75 research outputs found
TECHNOLOGICAL DESCRIPTION FOR AUTOMATING THE CULTIVATION OF BLUEBERRIES IN BLUEBERRY PLANTATIONS ESTABLISHED ON DEPLETED PEAT MILLING FIELDS
In order to increase the cost-effectiveness of blueberry (Vaccinium) cultivation in blueberry plantations, all of its technological operations should be automatized. It is reasonable to start the automation of blueberry cultivation from the technological operation of fertilising the blueberries as the main purpose of this operation is to dose a prescribed amount of fertiliser under the plant’s crown. When a new blueberry plantation is established on depleted peat milling fields, then the plants are set at pre-determined steps into parallel rows. Fertilisation of the plants in the first years of growth must be performed individually, i.e. each plant is fertilised separately. This is called precision fertilisation. In order to design the technological devices for blueberry cultivation, including the fertiliser robot, we must know the location of plants on the field or, more precisely, their position in the row. The goal of this study is to determine the position of blueberry plants in the plantation. In order to meet the goal, measurements were performed in the blueberry plantation and the position of plants in randomly chosen row was measured. It became clear from the study that plants are not positioned regularly at equal intervals in a straight line; therefore, the fertiliser robot to be designed must include the functions of plant identification and control of fertiliser jet to ensure individual or precision fertilisation of plants
EXPLORATION OF THE POSSIBILITIES FOR THE PRODUCTION OF TABLEWARE FROM THE BRAN OF VARIOUS CEREALS
Biodegradable and compostable tableware is significantly more environment and nature friendly than disposable tableware and drinkware made of plastic. Tableware made of wheat bran, but also corn and rice bran is already commercially available. It is reasonable to use the by-products of the milling of also other cereals, like rye bran, barley bran and oat bran, for the production of tableware. The aim of this research was to explore the possibilities for the production of tableware and drinkware from the by-products of the milling of wheat and also other cereals like rye and oat bran. In order to achieve the aim, compacts were moulded from rye bran and oat bran and mixtures of bran (wheat bran and rye bran) using various work modes. The moulding of the compacts included different temperatures of the mould, moulding durations and compressive forces. The mechanical properties like density and flexural strength of the compacts were determined and the compostability of the compacts was studied. The test bodies were placed inside a compost bin to check their compostability and to determine the duration of composting.Biodegradable and compostable tableware is significantly more environment and nature friendly than disposable tableware and drinkware made of plastic. Tableware made of wheat bran, but also corn and rice bran is already commercially available. It is reasonable to use the by-products of the milling of also other cereals, like rye bran, barley bran and oat bran, for the production of tableware. The aim of this research was to explore the possibilities for the production of tableware and drinkware from the by-products of the milling of wheat and also other cereals like rye and oat bran. In order to achieve the aim, compacts were moulded from rye bran and oat bran and mixtures of bran (wheat bran and rye bran) using various work modes. The moulding of the compacts included different temperatures of the mould, moulding durations and compressive forces. The mechanical properties like density and flexural strength of the compacts were determined and the compostability of the compacts was studied. The test bodies were placed inside a compost bin to check their compostability and to determine the duration of composting
Comparison between finite element analysis and rheological models for chip formation
In the process of cutting, often the selection of cutting parameters is done considering empirical methods. This approach is more expensive and does not usually lead to the best solutions. Numerical methods for simulating the chip formation have been under development over the last thirty years. The aim of the present research is to compare models based on rheological properties of metals with 2D Finite Element Models of chip formation process
Improving the quality of critical tractor parts through the dynamic stabilisation of the manufacturing process in regard to CNC machines
ArticleThis article focuses on the evaluation of a rod improvement which is considered in detail
below. The rod in question is part of an hydraulic cylinder manufacturing process which takes place
on CNC machines. The need for ensuring a process improvement in this area arose because the rod
often breaks down under operational conditions. It was found that the cause of this is a finishing
operation in the existing production process. The effect of charging which occurred during the
grinding process brings about the embedding of abrasive particles into the workpiece surface layer.
Therefore, at the running-in stage, the mating surfaces on the rod and the system being used to seal
the rings both experience intense wear in their contact areas, with this being caused by abrasive
microparticles which serves to reduce the performance characteristics of the part in question.
