Development of the System to Control Milk Acidity in the Milk Pipeline of a Milking Robot

Acidity characterizes the suitability of milk for primary processing and is one of the key parameters monitored when accepting it at a dairy plant. Therefore, it is important to timely separate milk with lowered acidity in the process of milking by a robot. However, no technical means for the detection and separation of milk with lowered acidity in a milk pipeline were designed for robotic milking systems.Based on the results of experimental study, we established a linear correlation dependence of milk acidity, using a traditional Turner method, on pH. We calculated parameters for the main and additional containers, for milk of superior grade and for non-standard milk in terms of acidity. Linear parameters are determined for inserting into the main milk pipeline of a robot the measuring pH-electrode and a tee with electromagnetic valve for the automated discharge of non-standard milk. Based on the experimental study and our calculations, we developed a project of the technical system for the robotic cow milking technology. A standard technology is complemented by a process of automated measurement of milk pH in a flow, which is implemented using a high-speed transistor pH-FT electrode with a measuring unit.Control over milk pH in a flow during milking makes it possible to operatively solve two tasks at a time ‒ to improve the accuracy of estimating the quality of starting raw materials and to correct the feed of cows in order to standardize the acidity of milk required for its acceptance at a milk processing plant. We thus exclude a labor-intensive laboratory operation for determining the acidity because this indicator has already been measured during robotic milking process. Therefore, our improvement of technology for robotic milking will make it possible to more accurately assess the quality of raw milk using milking robots that are included in the system of machines for precision cattle breeding

Identifying Changes in the Technical Parameters of Milking Rubber Under Industrial Conditions to Elucidate Their Effect on the Milking Process

Many years of experience in the operation of milking machines show that milking rubber was and remains a short-lived and unreliable link in the technological process of machine milking. During operation, rubber quickly loses its strength and elastic properties, becomes stiff and less elastic, deforms, and changes its shape. The purpose of this study is to identify changes in the technical parameters of milking rubber under industrial conditions in order to establish their impact on the milking process. The obtained results could make it possible to rationally choose the milking rubber for teat cups, which would ensure an effective milking process. During this study's initial stage, the physical and mechanical condition of milking rubber was experimentally established at steam disinfection and as a result of saturating the article with milk fats. The following stage implied detecting the effect of milking rubber tension in a teat cup on the speed of milking. It was established that milking rubber during operation is actively exposed to milk fat, which leads to the loss of its weight relative to its original value. On day 1,000 of work, the weight loss relative to the initial value (100 g), under the washing regime temperature of 85 °C, 50 °C, 35 °C, and 20 °C, was 1 g, 3.3 g, 5 g, and 4.2 g, respectively. The dependences have been derived for the swell mass of milking rubber M on the temperature of washing solutions T and the duration of operation t as a result of saturation with milk fats. The dependence of milk yield rate V on the tension force of milking rubber F in teat cups has been established. Thus, it was found that when the tension force of milking rubber changes from 25 to 60 N, the difference in the average intensity of milk yield is 0.13 kg/min (10.8 %). Regarding the amount of milk yield at the specified tension, the difference is 0.15 kg (2.5 %). At rubber tension from 60 to 25 N, the average milking time increases by 0.46 min (8.3 %). Thus, it was determined that a milking machine with milking rubber at different tension over a total milking time would unevenly milk different parts of the cow's udder. The study reported here expands the idea about the technical and manufacturing characteristics of rubber articles, namely changes in them at steam disinfection and as a result of saturation with milk fat

Construction of an Algorithm for the Selection of Rigid Stops in Steel­concrete Beams Under the Action of A Distributed Load

An algorithm has been developed to select rigid stops in steel-concrete beams under the action of distributed load. Concrete is connected rigidly to a steel sheet in order to perform the joint operation of the concrete and steel sheet. Such a connection in the beam is provided by rigid stops that prevent shifting efforts in the concrete and steel contact area. The efforts are determined through the turning angles between the two adjacent sections of the beam. A graph-analytical method for determining movements is used to determine the turning angles. In determining the deformations of a steel-concrete beam, the calculation is based on the reduced rigidities of cross-sections.The purpose of this study is to optimize the structure of a steel-concrete beam by selecting the rational number and arrangement of rigid stops. This optimization would allow a more rational utilization of the structure's material ‒ concrete and steel. That would reduce the cost of operations and the quantity of materials required in the production, installation, and operation of the considered structures.An earlier proposed algorithm for the selection of rigid stops in steel-concrete beams under the action of a concentrated force has been expanded for the case of an evenly distributed load. When selecting the number of rigid stops, it is assumed that the magnitude of the distributed load acting on a beam, the mechanical characteristics of materials (steel and concrete), as well as the span of the beam and the size of its cross-section, are kNown. In contrast to the beams with a concentrated force in the middle, where the forces abide by a linear law, in the beams with an evenly distributed load the efforts in a steel strip change in line with a square parabola. Therefore, while the same step has been obtained for stops, it is not possible to achieve a situation at which efforts in all stops have the same valu

