CA2579182A1 - A flow-restricting conduit and methods for manufacturing and assembling same - Google Patents

Abstract

A conduit is provided that is adapted to pass a fluid there-through and providing a flow restriction across an operational pressure drop between a fluid inlet into and an outlet from that restriction. The conduit comprises a cooperative plurality of mutually inter-fitting longitudinal sections. One such section comprises a trough section emerging from a well body. The well body defines an inlet passage extending transversely into a junction between the inlet passage and the longitudinally-extending passage of the trough section. The inlet passage originates at an inlet opening into the well body from a free end thereof. A complementary cap section is adapted to overlay the trough section and the well body adjacent the junction in order to enclose the passages as a contiguous channel for the fluid to be conducted through the conduit.

Description

Field of the Invention The present Invention relates to the construction, assembly and use of flow restricting conduits, particularly In relation to gas in liquid solutions and especially In beverage dispense applications - lnciuding without limiting the generality of the foregoing, the dispense of beer In short-run dispense Installations/appliances as for example, In the case of domestlc draft beer dlspensing systems.
8ackground of the Invention WO 2004 050535 relates to a conduit for conducting gasified 'Itquld, which has a flow restrictor arranged ln in-line relation therewith. The restrictor itself comprises an at least one aperture (although two or more can be used In series), with each such being adapted to pass the gasifled liquid flowing through the conduit and across a pressure drop from a higher-pressure upstream side of the aperture to a lower-pressure downstream side of the aperture. The aperture is operable to moderate the rate of change In pressure over a transltlonal pressure drop to mitigate the formation of localized pressures below a critical pressure at which off-gassing from the carbonated IiquCd results in substantial foam formation. The.condult may take the form of a dispensing tube for use in dispensing an aicohoiic beverage from a keg, the tube having a flexible wall deformable under the Influence of a restricting actuator to control the partial collapse of the wall and thereby form the restrictor. The tube or flow diameter downstream of the restrictor only gradually or slowly increase5.

WO 2006 082486 also relates to a conduit that is adapted to pass a fluid there-through and provides a flow restriction across an operational pressure drop between. a Ilqutd Inlet Into and an outlet from that restriction. However, unlike the previousiy mentioned patent, the conduit of WO 2006 082486 comprises a cooperative plurallty of mutually Inter-fitting longitudinal sections of an elongated tubular body enclosing a Iongltudinally-extending passage for the fluid to pass between respective mutually opposed surfaces thereof. The surfaces are conformed so that with the sections arranged in conjoined relation and the portions engaged In cooperatlve inter-fitting register, the flow restriction Is defined between the respective conformed surfaces. Thls prior art reference correctly points out that the production of flow-restricting conduits for conducting fluids there through, can be problematic. Ease/cost of manufacturing and the requlsite shaping/preclsion for the flow restriction surfaces can be at odds wlth the demands of the commercial application - especially In cases where disposable conduits are employed to conduct less than perFectly stable gas In liquid solutions, (as can be the case for example In domestic beer dispense -appliances where room and beer temperatures can be both wlde ranging and varlable).
Notwithstanding the Improvements associated with the last above mentioned patent, there continues to be a need in the art to provide further Insights and related Improvements in and Into flow restricting assemblies to deal with a multi-phase solution (especially gas In Iiquld solutions under relatively unstable conditions). This is especially the case In dealing with the particularly problematic Issues surrounding the dispense of beer from a keg system, and finally, in "short-run" beer dispensing appliances. More particularly, this Includes a need to provide an alternatlve to a current method for the construction/
assembly. Cost reduction Is absolutely criticai to the commercial utility of these assemblles.

Summary of the Inventlon:

Broadly speaking, the present Invention relates generally to a conduit, adapted to.pass a fluld there-through and providing a flow restriction across an operational pressure drop between a fluid Inlet Into and an outlet from that restriction.
More partlcularty, the conduit comprises a cooperatlve plurality of mutually Inter- fitting longitudinal sections of a longltudlnally-elongated tubular body. Those sections are adapted to enclose a longitudinally-extending passage for the fluid, between respective mutually opposed surfaces of those sectlon's.

These respective mutually opposed surfaces are conformed so that, (with the- sections arranged, In mutually conjoined relation), the flow .
restriction is defined between the respective conformed surfaces.
1s More particularly, the present Invention relates to a conduit, adapted to pass a fluid, (and especially liquids), substantially as hereinbefore described, but whereln the conduit comprises:
~ a trough section emerging from a well body, which well body defines an inlet passage extending transversely from a junction between said inlet=passage and said longitudinally-extending passage, from Its origins at an Inlet opening into said well body;
and, ~ a cap section adapted to overlay said trough section and sald well body adjacent sald junction to enclose sald passages as a contiguous channel for sald fluid to pass through sald conduit.

