Milking arrangement comprising a cleaning arrangement

Abstract

A milking arrangement comprising a milk delivery line (1), a plurality of milking stations (2) connected to the milk delivery line (1), a receiver (3) connected to the milk delivery line (1) and configured to receive milk delivered via the milk delivery line (1) from the milking stations (2) to the receiver (3), and a vacuum system (4) configured to supply a vacuum in the milk delivery line (1) via the receiver (3), a source of cleaning liquid (9) connected to the milk delivery line (1), a controllable injector (10) configured to introduce an amount of gas into the milk delivery line (1) thereby creating a temporary pressure increase therein, the temporary pressure increase resulting in a slug of cleaning liquid from the source of cleaning liquid (9) and being transferred through the milk delivery line (1), and a control system (19) configured to control operation of the injector (10). During a cleaning procedure, the control system (19) is configured to control slug characteristics by controlling the vacuum level supplied by the vacuum system (4) and / or the amount of gas introduced via the controllable injector (10).

Description

TECHNICAL FIELD

[0001] The present invention relates to a milking arrangement comprising a milk delivery line, a plurality of milk stations connected to the milk delivery line, a receiver connected to the milk delivery line and configured to receive milk delivered via the milk delivery line from the milk stations to the receiver, and a vacuum system configured to supply a vacuum in the milk delivery line via the receiver, a cleaning liquid source connected to the milk delivery line, a controllable injector configured to introduce an amount of gas into the milk delivery line, thereby creating a temporary pressure increase therein, which causes a slug of cleaning liquid from the cleaning liquid source to form and be transferred through the milk delivery line, and a control system configured to control operation of the injector. BACKGROUND

[0002] The milking arrangement comprises a cleaning arrangement provided for the purpose of repeatedly cleaning the milk stations, the milk delivery line and components provided along the milk delivery line, such as filters and heat exchangers. The cleaning comprises different procedures, such as a pre-rinse and a main clean.

[0003] Milking arrangements equipped with a vacuum system for supplying system vacuum are well known. The vacuum system can be arranged to supply vacuum to the milk delivery and to the cleaning liquid delivery. The cleaning system can be equipped with a controllable injector configured to introduce an amount of gas, typically atmospheric air, into the milk delivery line, thereby creating a temporary pressure increase therein, which causes a slug of cleaning liquid from the cleaning liquid source to form and be transferred through the milk delivery line. The slug is a column of liquid filling the cross section of the milk delivery line while travelling through the milk delivery line at high speed under the drive of the vacuum. The length of each slug is short compared to the length of the milk delivery line. The slug terminates in a so-called receiver, which is supplied with vacuum by the vacuum system. The receiver can be connected to a pump by means of which the liquid in the receiver is pumped back to the cleaning liquid source for creating a further slug. From the receiver, the milk delivery line continues via a milk pump, filters and heat exchangers to a milk tank. The pump for pumping the cleaning liquid back to the cleaning liquid source can be the milk pump, and thereby the cleaning liquid can be pumped through the filters and heat exchangers in that part of the milk delivery line.

[0004] According to the prior art, the opening time of the injector, which influences the slug characteristics, such as the initial length and speed of the slug, is set in relation to the calibration of the milking arrangement and then kept constant.

[0005] However, during operation of the milking arrangement, conditions in the milk delivery line influencing the slug characteristics can change. The conditions can be the amount of liquid present in the milk delivery line and / or the vacuum level in the milk delivery line. SUMMARY

[0006] The present inventor has realized the importance of being able to control the characteristics of the slug during the cleaning procedure, as well as the importance and advantages of using different slug characteristics for different cleaning procedures.

[0007] It is an object of the present invention to present a milking arrangement which enables control of the characteristics of the slug.

[0008] The object of the present invention is achieved by means of a milking arrangement comprising:

[0009] - a milk transport line,

[0010] - a plurality of milk stations connected to the milk transport line,

[0011] - a receiver connected to the milk transport line and configured to receive milk transported from the milk stations to the receiver via the milk transport line, and

[0012] - a vacuum system configured to supply a vacuum in the milk transport line via the receiver,

[0013] - a source of cleaning liquid connected to the milk transport line,

[0014] - a controllable injector configured to introduce an amount of gas into the milk transport line, thereby creating a temporary pressure increase therein, which causes a slug of cleaning liquid from the source of cleaning liquid to form and be transferred through the milk transport line, and

[0015] - a control system configured to control the operation of the injector, the milking arrangement being characterized in that, during a cleaning procedure, the control system is configured to control the characteristics of the slug by controlling the level of vacuum supplied by the vacuum system and / or the amount of gas introduced via the controllable injector.

