinematic parameters that would improve the stability in the performance of the technological process of harvesting sugar beet tops by means of developing the basic theory of the plane-parallel motion performed by the rear-trailed asymmetric top harvester. As a result of the analytical study, an equivalent scheme has been composed, on the basis of which a new computational mathematical model has been developed for the plane-parallel motion of the asymmetric top harvester in the horizontal plane on the assumption that the connection between the wheeled tractor and the rear-trailed top harvester is made in the form of a cylindrical hinge joint. Using the results of mathematical modelling, the system of linear second-order differential equations that determines the transverse movement of the centre of mass of the aggregating wheeled tractor and the rotation of its longitudinal symmetry axis by a certain angle about the said centre of mass as well as the angle of deviation of the rear-trailed asymmetric top harvester from the longitudinal symmetry axis of the tractor at an arbitrary instant of time has been obtained. The solving of the obtained system of differential equations provides for determining the stability and controllability of the motion performed by the asymmetric machine-tractor unit, when it performs the technological process of harvesting sugar beet tops.
Research into geometric parameters of digging shares used for lifting sugar beet roots from soil with assistance of vibration
(2021) Bulgakov, V.; Holovach, I.; Adamchuk, V.; Ivanovs, S.; Melnik, V.; Ihnatiev, Ye.; Olt, Jüri; Estonian University of Life Sciences. Institute of Technology
One of the important conditions in securing the high quality, when performing the work process of vibrational root lifting, is to avoid damaging the roots. It is obvious that the greatest probability of damaging and even breaking the lifted root arises, when the tool interacts with the root body during their first contact and in the time of the root passing in the throat between the operating shares. The aim of the study is to substantiate the rational design length for the working throat of the vibrational root lifter in its interaction with the sugar beet root while lifting the latter from the soil. As a result of the completed research, the minimum permissible tool oscillation frequencies have been determined for the specific values of the lifter’s translational velocity and the working throat rear part length, at which the event of the vibrational lifting tool gripping the root will occur at least one time. For example, when the length of the lifter’s working throat rear part is equal to 0.1 m and the oscillation frequency is equal to ν = 20.3 Hz, the satisfactory quality of the vibrational root lifting process is ensured, when the velocity of the translational motion performed by the vibrational lifter stays within the range of 1.3–2.55 m s –1 . In order to ensure the good quality of the vibrational root lifting process at the lifter’s translational velocity equal to V = 2.0 m s –1 and the frequency of its tool’s oscillations equal to ν = 10 Hz, it is necessary that the length of the lifter’s working throat rear part is equal to 0.2 m, at a tool oscillation frequency of 6.7 Hz - 0.3 m. As a result of the completed numerical calculations, the permissible values have been determined for the tool oscillation frequency, which can be recommended for the translational velocities within the range of 1.3–2.2 m s –1 , taking into account the limitation set for the tool oscillation frequency by the pre-condition of the guaranteed gripping of each root by the digging shares.
Seasonal sequestration capacity of chernozem under different agrotechnological impacts in agrocenosis
(Estonian University of Life Sciences, 2024) Bulgakov, V.; Gadzalo, I.; Pascuzzi, S.; Demydenko, O.; Holovach, I.; Ihnatiev, Ye.; Olt, Jüri; Estonian University of Life Sciences. Institute of Forestry and Engineering
The soil's sequestration capacity is primarily determined by the fine-dispersed fraction of the soil and strongly influences the properties and fertility level of the soil. To assess the sequestration capacity of C-CO2 humus in soil formation and fertility of typical chornozem (black soil), to identify the causes, rates, existing limits of the sequestration capacity decrease, it is important to study the seasonal dynamics of qualitative and quantitative indicators of humus state in time depending on the method of tillage and fertilization in agrocenoses of short rotation crop rotations in the central part of the Forest-Steppe region of Ukraine. During the research, a stationary field experiment was conducted to study the influence of methods of soil cultivation and fertilizer application on the sequestering capacity of chornozem. Laboratory studies were conducted to determine the content of humus and to calculate the seasonal reserves of absorbed carbon and phosphorus and to model the