The conducted studies have shown that a promising design and technological scheme of the mixer is a low-speed screw mixer of periodic action, the loading and unloading parts of which are connected by an active return channel having areas of interpenetration of feed mixture components.It is established that the cycle time consists of the time of passage of the components of the mixture through the sections of the screw winding, tangential blades and in the return channel under the action of an additional screw. The time spent by the mixture on the screw section and in the return channel is determined by the length of each section, the design parameters of the winding, the angle of installation of the housing to the horizon and the rotation frequency of the working body. When determining the time spent on the interpenetration site of the components of the mixture, it is necessary to take into account the filling factor of the return channel and the physico-mechanical properties of the components of the mixture.The duration of loading and unloading of the mixer is determined from the condition of the axial velocity of movement of the feed mixture components in each of the sections and corresponds to the cycle time.The residence time of the mixture at each of the sites is determined taking into account the design parameters and the rotation speed of each working body. The optimal ratio between the diameters of the auger and the additional auger from the condition of the maximum volumetric capacity of the mixer is revealed. Expressions are obtained for determining the supply of working bodies at each of the sections from the condition of continuity of the flow. Modeling of the volumetric feed allowed us to estimate the effect on the volumetric flow of the mixer depending on the ratio of the pitch of the screw turn to its diameter, the number of screw turns.
The improvement of the technological process of preparing dry loose feed mixtures is associated with an increase in the structure of feed rations for farm animals in the conditions of farms. It is noted that an increase in the digestibility and palatability of feed, a decrease in the specific energy consumption for the production of feed mixtures depends on the quality of their mixing. The methodological basis of the work was the results of studies of recent years by leading domestic scientists in the field of improving the technological processes for preparing feed mixtures, design and operating parameters of mixers. The analysis of sampling methods is given: periodic for batch mixers; cumulative, allowing to obtain a generalized sample, more representative of the mixing process, also applicable to the study of batch mixers; using special devices - samplers to obtain the most accurate samples. The importance of selecting a control component oriented to the functional features of the mixers, regardless of the sampling method used, is highlighted when monitoring the homogeneity of the mixture. The analysis of existing studies showed a wide range of control components, methods of sampling and separation of components in the study of the mixing process by machines of various designs and principles of operation. The analysis of the works showed that in order to reduce the time spent on isolating the control component and ensure the reliability of the studies, it is necessary to take into account the nature of the mixed cultures. When choosing seeds of sweet clover, clover, millet as control components, a sample mass of 5 grams is sufficient; seeds of beets, buckwheat, wheat and barley, a sample mass of 100 grams is sufficient; seeds of peas, corn, a sample mass of 300 grams is sufficient. A sieve classifier with optimal selection of the mixture with the possibility of separating in sieve or sieve analysis is noted as the most applicable for the isolation of the control component. It is recommended to focus on the method of periodic sampling when examining batch mixers. The cumulative sampling method using samplers is recommended for investigating the performance of continuous mixers and evaluating the overall quality of mixing in batch mixers.
The paper examines the processes of natural cooling of a medium-storage pile containing 3,650 tons of sugar beets. Adiabatic cooling and related processes are established to have a predominant effect on reducing the temperature in the pile while in storage. Piled sugar beet is cooled due to some natural water evaporation from the surface of sugar beets, followed by moisture saturation of the outside air. Such cooling leads to an uncontrolled decrease in the quality of beets, which has negative implications during further processing. A formula is presented for calculating post-harvest yield loss in sugar beets piled with one slope being across the prevailing wind.
Teat liner in direct contact with the animal's udder has a significant impact on the quality of the milking process and on diseases of the animal's udder. Foreign firms recommend not to carry out maintenance of the teat rubber, but to change it after 2500 milkings due to the high costs of maintaining the working condition of the teat rubber, which inevitably leads to underutilization of the resource. Taking into account the current situation, it is proposed to carry out diagnostic control of the state of the teat rubber on working milking machines in accordance with the developed method and to carry out culling, depending on the technical condition. Determination of the main parameters of the milking machine was carried out using devices to control the stability of the vacuum of the milking machine and to measure the pressure of the teat rubber on the teat. The studies were carried out in laboratory conditions and on a dairy farm. The developed method and technical means made it possible to conduct research and establish the dependence of the pressure on the end of the nipple for domestic teat rubbers. Dependences of the pressure of various types of teat rubbers on the teat on the values of regime parameters have been established. The dynamics of changes in pressure on the nipple during operation was studied. It is shown that the pressure on the nipple during operation can be regulated by both the operating vacuum and the tension of the liner, while the adjustment range is 35% of the range of permissible values. It has been established that teat rubbers can be operated in the mode of optimal pressure on the teat.
