Milk tank system, intermediate milk storage vessel for this, milking system for this, and method for cleaning this

Abstract

A milk tank system includes a first holder configured for intermediate storage of milk from several milkings of a milking device, and not being a milk glass; a second holder for storage of milk from the first holder; a transport device for transporting milk including a milk line from the first holder to the second holder, via which milk line the second holder may be brought into fluidic connection with the first holder, and a shut-off for shutting off the fluidic connection, in particular from the first holder to the milk line, wherein the transport device has a first operating state which is configured for collecting milk in the first holder, and a second operating state which is configured for transferring the milk from the first holder to the second holder, wherein the milk tank system further includes a control system for switching the transport device from the first to the second operating state when the milk in the first holder reaches a switching milk level which changes over time. Because the pumping of the milk from the intermediate milk storage vessel does not always begin at the same or comparable maximum milk level, but preferably at an ever increasing level, potentially caking milk residue is always rinsed away on a subsequent filling.

Claims

1. A milk tank system comprising: a first holder configured for intermediate storage of milk from several milkings of a milking device, wherein said first holder is not a milk glass; a second holder for storage of milk from the first holder; a transport device for transporting milk, said transport device comprising: a milk line from the first holder to the second holder, via which milk line the second holder may be brought into fluidic connection with the first holder; and a shut-off for shutting off the fluidic connection between the first holder and the second holder, wherein the transport device has a first operating state which is configured for collecting milk in the first holder without milk being able to flow to the second holder, and a second operating state which is configured for transferring the milk from the first holder to the second holder; and a control system for switching the transport device from the first operating state to the second operating state when the milk in the first holder reaches a switching milk level which changes over time during a time interval.

2. The milk tank system as claimed in claim 1, wherein the switching milk level is non-decreasing during the time interval, and the switching milk level has a different value for at least two time points during the time interval.

3. The milk tank system as claimed in claim 2, wherein the switching milk level is strictly increasing at least during the time interval.

4. The milk tank system as claimed in claim 2, wherein the switching milk level changes arbitrarily at least during the time interval.

5. The milk tank system as claimed in claim 4, wherein the switching milk level varies within a predefined bandwidth around a base value, and the base value has an increasing value during the time interval.

6. The milk tank system as claimed in claim 2, wherein the time interval has a predefined value, and wherein the switching milk level after expiry of the time interval is lower than a switching milk level during the time interval.

7. The milk tank system as claimed in claim 2, wherein the time interval is taken from a first cleaning action of at least the first holder to a successive second cleaning action of at least the first holder.

8. The milk tank system as claimed in claim 2, wherein the time interval has a predefined and fixed value, and wherein the switching milk level after expiry of the time interval is lower than a switching milk level during the time interval, and is equal to a lowest switching milk level during the time interval.

9. The milk tank system as claimed in claim 1, further comprising a milk level determination device configured for determining a level of the milk in the first holder and for emitting a level signal on the basis of the milk level determined.

10. The milk tank system as claimed in claim 1, wherein the transport device comprises a pump controllable by the first control system for transferring milk from the first holder via the milk line to the second holder.

11. The milk tank system as claimed in claim 1, wherein the first control system is configured to switch back from the second operating state to the first operating state at a return switching milk level of the milk in the first holder.

12. The milk tank system as claimed in claim 11, wherein the return switching milk level is changeable over time.

13. The milk tank system as claimed in claim 11, wherein the return switching milk level is either a predefined level difference or a predefined percentage lower than the switching milk level.

14. An intermediate milk storage vessel for use in the milk tank system as claimed in claim 1, comprising: a vessel for containing milk from several milkings; a supply for receiving the milk; a discharge for discharging the milk; a pump system for pumping milk from the vessel through the discharge; and the control system for switching the pump system from a first operating state to a second operating state at a temporally changeable switching milk level to be reached by the milk in the vessel.

15. A milking system comprising: a plurality of milking devices; and a milk tank system connected to the plurality of milking devices, wherein the milk tank system is as claimed in claim 1.

16. The milking system as claimed in claim 15, wherein the milking devices are in robot milking devices.

17. The milk tank system as claimed in claim 1, wherein the shut-off is configured to shut off the fluidic connection from the first holder to the milk line.

