scholarly journals Comparison of the operation of milking machine control valves and a newly designed regulating device

2012 ◽  
Vol 49 (No. 3) ◽  
pp. 110-114 ◽  
Author(s):  
J. Fryč

One of the basic demands for milking machines is to maintain a constant vacuum level if air consumption by milking machine is changed. The author designed a device with reducing valve for vacuum level regulation and a simultaneous vacuum pump control enabling electric power to be reduced. The paper deals with a comparison of the operation of standard control valves with the newly designed device used for vacuum regulation from the viewpoint of dynamic properties. When measuring vacuum stability by applying various regulation methods and a subsequent statistical evaluation of the results obtained it was proven that the function of the newly designed regulating device was comparable with the best reducing valves used so far.

Author(s):  
O. Kryshtal ◽  

The purpose of the research: comprehensive assessment of the individual milking unit of the company "Kurtsan" (Turkey) during operation. Methods of research: Analysis of the structural features of the individual milking unit performed by the observation method given to test sample, the quality of the machine was evaluated by standardized methods: the quality of the technological process and operational-technological indicators in accordance with the SOU 74.3-37-273, energy indices according to DSTU 2331, economic Indicators according to DSTU 4397, safety indicators and ergonomics according to DSTU IEES 60335-1, DSTU EN 60335-2-70. Research Results: The conducted research confirms a sufficiently high quality of the technological process of selection of milk in cows in the conditions of use of milking installation in a personal economy, which provides favorable conditions for the milking of the cow, taking into account its physiological features. Performance per hour of basic time is 10 heads. Milking installation works on the principle of a closed milking system, thanks to which milk does not contact the environment and immediately from the basin enters a sealed can. Such system protects milk from the possibility of bacterial and physical contamination. Milk obtained during milking by milking installation according to quality indicators (acidity, density, content of somatic cells, mass fraction of dry matter, mass fraction of fat) meets the requirements for the first grade according to DSTU 3662. Milking installation is equipped with a dry vacuum pump. Power consumption during installation does not exceed 0.54 kW. Specific electricity consumption for milking of one cow is 0.05 kWh / head. Annual operating expenses for milking of two cows in the farm are 1591.90 UAH / head. Conclusions. According to the testing of the individual milking plant manufacturing company "KURTSAN", it has been established that this installation reliably performs the technological process of machine milking of cows in milking can for their tethered maintenance and allows you to get milk of the first grade. The total duration of visiting one cow is 5.75 minutes. The average intensity of milk is 1.0 kg / min. Milking machine provides complete bodies of cows. The magnitude of the control manual feed is 50 ml. The milking machine is equipped with an adjustable pulsator of pairwise milking, which creates a manual milking process and works for a working vacuum of 40 ± 1 kPa, which prevents injury to dies and diseases of mastitis. In the cover the "Stop-Milk" system is installed, which prevents milk from entering a vacuum pump during the overflow of the poor, or water while washing All items are compactly assembled on a single cart. However, a small diameter of wheels on an unequal surface creates some inconvenience to the operator during the transportation of the machine with a filled milk capacity. The application of the installation increases the amount of milk received. Its gentle work does not harm the emotional and physical health of the cow: the dysfunctions during operation are not pushed, and light vibration creates a massage effect. Milking installation allows you to significantly reduce the labor of service personnel in an economy with a maintenance of 1 to 10 cows.


Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4344
Author(s):  
Olle Högblom ◽  
Ronnie Andersson

The multiphysics simulation methodology presented in this paper permits extension of computational fluid dynamics (CFD) simulations to account for electric power generation and its effect on the energy transport, the Seebeck voltage, the electrical currents in thermoelectric systems. The energy transport through Fourier, Peltier, Thomson and Joule mechanisms as a function of temperature and electrical current, and the electrical connection between thermoelectric modules, is modeled using subgrid CFD models which make the approach computational efficient and generic. This also provides a solution to the scale separation problem that arise in CFD analysis of thermoelectric heat exchangers and allows the thermoelectric models to be fully coupled with the energy transport in the CFD analysis. Model validation includes measurement of the relevant fluid dynamic properties (pressure and temperature distribution) and electric properties (current and voltage) for a turbulent flow inside a thermoelectric heat exchanger designed for automotive applications. Predictions of pressure and temperature drop in the system are accurate and the error in predicted current and voltage is less than 1.5% at all exhaust gas flow rates and temperatures studied which is considered very good. Simulation results confirm high computational efficiency and stable simulations with low increase in computational time compared to standard CFD heat-transfer simulations. Analysis of the results also reveals that even at the lowest heat transfer rate studied it is required to use a full two way coupling in the energy transport to accurately predict the electric power generation.


