WO2008127178A2

WO2008127178A2 - Milking system and method for transferring milk in a milking system

Info

Publication number: WO2008127178A2
Application number: PCT/SE2008/000267
Authority: WO
Inventors: Epke Bosma; Carina FJÄLLMYR; Mats Gudmundsson; Nils Erik Holmertz; Staffan Persson; Juoko Raninen
Original assignee: Delaval Holding Ab
Priority date: 2007-04-13
Filing date: 2008-04-11
Publication date: 2008-10-23
Also published as: SE0800092L; WO2008127178A3

Abstract

A milking system adapted to perform milking operations of animals is described. The milking system is arranged to extract milk from a milk producing animal and transfer the milk to a milk tank (2), and comprises milk extracting means (3, 4, 5), an intermediate container (6) and milk transferring means (7, 8, 9), wherein the extracting means is arranged to extract milk from the animal to the intermediate container, and the transferring means is arranged to transfer the milk from the intermediate container to the milk tank. The milk extracting means (3, 4, 5) comprises a plurality of teat cups (3) fluidly connected the intermediate container, and a vacuum source (4) arranged to selectively provide a suction vacuum in the intermediate container. In particular the system is adapted to inactivate the suction vacuum (4) during the transfer of the milk from the intermediate container, so that the pressure in the intermediate container is kept at atmospheric pressure.

Description

MIl-KING SYSTEM AND METHOD FOR TRANSFERRING MILK IN A MILKING SYSTEM FIELD OF INVENTION

The present invention relates generally to milking systems and particularly it relates to a milking system adapted to perform milking operations of animals and transfer of the milk to a storage tank. It also relates to a method for milking an animal and for transferring the extracted milk to a storage tank.

BACKGROUND

Modern milking systems comprise milking stations able to milk animals , such as cows, and transfer the milk to a storage tank, while waiting for transport to a dairy plant. The milk is a vulnerable food product, an emulsion of butter fat in water and is vulnerable to dynamical pressures and flows and rough mechanical treatment. Moreover, milk is sensitive to microorganisms and it is tested, for example, to identify animals that are infected. However, if there are milk remains in the system from one animal when milk from a subsequent animal is tested, there is a risk that the test will be adversely affected and possibly that a healthy animal is identified as infected if its milk is mixed with the milk from the other animal. Therefore, it is important to avoid mixing milk from animals, so that a milk sample from the subsequent animal is not contaminated.

SUMMARY OF THE INVENTION

An object of the present invention is to solve the problems mentioned above and provide a milking system handling milk carefully, lessen the risk of blending milk from different animals and being able to transfer the milk to a milk tank, comprising milk extracting means, an intermediate container and milk transferring means, wherein the extracting means includes a vacuum source arranged to selectively provide a suction vacuum in the intermediate container and is arranged to extract milk from the animal to the intermediate container, and the transferring means comprises a pump and is arranged to transfer the milk from the intermediate container to the milk tank.

The milking system according to the invention is characterised in that it inactivates the suction vacuum during the transfer of the milk from the intermediate container, so that the pressure in the intermediate container is kept at atmospheric pressure. By keeping the pressure at atmospheric pressure, when transferring the extracted milk to the storage tank, the pumping power can be kept low, which facilitates a gentle transfer of the milk. It also facilitates emptying of the intermediate container before the next animal is milked and prevents milk from remaining in the intermediate container, mixing with and affecting the analysis of milk from the next animal that is milked.

A gentle transfer is also facilitated, in an embodiment of the invention, where the milking system is arranged to transfer the milk from the intermediate container to the milk cooling tank before the milk is cooled, so that the milk is transferred near its original temperature, where it is less vulnerable. In this way milk can be carefully transferred by the pump through the transport line .

In one embodiment the system comprises milk level establishing means arranged to detect when the milk level in the intermediate container falls below a lower limit, wherein the system is adapted to stop the pump during the transferring process when this limit is reached. Preferably, the system resumes the transfer after a short pause, to transfer milk remains gathering during the pause. The pause being short compared to the time it takes to transfer the milk, it can for example for cows possibly be a few seconds as compared to a minute for the transfer. Also, the resumed transferring is stopped a second time after the second short transferring process, wherein the second transfer lasting a few seconds, for a cow, being short compared to the first and main transfer lasting for approximately a minute for transferring milk from one cow.

This pause and resumed transfer ensures transfer of milk from one animal and lessens the risk for carry over of milk from one animal to milk from a subsequent animal, so that it is possible to measure milk quality parameters, such as performing a somatic cell count, establish fat content, hormone levels, etc. for an individual animal without the samples being affected by milk from another animal.

