NZ208446A - Reverse washing of milking machines having large bore milk line. turbulent flow of wash liquid by air admission - Google Patents

Description

208446 NEW ZEALAND PATENTS ACT 1953 No.: 208446 Date: 11 June 1984 COMPLETE SPECIFICATION "Improvements in or relating to milking machines" KE, AHI OPERATIONS LIMITED, a company incorporated under the laws of New Zealand of 640 Great South Road, Manukau City, Auckland, New Zealand, hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: CHANGE OF NAME OF APPLICANT Ave.* ik£X\srft(e-s ki miTB-D 208446 v This invention relates to methods of operating a milking machine and/or milking machines of the type in which clusters of teat cups are connected by milk tubes to a milk line having an air entry plug or flap valve at an end remote from a releaser or milk pump connection point associated with the milk line and by pulsator droppers to a pulsation means, the milk line and the pulsation line being connected to a source of vacuum, and the milk line being connected through the releaser or milk pump to atmospheric air for discharge of the milk or other liquid (i.e. cleaning liquid during cleaning operations) from the milking machine.

It is an object of the present invention to provide a milking machine of the type described and/or methods of operating the same which will at least provide the public with a useful choice.

According in one aspect the invention consists in a method of cleaning parts of a milking machine of the type described/ and in which said milk line is of a sufficiently large volume per cluster of teat cups by virtue of being of large diameter when compared with current conventional milk lines as to obviate or at least reduce plugging or blocking of the milk line by milk therein, said method comprising the steps of connecting the teat cups of the milking machine through one or more cluster washers to a third line so as to form a washing circuit, connecting the washing circuit to a source of vacuum and to a supply of washing liquid and subjecting the washing liquid to a pressure greater than the pressure in said washing circuit to create a pressure -differential so that the washing liquid is passed through the washing circuit by said pressure differential and discharging. -:7 used washing liquid from said circuit and which inc es the step of causing said -2 208,148 milk line to be substantially or completely filled with washing liquid so that the supply of vacuum to that milk line is substantially or completely occluded resulting .

^ ^ St J UL in the admission of air into said milk lineXcausing a turbulent flushing action of the milk line and other parts of the milking machine being cleaned.

In a further aspect the invention consists in a milking machine of the type described in which said milk line is of a sufficiently large volume per cluster of teat cups by virtue of being of large diameter when compared with current conventional milk lines as to obviate or at least reduce plugging or blocking of the milk line by milk therein, and which includes a third line, a cluster washer for each set of teat cups in the milking machine each said cluster washer being connected to said third line, so that said milk line, said cluster washer and said third line form a washing circuit, valve means whereby said washing circuit is, for cleaning purposes, connected to the source of vacuum of the milking machine, and to washing liquid intake means connected in use to a source of washing liquid which in use is subjected to a pressure greater than the pressure supplied by the source of vacuum, the construction and arrangement being such that in use on vacuum being applied to said washing circuit of washing liquid a flow of liquid passes through said washing circuit for delivery away from the milking machine. 3 <0 -j \iLx -x;/ .satd nilltina^nraetTifK!*lb uuHHumeU-fclH^igfi-said clUStftfr washer to said third line, vacuum is applied to^said third line and vacuum is disconnected from s^tdmilk line by operation of said third line an^Uffilk line valves and said 5 liquid intake means conne^ed to said source of cleaning liquid in a manner s«r6h that a flow of liquid passes into said milk 1 ipa-ffrom said milk line through said teat cups to sa^d^cluster washer and said third line for delivery To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The 15 disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense 1imiting.

An existing milking machine and one preferred form of the invention will now be described with reference to the 20 accompanying drawings in which Figure 1 is a diagrammatic sketch of an existing milking machine installation, Figure 2 is as Figure 1 but modified to include the present invention, with connections and flows shown in the 25 milking phase configuration, Figures 3 and 4 show details of the modified forms of the invention shown in Figure 2, and - H - <.A* -X.. < 5 . ' <- 'J Cii-x Figure 5 is as Figure 2 but with connections and flows shown in the washing phase configuration.