[0016] According to one embodiment, the vacuum system comprises a vacuum pump and a controllable valve configured to introduce gas into a line connecting the receiver and the vacuum pump, and the control system is configured to control the level of vacuum supplied by the vacuum system by controlling at least one of the vacuum pump and the controllable valve.

[0017] According to one embodiment, the control system is configured to control the characteristics of the slug by controlling the amount of gas introduced per time unit via the controllable injector.

[0018] According to one embodiment, the controllable injector presents a passage with a controllably variable cross-section, and the control system is configured to control said variable cross-section of the passage for controlling the amount of gas introduced per time unit via the controllable injector. The cross-section is variable in a number of incremental steps between its fully open position and its fully closed position. The control system can also be configured to control the time during which the injector is open and introduces air into the milk transport line.

[0019] According to an embodiment, the characteristics of the slug controlled by the control system comprises at least one of a slug velocity of the individual slug and a length of the individual slug. A slug can be defined as a column of fluid filling the entire cross section of the conduit of the milk delivery pipeline. The length of each slug is only a fraction of the length of the milk delivery pipeline.

[0020] According to an embodiment, the control system comprises a first control mode dedicated for the first cleaning procedure and a second control mode dedicated for the second cleaning procedure, and the characteristics of the slug produced in the first control mode is different from the characteristics of the slug produced in the second control mode. Thus, the control system is configured to adapt and optimize the slug characteristics to the requirements of the different cleaning procedures.

[0021] According to an embodiment, the first control mode uses a first cleaning liquid and the second control mode uses a second cleaning liquid. Typically, the chemical composition of the cleaning liquid can be different between the different cleaning procedures. The temperature of the cleaning liquid can also be controlled by the control system and controlled to different temperatures for the different cleaning procedures.

[0022] According to an embodiment, the first cleaning procedure is a pre-rinse procedure and the second cleaning procedure is a main cleaning procedure, and the average velocity of the slug produced by the first control mode through the milk delivery pipeline is higher than the average velocity of the slug produced by the second control mode. Typically, the purpose of the pre-rinse is to flush the milk delivery pipeline and remove residues, and the main cleaning procedure relies on the contact time between the cleaning liquid and the milk delivery pipeline. Thus, a higher velocity of the slug produced by the first mode is preferred.

[0023] According to an embodiment, the first cleaning procedure is a pre-rinse procedure and the second cleaning procedure is a main cleaning procedure, and the average length of the slug produced by the second control mode is longer than the average length of the slug produced by the first control mode. Thus, a longer contact time between the cleaning liquid and the walls of the milk delivery pipeline is achieved in the second mode, which is preferred for the main cleaning procedure.

[0024] According to an embodiment, the vacuum level supplied by the vacuum system is higher in the first control mode compared to in the second control mode. Thus, a higher slug velocity is achieved in the first control mode

[0025] According to an embodiment, the length of the milk delivery pipeline is 100 meters or more, and the injector is arranged in connection with an end of the milk delivery pipeline opposite to the end where the milk receiver is provided.

[0026] According to an embodiment, a vacuum pump is connected to the receiver to supply a vacuum therein.

[0027] According to an embodiment, the injector is configured to introduce atmospheric pressure air into the milk delivery pipeline.

[0028] According to an embodiment, the milking arrangement comprises a sensor arrangement configured to measure at least one parameter related to the characteristics of the plug, and the control system is configured to receive the at least one parameter measured by the sensor arrangement and based thereon generate an indicator of the characteristics of the plug, and based on said indicator control the vacuum level supplied by the vacuum system and / or the amount of gas introduced via the controllable injector. Thus, information from the sensor arrangement is utilized for the purpose of controlling the characteristics of the plug. According to an embodiment, the sensor arrangement comprises a first sensor arranged in the vicinity of the location in the milk transport line where the plug is generated, preferably within 10 meters from that location, and a second sensor arranged in the vicinity of the receiver, preferably 10 meters from the receiver. Thus, the first and second sensors can be configured to measure the average speed of the plug between the first and second sensors based on the plug transit time detected by the respective sensors and based on the distance between the first and second sensors.