18. A milking method of using the milk tank system according to claim 1, comprising the steps of: obtaining milk using at least one milking device; intermediately storing the milk obtained from several milkings in the first holder, wherein the first holder is not a milk glass; determinating a milk level in the first holder; and connecting the transport device for transporting at least part of the stored milk from the first holder to the second holder when the milk level in the first holder reaches a switching milk level, which switching milk level is changeable over time.

19. The method as claimed in claim 18, further comprising the step of performing a cleaning action of the first holder, wherein between two successive cleaning actions of the first holder, the switching milk level is a non-decreasing function of time.

20. The method as claimed in claim 18, further comprising the step of performing a cleaning action of the first holder, wherein between two successive cleaning actions of the first holder, the switching milk level is a strictly increasing function of time.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will now be explained in more detail with reference to the drawing which shows a non-restrictive exemplary embodiment, and wherein:

(2) FIG. 1 depicts in a highly diagrammatic view a milking system 1 according to the invention,

(3) FIG. 2 depicts schematically a diagram of the milk level development in a milking system according to the prior art,

(4) FIG. 3 depicts a filling and pumping out regime according to the present invention, and

(5) FIG. 4 depicts a diagrammatic example of milk levels to be reached in the intermediate milk storage vessel 10.

DETAILED DESCRIPTION OF THE INVENTION

(6) FIG. 1 depicts a milking system 1 according to the invention in a highly diagrammatic view. The milking system 1 here comprises four milking robot devices 2 and a carousel 3. Each milking robot device 2 has milking cups 4 and a gripper arm 5 for placing the milking cups on the teats of a dairy animal. A milk glass 6 is also provided for capturing the milk from a milking, and a milking pump 7 for pumping the milk through the milk line 8 to a milk storage system 9, comprising an intermediate milk storage vessel 10 which is connected via a main milk line 11 to a milk tank 12 and which receives the milk 14.

(7) A control system is designated 13, a first discharge 21 and a second discharge 22 to an outlet capture unit 23 and a selection device 24. 25 indicates a pump system with a first pump 26 and a second pump 27. 30 indicates a sensor for the fluid quality, and 33 and 33 are milk level sensors.

(8) The milking system 1 shown here comprises a carousel 3 with a plurality of milking stands with milking cups 4, and also four milking robot devices 2. It is clear that the milking system may also comprise merely one carousel or a plurality of carousels, and also merely any number of milking robot devices such as two, eight, sixteen etc. Also, not all details relevant to the invention are shown, such as milking stands at the milking robot devices etc.

(9) Each milking robot device 2 is configured for milking a dairy animal at a milking stand (not shown). For this, using the gripper arm 5 or another suitable device, the milking robot device 2 places the milking cups 4 on the teats of the dairy animal. Here only two milking cups 4 are shown, which is sufficient for a goat or similar. For cows, four milking cups are required. The milk obtained with the milking cups 4 is captured per milking in the milk glass 6. The milking robot device 2 is furthermore configured to determine whether the milk from the milking, as consumption milk, should be transferred from the milk glass 6 to the milk tank 12. For this, the milking robot device 2 has apparatus not shown here, such as a milk quality device or a management system which, for example on the basis of an established animal identity, can determine whether the milk is suitable or unsuitable for human consumption. If the milk is found to be unsuitable, a discharge (not shown here) of the milk is created from the milk glass 6 e.g. to a drain or to a residual milk capture unit. If the milk is found suitable for human consumption, it is pumped by the milk pump 7 from the milk glass 6 into the milk line system 8. The milk is then captured in the milk storage system 9, which here comprises an intermediate milk storage vessel 10.

(10) The intermediate milk storage vessel 10 receives milk from several milkings, and for exampleas shown heremilk from a plurality of milk glasses and/or from a carousel 3. The volume of the intermediate milk storage vessel 10 is then selected accordingly, and for example comprises a few hundred liters.

(11) When the intermediate milk storage vessel 10 is sufficiently full, the milk is pumped out by the pump system 25 through the main milk line 11 to the milk tank 12. This is controlled by the control system 13, which is here depicted only highly diagrammatically. The same applies to the connections depicted between the control system 13 and the various components of the milking system 1 controlled by the control system 13, which connections are here only shown in part and highly diagrammatically. It is self-evident that an active connection is present between the control system 13 and the controlled components of the milking system 1, which connection may be hard-wired or wireless.

