WO2001070622A1

WO2001070622A1 - Flow control apparatus

Info

Publication number: WO2001070622A1
Application number: PCT/GB2001/001230
Authority: WO
Inventors: Ian David Woodward; Derek Lionel Tyrrell
Original assignee: Waddington & Duval Limited
Priority date: 2000-03-20
Filing date: 2001-03-20
Publication date: 2001-09-27
Also published as: AU4091701A; GB0006744D0; GB2360513A

Abstract

Flow control apparatus for use in dispensing a liquid from a container comprising a body member defining a first opening for passage (12) the liquid to atmosphere and a second opening (36) for passage of the liquid from the container and having formed therein a flat spiral flow passage between the first and second openings. The body member comprises a first plate member having the first opening (12) therein and a second plate member engageable with the first plate member to bring a face of each member into contact. The faces, when in contact, define between them the second openig (36) and the spiral flow passage. The face of one of the plate members (10) is formed with an open spiral channel (36) and the face (28) of the other plate member is substantially flat.

Description

FLOW CONTROL APPARATUS

This invention relates to apparatus for dispensing liquid from a container, in particular one where the liquid to be dispensed is held in the container at a relatively high pressure.

Carbonated liquids such as beer, lager, cider, sparkling wines and carbonated soft drinks have to be maintained at relatively high pressures both during shipment to the market and in shops and normally also in the period between initial opening of their packaging and final consumption of all the contents thereof, to maintain the carbonation of the liquid at a palatable level. Barrels of lager and beer, as used in public houses etc, are provided with relatively sophisticated tapping devices to reduce the pressure of the liquid from this high level between the container and the tap outlet and thereby ensure that the contents are dispensed satisfactorily without producing an unacceptable amount of froth. With smaller containers it is equally as necessary to reduce the pressure of the liquid before it reaches the outlet to avoid decarbonisation and consequent frothing and unpalatability. One arrangement for achieving this reduction in pressure is to connect a length of small bore tubing to the inlet of the tap. To reach the tap the liquid must pass along the tube which causes its pressure to be reduced to an acceptable, near atmospheric, level when it arrives at the tap outlet.

With containers which are laid on their side on dispensing, the tube is generally allowed to hang free since the tube then dips to the lowest point ensuring that the full contents of the container is dispensed.

In one type of dispensing apparatus, an example of which is described in U.S. Patent No. 4739901, a multi-compartment pouch is provided in the container. The compartments of the pouch are filled with chemicals which produce gas, e.g. carbon dioxide, the arrangement being such that successive compartments are opened and filled with gas, so that they expand, as the liquid contents of the container are dispensed. In other forms of this type of arrangement the pouch is inflated by supply of gas from an external source. In either case, each time a compartment is opened and expanded with gas there is a chance that the bag will thrust against the tube. This can cause kinking of the tube which results in unsmooth flow to the tap and consequently uneven dispensing which is likely to lead to frothing. Moreover if the tube is bent at the point where it is attached to the tap there is a danger that flow along the tube may be blocked or that the tube may be fractured.

One solution which has been suggested to this problem is to fix the tube in a spiral coil around the tap inlet against the mount whereby the tap is connected to the container. This keeps the tube safe and makes the tap easier to handle as the tube does not dangle downwards therefrom. However assembling the tube into the coil and holding it in this position presents difficulties and adds to the cost of the tap.

U.S. Patent 5050806 discloses an arrangement where the tube is formed into a plurality of coils mounted either on the inside or the outside of the container. When the tube is mounted outside the container, a protective housing has to be provided.

It is also known to replace the tube by two members which together define between them the elongate small bore flow passage for reducing the pressure of liquid flowing therealong. The above mentioned U.S. Patent No. 5050806 discloses an embodiment of such a flow control apparatus in which a flow regulator is held within a hollow core member, the outer surface of the flow regulator and inner surface of the hollow core member defining between them the liquid flow path. The drawback of this arrangement is that the flow control apparatus protrudes into the container and so can interfere with liquid flow in its vicinity and also give rise to the risk of pouch damage with a dispensing apparatus of the type including a multi-compartment pouch.

It is an object of the present invention to provide a flow control apparatus for use with a container in which liquid is contained at a relatively high pressure, the flow control apparatus providing for dispensing of the liquid at relatively low pressure while maintaining the relatively high pressure in the container.