[0029] According to an embodiment, the sensor arrangement comprises any one of a pressure sensor, an ultrasonic sensor, an electromagnetic sensor, an optical sensor or an accelerometer.

[0030] According to an embodiment, the milking arrangement comprises at least one flow meter configured to determine the amount of cleaning liquid present in the milk transport line, and the control system is configured to control the vacuum level supplied by the vacuum system and / or the amount of gas introduced via the controllable injector based on the amount of cleaning liquid determined by said at least one flow meter. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a schematic illustration of a milking arrangement according to the present invention. DETAILED DESCRIPTION

[0032] Figure 1 A milking arrangement according to an embodiment of the present invention is shown. The milking arrangement comprises a milk transport line 1 and a plurality of milking stations 2 connected to the milk transport line 1. Each milking station 2 comprises milking equipment for milking an animal. The length of the milk transport line 1 is 100 meters or more.

[0033] The milking arrangement further comprises a receiver 3 connected to the milk transport line 1 and configured to receive milk transported via the milk transport line 1 from the milking stations 2 to the receiver 3.

[0034] A vacuum system 4 is also provided, which is configured to supply a vacuum in the milk transport line 1 via the receiver 3. The vacuum system 4 comprises a vacuum pump 5 and a controllable valve 6, which is configured to introduce gas, preferably atmospheric air, into a line connecting the receiver 3 with the vacuum pump 5. The vacuum level supplied by the vacuum system can be controlled by controlling the action of the vacuum pump 5 and / or the opening and closing of the controllable valve 6. The vacuum system 4 further comprises a hygienic trap 7 and a buffer tank 8, which are arranged in series, via which the vacuum pump 5 is connected to the receiver 3. The vacuum system 4 is used to supply a vacuum to the milk transport line during milking. However, as will be described later, the vacuum system 4 will also be used to control the cleaning procedure.

[0035] A cleaning liquid source 9 is connected to the milk transport line 1. The cleaning liquid source 9 can comprise one or more containers containing cleaning liquid, preferably cleaning liquid of different properties, typically of different chemical composition and / or of different temperature, for different cleaning procedures.

[0036] A controllable injector 10 is also provided, which is configured to introduce an amount of gas, preferably atmospheric air, into the milk transport line 1, thereby creating a temporary pressure increase therein, which results in the formation of a slug of cleaning liquid from the cleaning liquid source 9 and the transfer thereof through the milk transport line 1. The liquid source 9 is connected to the milk transport line in the vicinity of the injector 10 via a pipe 11 and a controllable valve 12. The equipment of the milking station 2 can also be connected to the liquid source 9 in a manner known per se via the pipe 11 and a controllable valve 13. Flow meters 14, 15, 16, 17 are provided, which are connected to the injector 10 and to the milk station 2, for measuring the flow of cleaning liquid into and occupying at least a part of the milk transport line 1.

[0037] A pump 20 is provided, via which cleaning liquid is pumped from the receiver 3 to the cleaning liquid source 16. In the specific embodiment shown, the pump 20 is also configured to pump milk from the receiver to a milk tank 21 during milking. In the embodiment shown, the cleaning liquid pumped by the pump 20 is pumped to the liquid source 9 via a filter 22 and a heat exchanger 23 arranged between the pump 20 and the milk tank 21. A controllable valve 25 is provided for the purpose of directing the pumped cleaning liquid towards the cleaning liquid source 9 and not towards the milk tank 21. During cleaning, the controllable valve 25 prevents the cleaning liquid from flowing into the milk tank 21.

[0038] The milking arrangement further comprises a control system 19 configured to control the operation of the syringe 10, the vacuum pump 5 of the vacuum system 4 and the controllable valve 6. The control system 19 is configured to control the vacuum level supplied by the vacuum system 4 by controlling at least one of the vacuum pump 5 and the controllable valve 6. Thereby, the control system is configured to control the rotational speed (rpm) of the vacuum pump 5 and the opening time of the controllable valve 6. A pressure sensor (not shown) can be provided in the line connecting the vacuum pump 5 with the receiver 3 and the control system 19 can be configured to control the vacuum system 4 based on input from said pressure sensor. The control system 19 is further configured to control the slug characteristics by controlling the amount of gas introduced per time unit via the controllable syringe 10. The controllable syringe 10 presents a passage with a controllably variable cross section and the control system 19 is configured to control said variable cross section of the passage for controlling the amount of gas introduced per time unit via the controllable syringe 10. Thereby, the slug characteristics controlled by the control system 19 comprise the slug speed of the individual slug and the length of the individual slug.