However, even if we dispense with the grinding process, ensuring the necessary roughness of
Ra = 0.63 μm at the machining stage alone will present problems of their own for a number of
reasons. First and foremost is the connection with the phenomenon that results in an autooscillation processes which is generated by the manufacturing system, as well as the formation
of flow chips during machining on CNC machines. In this regard, in order to avoid any negative
factors creeping into the process, we propose that a new approach be taken in achieving the
necessary surface roughness, one which is based on the suppression of the auto-oscillation process
during machining by means of creating a selective metastable structure. At the machining stage, any
inhomogeneous structure in the local chip formation area will be destroyed, thereby suppressing the
auto-oscillation process and reducing the surface roughness. Eventually, the proposed method will
allows the grinding operation to be dispensed with entirely from the manufacturing process
The theory of cleaning the crowns of standing beet roots with the use of elastic blades
ArticleA standing beet root crown cleaner has been designed. The design comprises the
vertical drive shaft that carries two flat elastic cleaning blades installed on axes and connected
through the articulated connection. The aim of the study was to develop the new theory of
cleaning the crowns of standing roots with the use of an elastic blade installed on the vertical
drive shaft in order to determine its optimal design and kinematic parameters. The first step was
to design an equivalent schematic model of the interaction between the elastic cleaning blade
installed on the vertical drive shaft and the spherical surface of the beet root fixed in the soil. The interaction between the blade and the root's crown took place at the point, where all the forces that can arise during such interaction are applied. A three-dimensional coordinate system was set
and the design and kinematic parameters of the considered interaction were designated. Using the
original differential equations projected on the set coordinate axes, the system of four nonlinear
differential equations of the three-dimensional motion of the elastic cleaning blade on the
spherical surface of the root crown was set up, then it was transformed into the system of two
differential equations in the normal form. Further, to determine the force that strips off the
remaining haulm, which is part of the obtained system of differential equations, the problem of
its analytical determination was solved separately. Also, the additional equivalent schematic
model of the interaction between the elastic blade as a cantilever beam and the root's crown was designed, the differential equation of the beam's deflection curve (taking into account the beam's simultaneous bending and twisting) was set up and, on the basis of it, the projections of the
stripping force on the coordinate axes were found. The values of the force were substituted in the
earlier obtained system of differential equations
A theoretical and experimental study of the traction properties of agricultural gantry systems
Saabunud / Received 12.04.2020 ; Aktsepteeritud / Accepted 18.05.2020 ; Avaldatud veebis / Published online 18.05.2020 ; Vastutav autor / Corresponding author: Jüri Olt e-mail: [email protected] movement conditions experienced by an agricultural
gantry system along the solid and level ground surface of permanent
artificial tracks must make it possible to generate most of its maximum
tractive force. Concurrently, the adhesive ability of the agricultural gantry
system on the ground surface of such permanent artificial tracks must be
sufficient to generate nominal drawbar pull when working at a certain level
of slip. This means that there exists the need to seek out the following
compromise: the maximum slippage experienced by the wheeled chassis
of an agricultural gantry system must be such that, in a situation in which
the level of adhesion with the surface of permanent artificial tracks is
suitable, it will be able to generate the maximum possible tractive force.
The effect of the parameters that involve an agricultural gantry system's
wheels – and the physical and mechanical properties of the ground surface
along which they move – on potential slippage has not yet been sufficiently
studied. This effect cannot be taken into consideration without taking into
account the dynamics of any rolling resistance being offered by the
agricultural gantry system's chassis. The purpose of this particular study is
to research the traction properties of an agricultural gantry system's
wheeled chassis in terms of its movement along compacted and level
ground upon which have been mounted permanent artificial tracks. The
research determines that the wheels of such an agricultural gantry system
that are rolling along permanent artificial tracks suffer less slippage and
therefore generate a higher level of tractive force. As a result, the
agricultural gantry system loses less of its speed of movement and,
therefore, uses less energy in that movement. When an agricultural gantry
system moves across an agricultural field that has been prepared for
sowing, the research also determines the maximum tractive force that its
wheels can develop when the adhesion coefficient is set at a figure that is
between 0.22–0.24. Once such movement begins along permanent
artificial tracks, this coefficient decreases to between 0.15–0.17. An
agricultural gantry system's wheels are able to generate a higher level of
tractive force when moving along on permanent artificial tracks. This
figure is at least 30% higher when its movement has to be considered
across an agricultural field that has been prepared for sowing
Theoretical research of force interaction of a flexible cleaning blade with a beet root head
ArticleThe most common technology of removing the sugar beet haulm in the world is a
continuous cut of the entire mass of the green haulm with further additional removal of the upper
parts of the sugar beet heads, which is carried out without extracting the roots from the ground.
This is the scheme according to which most top harvesting machines, manufactured in the world,
now operate. However, we have found in our studies that, due to additional cutting off the upper
parts of the root crop heads, up to 10% of the sugar-bearing mass is lost. Besides, there is an
urgent need for immediate processing of the sugar beet root crops, as losses of the sugar juice
occur, and bacteria enter inside of the root crop through the cut-off part, causing rotting.