The present invention provides flow control apparatus for use in dispensing a liquid from a container comprising a body member defining a first opening for passage of the liquid to atmosphere and a second opening for passage of the liquid from the container and having formed therein a flat spiral flow passage between the first and second openings, wherein the body member comprises a first plate member having the first opening therein and a second plate member engageable with the first plate member to bring a face of each member into contact, and wherein the contacting face of one of the plate members is shaped and the contacting face of the other plate members is substantially flat, the shaping of the contacting face of said one plate member including an open spiral channel and being such that the faces, when in contact, define between them the spiral flow passage and the second opening.

By providing the flow passage in flat spiral form, the extent of protrusion of the body member into the container can be limited and hence too its effect on liquid flow in its vicinity and the risk of pouch damage in a container of the type including a multi compartment pouch. Furthermore, by forming the passage in a body member, it is not necessary to employ a small bore tube with its associated technical and high cost issues.

The use of plate members to provide the spiral flow passage minimises protrusion into the container, whilst making the face of one plate member substantially flat gives manufacturing cost efficiency since only one of the plate members has to have a profiled face and the other can be very simply formed.

Suitably the plate member with the open spiral channel is the second plate member and this is in the form of a disc. The disc can be, and preferably is, manufactured by injection moulding which is a cheap but effective way of providing the open spiral channel and hence the flat spiral flow passage. Furthermore, the use of a flat disc allows automatic handling and high assembly speeds.

The material chosen for the disc is suitably one which allows the disc to distort and take up any imperfections in the mating faces as well as accommodating deflections which occur in other components. The overall effect is good interfacial sealing between the disc and the first plate member so as to give the desired dispensing performance.

The flexural modulus properties of the disc and selection of material will depend on the pressures which will be experienced by the disc within the container during transit, storage and use. Suitable materials, the choice from which will be made according to the anticipated pressures, include metallocene polyethylenes, ethylene-vinylacetate copolymers, polyurethanes and other suitable thermoplastic polymers including thermoplastic elastomers based for example upon polyester-polyethers.

The spiral flow passage may have a constant or a varying cross- sectional area. The advantage of the latter is that it will enable modification to the dispensing characteristics. The dispensing characteristics will also depend on the cross-sectional shape of the spiral flow passage. This can be varied from near circular, oval, D to rectangular depending on the desired dispensing characteristics, in particular, frothing behaviour. The flow control apparatus may include at least one further plate member which is engageable with the body member, the or each further plate member defining, when so engaged, a further spiral flow passage and an inlet and an outlet arranged such that passage of liquid from the container to the spiral flow passage defined by the first and second plate members is via the further spiral flow passage(s). As the length of the flow passage travelled by the liquid between the container and atmosphere also affects flow and frothing, the provision of at least one further plate member allows the length to be increased to thereby fine tune performance. Preferably the further plate member is also in the form of a disc and the arrangement is such that the additional disc(s) can be stacked behind the first which retains the advantages discussed above of ease of manufacture and assembly and minimal protrusion into the container.

The flow control apparatus may form part of a tap for attachment to the container, the tap comprising an inlet and an outlet with the first opening of the flow control apparatus connecting to the inlet. The first plate member is suitable integral with the tap body which may be formed by injection moulding. As will be appreciated, the flow control apparatus could be provided separately or as part of the container but inclusion as part of a tap is particularly advantageous as it allows ready retrofitting of a container to provide flow control of liquid carried therein.

The invention will now be further described by way of example with reference to the accompanying drawings in which:

Figure 1 is a side view, partly sectional, of a tap incorporating a flow control apparatus in accordance with the invention;

Figure 2 is an exploded view of the parts of the tap of Figure 1 ; Figure 3 is a plan vies of a disc reducer forming part of the tap of Figures 1 and 2, and,

Figure 4 is a side view, partly sectional, of another embodiment of a tap incorporating a flow control apparatus in accordance with the invention.

The tap 2 shown in Figure 1 comprises a body 4, valve 6, button 8 and disc reducer 10.

The body 4 is formed from a plastic material for example polypropylene or a high density polyethylene and comprises an inlet 12 and an outlet 14 separated by a valve chamber 16.

The valve element 6 comprises a valve stem 18 with a flared mouth 20 which is shaped to seal with the body 4 around the inlet 12.