absorption capacity of chernozem. When processing with chisel plows and applying fertilizers, the increase in the C-CO2 reserve during the April-July period was +21 t ha-1 (0–0.2 m) and +36 t ha-1 a (0–0.3 m). Under moldboard plowing, the growth tended to increase by 1.52 times (0–0.2 m) and 1.25 times (0–0.3 m), but occurred at a lower quantitative level, and in the period July-September, the change in the humus C-CO2 stock was insignificant, indicating the predominance of C-CO2 sequestration processes in the summerautumn period with chisel plowing. With chisel plowing, the reserve of labile organic substances (LOS) in April exceeded the stock for plowing in the thickness of 0–0.3 m by 4.34–7.67 times (without fertilizers), 1.5–2.76 times (with fertilizers); in July - by 4.59–8.90 times (without fertilizers) and 1.32–3.16 times (with fertilizers); in September - by 4.52–4.04 times (without fertilizers) and by 1.11–1.93 times (with fertilizers), and the C-CO2 stock of the LOS compared to fallow land under chisel plowing without fertilizers in April, July, and September was 1.59–1.78 times, 2.31–3.29 times, and 1.4–1.78 times higher, and under fertilization - by 1.99–2.0, 1.86–4.50, and 1.7–2.6 times, respectively, depending on the seasons. Under fallow land maintenance, the seasonal dynamics of the C-CO2 stock of the LOS is subject to the seasonal dynamics of Porg(LOS). A direct strong correlation was found at the level of R = +0.89 ± 0.02; R2 = 79. In the period April-July, the decrease of Porg(LOS) stock in the thickness of 0–0.2 m was found to be 1.15 times, and in the thickness of 0–0.3 m - 1.1 times. From summer to autumn, the stock of Porg(LOS) was restored, and the stock in the thickness of 0–0.3 m increased by 1.10 times. Conclusions. Trends in C-CO2 stocks of humus and LOS indicate that in the series plowingchiseling-fallow land, the cyclicality index under chisel plowing was closer to the value of the seasonal cyclicality of fallow land than the seasonal cyclicality under plowing, which indicates the restoration of the CI. Trends in C-CO2 stocks of humus and LOS indicate that in the series plowing-chiseling-fallow, the index of cyclicality under chisel plowing was closer to the value of the seasonal cyclicality of fallow land than the seasonal cyclicality of plowing, which indicates the restoration of the ISC. However, the timing of changes in the Porg(LOS) stock indicates that in the series plowing-chiseling-fallow, chisel plowing is directed to fallow land by its seasonal cyclicality. The general regularity of seasonal cyclicality for all parameters of humus condition lies in the fact that a decrease in the values of ISC, as in fallow land or under moldboardless tillage, indicates the ordering of ISC, and an increase in the index of cyclicality to destruction, as under plowing.
Structural-aggregate condition and utilization of productive water reserve depending on the tillage method of podzolized chernozem in agrocenosis
(Estonian University of Life Sciences, 2024) Bulgakov, V.; Gadzalo, I.; Chernovol, M.; Demydenko, O.; Holovach, I.; Ihnatiev, Ye.; Trokhaniak, O.; Mitkov, V.; Olt, Jüri; Estonian University of Life Sciences. Institute of Forestry and Engineering
The work established the features of formation of the structural-aggregate condition and determine the main patterns of the formation of spring productive water reserves and its consumption in a five-field crop rotation when cultivating winter wheat and spring cereal crops using different tillage methods (plowing, systematic surface tillage, No-till systems based on plowing and systematic surface tillage) of podzolized chernozem (black soil) in the conditions of the central part of the Forest-Steppe of Ukraine. Common research methods were applied: field, laboratory, mathematical, and comparative-computational. Analysis of the results showed that during surface treatment, water-resistant aggregates are enlarged into the most valuable fraction, which affects the more rational use of productive water reserves during the growth of crops in crop rotation. Under the No-till system (in years 2–3), there is an accumulation of productive moisture in the soil layer of 0–1 m by 8–12 mm more compared to conventional tillage, and relative to the water reserves in 2022, the water reserve in 2023 increased by +19.0 mm (after conventional tillage) and by +14.0 mm (under surface tillage). Under the no-till system, in June and July, the average productive water reserve for the years 2022–2023 was higher compared to conventional tillage by 5–10 mm and 7–10 mm, respectively, and compared to surface tillage by 10–12 mm and 18–21 mm, respectively. In 2023, the productive water reserve in July under the No-till system exceeded that under conventional tillage by 17 mm, and compared to surface tillage by 31 mm. This improvement in soil structure water resistance in June and July was due to the increase in the content of water-stable aggregates sized 3–0.5 mm.
