Sirvi Autor "Melnik, V." järgi

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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 research into new harrowing unit based on gantry agricultural implement carrier
(2021) Kuvachоv, V.; Bulgakov, V.; Adamchuk, V.; Kaminskiy, V.; Melnik, V.; Olt, Jüri; Estonian University of Life Sciences. Institute of Technology
From the point of view of energy saving, research into agricultural gantry units equipped with new implements specially adapted for operation in such systems and capable of efficiently functioning in controlled traffic (permanent lane) and wide span (gantry) systems is an important and topical issue in soil tillage science. The range of wide span systems includes harrowing units for fallow land tillage. This paper describes the experimental determination of the operating characteristics of the harrowing unit, in which a gantry implement carrier propels harrows for fallow land tillage, for the purpose of establishing the compliance of their parameters with the fundamental principles of the effective implementation of the controlled traffic and wide span soil management. The experimental investigations were done using strain-gauge and control-and-measuring equipment with analogue-to-digital conversion of the signals received from the sensing elements. An agricultural wide span unit with a track width of 3.5 m and harrows for fallow land tillage were investigated. The results show the harrowing unit is well adapted to operation in controlled traffic and wide span soil tillage systems and delivers high quality performance of the harrowing process. The latter effect is also due to the fact that the gantry travels on the compacted tracks which have a few surface irregularities compared to cultivated soil. The coefficient of variation of the draught force applied to the hook of the gantry during harrowing operations did not exceed 10%. This is evidence of the high stability (low variability) of the harrowing process, which has a positive effect on the motion stability of the harrowing unit based on the gantry tractor.
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.
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.
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.

Sirvi Autor "Melnik, V." järgi

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