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abstract
milking machine is the machine, which is used to milk cattle. it revolutionized the dairy farm industry, as it is an efficient and time saving means of milking machine. the development of the milking machine has been by trial and error from a very early time. its development is still continuing. this paper deals with the explanation of the parts involved in the milking machine.
this also involves the working of the milking machine and the certain advancement involved in it.
introduction
milking machine as the name just is the machine, which is used to milk cows. it plays an important role on the dairy farm as an efficient means of milking cows. this machine is one of the few devices which has direct contact with living animal tissue. a milking operation that results in discomfort to the cow and is caused by faulty milking equipment or techniques may lead to injury or mastitis.
consequently, a person should thoroughly understand the basic operation of the milking equipment and fully realize the significance of maintaining the equipment in good condition at all times and of employing good milking techniques. this fact sheet describes the basic operations involved to help give a better understanding of milking machines.
milking machine operates on the principle of partial vacuum. vacuum is created in a closed space when the air from the closed space is removed. partial vacuum when air is partially removed
the frequent question that comes to everyones mind is that is it only for cows no it is not ,it can be used for others cattle also such as sheep, goat etc. but with appropriate changes made to the machine.
function
the milking machine performs two basic functions:
1. it causes milk to flow from a teat by exposing the teat end to a partial vacuum.
2. it massages the teat in an effort to relieve the effects of a continuous milking vacuum
early cow milking machines
development of a usable milking machine took several decades of trial and error, unlike the rapid development and acceptance of other dairy innovations. there was a lot of discouragement towards milking machine, stating that it was unnatural or intrinsically injurious to the cow.
the great variety and number of early milking machines can be categorized into two groups, the first group are those that tried to emulate hand milking and they were called mechanical pressure devices. the second group are those that tried to emulate the sucking calf and they were called vacuum devices.
the earliest devices for mechanical milking were tubes inserted in the teats to force open the sphincter muscle, thus allowing the milk to flow. wooden tubes were used for this purpose, as well as feather quills. skillfully made tubes of pure silver, gutta percha, ivory, and bone were marketed in the mid-19th century.
the earliest vacuum milkers used a large gutta percha cup, fitting over the entire udder, and connected to a hand pump. hodges and brockenden secured an english patent for such a device in 1851. a hand cranked suction pump drew milk from all four teats at once. such devices created a continuous suction on the udder, damaging the mammary tissue and frequently causing the cow to kick.
early vacuum machine
the first successful use of teat cups with a vacuum milker is found in the 1860 patent of l.o. colvin. however, the colvin milker still subjected the cow's teats to constant vacuum, causing blood to pool there. william murchland invented a very successful vacuum milker in 1889, which hung suspended under the cow. he was granted a u.s. patent in 1892.
the pulsator was first introduced in the "thistle" milker, using a steam driven vacuum pump. while the thistle machine presented problems of sanitation, it proved an efficient milker. the pulsator, resulting in this intermittent flow is what finally led to a really workable milking machine.
there were a great variety of mechanical devices to simulate hand milking. most of these devices incorporated rollers or fingers that intermittently pressed on the teat, often working from top to bottom. some of these devices were simple; others composed of hundreds of parts and worked by cranks.
mechanical milkers could not compensate for the changing size of the cow's teats as milking progressed, and did not milk to completion. these disadvantages inturn led to the development of vacuum devices.
The creation of the modern milking machine actually took place over many years of trial and error. As the industrial revolution of the 19th century swept through industry, many recognized the potential efficiencies of mechanical milking machines, but farmers were resistant to the idea. And no wonder! Milking machines that would be horrific by modern standards were used as late as the 20th century. They used catheters and tubes made of “pure silver, gutta percha, ivory, and bone”. The first true vacuum pump milking machines were developed in 1851 in England and 1859 in America, however they did not use the large, industrial-size vacuum pumps of today. Instead, they used a rudimentary “hand cranked suction pump [that] drew milk from all four teats at once”. Just picture Greg Focker explaining this at Thanksgiving dinner! Fortunately, in 1898, the USDA approved a foot-pedal-powered milking machine that allayed farmer’s concerns about harming their valuable livestock. As you can see, it took about 50 years for an acceptable mechanical milking machine to be developed.
Modern Milking Machines
The modern milking machine has become a standardized device. Its goal is to collect milk from a cow by vacuum suction. These milk extraction systems are comprised of several components including vacuum pumps, reserve tanks, vacuum regulators, pipelines, and pulse tubes. In addition, pulsators that alter the force of vacuum on the cow are used, as are various valves, which control the flow and suction. No proper system would be complete without milk tubes and receivers that transport the milk from the vacuum pump system to a bucket, pump, pipeline, and so on.
The Role of Vacuum Pumps
Essentially, vacuum pumps are used to evacuate (remove air) the pipelines and tubes connecting the milking machines to the cows. By removing the air molecules from the system, its overall pressure is reduced well below atmosphere*. Then simple vacuum physics takes over and the higher pressure milk flows through the lower pressure pipelines from the cows to the milking receptacle.
Interestingly, a key component of the vacuum pump milking machine is the use of an interceptor. The interceptor is fitted to the primary vacuum line and acts to prevent solid and liquid material from getting sucked into the vacuum pump. As one can imagine, the absence of the interceptor would be detrimental to the performance and longevity of the vacuum pump, and thus to the milking machine.
As with any vacuum system, limiting downtime on a milking application relies on the use of both the proper ancillary equipment (interceptors, particulate traps and filter, etc.) as well as proper system maintenance including vacuum pump oil changes, pipeline preventative maintenance/cleaning, and leak detection and prevention.
Atmosphere or atmospheric pressure (the pressure all things are exposed to in everyday life) is one level of vacuum or pressure. Typically pressures above atmospheric pressure are expressed in common measurements, such as pounds per square inch (PSI), whereas pressures below atmosphere are expressed in atmospheres (atm), inches or mm of mercury, pascal (Pa), or torr. Stay tuned for our next blog where we’ll discuss pressure measurements in greater detail.
If you have questions about how to keep your vacuum based system in tip top shape, feel free to contact us at United Vacuum for assistance.
The way vacuum pumps actually work, if you have never considered it, is by lowering the pressure to below-atmospheric levels. When the vacuum pumps are switched on, the air pressure inside the lines and tubes drops, making a difference between the atmospheric pressure and the pressure inside the lines. This difference is call the “vacuum level”, and that’s measured by a mercury manometer. (You may recognize the word “manometer” from getting your blood pressure checked.) The unit of measurement for pressure is sometimes still referred to as mm of mercury (a literal description, if you think about it), but the international standard to measure the vacuum level of milking equipment is the Kilo PAscal (Kpa). For point of reference, 1 mm Hg = 0.1333 Kpa.
That basically covers the role of vacuum pumps in milking machines and dairy operations. Hopefully, that clears up any questions you might have.