Tag Archives: Milking machine

602–614 H. Unal, S. Arslan and H. Erdogan
Effect of altitude and vacuum pressure on flow rate of vacuum pumps on milking machines driven by gasoline engine and a generator
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Effect of altitude and vacuum pressure on flow rate of vacuum pumps on milking machines driven by gasoline engine and a generator

H. Unal*, S. Arslan and H. Erdogan

University of Uludag, Faculty of Agriculture, Department of Biosystems Engineering,
Nilufer, TR16059 Bursa, Turkey
*Correspondence: hunal@uludag.edu.tr

Abstract:

The objective of this study was to compare the performances of two vacuum pumps driven by an internal combustion (gasoline) engine (Vacuum Pump 1) and a generator powered electrical motor (Vacuum Pump 2) under different altitude and vacuum pressures. The vacuum pumps delivering a flow rate of 350 l min-1 at 50 kPa vacuum pressure were tested, which are commonly used in bucket type milking machines. Atmospheric pressures, maximum vacuum pump pressures, and air flow rates at milking pressures (38–50 kPa) were measured at altitudes from 0 to 2,000 m with 200 m increments. Maximum pump pressure reduced by 3.8, 11.3, and 19.9% for Vacuum Pump 1 at altitudes of 400, 1,200, and 2,000 m, respectively whereas Vacuum Pump 2 had 4.4, 12.3, and 20.4% less maximum pressure at the same altitudes. Air flow rate (457.7 l min-1) of Vacuum Pump 1 at the sea level at 38 kPa working pressure reduced by 22.7% at the altitude of 2,000 m. The air flow rate reduced more (28.1%) at the operating pressure of 50 kPa for Vacuum Pump 1 at 2,000 m, compared to the sea level. Similarly, for Vacuum Pump 2, the measured flow rate at 38 kPa showed 19.1% reduction at 2,000 m while at 50 kPa the air flow rate reduced 26.4%, corresponding to 352.3 l min-1. Differences in the air flow rates of vacuum pumps 1 and 2 under different vacuum pressures were insignificant (P > 0.05). However, the effect of altitude and vacuum pressure on measured air flow rates was significant for each pump at 5% level. The regression equations were also obtained for atmospheric pressure-altitude, maximum pump pressure-altitude, air flow rate-altitude, and air flow rate-pump vacuum-altitude. High determination coefficients that were found for these relationships suggest that pressure setting can be accurately done as the altitude at which milking needs to be changed without suffering from air flow rate during milking with bucket type machines.

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590–603 H. Unal and H. Erdogan
Determination of the physical properties of different types of milk claws and air leaks in the claw according to rotameter-milk bucket methods
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Determination of the physical properties of different types of milk claws and air leaks in the claw according to rotameter-milk bucket methods

H. Unal* and H. Erdogan

University of Uludag, Faculty of Agriculture, Department of Biosystems Engineering,
Bursa, Turkey; *Correspondence: hunal@uludag.edu.tr

Abstract:

In this study, physical properties (internal volumes, weight and the diameters of the hole in the milk and pulse tubes) of eighteen different types of milk claws which are one of the significant components of milking machine and the amount of air leaks in the claws were examined according to the flow meter (rotameter) and milk bucket experiment methods. ‘L’ type milking claw was 70 ml in volume which was lower than the standard minimum volume of 80 ml, however, others were higher. Five of the claws (‘C’, ‘D’, ‘E’, ‘H’ and ‘Q’ types of claws) were lower than 500 g, the minimum recommended standard for weight. Internal diameters of the short milk tube of the claws were between 5.5 and 10.8 mm. Internal diameters of all but one of the claws’ main milk output tubes (with a diameter of 11. 9 mm in ‘L’ type) were under the  minimum diameter (12.5 mm).
In experiments conducted with rotameter, the values of the leaking of the claw tap were between 0.0 and 11.0 l min-1. Air leakages of twelve claws (‘A’, ‘C’, ‘E’, ‘F’, ‘H’, ‘I’, ‘J’, ‘K’, ‘L’, ‘N’, ‘P’ and ‘R’ types of claws) were below the standard maximum level of 2 l min-1. The amounts of leaks in the tap of claws were between 0.0 and +14 l min-1. Ten milk claws in here (‘A’, ‘B’, ‘C’, ‘D’, ‘F’, ‘G’, ‘M’, ‘O’, ‘P’ and ‘R’ types of claws) did not meet the minimum and maximum flow rates. The total amounts of air leak in the claws in the experiments performed with a milk bucket were between 4.1 and 33.9 l min-1. Although the calculated amount of total air leak in all the claws was above the recommended minimum amount (4 l min-1), eight claws (‘B’, ‘C’, ‘D’, ‘E’, ‘H’, ‘J’, ‘K’, and ‘O’ types of claws) exceeded the maximum limit (12 l min-1).

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