[0039] The control system 19 is further configured to control the operation of the controllable valves 12, 13 via which cleaning liquid from the cleaning liquid source 9 is allowed to enter the milk transport line 1 either via the syringe 10 or via the milking equipment of the milking station 2. The control system 19 is further configured to control the operation of the pump 20 via which cleaning liquid is pumped from the receiver 3 to the cleaning liquid source 9.

[0040] The control system 19 is here exemplified by a control unit comprising a processor and a readable memory. Alternative embodiments are of course also conceivable, such as a cloud based solution.

[0041] The control system 19 comprises a first control mode dedicated to the first cleaning procedure and a second control mode dedicated to the second cleaning procedure. In the first control mode the characteristics of the produced slugs are different from the characteristics of the slugs produced in the second control mode.

[0042] In the presented embodiment the first control mode uses a first cleaning liquid and the second control mode uses a second cleaning liquid.

[0043] The first cleaning procedure is a pre-rinse procedure and the second cleaning procedure is a main cleaning procedure. The average speed of the slugs produced by the first control mode through the milk transport line 1 is higher than the average speed of the slugs produced by the second control mode. The average length of the slugs produced by the second control mode is longer than the average length of the slugs produced by the first control mode. The vacuum level supplied by the vacuum system 4 is higher in the first control mode than in the second control mode. A higher vacuum level is referred to as a lower pressure level.

[0044] An indication of the slug characteristics at the time of the slug entering the receiver 3 is measured by means of a 3D accelerometer 27 provided outside the receiver 3. The slug will generate a movement of the receiver, which movement corresponds to the velocity and length (mass) of the slug. This movement is recorded by the accelerometer 27. The control system 19 comprises a readable memory in which a look-up table with set values is stored, each value representing a value of a slug characteristic. The control system is configured to compare the measurements of the accelerometer 27 with the set values in the look-up table and to determine that the slug characteristic, velocity and / or length of the slug corresponds to the preset value that is closest to the value measured by the accelerometer. For a predetermined combination of receiver design, accelerometer design and accelerometer position on the receiver, the correlation between the set values and the slug characteristics can have been determined in a laboratory environment.

[0045] Based on the knowledge of the slug characteristics, measures can be taken to control the milking arrangement, preferably the controllable injectors and / or the vacuum system, for the purpose of achieving the required slug characteristics. Thereby, the control system can be configured to perform an iterative process, typically a closed loop process, to obtain slug characteristics that correspond to the required slug characteristics for each respective cleaning procedure.

[0046] In the shown embodiment, the milking arrangement comprises a sensor arrangement comprising a first pressure sensor 26a arranged at a first position in the milk transport pipeline and a second pressure sensor 26b arranged at a second position at a predetermined distance from the first position. The passage of a slug causes a change in pressure, which change can be measured by the respective sensors 26a, 26b. Based on the known distance between the pressure sensors 26a, 26b and the point in time at which the respective sensors detect the passage of a slug, the control system 19 is configured to determine the average velocity of the slug. The average length of the slug can also be determined based on the measurements of the pressure sensors 26a, 26b, e.g. as described in WO2017 / 091126. The first pressure sensor 26a is arranged in the vicinity of the position in the milk transport pipeline where the slug is generated, preferably within 10 meters from this position, while the second pressure sensor 26b is arranged in the vicinity of the receiver 3, preferably 10 meters from the receiver 3. Thereby, the first pressure sensor 26a and the second pressure sensor 26b can be configured to measure the average velocity of the slug between the first and the second sensor based on the time of passage of the slug detected by the respective sensors and based on the distance between the first and the second sensor.

[0047] The pressure sensors 26a, 26b will give information about the slug characteristics at predetermined positions in the milk transport pipeline 1, while the accelerometer 27 gives information about the slug characteristics in the receiver 3. The control system 19 can be configured to combine the information in any suitable way in order to control the injectors 10 or the vacuum system 4.

[0048] The control system 19 is further configured to control the vacuum level supplied by the vacuum system 4 and / or the amount of gas introduced via the controllable syringe 10 based on the amount of cleaning liquid determined by the flow meters 14-17.