Referring to the drawings, the invention is applicable to milking machines of the type described, which are well 5 known, but has been devised particularly though not solely for use in cleaning a milking machine having a large volume milk line which broadly replaces the usual receiving can of a milking machine.

Referring to the drawings a typical milking machine 10 installation (see Figure 1) consists of clusters of teat cups 1 each cluster being connected to the teats of an animal for the well known purpose of extracting milk therefrom.

The teat cups are connected together by means of 15 nipples 2 in claw body 3 and the claw is connected to the «A milk collection system by means of a flexible tube 4 from & the nipple/ 5 on the claw, to nipple 6 on the milk * collection system which may be a pipe line in a larger plant or may be a simple bucket as distinguished from a 20 milk line in a small e.g. single cluster installation.

A small orifice 7 in the claw body, typically 0.8mm diameter admits air under atmospheric pressure to the claw. This air, passing to the milk line 8 which is maintained under vacuum i.e. at a pressure lower than 25 atmospheric pressure (typically 30 kPa to 50 kPa below atmospheric pressure) and the milk line 8 conveys milk from the claw 7 to a receiver can 13. v Ci'i ;> A further line 9 is mounted adjacent to milk line 8 to support the pulsator valves 10.

These pulsator valves 10 operate to switch pulsator pressure, which varies between atmospheric pressure or close to atmospheric pressure and the lower pressure (30 kPa to 50 kPa below atmospheric) typical]y called the "vacuum" level to the outer chamber 11 of teat cup(s) 1.

When vacuum cr the lower pressure is rpplied to outer chamber(s) 11 of the teat cup(s), this vacuum or lower pressure counteracts the milking vacuum applied to the chamber 12 inside the liners of the teat cups to hold the liners open and allow milking to continue. When the pulsator valve operates to connect air pressure to the outer chamber(s) 11, the air pressure collapses the liner about the teat to squeeze the teat to de-congest it from blood which is drawn down to the tissues in the teat end under the influence of the milking vacuum.

The milk line 8 leads to milk receiver can 13 which is connected by means of tube 14 to the pulsator line 9» vacuum tank and/or moisture trap 15 and line 16 to a vacuum pump or more correctly an air extraction pump which is used to reduce the pressure level in the pulsation and milk lines to the desired level (typically 30 kPa to 50kPa below atmospheric pressure).

Vacuum regulator 17 operates to admit air to the system as required so as to maintain the system reduced pressure to the required level. «>, 'i. 'jL Milk Pump 18 operates to extract milk from receiver can 13 against the influence of the system reduced pressure and convey the milk via conduit 19 to storage tank 20.

A major disadvantage with a typical milking system as described above lies in the size of the "milk line" 8 through which all milk must flow to the Receiver Can 13 and milk pump 18.

With larger installations in which milk line 8 must necessarily be relatively long (approx 900 mm per milking point) and with high yield cows, the milk line 8 may easily "fill" and "plug" with milk. This effectively shuts off the milking "vacuum'1 from clusters on that side of the plug which is farthest from the receiving can 13.

A reduction in or shutting off of the vacuum supply may result in clusters dropping off the animals being milked with the possibility of foreign matter being drawn from the floor, into the teat cups and/or the increased turbulence which may result in localised areas of the milk line 8 as the milk blockage is reduced may result in damage to the fat particles in the milk (Lypolysis), milk flavour tainting and reduced milk quality.

Such equipment is cleaned according to the invention by use of the following changes. A connection 30 to the milk line 8 is normally plugged for milking but the plug is removed (or a valve operated) so that a connection 31 to a vessel 32 of washing liquid is made leading to the milk line 8. A valve 33 is operable to close the passage from fw-.- the milk line 8 to the receiver can 13. A third line 34 is provided with washing jetters 35 onto which the teat cups 1 are fitted during washing. A valve 36 connects the third line 34 to the receiver can 13 and this valve is closed for ConJUil' milking and open for washing. The conneatlew 19 may be positioned as shown in pecked lines at 37 to direct washing liquid back into the vessel 32 in which the upper surface of the liquid is exposed to a pressure greater than the pressure created by vacuum pump connected to pipe 16 -preferably atmospheric pressure.