Identifying Changes in the Milking Rubber of Milking Machines During Testing and Under Industrial Conditions

Milking rubber is the only part of the milking equipment that comes into direct contact with the cow's teats. The task is to establish the high-quality technical and technological characteristics of the rubber liners for milking machines. It has been established that milking rubber after 600‒650 hours of operation acquires significant deflection in the range of 5.5±0.03–3.7±0.04 mm while a teat cup deformation varies within 1.3±0.02–3.5±0.05 mm. A positive correlation dependence of the milking rubber elasticity on the deformation of its teat cup (r=+0.948) has been found.The method of passing the electric discharge was used to assess the readiness of milking rubber for use, whereby a variation coefficient of υ˂10 % was determined for the milking rubber DD 00.041A AO «Bratslav», which makes it possible to estimate the product quality.It was found that the change in the mass and volume of milking rubber over 72 hours of its treatment with the liquid SZHR-3 at t=150 °C exceeds the indicators obtained in contact with the liquid Skydrol LD-4 by more than 2.5 times. A positive correlation dependence of the milking rubber mass on its volume (r=+0.965) has been established.It was found that at a rubber tension in the range of 0 to 90 N the duration of the deformation loss experienced by the milking rubber shell was not long; it is 0.05‒0.06 s. With an increase in the service life of milking rubber to 4 months, there is a decrease in its tension, from 56‒60 N to 43‒45 N, which adversely affects the maximum speed of milk yield – it decreases by 1.5 times.A positive correlation dependence of the milking rubber service life on the level of its bacterial insemination (r=+0.960) has been establishe

Identifying Changes in the Milking Rubber of Milking Machines During Testing and Under Industrial Conditions

Milking rubber is the only part of the milking equipment that comes into direct contact with the cow's teats. The task is to establish the high-quality technical and technological characteristics of the rubber liners for milking machines. It has been established that milking rubber after 600‒650 hours of operation acquires significant deflection in the range of 5.5±0.03–3.7±0.04 mm while a teat cup deformation varies within 1.3±0.02–3.5±0.05 mm. A positive correlation dependence of the milking rubber elasticity on the deformation of its teat cup (r=+0.948) has been found.The method of passing the electric discharge was used to assess the readiness of milking rubber for use, whereby a variation coefficient of υ˂10 % was determined for the milking rubber DD 00.041A AO «Bratslav», which makes it possible to estimate the product quality.It was found that the change in the mass and volume of milking rubber over 72 hours of its treatment with the liquid SZHR-3 at t=150 °C exceeds the indicators obtained in contact with the liquid Skydrol LD-4 by more than 2.5 times. A positive correlation dependence of the milking rubber mass on its volume (r=+0.965) has been established.It was found that at a rubber tension in the range of 0 to 90 N the duration of the deformation loss experienced by the milking rubber shell was not long; it is 0.05‒0.06 s. With an increase in the service life of milking rubber to 4 months, there is a decrease in its tension, from 56‒60 N to 43‒45 N, which adversely affects the maximum speed of milk yield – it decreases by 1.5 times.A positive correlation dependence of the milking rubber service life on the level of its bacterial insemination (r=+0.960) has been establishe

Establishing Changes in the Technical Parameters of Nipple Rubber for Milking Machines and Their Impact on Operational Characteristics