Claims

1. A milking arrangement, comprising: - Milk delivery pipeline (1). - Multiple milk stations (2) connected to the milk delivery pipeline (1). - Receiver (3), which is connected to the milk delivery line (1) and configured to receive milk delivered from the milk station (2) via the milk delivery line (1) to the receiver (3), and -A vacuum system (4), which is configured to supply a vacuum in the milk delivery line (1) via the receiver (3), - Cleaning liquid source (9), which is connected to the milk delivery line (1). - A controllable injector (10) configured to introduce a certain amount of gas into the milk delivery line (1), thereby creating a temporary pressure increase therein, the temporary pressure increase causing slugging of the cleaning fluid from the cleaning fluid source (9) and its transfer through the milk delivery line (1), and - A control system (19) configured to control the operation of the controllable injector (10), wherein the milking arrangement is characterized in that, during the cleaning process, the control system (19) is configured to control the slug characteristics by controlling the vacuum level supplied by the vacuum system (4) and / or the amount of gas introduced via the controllable injector (10). The slug characteristics controlled by the control system (19) include at least one of the slug speed and the length of the individual slug. The control system (19) includes a first control mode dedicated to the first cleaning process and a second control mode dedicated to the second cleaning process, and the characteristics of the slug generated in the first control mode are different from the characteristics of the slug generated in the second control mode.

2. The milking arrangement according to claim 1, characterized in that, The vacuum system (4) includes a vacuum pump (5) and a controllable valve (6) configured to introduce gas into a line connecting the receiver (3) and the vacuum pump (5), and the control system (19) is configured to control the vacuum level supplied by the vacuum system by controlling at least one of the vacuum pump (5) and the controllable valve (6).

3. The milking arrangement according to claim 1 or 2, characterized in that, The control system (19) is configured to control the slug characteristics by controlling the amount of gas introduced per unit time via the controllable injector (10).

4. The milking arrangement according to claim 3, characterized in that, The controllable injector (10) presents a channel with a controllable variable cross-section, and the control system (19) is configured to control the variable cross-section of the channel for controlling the amount of gas introduced per unit time via the controllable injector (10).

5. The milking arrangement according to claim 1, characterized in that, The first control mode uses a first cleaning solution and the second control mode uses a second cleaning solution.

6. The milking arrangement according to claim 1 or 5, characterized in that, The first cleaning process is a pre-rinse process and the second cleaning process is a main cleaning process, and the average speed of the blockage generated by the first control mode through the milk delivery line (1) is higher than the average speed of the blockage generated by the second control mode.

7. The milking arrangement according to claim 1, characterized in that, The average length of the slug generated by the second control mode is longer than the average length of the slug generated by the first control mode.

8. The milking arrangement according to claim 1, characterized in that, The vacuum level supplied by the vacuum system (4) is higher in the first control mode than in the second control mode.

9. The milking arrangement according to claim 1, characterized in that, The milk delivery line (1) is 100 meters or longer, and the controllable injector (10) is arranged to be connected to an end of the milk delivery line (1), the end being opposite to the end providing the receiver (3).

10. The milking arrangement according to claim 2, characterized in that, The vacuum pump (5) is connected to the receiver (3) to supply a vacuum therein.

11. The milking arrangement according to claim 1, characterized in that, The controllable injector (10) is configured to introduce atmospheric pressure air into the milk delivery line (1).

12. The milking arrangement according to claim 1, characterized in that, It includes a sensor arrangement (26, 27) configured to measure at least one parameter related to the slug characteristics, and the control system (19) configured to receive the at least one parameter measured by the sensor arrangement (26, 27) and generate an index of the slug characteristics based on the at least one parameter, and control the vacuum level supplied by the vacuum system (4) and / or the amount of gas introduced via the controllable injector (10) based on the index.

13. The milking arrangement according to claim 12, characterized in that, The sensor arrangement (26, 27) includes any one of a pressure sensor, an ultrasonic sensor, an electromagnetic sensor, an optical sensor, or an accelerometer.

14. The milking arrangement according to claim 1, characterized in that, It includes at least one flow meter (14-17) configured to determine the amount of cleaning fluid present in the milk delivery line (1), and the control system (19) configured to control the vacuum level supplied by the vacuum system (4) and / or the amount of gas introduced via the controllable injector (10) based on the amount of cleaning fluid determined by the at least one flow meter (14-17).

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