During washing the liquid in vessel 32 is forced by the pressure on it into the milk line 8 through the teat cups 1 into the jetters 35, through the third line 34 to the receiver can 13 and thus to pump 18 for delivery from the machine either to waste or back to the vessel 32.

Refer now to Figure 2.

In this installation the vacuum system and the pulsation system are retained but milk line 8 in Figure 1 which would normally be of say 40 - 50 mm diameter is replaced by larger diameter milk line 21 of say 100 mm diameter or even larger. With the average milk line length of 900 mm per milking point this gives a volume of milk line per cluster of teat cups of about seven litres. Milk receiving can 13 is eliminated. A simple function fitting 22 may replace can 13 and a washing line 25 having washing jetters 26 controlled by valve 27 may be connected to vessel 29. **> -J U'i'i \t Milk Pump 18 operates as before to remove milk from the system and convey said milk to storage tank 20.

VJith a very large installation say with 12 to 18 or more milking points, fitting 22 may be replaced by an X fitting 28 (see Figure 3) inserted in a milk line 21 at a point intermediate of the length and preferably close to or at the centre of line 21 so that milk flows from both sections of milk line 21 towards fitting 28 from which the milk pump will extract said milk.

This central location of 28 will greatly reduce the milk quantity and flow in each section of milk line 21, thus further reducing the risk of plugging, blocking or flooding and fat damage.

A transparent viewing means e.g. a transparent flap valve 24 or a cap may be fitted to the outer ends of line 21 to allow visual inspection of flow conditions and system cleanliness and to assist cleaning as will be described later* • < \t A transparent cap flap valve 24a or^» cap* is also fitted to fitting 22, Figure 4, when fitting 22 is installed at the end of line 21.

A spigot 40 leading to the milk line 21 is plugged for milking and to enable washing of this equipment to be carried out, spigot 40 is unplugged and a pipe 41 connected to a vessel 42 in which washing liquid is contained with its upper surface exposed to a pressure greater than the milking pressure (vacuum) e.g. atmospheric pressure. A Q, 0* Lf C valve 43 connecting the milk line 21 to the vessel 29 which is open for milking is closed for washing and valve 27, which is closed for milking, is opened, conduit 22a is disconnected from milk line 21 and connected to the nipple 29a on tank 29. The teat cups 1 are placed on the jetters 26. When these steps have been completed washing is effected by the washing liquid flowing in reverse direction to milk flow, i.e. from vessel 42 through milk line 21, through the teat cups 1 and jetters 26 to the third line 25 through valve 27 to the vessel 29 thence through pump 18 and pipe 44 back to the vessel 42, or to waste as desired.

When flap valve 24 or 24a is provided the rate of flow of cleaning liquid is arranged so that the milk line is substantially or completely filled with cleaning liquid so that the supply of vacuum to that milk line 21 is substantially or completely occluded and vacuum is lost adjacent flap valve 24 or 24a resulting in the admission of air through flap valve 24 or 24a into the milk line 21 causing a turbulent flushing action of the milk line and other parts of the milking machine being cleaned.

It may be seen that at least in the preferred form the present invention provides the following features or advantages. 1. Washing solution is moved through the plant in a reverse direction to milk flow during milking and under vacuum. 2. The large diameter milk line allows for the transparent inspection cover 24 or 24a(A valuable hygiene feature) The large diameter also permits the mounting " " " "s"" - thereon of the milk line valve, cleaning fluid inlet, and milk outlet.