Therefore, a more favourable operation for harvesting root crop tops is not cutting off their heads
but cleaning them from the residues of the foliage. In addition, the operation of cleaning the sugar
beet roots from the residues of the foliage is subject to rather high requirements due to the absence
of the green and dry residues on the heads of the roots, as well as the losses and damage of the
root crops themselves. The purpose of this investigation is to develop a theory of the force
interaction of the flexible cleaning blade with the sugar beet head in the process of its cleaning
when the blade is mounted on the vertical driving shaft. The methods used of the investigation
are those of modelling, higher mathematics and theoretical mechanics, as well as programming
and numerical calculations on the computer. As a result of the research, an equivalent scheme
was developed and a mathematical model was constructed describing the force interaction of the
flexible cleaning blade with the surface of the sugar beet root
Intensification of rapeseed drying process through the use of infrared emitters
ArticleThe 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 i
ndustry 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
a
cceptance. 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 reas
on, 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 exi
sting
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
parameter
s (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 on the thermophysical analysis of the material’s structure. The
experimental studies were carried out with the use of monitoring and measuring equipment, up
-
to
-
date methods and instruments, including solutions developed by the authors. The analy
tical
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
investigatio
n
of the effect that the
operating
parameter
s (specific load and power) have on the rape seed IR
-
drying kinetics had been
accomplished
Precision fertilisation technologies for berry plantation
Increased cost-effectiveness in crop production can be achieved by automating
technological operations. This is also the case for berry cultivation in plantations. Starting any
berry cultivation automation process should, quite naturally, begin with fertilisation, since this is
the first technological operation to be carried out during the vegetation period and is a relatively
simple one. The main task here is to apply the correct amount of fertiliser under the canopy
of plants. Blueberry plantations that have been established on milled peat fields have plants that
have been planted in parallel rows at a pre-designated interval. The fertilisation of plants must
take place individually in the first years of their growth, so that each plant is fertilised separately.
This form of fertilisation can be referred to as precision fertilisation. The aim of this paper was
to provide an overview of the levels of technology now available when it comes to precision
fertiliser equipment and to introduce the concept of a new precision-automated fertiliser unit, while also justifying the efficiency of using automated equipment. The automated fertiliser unit
that is to be designed will be autonomous, will move unmanned through the plantation, and will
include the necessary sub-systems for the precision fertilisation of individual plants, such as a
plant detection system, a fertilising nozzle, a motion system and, additionally, a service station. On the basis of the results obtained, it can be argued that the use of an automated precision
fertilisation unit increases productivity levels by approximately 2.25 times and decreases the
specific fertiliser costs by approximately 8.4 times when compared with the use of a portable spot
fertiliser
Experimental research into uniformity in spreading mineral fertilizers with fertilizer spreader disc with tilted axis
Received: February 2nd, 2021 ; Accepted: March 27th, 2021 ; Published: April 7th, 2021 ; Correspondence: [email protected] the efficiency in the work process of mineral fertilizer dressing is a topical
problem in today’s agricultural industry. The authors have developed a design of the fertilizer
spreading tool with a tilted axis and carried out field experiment investigations on it. It has been
established by the results of the investigations that the non-uniformity in the spreading of mineral
fertilizers along the line of their departure from the fertilizer spreading tool with a tilted axis is
most strongly affected by the disc rotation frequency. The obtained results provide for selecting
the optimum parameters and modes of operation for the tool under consideration in the situation,
when it is installed in fertilizer placing machines. Also, it has been established that increasing the
spreading disc rotation frequency in such a tool from 600 to 800 rpm results in the growth of the
effective range of mineral fertilizer spreading along the placing line at a level of 10.5 m.
Increasing the disc’s angle of inclination to the horizontal plane to 20º results in the rise of the
effective fertilizer spreading range at a level of the 48th tray (24 m) inclusive as well as the
increase of the distance between the tool and the tray that contains the maximum share of the
spread fertilizers (5.1%) to 24 trays (12 m). At a constant rotation frequency of the disc in the
tilted-axis fertilizer spreading tool, in all its kinematic modes of operation, an increase in the
angle of its disc’s inclination to the horizontal plane results in the rise of the indices representing
the distribution of the mineral fertilizers over the trays along the line of their placing. The width
of the mineral fertilizer spreading can be controlled by adjusting the rotation frequency of the
disc in the tilted-axis fertilizer spreading tool, when it is set at an angle to the horizontal plane,
similar to how it is done in state-of-the-art fertilizer placing machines with horizontally positioned
discs in their centrifugal spreading tools. The rotation frequency of the disc in the tilted-axis
fertilizer spreading tool has the most significant effect on the coefficient of variation incidental
to the distribution of the mineral fertilizers along the line of their placing
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