NZ260167A - Milking washing system: washing liquid drawn into the accumulator is forced by higher pressure air into the milk line via a conduit - Google Patents

Description

260167 PATENTS FORM NO. 5 Fee No. 4: $260.00 PATENTS ACT 1953 COMPLETE SPECIFICATION After Provisional ,v '' < No: 260167 ' %^'jUlU94 Dated: 23 March 1994 ^ WASHING SYSTEMS AND APPARATUS We Nu Pulse New Zealand Limited, of 82 Greenwood Street, Hamilton, New Zealand, a New Zealand company 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: 2 6 0 A 6 7, Washing Systems & Apparatus Technical, field This invention relates to washing systems and in particular to washing systems for use with milking machine apparatus. background art Hygiene requirements are strict in the dairy industry as milk is a substance that can readily become contaminated. Bacterial contamination, fat build-ups and milk stone build-up all occur in milking machines. Every new milking machine or washing system device is rigorously tested for possible sources of contamination before being approved by the Ministiy of Agriculture and Fisheries.

There is now a trend towards milking machines that have large round milk lines and rounded receivers. Unfortunately it is difficult for washing systems to cleanse the top of these milk pipes and milk receivers due to their size and curvature. Furthermore, in most milking systems there are airline pipes through which milk vapour escapes and subsequently collects on the walls thereof and in sanitary traps. These areas are traditionally difficult to clean by conventional washing systems.

Our New Zealand Patent No. 224545 describes a FULFLO washing system developed by us which has proved to be satisfactory in use and for convenience is described herein by way of example in relation to Figures PRIOR ART 1 and 2. 2 260 167 Figure 1: is a diagrammatic view of one embodiment of the FULFLO invention in the milking cycle phase, and Figure 2: is a diagrammatic representation of the FULFLO in the washing phase.

Figures 1 and 2 illustrate a milking machine system generally indicated by arrow 1 comprising a milk line 2, a wash line injector 3 at one end of the milk line and a receiver 4 at the other end of the milk line.

The milk line 2 is approximately 100mm in diameter which allows sufficient through flow of milk in the line. The receiver 4 is approximately 11 litres in volume and functions as a buffer to eliminate surging in the milk as well as providing a steady milk flow to the milk pump (not shown) via pipe 5. This receiver is somewhat smaller than receivers in traditional milking machines as by having less volume, less cleansing fluid is required to clean it.

Attached to the milk line 2 is a pulsator unit which is connected to milking claws 7 and clusters 8. The claws 7 in pulsators 6 are connected to the milk line 2 by hosing 9 and 10 respectively. Underneath the milk line is a jetter line 11 attached to which are jetters 12. Both the milk line 2 via the wash line injector 3 and the jetter line 11 are connected via pipe 13 to a cleansing liquid source 14.

Extending upwardly from the receiver 4 is an airline pipe 15 which connects to sanitary trap 16. Milk vapour from the receiver 4 tends to collect on the walls of the airline pipe 16. e« ^ *■ /* c-\- \ 2" JUU996 26 0 167 The sanitary trap 16 has a safety mechanism generally indicated by arrow 17. The safety mechanism comprises a pipe 18 which is connected to the vacuum source (not shown), a cage 19 and a ball float 20. As the liquid level in the trap 16 rises, so does the ball float 20 which acts to shut off the pipe 15 once the liquid reaches a maximum level. This shuts off the vacuum source and the milking system closes down.

A further pipe 21 connects from the bottom of the sanitary trap 16 to the pipe 5. Pipe 21 has a valve 22 close to its connection to the pipe 5. Pipe 5 has a valve 23 which is positioned between the receiver 4 and the connection with pipe 21.