2003 ◽  
Author(s):  
Antonio Pazzona ◽  
Lelia Murgia ◽  
Lucio Zanini ◽  
Mario Capasso ◽  
Douglas J. Reinemann

Animals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 40
Author(s):  
Gema Romero ◽  
Joel Bueso-Ródenas ◽  
Manuel Alejandro ◽  
Francisco Moya ◽  
José Ramón Díaz

The Murciano-Granadina goat breed has been described as a slow milking breed. As milking machine parameters can affect milk extraction in terms of yield and time employed, two experiments of one-month duration were performed with 88 goats in Latin square design to find the best combination of these parameters. One of them was carried out in a mid-line milking machine and one in a low-line milking machine. For each of them, two vacuum levels (36 and 40 kPa), two pulsation rates (90 and 120 cycles/min) and two pulsator ratios (50 and 60%) were used and milking efficiency, sanitary status of the mammary gland, milk cortisol, and teat end status were evaluated. Results showed that in milking machines installed in mid- and low-line, the use of 40 kPa system vacuum, 60% pulsator ratio and 90 or 120 cycles/min pulsation rate achieved optimum milking fractioning and efficiency. In the case of low-level milking machines, a similar combination with 36 kPa not only showed worse milking fractioning values, but also provided better values of teat end status and cortisol level.


2008 ◽  
Vol 53 (No. 3) ◽  
pp. 112-118 ◽  
Author(s):  
B. Skapetas ◽  
J. Katanos ◽  
V. Laga ◽  
Ε. Sinapis ◽  
I. Hatziminaoglou

The aim of this paper was to study some of the teat characteristics involved in the milking ability of indigenous Greek goats such as the vacuum level of the milking machine that is required for the opening of the teat canal sphincter and the changes in the teat end wall thickness induced by milking. Thirty-six dams (12 of the first, 12 of the second and 12 of the third and subsequent lactations) were used after weaning (60 ± 5 days). Dams were milked twice a day (8:00 and 18:00 h) for 12 weeks in a milking parlour 1 × 12 side by side of Casse type with 6 milking units and a low milk line and air pipeline. The main functional characteristics of milking machine were: vacuum level 44 kPa, pulsation rate 90 pulsations/min and pulsation ratio 50:50. Every 14 days, during morning and evening milking the vacuum level that was required for the opening of the teat sphincter (VOTS) was measured. The measurement of teat end wall thickness (TEWT) was performed before and after milking. The results of this study showed that during the experimental period the mean VOTS was 23.57 ± 0.36 kPa and decreased significantly as the stage of lactation progressed (<I>P</I>< 0.001). The post-milking TEWT was 3.55% higher in comparison with that before milking (<I>P</I> < 0.01). A continuous and significant decrease in teat thickness was observed during the lactation stage (<I>P</I> < 0.001), which suggests a reaction to intramammary pressure and milk quantity in the udder. The TEWT was affected significantly by the parity (<I>P</I> < 0.01). A positive correlation was found between VOTS and TEWT before and after milking (0.4 and 0.36, respectively). It could be said that a lower vacuum level is required for the opening of the teat sphincter of the udder in goats of the indigenous Greek breed. The thicker teat end wall and more resistant sphincter could be less favourable in the machine milking of goats.


2002 ◽  
Vol 69 (4) ◽  
pp. 501-509 ◽  
Author(s):  
ODD RøNNINGEN

Transient vacuum drops in the milkline during one ordinary milking were recorded as a measure of vacuum stability in milking installations on 184 Norwegian dairy farms in the summer of 1997. An association between the frequency of vacuum drops and technical data including milkline diameter, length and slope, number of milking units and effective reserve was demonstrated. The direct connection between the transient vacuum drop and its cause could be established for most drops during milking observations. A high frequency of transient vacuum drops in the milkline was associated with a high level of mastitis and a high new infection rate as inferred from changes in somatic cell counts for individual cows. The frequency of vacuum drops during one milking is only a rough indication of the long-term vacuum stability in a specific installation, and must be interpreted with care. The dimensions and slope of the milkline and the effective reserve probably give as good information about the installation's ability to maintain a stable vacuum.


2016 ◽  
Vol 20 (3) ◽  
pp. 95-104 ◽  
Author(s):  
Stanisław Lis ◽  
Henryk Juszka ◽  
Mateusz Mendyk

AbstractDesign intents for an actuator of the suction pressure control system in an autonomous milking machine were presented. For determination of its dynamic properties step characteristic was taken. The considered object was described with transmittance and thermodynamic models. Models were identified and their parameters were adjusted. Computer simulation was carried out in MATLAB®-Simulink. Analysis of research results proved that the thermodynamic model allows more detailed reflection of dynamic characteristic of the real object. Its degree of imperfections is 0.99%. For the transmittance model a degree of imperfection with the value of 2.02% was obtained.


1983 ◽  
Vol 50 (2) ◽  
pp. 141-148 ◽  
Author(s):  
George R. Olney ◽  
Robert K. Mitchell

SummaryThe effect of milking vacuum levels and overmilking on the somatic cell count of milk from cows free of intramammary infections was determined. In the first experiment, 4 levels of vacuum ranging from 35 to 70 kPa were compared in a Latin square design with 20 cows being milked at each of the 4 vacuum treatments for periods of 19 d. In the second experiment 40 cows were milked for 16 weeks at either 50 or 70 kPa with or without 5 min overmilking. Neither vacuum level nor overmilking affected somatic cell count and it is concluded that these factors do not cause stress or irritation that will lead to an increase in somatic cell count in the absence of mastitis infections.


2009 ◽  
Vol 52 (1) ◽  
pp. 247-252 ◽  
Author(s):  
A. Pazzona ◽  
M. Caria ◽  
L. Murgia

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