milking machine final report

7/31/2019 Milking Machine Final Report

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Seminar Report 05 Milking Machine

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 basicoperation 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

Dept of Mechanical Engg MESCE, Kuttipuram1


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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 vacuumdevices.

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.



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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



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cow's teats as milking progressed, and did not milk to completion. These

disadvantages inturn led to the development of vacuum devices.

MILKING MACHINE



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PARTS

The main parts of milking machine parts are

Pulsator

Teat cup shells and liners

Milk receptacle

Vacuum pump and gauge

Vacuum tank

Regulator

The other parts help in the proper working of the milker units. The

vacuum pump removes air from the vacuum tank. The vacuum tank consists of

milking line and pulsating line. Regulator is placed in the milking line. The teat

claw is connected to milking line through the long milk hose. The milk from

teatclaw reaches the receptacle through the milking line. The pulsator along

with vacuum gauge is connected the pulsating line.

1. Pulsator: -

The pulsator is the heart of the milking machine and it works like the

heart, it has a valve and it oscillates alternatively allowing air and vacuum

into the system.

The function of the pulsator is to allow intermittent massage of the teat

end to prevent swelling. The working of pulsator brings about the working of

the milker unit. As the pulsator operates, it causes the chamber between the

shell and the liner to alternate regularly from vacuum to air source.

There are two classifications of pulsator and they are based on: -



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1. Pulsations

2. Activation

Based on pulsations

Simultaneous Pulsation

Milking machines are designed to operate with all four teat cups

simultaneously milking and then all four teat cups massaging.

Alternating Pulsation

Pulsators are of an "alternating" type. Operate with an alternating action;

that is, while two teat-cup liners are milking the other two liners are massaging.

Depending on the manufacturer, the alternating action may be from the left side

to the right side or it can be from front quarters to back on an individual cow.

This results in alternately milking the front and then rear quarters. This helps to

even out the milk flow and reduce flooding of the claw

Based on activation

Vacuum operated

Pulsators can be vacuum operated. The vacuum-operated pulsator uses

air to move the plunger or slide valve, which covers or uncovers the air

passages to produce the pulsating action. The plunger or slide valve may be

housed in oil for smoother action. The rate of pulsation is controlled by a needle

valve, which may be factory set or may be manually adjustable. Temperature

changes tend to affect the pulsation rate of vacuum-operated pulsators; so be

conscious of this factor and maintain the pulsator at normal operating

temperatures to help reduce rate variations.



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Electrically operated

Pulsator can be electrically operated. The electric pulsator may be

operated by a master control which sends, via an electric current, the proper

command to the pulsator to perform a preset pulsation rate and ratio. The

electric pulsator is unaffected by temperature and therefore, has the advantage

of producing a constant pulsation rate

Some Terms Related to the Pulsator

Pulsator Cycle

A cycle refers to the total time in seconds that a pulsator takes to

complete one milk phase and one massage phase.

Pulsator Rate

The pulsation rate refers to the number of cycles that the pulsator makes

in one minute. Pulsators on the market have pulsation rates ranging from 40 to

60 cycles per minute.

Pulsation Ratio

The pulsation ratio is the length of time in each cycle that the pulsator is

in its milk phase compared to its massage phase. The pulsation ratio may be

expressed as a simple ratio or it can be expressed as a percentage. Examples

of pulsation ratios are as follows: 60:40 pulsator means that within any given

cycle the teat-cup liner will be open and milking 60% of the time and closed or

massaging the teat 40% of the time.



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2. Teat Cup Shells & Liners

The teat cup shells and liners are the milking unit. The shell liner is made

of synthetic rubber or silicon and the teat cup shells are made of stainless steel.

The liner inside the teat cups of the milking unit is the only part of the machine

that comes in contact with the udder of the cow.

Thus the weight of the unit is usually adjusted to the vacuum level to

provide the desired tension on the teat to allow proper positioning and

adequate milking action.

The teat cup shells and the shell liner form a vacuum chamber betweenthem, which allow milk to be removed from the teat and also provides massage

of the teat end. The size inflation used should correspond to the shell size.