(12) Milk 14 is present in the milk storage vessel 10 to a specific level. This level may be determined with the milk level meter 33, 33. The milk level meter 33, 33 may for example be a weighing cell which is arranged below the intermediate milk storage vessel 10, or alternatively or additionally an array of conductivity pins 33 arranged along the wall of the vessel 10, a pressure sensor etc. Depending on the level of the milk 14 in the vessel 10, the milk level meter 33, 33 emits a specific signal which can be processed by the control system 13. When a specific milk level is reached in the vessel 10, the control system 13 may switch on the pump system 25 to lower the level of the milk 14 and pump the milk 14 to the milk tank 12 via the main milk line 11.

(13) Each milking device is cleaned after one or more milkings. Preferably, all milking devices, such as the milk robot devices 2 and the carousel 3, are cleaned in one cleaning action, either in parallel or sequentially or in combination. These details however lie outside the scope of the invention and are not discussed here.

(14) It is also pointed out that the pump system 25 here comprises a first pump 26 and a second pump 27. The pump system 25 may thus for example pump at several pump speeds, such as at a first pump speed set by the first pump 26 for pumping the milk, and at a second higher pump speed for pumping cleaning fluid using the second pump 27 or both pumps 26 and 27; this can also be achieved with a single controlled pump.

(15) FIG. 2 depicts schematically a diagram of the development of the level of the milk 14 in a storage vessel 10 according to a milking system of the prior art. It is evident here that at time t.sub.0, the milk level h.sub.m begins to rise from 0 until it reaches a height h.sub.max at time t.sub.1. At that moment, a pump system is switched on and the milk level begins to fall towards 0. The pump system is then switched off and the milk level begins to rise again until at time t.sub.2 it has again reached the same level h.sub.max. The same cycle is repeated again from pumping out to 0, allowing the milk level to rise to h.sub.max and then pumping out again (such is now at time t.sub.3). With such a system, pumping out always begins at the same maximum milk level, so that in a storage vessel, caking of for example milk fat or similar can occur at level h.sub.max. On the subsequent cleaning, this caking can be removed; however this is not always easy.

(16) FIG. 3 in contrast shows a filling and pumping out regime according to the present invention. This again begins at time 0 with a milk level 0, which then rises until a height h.sub.m1 is reached at time t.sub.1, after which milk is pumped out to a stop level h.sub.s1. Then the milk level rises again but now until at time t.sub.2, a height h.sub.m2 is reached after which pumping out takes place to a higher stop level h.sub.s2. Then, after the milk level has reached level h.sub.m3, pumping out begins again at time t.sub.3, now until a stop level h.sub.s3, and so on. In this regime, there is no fixed height at which pumping out begins, so there is no fixed height at which milking deposits can occur. Each highest level can then be rinsed by the next filling, because the inflowing milk can partially dissolve and dissipate the deposits. Only the highest pumping out level cannot be rinsed by a subsequent higher filling. This is not however serious because it is precisely this highest filling which has only a very short time to dry and cake, because the subsequent cleaning preferably takes place directly after pumping out from the highest fill level.

(17) FIG. 4 depicts a diagrammatic example of milk levels to be reached in the intermediate milk storage vessel 10. For example, pumping out begins for the first time when milk level h.sub.1 is reached. On the next filling of the storage vessel 10, the milk level can rise to level h.sub.2, then h.sub.3, then h.sub.4 and then h.sub.5. After pumping from this last level, for example a cleaning of the intermediate storage vessel 10 may take place. It is noted that the levels h.sub.1 to h.sub.5 shown may in practice vary in number and in height relative to the intermediate milk storage vessel 10. For example there is no point in pumping out from a very low first level h.sub.1, because the number of pump cycles would become unnecessarily high. For example, level h.sub.1 may be at least three-quarters of the maximum milk level to be reached in the vessel 10. Nonetheless, any other ratio between the lowest pumping level and the highest pumping level is possible. This can be determined in practice, for example from the time between pumping actions.

(18) It is again stated here that a great advantage of the present invention is that pumping out of the milk from the intermediate milk storage vessel 10 does not begin at the same or comparable maximum milk level, but preferably at an ever increasing level, so that any caked milk residue is in each case rinsed away on a following filling. Cleaning is then performed only at the (very) highest level, so that no caking problems occur.

(19) The embodiments shown are only intended as non-limitative examples. The scope of protection is determined from the enclosed claims.