All these simple strong cost saving features e.g. inspection cover, milk line valve, cleaning fluid inlet and milk outlet can be combined in a prefabricated milk line manifold ready for easy and quick installation. 14^5

Claims (12)

WHAT WE CLAIM IS: v' •« V ^v\ v*

1. A method of cleaning parts of a milking machine of the type described, and in which said milk line is of a sufficiently large volume per cluster of teat cups by virtue of being of large diameter when compared with current conventional milk lines as to obviate or at least reduce plugging or blocking of the milk line by milk therein, said method comprising the steps of connecting the teat cups of the milking machine through one or more cluster washers to a third line so as to form a washing circuit, connecting the washing circuit to a source of vacuum and to a supply of washing liquid and subjecting the washing liquid to a pressure greater than the pressure in said washing circuit to create a pressure differential so that the washing liquid is passed through the washing circuit by said pressure differential and discharging used washing liquid from said circuit and which includes the step of causing said milk line to be substantially or completely filled with washing liquid so that the supply of vacuum to that milk line is substantially or cc resulting in the admission of air into causing a turbulent flushing action of the milk line and other parts of the milking machine being cleaned.

2. A method as claimed in Claim 1 including the steps of arranging said third line to be supplied with vacuum from the source of vacuum of the milking machine, arranging a connection from the milk line of the milking machine to said supply of washing liquid causing its washing liquid ,to be drawn into the milk line and through the teat cups - 12 - :ompletely occluded. i t »*. said milk line*^ 208446 * and milking clusters into said third line by operation of the source of vacuum.

3. A method of cleaning parts of a milking machine when effected substantially as herein described with reference to and as illustrated by the accompanying drawings.

4. A milking machine of the type described in which said milk line is of a sufficiently large volume per cluster of teat cups by virtue of being of large diameter when compared with current conventional milk lines as to obviate or at least reduce plugging or blocking of the milk line by milk therein, and which includes a third line, a cluster washer for each set of teat cups in the milking machine each said cluster washer being connected to said third line, so that said milk line, said cluster washer and said third line form a washing circuit, valve means whereby said washing circuit is, for cleaning purposes, connected to the source of vacuum of the milking machine, and to washing liquid intake means connected in use to a source of washing liquid which in use is subjected to a pressure greater than the pressure supplied by the source of vacuum, the construction and arrangement being such that in use on vacuum being applied to said washing circuit of washing liquid a flow of liquid passes through said washing circuit for delivery away from the milking machine, admission of air through the air entry plug or flap valve at the end of the milk line remote from the releaser or milk pump into said milk line causing a turbulent flushing action in the milk line and other parts of the milking machine being cleaned.

5. A milking machine as claimed in claim 4 wherein said milk line has a diameter of 100 millimetres or larger.

6. A milking machine as claimed in claim 4 or claim5 wherein said milk line provides a volume of about seven 1." cluster of teat cups. -13- 2<>814fi

7. A milking machine as claimed in any one of the claims 4 to 6 wherein said milk line terminates in a junction and said pulsator system includes a pulsator line connected to said junction.

8. A milking machine as claimed in Claim 7 wherein said junction is an X janction provided intermediate of the length of said milk line and close to or at a central disposition.

9. A milking machine as claimed in any one of the claims 5 to 8 wherein a transparent viewing member is provided to enable flow conditions and system cleanings to be inspected.

10. A milking machine as claimed in any one of claims 4 to 9 wherein said milk line has a flap valve adjacent the point at which said liquid admitting lines are positioned, said flap valve being arranged so that in use when said milk line is filled or substantially filled with cleaning liquid, said flap valve will open to admit air into the milk line for the purpose of providing turbulent flow in said milk line and other parts of the milking machine being cleaned by the flow of cleaning liquid therethrough.

11- A milking machine as claimed in any one of claims 4 to 10 wherein there is provided a third line valve whereby said third line may, for cleaning purposes, be connected to the source of vacuum of the milking machine, a milk line valve for disconnecting the milk line from the source of vacuum during cleaning operations, and said cleaning liquid intake means are connected to said milk line, the construction and arrangement being such that in use each - 14 - 20844R set of teat cups of said milking machine is connected through said cluster washer to said third line, vacuum is applied to said third line and vacuum is disconnected from said milk line by operation of said third line and milk line values and said liquid intake means connected to said source of cleaning liquid in a manner such that a flow of liquid passes into said milk line, from said milk line through said teat cups to said cluster washer and said third line for delivery away from the milking machine.

12. A milking machine when constructed arranged and operable substantially as herein described with reference to and as illustrated by the accompanying drawings. AJ. PARK & SON AGENTS FOff i.rciC'V