The search for a rational design of an animal feed mixer is reduced to determining the structural and operational parameters of a machine that, in terms of its quality and energy costs, would most fully meet the zootechnical and technical and economic requirements. The analysis of the most typical designs of feed mixers was made. Their main shortcomings were revealed: low productivity, complexity of hardware solutions of the main processes, high energy consumption of the mixing unit and the probability of jamming when objects hit the sides; lack of control over the mixing parameters; complexity of the process of unloading the finished product and its automation; manual control of nodes. The classification of feed mixers is proposed according to the indicators of the greatest influence on the quality of the mixture and the energy consumption of the process: the type of feed; kinematic mode; the nature of mixing; the constructive sign; the design of the hopper; the number of mixing shafts; the location of the working body; the method of mixing; by the type of movement of the components being mixed; by the type of working body. A promising design was chosen: according to the type of feed – for dry; according to the kinematic mode - slow–speed; by the nature of mixing – periodic action; by the structural feature - with a fixed body; by the design of the hopper – round shape; by the number of mixing shafts – two–shaft; by the location of the working body – inclined; by the method of mixing – forced action; by the type of movement of the components being mixed - circulating; by the type of working body – screw with an active reverse channel. The use of such a design will ensure high quality of mixing; will increase the technological reliability of the mixing units; it will reduce the specific energy costs for the process of preparing a portion of the lump mixture.
Introduction. Road safety is largely determined by the technical condition of the vehicle, and especially control systems. The braking system is one of them. To improve its efficiency, various assistive electronic systems are now widely used. These systems control the vehicle through wheel braking mechanisms. Brake pads are a constituent element of a friction-type wheel brake mechanism. The efficiency of the vehicle braking system depends on its quality, regardless of the presence of auxiliary electronic systems. The use of brake pads with a wide spread of friction coefficients can have a significant impact on braking performance.Materials and methods. To conduct experimental studies, a methodology for conducting them and processing experimental data was developed, as well as a laboratory setup was made. Arduino Uno R3 analog-to-digital converter was used as an instrumental component of the stand for converting mechanical movements into an electronic signal.Results. In accordance with the proposed methodology, four pairs of brake pads were tested. As a result of processing the experimental data, it was found that the difference in the values of the friction coefficients of the brake pads can cause a difference in the magnitude of the braking forces on the wheels from 8 to 19%.Discussion and conclusions. The difference in the coefficients of friction of the brake pads has a significant impact on the magnitude of the braking forces and the stability of the vehicle during braking. One of the reasons for this may be the poor quality of the pad material or a violation of operating conditions. The proposed improved technique for determining the coefficients of sliding friction makes it possible to obtain more accurate values through the use of an analog-to-digital converter, reducing the influence of the accuracy of measuring instruments and the human factor.
The purpose of the research was to determine the functional dependencies of the friction parameters of root crops on various surfaces for subsequent use in energy calculations of working bodies. The research methodology provided for the experimental determination of static and kinetic friction coefficients on various surfaces and subsequent statistical processing of experimental data to obtain a regression model of indicators from the pressure of compression. Based on the research, equations were obtained that characterize the friction processes of root crops on various surfaces (steel, rubber, painted steel), which will serve for their further use in the design of machines and energy calculation. The highest friction coefficient corresponds to a pressure of 4.0-5.0 kPa, regardless of the static or dynamic loading method. At motion speeds of surfaces up to 2.0…2.6 m/s, the released juice manages to squeeze out of the contact zone. This increases the friction coefficient. At speeds from 2.000…3.095 m/s, the resulting juice does not have time to leak out of the contact zone, and therefore works as a liquid lubrication. As the speed increases, the friction coefficient decreases.
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