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2020, Vol. 18, No. 2

Selle kollektsiooni püsiv URIhttp://hdl.handle.net/10492/5999

Sirvi

Sirvi 2020, Vol. 18, No. 2 Autor "Bulgakov, V." järgi

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  • Pisipilt
    Kirje
    Theoretical and experimental research into impact of threshing tools in combine grain harvesters on quality of cereal crop seeds
    (2020) Derevjanko, D.; Holovach, I.; Bulgakov, V.; Kuvachev, V.; Olt, Jüri; Estonian University of Life Sciences. Institute of Technology
    The theoretical and experimental research into the micro-damaging of cereal crop seeds in the process of their harvesting by combine grain harvesters in relation to the strains, forces and stresses imparted to them by the threshing tools has been carried out. The propagation of deformations and cracks in the seeds as well as the nature of their strength and the damage that is sustained, when the critical load is applied, have been investigated. It has been established that the onset of cracks, the direction of their propagation and their quantity in the bodies of grain seeds depends in the majority of cases on the direction of action of the external forces and the specifics of the seeds’ internal biological properties. It has been established that the strength of the grain seed is, apart from the arisen cracks, also under the significant effect of the microtraumas in the germ, endosperm as well as the seed coat and shell. Theoretical calculations have been carried out on the PC and the effect that the drum and rotor threshing apparatus have on the deformation and damage sustained by cereal crop seeds has been substantiated. The said calculations and the obtained graphic relations support the results of the experimental investigations and prove that the macro- and especially micro-damage sustained by the seeds of winter wheat and rye is different, when they are threshed with the use of different types of threshing apparatus, which has a considerable impact on the final quality of the harvested cereal crop seeds. The results obtained in the experimental investigations, field and laboratory tests on the topic of the effect of mechanical loading on the sustained damage and quality of seeds indicate that the damage rate accounted for the work processes of the reaping and postharvest treatment of the cereal crop heaps of different winter wheat varieties with the use of rotor threshing apparatus is 3.1% as compared to the drum threshing apparatus – 6.4%, that is, 2 times lower. The total amount of the seeds with microtraumas collected in the hopper after threshing amounts to 23.0% and 54.0%, respectively, which is a significant difference. Similar results have been obtained in the experimental investigations on the effect of the equipment on the sustained damage and quality of seeds in the cleaning, chemical treatment and sowing of cereal crops.
  • Pisipilt
    Kirje
    The theory of vibrational wave movement in drying grain mixture
    (2020) Bulgakov, V.; Holovach, I.; Kiurchev, S.; Pascuzzi, S.; Arak, Margus; Santoro, F.; Anifantis, A.S.; Olt, Jüri; Estonian University of Life Sciences. Institute of Technology
    This paper outlines a theory that involves the vibrational wave transportation of bulk grain during the course of passing that grain under an infrared radiation source, in a working thermal radiation drying chamber, and using a vibrational wave transporter belt that has been developed by the authors of this paper. The main outstanding feature of the proposed design is the presence of mechanical off-centre vibration drives which generate the vibration in the working rollers at a preset amplitude and frequency, thereby generating a mechanical wave on the surface of the flexible transporter belt which ensures the movement of bulk grain along the processing zone which itself is being subjected to infrared radiation. A calculation method was developed for the oscillation system that is used in conjunction with the vibrational transportation of the grain mass, in order to be able to determine the forces that may be present in the vibrational system and to prepare the differential calculations for the movement of the vibrational drive’s actuators, utilising for this purpose Type II Lagrange equations. The solving of the aforementioned integral equations on a PC yielded a number of graphical dependencies in terms of kinetic and dynamic parameters for the vibrational system described above; the analysis of those dependencies provided a rational structural, along with kinetic and dynamic indicators. According to the results that were taken from theoretical and experimental studies on the functioning of the developed infrared grain dryer combined with a vibrational exciter, stable movement for its working roller takes place if the angular velocity of a drive shaft is changed within the range of between 50–80 rads–1 , whereas the amplitude of the indicated oscillations falls within the range of 3.0–4.0 mm. It has been discovered that a rational speed when transporting soy seeds during infrared drying falls between the range of between 0.15–0.60 cm s -1 , whereas the amplitude of the indicated oscillations falls within the range of 3.0–4.0 mm. An increase of this parameter within the stated limits increases the time that it takes to achieve the stage in which a constant drying soy speed is reached by more than 2.5 times (from 205 seconds to 520 seconds), stabilising the figure at a level of 520 seconds, which makes it possible to recommend a range of transport speeds of between 0.15–0.40 cm s –1 under infrared radiation for the seeds in order to achieve the required moisture content with a single pass of the produce on the wave transporter. With that in mind, the power consumption levels for the vibrational exciter do not exceed 50W, while the angular velocity of the drive shaft’s rotation falls within the range of between 100– 120 rads–1 . The results of the experimental study that has been conducted indicated that a rational transportation speed for the soy seeds on the wave transporter under infrared radiation is between 0.15–0.40 cm s –1.