The other end of the valve stem 18 is provided with a stud 22 which is snap fit into a socket 24 provided in the button 8. The snap fit connection between the valve 6 and button 8 holds these two parts to the body 4 with the valve mouth 20 and part of the valve stem 18 extending through the valve chamber 16. The button 8 includes a flexible cap 26 which is deformable under manual pressure to move the valve mouth 20 out of the valve chamber 16, that is, to the left in the sense of the Figures, and thereby to open the inlet 12. The material of the cap 26 is sufficiently resilient that, on release of the manual pressure, the cap 26 returns to its original shape as shown in the Figures so drawing the valve stem 18, and hence the valve mouth 20 back to seal the inlet 12.

The body 4 has a portion around the inlet 12 which provides a flat annular surface 28. A flange 30 extends around the flat annular surface 28 to define a space for receipt of the disc reducer 10. The body 4 also defines a rim 32 around the flat surface 28 and extending parallel thereto by which the tap 2 can be connected to a container. The disc reducer 10 essentially comprises a circular plate which is formed on a face thereof with an open spiral channel 34. An opening 36 extending through the plate connects to the start of the open spiral channel 34.

When the disc reducer 10 is positioned against the surface 28 of the body 4 and within the annular flange 30, the open spiral channel 34 and flat surface 28 define together a flat spiral passage leading from the opening 36 to the inlet 12. When the tap 2 is fixed to a container, liquid within the container can flow along the flat spiral passage and out to atmosphere when the inlet 12 is open. The disc reducer 10 includes a recess 38 to accommodate the flared mouth 20 of the valve 6 on opening of the inlet 12.

In use, the tap 2 is connected to a container holding liquid at high pressure by the rim 32 or any other suitable connection device. When the button 8 is pressed to move the valve 6 and open the inlet 12, liquid within the container flows through the opening 36 and along the flat spiral flow passage defined between the open spiral channel 34 and the surface 28 until it reaches the recess 38 and passes through the inlet 12 and out of the tap 2 via the outlet 14. As the liquid flows through the flat spiral tube a pressure drop occurs and so the liquid dispensed from the outlet 14 is at lower pressure than that held within the container. Thus, undue foaming of the liquid is prevented.

The disc reducer 10 could be integrally formed with the body 4 or at least the inlet defining portion thereof. However for ease of manufacture it is preferred to form the disc reducer separately and this can be done, for example, by injection moulding of a plastics material. Another advantage of separate formation of the disc reducer 10 and from plastics material is that, by choosing an appropriate material, the reducer disc 10 may be capable of distorting and taking up imperfections in the surface 28 of the body as well as accommodating any deflections which occur in the body 4. The result is good interfacial sealing between the disc reducer 10 and the body 4 so as to give desired dispense performance. The sealing effect will be enhanced by the pressure of the liquid in the container which will force the disc reducer 10 against the surface 28 of the body 4.

The flexural modulus properties of the material for the disc reducer 10 required to give good sealing will depend upon the pressures which the disc reducer 10 will experience in the container during transit, storage and use. Suitable materials include metallocene, polyethylenes, ethylene-vinylacetate copolymers, polyurethanes and a number of thermoplastic elastomers, for example based upon polyester-polyethers.

The dispensing characteristics, in particular, the degree of foaming and/or frothing can be varied by varying the cross-sectional area and/or the cross-sectional shape of the flat spiral passage and therefore by varying the cross-sectional area and/or cross-sectional shape of the open spiral channel 34. Possible cross-sectional shapes include near circular, oval, D and rectangular, each of which will produce different foaming and/or frothing behaviour. The cross-sectional area can be varied by, for example, making this gradually reduce or include an intermediate smaller area section, and again this will cause a variation in foaming and/or frothing behaviour.

The length of the flat spiral passage also affects flow and frothing and so can be used to fine tune performance. The length is determined by the channel cross section and the land area between the loops of the open spiral channel 34. The maximum length of the spiral passage is governed by the diameter of the disc 10, channel cross section and the minimum sensible land width between the loops. If extra length beyond the maximum possible with a given disc is desirable, one or more additional discs can be stacked behind. This is illustrated in Figure 4 which shows a second embodiment of a tap 2A which has many features in common with tap 2 of Figure 1 and like reference numerals will therefore be used for like parts.

The tap 2A includes two reducer discs 10A and B. The first reducer disc 10A is similar in form to the reducer disc 10 of the tap 2 of Figure 1 but the outer wall thereof is elongated to provide an annular flange 40 for receiving and retaining second reducer disc 10B. The two discs 10A and 10B engage such that an open spiral channel 34A in the face of disc 10B which engages disc 10A is closed off to form a flat spiral passage having an inlet for liquid from the container, part of which is shown at 42 in Figure 4, and an outlet which leads to the inlet of the flat spiral passage in disc 10A.