The milking phase is illustrated in Figure 1. To operate the system, a wash line injector clamp 24 is closed between the wash line injector 3 and the milk line 2. A drain valve 25 on pipe 5 below the receiver 4 is closed along with valve 22. Valve 23 is opened. This opening and closing of valves enables milk to flow along milk pipe 2 into receiver 4 down through pipe 5 and out to the milk pump (not shown). In operation the pulsators 6 operate the milking claws 7 and clusters 8. Milk through the claws 7 travel along hosing and into the milk line 2 along the path described above. Milk vapour from the receiver 4 may collect on the walls of the airline pipe 15.

Figure 2 illustrates the washing phase. To operate, valve 22 opens a path from the sanitary trap 16 to pipe 5. The wash line injector clamp 20 is opened and valve 23 on the direct route from the receiver to the milk pump is closed. Milking clusters 8 are plugged into the jetters 12 on the jetter line 11. The pulsators are then started along with the wash line injector 3. Cleansing fluid passes from the source 14 i 3 4 26 0 1 67 11, through the jetters 12 and into the milking claws 7 and clusters 8. The cleansing fluid then flows through hosing 10 into the milk line flooding same and filling the receiver 4. The fluid then flows up the receiver airline pipe 15 (removing condensed milk vapour) and into the sanitary trap 16. From the trap 16 the cleansing fluid passes through pipe 21 and emerges out of pipe 5 to travel to the milk pump.

The wash line injector 3 (which may be a specialised pulsator) draws cleansing fluid from the source 14 and sprays it into the end of the milk line 2. The turbulence caused by the spray from the wash line injector 3, and air admission from the jetters and pulsators increases the cleansing power of the system.

At the end of the washing phase, the drain valve 25 is then opened to remove traces of the cleansing fluid.

The FULFLO system, and others of similar principle are designed to provide stratified milk flow conditions and give very stable milking vacuum but as discussed are difficult to clean. Washing systems developed to date do not clean some parts well and other parts (e.g. receiver airlines) not at all.

Some systems tend to push the washing liquids through the milk line in a wave form and regions where the wave is not fully built up are not cleaned.

The above-mentioned draw backs have been recognised by others. Our parent company Alfa Laval Agri has previously proposed the use of a P-trap U, or W-bend positioned close to washing system milk lines to improve vacuum stability in a milk line and to enable an accumulated water plug to be pushed down the milk line periodically to improve the O- JUL 1996 Y** -O. 260 167 washing action of the system. We have experimented with similar concepts however and have found that improvements in the washing system were minimal and it appears that these systems are insufficiently accurate and tend to flood the system and adversely affect vacuum levels within the system.

It is an object of the present invention to provide improvements to washing systems such as previously described.

Further objects and advantages of the present invention will become apparent from the ensuing description.

DISCLOSURE OF THE INVENTION According to the present invention there is provided a method of introducing into a milk line & intermittent flow of a liquid comprising the steps of accumulating a predetermined quantity of the liquid in an accumulator which is communicable with a source of air at atmospheric pressure and a source of air at a pressure lower than atmospheric pressure and periodically purging the accumulator utilising pressure differentials to accelerate the liquid and push it through said milk line via a connecting conduit said conduit having a spout which extends into the interior of the accumulator.

The spout can be provided with a pressure equalising orifice coincident with upper regions of the accumulator.

The spout can be sealed off as the liquid is being drawn into the accumulator whilst it is subject to partial pressure and the orifice provides for continuity of low pressure within the accumulator to allow it ali'''* •' Jl' ,| ■ ' ' ''A to fill to capacity prior to the introduction of air aboveJhe* accumulated 5 liquid. p' 26 0 167 The conduit can have t connection to the xnilk line which is co-axial therewith.

According to a further aspect of the present invention there is provided a washing system for a milking apparatus including an accumulator having a washing water inlet and being connected to a milk line via a conduit, a source of low pressure air communicable with said milk line and a source of higher pressure air communicable with said milk line via the accumulator, ji actuator associated with the source of higher pressure air adapted to inject higher pressure air into the accumulator at predetermined intervals wherein the conduit is of a lesser cross-sectional area than the accumulator, the arrangement and construction being such that when the milk line and accumulator are subject to a vacuum, washing water is drawn into said accumulator, said actuator can be actuated to introduce higher pressure air into the accumulator to force the accumulated washing liquid from the accumulator into said milk line via the conduit.