Further preferred embodiments are defined by the dependent claims. BRIEF DESCRIPTION OF DRAWINGS

The invention is described below, by way of example, with reference to the accompanying drawings, in which:

figure 1 illustrates parts of a milking system being used during milking,

figure 2 illustrates parts of a milking system being used during transfer of milk from a milking station to a milk tank,

figure 3 illustrates an embodiment of the milking system comprising the parts of figure 1 as well as the parts of figure 2,

figure 4 illustrates a milking system comprising a plurality of milking stations connected to a milk tank via a common milk transfer conduit.

The figures illustrate the main parts of a system in accordance with the invention schematically and they are not drawn to scale.

DETAILED DESCRIPTION OF EMBODIMENTS

In the following a detailed description of embodiments of the present invention will be given. The figures 1 and 2 illustrate the milking system during different operations , figure 1 during milking and figure 2 during transfer of milk.

Figure 1 illustrates a milking station 1 for extracting milk from milk producing animals, such as cows. The station comprises milk extraction means in the form of four teat cups 3, a vacuum source 4 and teat cup conduits 5 illustrated as one bundle 5 of conduits. The teat cups are connected to an intermediate container 6 via the teat cup conduits 5. The vacuum source 4 is connected to and arranged to selectively apply a low suction pressure to the intermediate container 6. During milking of an animal, the teat cups 3 are attached to the teats of the animal, and milk is sucked through the conduits 5 to the intermediate container 6 by means of the low pressure provided by the vacuum source 4 to the intermediate container. Thus, the intermediate container is connected to the vacuum source on one side and to the teats of the animal, via the teat cups and conduits, on the other side during milking. The intermediate container is designed to contain at least the amount of milk produced during milking of one animal. It is also suitable to provide milk testing equipment in association with the intermediate container so that the quality of the milk can be tested.

Figure 2 illustrates a milk transferring system for transferring the milk from the intermediate container to a milk tank 2, such as a milk cooling tank. The transferring system comprises a pump 8 and a transport conduit 9 forming a transport line from the intermediate container to the milk tank. The transferring system is arranged to transfer milk from the container to the tank after an animal has been milked. During this transfer the vacuum source (4 in figure 1) is inactivated and the intermediate container 6 is, preferably, brought to atmospheric pressure by, e.g., opening the container to the surrounding air by a pressure relief valve, indicated by 7. The pump is adapted to provide a suitable pumping power so that the milk is transferred by a pump capacity high enough to overcome flow resistance in the transferring system and differences in height levels, but should be kept low to prevent affecting the milk in a negative way, such as risking to increase the levels of free fatty acids in the milk due to high pumping speed and power. For a gentle transfer, the milk can be held at its original temperature, ca 35- 38° C, in the intermediate container 6, which can be insulated, and be cooled firstly when arriving in the milk tank. During the transfer of the milk an animal that is going to be milked can replace the animal that has been milked and this further animal is suitably cleaned before it is milked. The milking station can be an automatic milking station provided with means for cleaning at least the teats of the animal prior to applying the teat cups and extracting milk from the further animal. However, the cleaning of the animal is not discussed since it is not a major aspect of the inventive system.

Figure 3 illustrates the extraction means 3, 4, 5 and the intermediate container 6 of figure 1 as well as the transferring means 8, 9 with pressure relief valve 7 at the intermediate container 6 , and the milk tank 2 from figure 2. The system is adapted to selectively provide vacuum 4 and atmospheric pressure 7 to the intermediate container during the extraction and transfer, respectively. Figure 3 illustrates an embodiment including a control unit 11 controlling the functioning of the station and its parts during the extraction and transfer, and valves 10, 12, 14 where a milk tank valve 12 and a drain valve 10 selectively leads the milk from the pump 8 to the milk tank 2 and a drain, respectively. A minor outlet from the pump is connected via a sample valve 14 to a milk sample unit 15, so that a minor flow of milk, as compared to the major flow to the milk tank, can be transferred to the sampling unit for analysis. The sampling unit 15 can for this purpose comprise means for sampling milk into bottles and/or analysing means, such as a cell counter, for analysing the quality of the milk. Milk in the minor flow that is not sampled is lead further via a non-return valve 13 to the transport conduit 9, back to the milk in the major flow.

Alternatively, a line (not shown) can be arranged between the sampling unit 15 and the intermediate container 6, leading this minor flow of non-sampled milk back to the container 6 instead. The transfer can be arranged so that milk is continuously transferred in both the major and minor flow.

The intermediate container 6 is also equipped with a level sensor or detector 16 informing the system of the milk level in the intermediate container, which level includes a minimum level 17 at the bottom of the intermediate container provided in the outlet from the intermediate container to the pump 8 , so that the system receives information when the intermediate container is emptied. The system is adapted to stop the transfer of milk from the intermediate container 6 to the milk tank 2 when this minimum level is reached. The system can also be adapted to resume the pumping after a short pause, so that the last milk in the intermediate container 6, from the extraction of one animal, is allowed to gather and be transferred. The first transfer before the first stop will transfer almost all of the milk from one extraction, and the second transfer after the pause will transfer milk remains so that a carry over of milk from one animal to milk from a subsequently- milked animal is prevented. Thus, the short extra pumping provided at the end of the transferring process will lessen the risk that milk being sampled in the sample unit comprises milk from two animals , and will therefore contribute to a more accurate analysis.