The surface of the shell liner becomes pitted with use and cleaning

which aid in the spread of infectious bacteria which cause mastitis. So they

must be changed on schedule. They also lose their elasticity, with use, and will

not provide proper teat massage.


Teat cup shells

Shell liners


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3. Teat-Cup Claw

The milking claw connects and supports the four shells and inflations andserves as a collection site for the milk from the four quarters. The "tail piece" of

the inflation carries the milk from the teat end into the claw .The claw is

connected to the milk receptacle by the long milk hose and milk flows from the

claw to the milk receptacle through this long milk hose. The claw should be of

adequate size to avoid flooding. Most claws admit air through a small hole in

the claw to aid milk flow.


Claw


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4. Regulator

The function of the regulator is to admit air into the system to keep the

vacuum at the recommended level. It is placed in the milking line. Normally, the

vacuum pump creates a level of vacuum greater than needed in the milking

unit.

The regulator senses the changes in vacuum (due to leaks, attaching

and removing the milking units, slippage, etc.) and controls the amount of air

admitted into the vacuum system or it closes down to exclude excess air inorder to maintain the desired vacuum level within a very narrow range. The

controller may be a weighted diaphragm or spring-operated device.

5. Vacuum Pump

Milking machines depend upon a partial vacuum for their operation. The

function of the vacuum pump is to remove air from a closed system, therebycreating a partial vacuum thus reducing the pressure of the air.



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Atmospheric pressure will cause mercury to rise in a column to 29.9 inches

high at sea level. Most milking systems will create a partial vacuum of 10.5-12.5

inches of mercury.

6. Vacuum Gauge

The vacuum pressure is measured by a vacuum gauge. It is still

measured in inches of mercury (Hg) or in kilopascals (kPa) to indicate the

vacuum pressure present. One inch of mercury is equal to 3.38 kPa. A vacuum

gauge should be located on the vacuum line.



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WORKING

The milking process consists milk phase and massage phase. As the

pulsator operates, it causes alternative closing and opening between the shell

and the liner to alternate regularly from vacuum to air source. Keep in mind that

the inside of the teat-cup liner is under a milking vacuum at all times.

Massaging phase

In this phase air is admitted between the shell and liner, the liner

collapses around the cow's teat. The pressure of the collapse liner is applied to

the teat giving a massaging action. This is called the rest ormassage phase.

Milk does NOT flow from the teat during this phase.

Milking Phase



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In the milk phase, the space between the liner and the shell is exposed

to the vacuum by way of the pulsator. The fact that there is now equal pressure

on both sides of the liner causes it to open. The end of the cow's teat exposed

to the vacuum and the influence of internal milk pressure within the cow's udder

causes the milk to be drawn out through the teat opening because the pressure

is lower outside the teat end.



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MAINTENANCE

It is essential that inflations be installed properly and in the correct shell.

Twisting will prevent normal function. Some inflations are square, others have

ribbed sides or special tops. Some admit air into the tailpiece of the liner and

are called a vented inflation. This is done to avoid flooding with milk. It is very

important that inflations are changed on schedule; otherwise they become

worn, allow buildup of milk deposits and bacteria and assist in the spread of

contagious forms of mastitis. Tubes where the liners are attached to the claw

are not bent or damaged, as this will block milk flow, slow milking and causeteat irritation. Be sure the long milk hose is in good condition,does not leak, is

not too long. Avoid loops in this line that may cause a "backup" of milk & flood

the claw.



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CLEANING SYSTEMS

The basic cleaning steps recommended for use in all systems are:

Plenty of cold-water rinse to flush milk from the machines

Hot detergent wash

Hot water rinse to remove detergent residues

Optional sanitizing rinse with chemical sanitizer or hot water before

milking

Three systems can be used to clean milking machines

Jetter

Reverse flow

Bucket.

Jetter Cleaning

The jetter or third-line cleaning system has become the most popular

and efficient cleaning system for milking machines. This method relies on

vacuum to draw the cleaning solutions from holding vessels located in the end

of the pit or milkroom through a separate third line set up with jetters for

attachment to each milking cluster.