The conduit may include a spout which extends into the interiors of the accumulator.

The spout can be provided with a pressure equalising orifice coincident with upper regions of the accumulator.

An inlet orifice of the spout can be of a similar diameter to the co-axial connection with the milk line.

The milk line can be substantially the same diameter as the accumulator. t N A* t V 2-JUL 1996 26 0 167 Aspects of the present invention will now be described with reference to the accompanying drawings in which: Figure 3: is a diagrammatic side view of a washing system in accordance with the present invention, and Figure 4: is a perspective view of the body of an accumulator for the washing system of Figure 3.

With respect to Figures 3 and 4, the washing system is associated with a milk line 30 and includes an accumulator generally indicated by arrow 31 communicable with the milk line 30, a source of cleaning liquid (not shown) which can be drawn to the accumulator 30 via jetter washer line The washing system includes a valve generally indicated by arrow 33, an air injector 34, a shut off valve 35. Air lines 36, 37 connect valve 33 to valve 35 and valve 33 to the injector 34. Conduits 38, and 39 provide passages for fluids between the milk line 30 and the accumulator 31 and between the jetter line 32 and the accumulator 31 via valve 35.

Valve 33, which may be operated by a solenoid, is controllable to supply air at atmospheric pressure to air lines 36, 37 and valve 35 is an air pressure valve controllable to allow cleaning fluids to pass into the accumulator or to shut off the supply.

During the milking phase valve 35 closes and cleaning fluid cannot pass into the accumulator 32 and milk line 30. During the cleaning phase valve 35 is kept open allowing cleaning fluid to be drawn under vacuum 32. into the accumulator 31 and milk line 30. 260 167 Valve 33 has an associated timing device (not shown) which allows air to flow to the injector 34 from line 38 for a period of time which is coincident with the time it takes to accumulator to fill or to a predetermined level. Once the predetermined level is reached the injector 34 releases atmospheric air to the accumulator 31. Because the cleaning fluid within the accumulator has a vacuum applied below it (via the milk line) and because of the pressure differential created by the introduction of atmospheric pressure above the liquid within the accumulator all liquid within the accumulator 31 is instantaneously purged and travels in the form of a "plug" at considerable velocity to the milk line 30 via the conduit 38. As the fluid passes from the conduit 38 to the milk line 30 it fans out as it mixes with air and the "plug" of cleaning fluid has sufficient momentum to spread to all surface areas of the milk line and continues to travel in the form of a cylindrical plug (albeit in an aerated form) to the end of the milk line washing covering all surfaces of the milk line.

The accumulator 31 can be formed from a cylindrical tube 40 having end caps 41. The accumulator has a fluid outlet tube 42, an air inlet tube 43 and a wash water connector 44. The fluid outlet tube 42 has a spout 45 which extends into the accumulator and has its opening 46 within the lower regions of the accumulator. In the upper regions of the spout 45 an orifice 47 is provided.

As the accumulator 31 fills with wash water, via inlet 44 the level of water in the accumulator will rise and seal the accumulator from the milk line vacuum by effectively closing the opening 46. & h r K 7s o V 2- JUL 1996 26 0 1 67 A pressure equalising orifice 47 is provided in the spout 45. This orifice maintains communication between the vacuumised milk line and the accumulator whilst it continues to fill.

The orifice 47 also acts to permit a steady flow of wash water into the milk line to assist the "pre-loading" of the milk line so that when the plug is injected into the milk line, there is a body of water to maintain the plug integrity.