In use, liquid from the container 42 flows along the flat spiral passage in disc 10B, back to the start of the flat spiral passage in disc 10A, along that flat spiral passage and thence to the recess 38. The form of the flow control apparatus, as one or more flat discs, allows the length of the flat spiral passage to be increased whilst still retaining the advantages of ease of manufacture and assembly as well as minimal protrusion into the container discussed above.

As noted, the tap 2A of Figure 4 has many features in common with tap 2 of Figure 1. The differences only will therefore be described. The first of these is that the body 4 of the tap 2A includes a finger stop 44 which facilitates the application of pressure on the button 8. Secondly a cap 46 is provided which, in combination with the rim 32, serves to hold the tap 2A to the upper end of the container 42. Furthermore within the valve channel 16 a guide sleeve 48 is formed for the valve stem 18 which ensures that this moves axially and that the flared mouth 20 consistently seals with the inlet 12.

The tap 2 or 2A provide for pressure reduction of high pressure liquid in a simple and cost effective fashion but will not affect fluid flow within the container nor give rise to any risk to a multiple compartment pouch carried by the container.

Although described above as forming part of the tap 2, it will be appreciated that the disc reducer 10 could be provided separately or as part of a container. As noted above, the flat spiral flow passage can be provided either within the disc reducer itself or, as in the illustrated embodiment, by forming the disc reducer with open spiral channel and using it in conjunction with another member which provides a flat surface which is overlaid across the channel. In the case where the disc reducer is provided separately or as part of the container, the other member can also be separate or part of a container.

Claims

1. Flow control apparatus for use in dispensing a liquid from a container comprising a body member defining a first opening for passage of the liquid to atmosphere and a second opening for passage of the liquid from the container and having formed therein a flat spiral flow passage between the first and second openings wherein the body member comprises a first plate member having the first opening therein and a second plate member engageable with the first plate member to bring a face of each member into contact, and wherein the contacting face of one of the plate members is shaped and the contacting face of the other plate members is substantially flat, the shaping of the contacting face of said one plate member including an open spiral channel and being such that the faces, when in contact, define between them the spiral flow passage and the second opening.

2. Flow control apparatus as claimed in Claim 1 wherein the said one plate member is the second plate member.

3. Flow control apparatus as claimed in either Claim 1 or Claim 2wherein the second plate member is in the form of a disc and the first plate member includes a flange around the face which contacts the second plate member, the flange being dimensioned to receive and hold the disc in position against the face of the first plate member.

4. Flow control apparatus as claimed in any preceding claim wherein at least one further plate member is provided which is engageable with the body member, the or each further plate member defining, when so engaged, a further spiral flow passage and an inlet and an outlet arranged such that passage of liquid from the container to the spiral flow passage defined by the first and second plate members is via the further spiral flow passage(s).

5. Flow control apparatus as claimed in Claim 4 when dependent on Claim 3 wherein the further plate member is in the form of a disc.

6. Flow control apparatus as claimed in either Claim 4 or Claim 5 wherein the disc is formed from a plastics material by injection moulding.

7. Flow control apparatus as claimed in any one of Claims 3, 5 or 6 wherein the dimensions of the disc and the material from which it is formed are such that the disc is deformable out of the plane thereof to accommodate deviations of the plate member with which it engages from planar and to seal thereagainst.

8. Flow control apparatus as claimed in any one of Claims 3 or 5 to 7 wherein the disc is formed from metallocene, polyethylenes, ethylene- vinylacetate copolymers, polyurethanes or a thermoplastic elastomer.

9. Flow control apparatus as claimed in any preceding claim wherein the spiral flow passage has constant cross-sectional area.

10. Flow control apparatus as claimed in any one of Claims 1 to 8 wherein the spiral flow passage has varying cross-section along the length thereof.

11. Flow control apparatus as claimed in any preceding claim wherein the spiral flow passage has a near circular, near oval, rectangular or D-shaped cross-section.

12. A tap for attachment to a container comprising a body having an inlet and an outlet and a flow control apparatus as claimed in any preceding Claim, the first opening of the flow control apparatus connecting to the inlet.

13. A tap as claimed in Claim 12 wherein the tap includes a body defining the inlet and the outlet and wherein the first plate member is integrally formed with the body.

14. A tap as claimed in Claim 13 wherein the tap body is a single member formed by injection moulding.

15. A tap as claimed in either Claim 13 or Claim 14 wherein the tap further includes a valve member for controlling the outlet.