Nipple rubber is an important part of a milking machine, one of its key elements. This is the only component of a milking plant that has direct contact with the surface of a cow udder. In addition, nipple rubber is the most loaded component of a milking machine. During the milking process, it is compressed and unclenched more than 400 times. In order to maximize the effect of the use of rubber, it is necessary to calculate the conditions of its use correctly, to monitor technical parameters in due time. The task of the study is to establish changes in the technical parameters of the nipple rubber of milking machines and their impact on the performance of the article.In the course of the research, it was established that the service life of all kinds of nipple rubbers was 1,000 hours, which, if used for 8 hours a day, corresponds to 125 days or 4 months of operation. When used for 1,000 hours, the rubber stiffness varies within significant limits and an average is: for products made of silicone 2,849.61±52.23–3,343.76±51.26 N/m; made of the material of rubber mixtures – 2,597.76±78.26–2,821.43±55.24 N/m. The readiness coefficient of all products is 1. Using electron microscopy, it was possible to establish the changes of the inner surface of nipple rubber after operating for 125 days/1,000 hours and after operating for 250 days/2,000 hours. It is proved that all its basic parameters change during operation. The weight of an article changes by 8.5 %, the depth – by 37 %, the wall thickness – by 2.5 %, and the stretching length – by 27 %. The high positive correlation dependence (r=+0.939) between the nipple rubber stiffness and milking intensity was found.The studied indicators are important for determining the performance and nipple rubber suitability for use. The conducted research offers a real possibility of taking into consideration the qualitative parameters of nipple rubber during their selection and subsequent operatio

Improving the Algorithm of Choosing Spacing and Number of Stiff Supports Against A Concentrated Force in Steel-concrete Beams

A steel-concrete beam was taken as the study object. The algorithm of selecting the number of stiff supports for the steel-concrete beam loaded with a concentrated lateral force in the middle of the span has been refined. Stiff supports served to join the steel strip with concrete to ensure their joint performance. The algorithm was refined based on the condition of equality of the longitudinal force in the steel strip from the action of the calculated load and the maximum longitudinal force obtained after setting the supports. In this case, the longitudinal forces in all stiff supports, as well as the spacing of the stiff supports should be the same. A disadvantage of the known algorithm consists in the complexity of determining the coefficient φb2 taking into account the effect of long-term concrete creep on the element deformation without cracks. This coefficient fluctuates widely and depends on many factors. Besides, it is also insufficiently studied. Calculations for determining the number and spacing of stiff supports in a steel-concrete beam were conducted according to the proposed algorithm and in the Lira software package. The forces acting on the supports and spacing of the supports were the same. The force acting in the support was 8941.5 N. When selecting characteristics of the steel-concrete beam, maximum longitudinal force in the steel strip was obtained. The longitudinal force amounted to 35726 N. The same longitudinal force was obtained from the diagram of longitudinal forces obtained after setting the supports. This study was aimed at improving the design of steel-concrete beams. A rational number and placement of stiff supports ensure savings: the required amount of building materials is reduced and their cost is reduced due to cutting labor costs for their manufacture and operatio

Determining the Efficiency of Cleaning A Milk Line Made From Different Materials From Contaminants

While moving along the milk-conducting systems in a milking machine, milk is in contact with the inner surface whose area exceeds 20 m2. That leads to the formation of protein-fat biofilms of contamination, which are a nutrient medium for the development of microorganisms. With insufficiently effective cleaning of these contaminants, in the periods between milking, the number of microflorae located in milk-conducting systems increases by tens of thousands of times. When cleaned with ineffective cleaning agents, mineral elements from milk are adsorbed on the surface of a protein-fat bio-film, which are subsequently compacted, changed, and converted into milk stone. In this case, the technical implementation of milk conducting systems is of critical importance. It has been established that a milk line made from any material is better cleaned with a hot washing solution than a cold one. Thus, with an increase in the temperature of a washing solution from 60 °C to 85 °C, the cleaning time of the milk line is reduced from 9.5 minutes to 1.5 minutes, or by 6 times. It was established that during the washing phase of a milk line there is a significant decrease in the temperature of the washing solution (≈30 %), which reduces the effectiveness of cleaning the parts of the system. Therefore, there is a need to maintain the solution temperature throughout the entire cleaning process. It is proved that the specific energy of adhesion of pollution in water is 2 times higher than that in a washing solution. With an increase in the temperature of the solution for every 10 °C, the decrease in the specific energy of pollution adhesion is on average 13 %. With an increase in the period after the end of milking before washing the milk line, the specific energy of its purification increases. The study reported here could lead improve the productivity of milking machines and the quality of the resulting product. That involves designing milking and dairy equipment from innovative materials