Near the outlet of the pump 8 into the transfer conduit 9 is a non-return valve 18 arranged to prevent milk flow backwards into the pump. When the transfer of the extracted milk to the milk tank is finished the vacuum 4 is preferably activated again,, which also will assure closure of this non-return valve 18, and further prevent carry over of milk from one animal to milk from another. For example, milk from the sample unit 15 being transferred back to the main flow in the transfer conduit 9 is prevented from being lead into the pump 8 from the transfer conduit 9 by the non-return valve, the functioning of which improves upon reactivation of the vacuum in the intermediate container 6.

Figure 4 illustrates a system comprising a plurality of milking stations 6a, 6b, 6c connected to a common milk transfer conduit 9. Each milking station 6a-c comprises a pump 8a-c arranged to transfer milk to the common milk transfer conduit via a respective milk station valve 12a-c for selectively connecting each station to the common transfer conduit. Each milking station 6a-c is provided with a non-return valve 18 between its pump 8a- c and the common transfer conduit 9 and/or provided with electronically activated pump valves 20a-c in its outlet conduit to the pump 8a-8c selectively leading extracted milk to the pump for subsequent transfer to a milk tank 2 via the common transfer conduit 9. A valve arrangement 10a, 10b is provided at the milk tank, for leading milk from the stations to the tank or bypassing the milk tank

The invention has been described in embodiments primarily for milking cows, but can be used for other kinds of milk producing animals, where the system suitably is adapted for the type of animal, e.g. in size, in power levels and number of teat cups and so on. A person skilled in the art realises that the inventive system could be further varied within the scope of the appended claims.

Claims

1. A milking system for extracting milk from a milk producing animal and transferring the milk to a milk tank (2), comprising milk extracting means (3, 4, 5), an intermediate container (6) and milk transferring means (7, 8, 9) , wherein the extracting means is arranged to extract milk from the animal to the intermediate container, and the transferring means is arranged to transfer the milk from the intermediate container to the milk tank, wherein the milk extracting means (3, 4, 5) comprises a plurality of teat cups (3) fluidly connected with the intermediate container, and a vacuum source (4) arranged to selectively provide a suction vacuum in the intermediate container, wherein the milk is sucked to the intermediate container (6) during extraction, and c h a r a c t e r i s e d in that the system is adapted to inactivate the suction vacuum (4) during the transfer of the milk from the intermediate container.

2. Milking system according to claim 1, arranged to transfer the milk from the intermediate container to the milk tank before the milk is cooled.

3. Milking system according to any of claims 1-2, wherein the milk tank comprises cooling means arranged to cool and keep the milk cool in the tank.

4. Milking system according to any of claims 1-3, comprising a plurality of intermediate containers (6a, 6b, 6c) fluidly connected to a common transport conduit.

5. Milking system according to any of claims 1-4, comprising level establishing means (16) arranged to detect a minimum level (17) of milk in the intermediate container (6) .

6. Milking system according to claim 5, being adapted to stop the transfer of milk from the intermediate container (6) upon reaching the minimum level (17).

7. Milking system according to claim 6, being adapted to resume the transfer after a pause immediately following said transfer stop, so that milk remains can gather and be transferred.

8. Milking system according to any of claims 1-7, being adapted to activate the suction vacuum ( 4 ) promptly after the transfer.

9. Milking system according to any of claims 1-8, being an automated robot milking system.

10. A method for transferring milk in a milking system comprising milk extracting means (3, 4, 5), an intermediate container (6) and milk transferring means (7, 8, 9), wherein the extracting means comprises a plurality of teat cups (3) fluidly connected with the intermediate container, and a vacuum source (4) arranged to selectively provide a suction vacuum in the intermediate container, and being arranged to extract milk from a milk producing animal to the intermediate container, and the transferring means is arranged to transfer the milk from the intermediate container to the milk cooling tank, said method being c h a r a c t e r i s e d by the step of :

- inactivating the vacuum provided to the intermediate container during the transfer of milk to the milk tank.

11. Method for transferring milk according to claim 10, wherein the transfer is performed before the milk is cooled.

12. Method for transferring milk according any of claims 10-11, wherein the milk is cooled in the milk tank.

13. Method for transferring milk according to any of claims 10-12, wherein a minimum level (17) of milk in the intermediate container (6) is detected and the transfer of milk from the intermediate container (6) is stopped upon reaching the minimum level (17).

14. Method for transferring milk according to claim 13, wherein the transfer of milk is resumed after a pause immediately following said transfer stop, to let milk remains in the intermediate container gather and be transferred.

15. Milking system according to any of claims 10-14, comprising the step of activating the suction vacuum promptly after the transfer.