Study of heat exchange processes in the cooling system of a poultry house with side ventilation
(Estonian University of Life Sciences, 2024) Trokhaniak, V.; Nasieka, Y.; Ihnatiev, Ye.; Synyavskiy, O.; Skliar, O.; Olt, Jüri; Estonian University of Life Sciences. Institute of Forestry and Engineering
Modern systems for cooling the supply air in poultry houses are based on the use of spraying or evaporative systems. Both systems rely on the principle of adiabatic cooling, where water transitions from a liquid to a gaseous state through free evaporation, allowing for the reduction of the temperature of the external heated air in poultry premises. The objective of the research study was development of theoretical basis for using new method of cooling the outside air in poultry house ventilation systems is proposed, based on the use of water from underground wells and recuperative heat exchangers to cool the supply air. This method enables the reduction of the outside air temperature without increasing its relative humidity, unlike water spraying cooling systems, for example. Numerical modeling was conducted to obtain velocity fields, temperatures, and pressure differentials in the air environment of the poultry house. The results show that the air temperature exiting the heat exchangers at 20 °C is heated up to 26.6 °C inside the poultry house. Thus, the temperature of the supply air with this cooling system does not exceed permissible norms. The velocities and pressure differentials are sufficient to ensure that the air exiting the supply valves reaches the middle of the poultry house.
Theoretical research into operation of rotary potato harvester
(2021) Olt, Jüri; Bulgakov, V.; Bonchik, V.; Ruzhylo, Z.; Volskiy, V.; Melnik, V.; Ihnatiev, Ye.; Kaletnik, H.; Estonian University of Life Sciences. Institute of Technology
The topic of the paper is the determination and justification of the rational design and kinematic parameters of clod breaking tools in rotary potato harvesters with the aim of improving their separating efficiency. A new mathematical model has been developed for the motion of a soil particle on the working surfaces of the cone-shaped and cylindrical vanes in the rotary tool of the new design developed by the authors. Differential equations have been generated for the motion of a soil clod as a material particle from the moment of its arrival to the surface of the vane until the moment of its departure from the said surface. As a result of the completed investigations, relations have been established between the time of contact and absolute displacement of the soil particle and the velocity of its departure from the rotor vane surface, on the one hand, and the kinematic and design parameters of the rotor, on the other hand. For example, when the machine translation velocity increases, the absolute displacement of the soil particle within the interval from the time zero to the moment of its departure from the vane surface increases from 0.59 m to 0.65 m, the velocity of soil particle departure from the vane surface - from 1.61 m s–1 to 1.81 m s–1. The highest values of the absolute displacement of the soil particle and the velocity of its departure from the vane surface are achieved at a machine translation velocity of 2.0 m s–1. The time of the contact between the material particle and the vane surface decreases with the rise of the translation velocity. When the rotor rotation frequency varies within the range from 20 min–1 to 100 min–1, the absolute velocity, with which the soil particle leaves the vane surface, rises to 4 m s–1. The duration of the contact between the material particle and the vane reaches its maximum value of 0.33 s, when the rotor rotation frequency varies within the range of 30–40 min–1.
Theoretical study on forced transverse oscillations of root in soil with provision for soil’s elastic and damping properties
(2020) Bulgakov, V.; Holovach, I.; Ruzhylo, Z.; Melnik, V.; Ihnatiev, Ye.; Olt, Jüri; Estonian University of Life Sciences. Institute of Technology
The topic of the paper is the theory of the forced transverse oscillations performed by the root fixed in the soil under the action of the harmonic perturbing force vectored at right angle to the root’s centreline and along the line of the translational motion performed by the lifter. On the basis of applying the Ostrogradsky-Hamilton variational principle and using the equivalent schematic model developed by the authors, the expressions have been obtained that allow to determine the amplitude of the forced transverse root body oscillations as function of the perturbing force amplitude value as well as the soil’s elastic deformation and damping coefficients. The ranges of the elastic soil deformation coefficient values, at which the resonant behaviour is observed, that is, at which the forced elastic root body oscillation amplitude value exceeds the tolerance limits, have been determined for the 10, 15 and 20 Hz frequencies of the perturbing force produced by the vibrational lifting tool. That said, the mentioned oscillation amplitude values can vary from 0.58 to 0.45 m, which is sufficient to result in the root breaking. Moreover, it has been proved that, with the increase of the perturbing force frequency, the resonant behaviour ranges shift towards the increased values of the elastic soil deformation coefficient. Therefore, such elastic soil deformation coefficient ranges should be avoided in case of the lifting tool design proposed in the paper. As regards the damping properties of the soil, it has been proved that they do not cause any resonance phenomena.