When the injector 34 is opened an instantaneous and major change of pressure evacuates the accumulated wash water and accelerates it down the milk line 30 as a "plug".

It is a feature of the accumulator 31 that the opening 46 of the spout 45 is at the bottom of the accumulator to provide a complete and controlled evacuation of the wash water. Injected air will act on the water surface, and none can "escape" past the water plug, reducing the effectiveness of the air injection.

Another aspect of the present invention is that the body of the accumulator is of a similar diameter to the milk line and inlet tube 43 and outlet tube 42 are of reduced diameter. Washing liquid purged from the accumulator is therefor accelerated as it is forced from the accumulator to the milk line via outlet tube 42 and line 38. Line 38 is configured to introduce effected fluid co-axially with the milk line 30.

The acceleration given to the fluid which accumulates within the accumulator can be fine tuned by adjusting conduit sizes, the capacity of the accumulator, and the timing of introduction of air behind the 14 t accumulated fluid and relative pressures within the system. .. .,1 «VI trt'i -y V*2" JUL 1996 26 0 1 67 Our experiments and trials to date have indicated that the present systems alleviates a long standing problem of "dry" spots in larger sized milk lines.

The washing system can be incorporated in existing plants with very little disruption.

Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof as defined in the appended claims. 11 26 0 167

Claims (5)

WHAT WE CLAIM IS:

1. A method of introducing into a milk line an intermittent flow of a liquid comprising the steps of accumulating a predetermined quantity of the liquid in an accumulator which is communicable with a source of air at atmospheric pressure and a source of air at a pressure lower than atmospheric pressure and periodically purging the accumulator utilising pressure differentials to accelerate the liquid and push it through said milk line via a connecting conduit said conduit having a spout which extends into the interior of the accumulator.

2. A method as claimed in claim 1 wherein the spout is provided with a pressure equalising orifice coincident with upper regions of the accumulator.

3. A method as claimed in claim 2 wherein the spout is sealed off as the liquid is being drawn into the accumulator whilst it is subject to partial pressure and the orifice provides for continuity of low pressure within the accumulator to allow it to fill to capacity prior to the introduction of air above the accumulated liquid.

4. A method as claimed in any one of claims 1 to 4 wherein the conduit has a connection to the milk line which is co-axial therewith.

5. A washing system for a milking apparatus including an accumulator having a washing water inlet and being connected to a milk line via a conduit, a source of low pressure air communicable with said milk line and a source of higher pressure air communicable with said milk line via the accumuIa^pMLNafctuator associated with the source of higher pressure air atfcpted to inject "*2311311896 ' ' A 12 26 0 167 higher pressure air into the accumulator at predetermined intervals wherein the conduit is of a lesser cross-sectional area than the accumulator, the arrangement and construction being such that when the milk line and accumulator are subject to a vacuum, washing water is drawn into said accumulator, said actuator can bp actuated to introduce higher pressure air into the accumulator to force the accumulated washing liquid from the accumulator into said milk line via the conduit. A washing system for a milking apparatus as claimed in claim 5 wherein said conduit includes a spout which extends into the interiors of the accumulator. A washing system for a milk line as claimed in claim 6 wherein the spout is provided with a pressure equalising orifice coincident with upper regions of the accumulator. A washing system as claimed in any one of claims 5 to 7 wherein the conduit has a co-axial connection with the milk line. A washing system as claimed in any one of claims 5 to 8 wherein an inlet orifice of the spout is of a similar diameter to the co-axial connection with the milk line. A washing system as claimed in any one of claims 5 to 9 wherein the milk line is substantially the same diameter as the accumulator. A method of introducing into a milk line an intermittent flow of a liquid substantially as herein described with reference to Figures 3 and 4 of the accompanying drawings. 26 0 167 A washing system for a milk line substantially as herein described with reference to Figures 3 and 4 ofthe accompanying drawings. NU PULSE NEW ZEALAND LIMITED ^2- JUL 1996 14