Several types of jetters are available. They range from individual rubber

cups into which the teat cups are inserted to those that are fixed so that the

cups can be quickly fitted over protruding fingers.

Disadvantages

Time spent on putting cups on jetters

Some types of jetter can cause distortion in the mouthpiece of liners

Some lines are not compatible with all types of jetters

Temptation to circulate for too long or too often



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Reverse-flow cleaning

After milking, the vacuum pump is switched off and the dropper taps or

clamps are opened and cleaning solutions are pumped into the receiver and

then to waste through the cups. Regardless of the size of the milking machine,

cleaning can be completed in five to ten minutes by reverse flow. However, the

operating cost of reverse-flow cleaning is from two to three times that of jetter

or bucket cleaning systems because more water and special liquid detergents

are used.

Advantages

Safer as it eliminates carrying water and dangerous chemicals

Reasonable cost to install and operate

Low maintenance costs

Allows flexibility in cleaning programs

Ease of operation encourages a full cleaning procedure

The bucket system

This is time-consuming, hard work, and involves carrying buckets of

near-boiling water. However, bucket cleaning still exists in smaller sheds.



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ADVANCEMENTS

Portable milking machine

The specifications of the portable machine

Frame is made from hot dipped galvanized mild steel giving a long life

0.5hp oil free, direct drive vacuum pump

Runs from 220 - 240v 50hz 13A socket.

140 litres per minute pump capacity

15 litre interceptor tank, made from galvanized mild steel

Easily adjustable vacuum regulator

Reliable, easy to service pulsator

30 litre plastic milking bucket

High capacity claw piece

Stainless steel teat cup shells

Medium bore liners



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Solar powered milking machine

With power cuts hampering dairy farms, a new machine has been

introduced in the market which uses solar power to milk animals.

The machine creates no sound or air pollution, The machine comprises a

pulsator and vacuum pump apart from the solar panels and battery to store

power.

The solar milking machine ensures hygienic milking practice matching

international standards. The machine needs about 2 sq. m to install near the

cowshed so that the solar panels are exposed to sunlight for about six hours. It

provides power for milking 25 animals twice a day. The machine can be utilized

as a solar power station in case it is not to be used for milking.

A direct current motor will have to be connected to the device for

converting power for use in the household electric circuit. The machine will be

of much use to dairies as well as rural households.



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CONCLUSION

Milking machine is very popular in developed countries like Australia,

United Kingdom, and New Zealand. But now it is gaining importance in

developing countries such as India, Pakistan etc. But the implementation in

developing countries is by making minor modifications to the machine. The

development in milking machine has been incredible and is still increasing to

make milking of cattle more efficient, hygienic, economical and time saving.



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REFERENCES

http://www.dailytimes.com

http://www.earlycowmilkingmachines.com

Influence of Vacuum Level and Overmilking on Udder Health and Teat

Thickness Changes in Dairy Ewes, C. Peris, J. R. Diaz, S. Balasch, M. C.

Beltran, M. P. Molina, and N. Fernandez., December 1, 2003



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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.



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CONTENT

INTRODUCTION 1

EARLY COW MILKING MACHINE 2

MILKING MACHINE 4

PARTS 5

Pulsator 5

Teat cup shells and liner 8

Teat claw 9

Regulator 10Vacuum pump 10

Vacuum gauge 11

WORKING 12

MAINTENANCE 14

CLEANING SYSTEM 15

ADVANCEMENT 17

CONCLUSION 19

REFERENCES 20



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ACKNOWLEDGEMENT

I express my deep gratitude to God-Almighty, for bestowing his blessings

upon me in my entire endeavor.

I would like to express my sincere gratitude and profound obligation to

Dr.T.C.Peter, Head of the department of Mechanical Engineering and Mr. Alex

Bernad V K, staff in charge who gave his full support for my seminar. I also

would like to thank all the staff of Mechanical Engineering Department for their

whole hearted cooperation.

Last but not the least I would like to express my gratitude to my family,

especially my friends who gave me moral support and helped me bring this

seminar to success.

milking machine final report

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