Theory of motion of grain mixture particle in the process of aspiration separation
(2020) Bulgakov, V.; Nikolaenko, S.; Holovach, I.; Boris, A.; Kiurchev, S.; Ihnatiev, Ye.; Olt, Jüri; Estonian University of Life Sciences. Institute of Technology
The paper describes the development of a mathematical model for the motion of a seed mixture particle in the aspiration channel of the separator after the particle passes the cone-shaped spreader and enters the workspace of the aspiration channel in the pneumatic dynamics and vibration unit devised by the authors. The unique feature of the proposed new design is the presence of the central pipe with sail members in the aspiration channel. The sail members in the air stream generate the self-oscillatory mode of motion of the central pipe, which results in the efficient separation of the grain seed mixture into the required fractions. On the basis of the prepared equivalent schematic model, the differential equations of the motion of a seed mixture particle in the process of aspiration separation have been generated. Basing on the results of the PC-assisted numerical modelling of the motion paths, on which the material particles (seeds) of the heavy and medium fractions travel, it has been established that they move on different courses, and the course of the heavy fraction seeds is such that, after they pass the cone-shaped spreader and advance further in the air stream through the space of the aspiration channel, they move closer to the pipe of the aspiration channel. Also, their velocities and accelerations are greater than the same kinematic parameters of the medium fraction seeds. The seeds of the light fraction move upwards under the action of the air stream and leave the aspiration separator at its top.
Theory of oscillations performed by tools in spiral potato separator
(2020) Bulgakov, V.; Holovach, I.; Ruzhylo, Z.; Fedosiy, I.; Ihnatiev, Ye.; Olt, Jüri; Estonian University of Life Sciences. Institute of Technology
The aim of this study is to provide for the intensification of the process of removing impurities from the potato heap by oscillating devices, which takes place, when potato tubers are cleaned in the spiral separator during their lifting. The authors have devised a new design of the spiral separator, which can be used in the process of lifting potatoes from the soil. It comprises cantilever cleaning spiral springs, which in their simultaneously rotary and oscillatory motion clean and transport the potato tubers with good quality. However, the removal of impurities from the cleaning area and the cleaning of the side surfaces of potato tuber bodies from the stuck soil can be significantly more effective, if the spiral springs perform their oscillatory motions in the longitudinal and vertical plane during their operation more intensively. In order to achieve that, the authors have worked out a new theory of the oscillatory motion of the cleaning spiral working under the action of the potato heap. That promotes the intensification of the process of cleaning potato bodies from the stuck soil. The authors have generated a new partial differential equation, which describes the oscillations of the cantilever cleaning spiral. The PC-assisted numerical solving of the said differential equation and further numerical modelling have made it possible to obtain the analytic expressions of the relations between the change in the helix pitch distance of the cleaning spiral and its deformation, in particular, the simultaneous longitudinal extension and transverse bending. That result, in its turn, provided for finding the maximum limit amount of the above-mentioned deformation under the condition that the potato tubers may not fall through the spaces between the spiral turns, taking into account the design and kinematic parameters of the cleaning spiral itself, the material it is made of and the process-dependent mode of operation of the separator. As a result of the PC-assisted numerical modelling, it has been found that the total deflection of the spiral on its length varies within the range of 0 to 0.05 m under the following parameters: angular velocity of rotation of the spiral ω = 30 rad s-1, density of the material of the spiral ρ = 7,700 kg m-3, elastic modulus Е = 2∙1011 Pa, cleaning spiral bar stock radius r = 8.5 mm and a uniform load intensity of 1000 N m-1. Such variation ensures the good quality of cleaning and transportation of potato tubers. According to the results of the PC-assisted numerical calculations, the helix pitch distance of a cleaning spiral with the above parameters and the original helix pitch distance S = 48 mm, due to the spiral’s deformation under the proposed transverse oscillations, can change up to 54 mm, which makes impossible for potato tubers to fall out of the cleaning unit. Experimental studies fully support the results from the theoretical calculations to determine the displacement of the ends of the cleaning unit’s spiral springs.

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