Volodymyr Bulgakov

Intensification of rapeseed drying process through the use of infrared emitters

The theoretical basis of the agricultural material drying techniques has been formed in the world for two and a half centuries. Nevertheless, despite the multitude of studies well presented in the literature, the industry still lacks universally recognized methods of design calculation for the majority of drying problems. Presumably, this is due to the fact that the dehydration of foodstuffs is one of the most energy-intensive and complicated work processes. In the process of thermal treatment during the drying, the physical state of the water in the treated item changes, the properties of the item itself are altered. Recently, the drying of foodstuffs by means of infrared (IR) radiation has been gaining ever wider acceptance. At the same time, the technologies for dehydrating foodstuffs and materials are now far ahead of the theory of drying. Not only the classical literature on the drying problems, but even special studies on the subject cannot provide any specific recommendations for the design of installations with the electro-magnetic principle of energy input. Whereas that is exactly the type of installations that are now actively making headway, while offering serious challenges in their modelling. For that reason, experimenting has until now been the only reliable way of their studying. Despite the available extensive scientific literature on the drying, including works on IR units, the practical issues of engineering IR driers have not been tackled. All the existing studies consider solely particular cases. This study discusses the process of drying the fixed bed of rapeseeds with the use of the electromagnetic infrared emitter. The energy intensity of the process and the optimum thickness of the product bed are determined. The aim of the paper is to examine the effect that the operating condition parameters (energy input intensity, temperature, grain bed thickness) have on the drying kinetics and the energy characteristics of the process. The methods of research are based o experimental studies were carried out with the use of monitoring and measuring equipment, upto-date methods and instruments, including solutions developed by the authors. The analytical treatment was performed with the use of the software packages: MathCAD, Excel. The sample testing and examination took place in the laboratory and the methods were in compliance with the applicable standards. A comprehensive experimental investigation of the effect that the operating parameters (specific load and power) have on the rape seed IR-drying kinetics had been accomplished

Experimental Study of Operational Properties of Two-Machine Drilling Aggregate

Abstract The purpose of this study is to improve the technical and economic performance of the enhanced two-machine seeder based on the wheel-type tractor of traction class 1.4. Experimental research is based on the general provisions of the standard methodology for operational and technological evaluation of the operation of machine-tractor units in the field. Processing of results from experimental study was carried out by means of developed programs on a PC. Results obtained from field experiments testing the aggregate consisting of two-machine seeder of traction class 1.4, two SZ-3.6 seeders and a semi-mounted coupler indicate its high operational and technological efficiency in comparison to both single-machine and similar two-machine units as part of a conventional trailer hitch. Although it shows an increase in specific time losses at headland of up to 5%, due to the wider working width, utilization of a new two-machine unit on the basis of a semi-mounted coupling in comparison with a single-machine unit allows increasing the productivity of the work by 1.96 and reduction of fuel consumption by 20%. In order to ensure that two-machine unit will perform turning on headland in the optimal mode, it is necessary to equip it with a special automatic device that would change the speed of movement in compliance with the angular speed of tractor‘s steering wheels according to the developed algorithm.

Theoretical Consideration of The Controllability Indicator of Machine-Tractor Unit Movement

Abstract The paper is focused on the issues of controllability of machine-tractor units based on wheel-type tractors during their non-straight driving on the soil surface, which is positioned at an angle to the horizon. There were obtained analytical expressions for the determination of the actual indicator of control λd, including both the power and the design parameters of the machine-tractor unit, which affect the abovementioned indicator in the longitudinal vertical plane. These expressions are obtained for the tractor driving on both road and also driving during field operation. In addition, the paper discusses the conditions under which there may occur the cross-slip of the tractor steering wheels in the transversal horizontal plane. As a result of this review, there were obtained the analytical expressions for determining the required indicator of the controllability λd of machine-tractor unit in the horizontal plane, excluding the possibility of lateral sliding of the unit by turning its steering wheels at a certain angle. These expressions are obtained for the two modes of the machine-tractor unit: for driving during transport on the road and during the operation in the field. The machine-tractor unit based on the wheel-type tractor with rear mounted 3-mouldboard plough was analytically investigated. By means of computer calculations, there was observed the fact that when moving in non-straight direction on the soil surface, inclined to the horizon at an angle of 12°, the machine-tractor unit is controllable only when the angles of the steering wheel of the given tractor do not exceed 9°. During the working movement (ploughing) of the given machine-tractor unit on an inclined field surface, its controllability will be preserved on condition that the angle of the tractor steering wheels does not exceed 11°. According to obtained results, it can be stated that the controllability of the machine-tractor unit is determined by the indicator of controllability, taking into account the value of the vertical load acting on the tractor steering wheels, the possibility of their turning in the horizontal plane, as well as the withdrawal of the machine-tractor unit from rectilinear motion and its movement on the field surface, inclined at an angle to the horizon.

Theory of Vibrations of Sugar Beet Leaf Harvester Front-Mounted on Universal Tractor

Abstract The harvest and transport of sugar beet leaves during harvesting can be considered a current task in the area of sugar beet growing system development. A rotary sugar beet leaf cutting mechanism is used for achieving the significant increase in the harvester forward speed during harvest. This leads to intensive vibrations of the topping mechanism in the longitudinal vertical plane causing the decrease of harvest quality. Therefore, it is necessary to analytically determine the effect of kinematic and design parameters of the sugar beet topping mechanism front-mounted on the tractor and to discover the value of the amplitude of oscillations in the longitudinal vertical plane of its sugar beet topping mechanism. We have constructed a mathematical model of the estimated motion of this machine by means of dynamics equations in Lagrange II-kind form. A system consisting of two non-linear differential equations was obtained by developing the equivalent scheme of selected generalized coordinates and by performing the necessary mathematical transformations. This system describes the vibrations of the sugar beet topping mechanism in the longitudinal vertical plane. The optimal design and kinematic parameters of the sugar beet topper mechanism front-mounted on the tractor were determined by means of our own software and numerical solution of the differential equation system, which allows the reduction of mentioned vibrations.