In a preferred form of the present inventlon, the flow restriction Is a flow restrlcting venturi-type constriction within the passage. In the case of the present Invention "venturt type" flow constriction does not necessarily mean a tube In wh(ch pressure drop Is used to measure fluid flow, as is sometimes more generally the application of a venturi in the art. For the present purposes however, a venturl Is a tube with a tapering constriction that causes an increase In the velocity of flow of a fluid and a corresponding decrease In fluid pressure. Although this type of tube can useful In measuring fluid flow or for creating a suction (as in applications for driving aircraft instruments or drawing fuel Into the flow stream of a carburetor), the use of a venturl- type tube in the context of the present invention ls focused on managing the pressure transltion of a fluld across the above-mentlonedd tapering constriction, More precisely, the term as used herein refers to a tube which provides,for convergent flow between tapering sldewalls on an upstream slde, followed proximately (but not necessarily Immediately), by divergently tapering sidewalls downstream thereof. Additionaily, as in, for example, the instance of a beer dispense system (such as is described more elaborately elsewhere herein), the application of thls venturi-type tube collaterally manages the delivered volumetric flow rate through the tube from a relatively high upstream supply pressure, to a relatlvely low pressure downstream of the tube.

In a particularly useful application of the present inventlon, a condult, Is adapted to pass a gas-in-liquid solution (such as a'Tcarbonated"
liquid, for example) there through. In this appllcation the conduit is adapted to provide a flow restricting venturi for mitigating, whether In whole or at least in part, against foam productlon dur(ng the transit of the carbonated llquid across an operational pressure drop between a liquid inlet into and an outlet from sald venturi. This application of the Invention Is particularly concerned with liqulds that hold gas In solutlon theretn, in such proporttons that the gas can be fairly readily released there from. Typical examples might be carbonated soft drinks, but In particuiar, many beers contain soluble gases such as carbon dioxide and/or nitrogen, and these two fall within the Intended scope of this application of the present inventlon.

Preferred Embodiments of the Present Invention:
A preferred embodiment of the present Invention comprises a beverage dispense system that in combination, adapted to pass a beverage from a reservoir to a dispensing tap, across a pressure drop there between, and In particular through a conduit adapted to pass a fluid there-through and providing a flow restrlction- acrossan operational pressure drop between a fluid iniet.lnto and an outlet from that restriction. In general, in this embodiment, the conduit comprises the previously described cooperating sections form an enclosed, longitudinally-extending passage for the fluid to pass between respective mutually opposed surfaces of those sections. More specifically the respective mutually opposed surfaces are so conformed as to provide, (with the sections arranged In conjoined relation and the portions engaged In cooperative lnter-fitting register), for the venturt type flow restriction between these respectively conformed surfaces.
Beer, (however 1t may have been packaged), typically contains greater or lesser amounts of dissolved gases (in most cases, carbon dioxide, but In some cases also nitrogen, or mixtures of nitrogen and carbon dioxide). The dissolved gas and the change 1n partlal pressures that usually occur when the beer is poured from Its primary packaging, results in the production of foam. In some measure, this can be a deslrable outcome: the "foam head" of.a beer is considered by many to be aesthetically pleasing part of the overall beer experience with ' considerable science and poetry having been devoted to its description and merits.
Ironically, what makes beer so special to its adherents, poses spectal problems, (or at least manlfestly exacerbates these problems), in the management of Its dlspense. Soft drlnks are not nearly so sensltlve -with the constituency of- beer being ever so much more inherently and signiflcantly sensitive to foaming Issues, in part because of the higher C02 content and more particularly because of the protein and carbohydrate constituents. In dispensing beer using any of the so-called draft (or draught, or keg beer) systems, the production of foam can be partlcularly problematic. The dlfflculty can arise for a number of reasons, but In particular, there is a need to manage the pressure durfng dispensing of the beer so that the amount of foam that Is produced does not become excesslve.

Managing the pressure In this sense comes down to managing transitions in the degree and rate of change of partial pressures of the dissolved and un-dissolved gas (or gases as the case may be), as the beer Is. dispensed from a higher packaged gauge pressure to a lower ambient gauge pressure. A so-called "balanced" dlspense system is required to achieve these ends.
In a "balanced" beer dispense system, the beer can be served with close to the dissolved gas levels at which it was produced, with expected .losses glven over to the production of approprlate and expected amounts of foam in the beer's "head". The kinesthetic and organoleptic properties of the beer are'in this sense, not compromised by the dispensing operatlon. The balance of the dispense pressures that are needed for -this purpose, Is accommodated by, using sufficient flow restrictlon In the dispense line such that the velocity at the faucet Is reasonable while the loss of dissolved gas or gasses remains within the bounds of expectations. Line length, diameter, and flow restrlctions such as in-line venturi-type flow constriction. For the purposes of the present invention, the overall design and operation of an appropriateiy balanced beer dispense system Is, In general, well within the skill of persons skilled In the beer dispense art.
Accordingly, the present Invention is particularly concerned with the application thereof in reiation to the dispense of beer. In that, connection and in a particularly preferred form of the Invention, the condult as.varlousiy described herein before, is an inexpensive, plastic disposable device - and Is embodied as a cartridge that is adapted for use in a beer dispense appliance, Including In partlcular such devices as are useful In home dispense applications. Note that the Importance, if not the critlcallty, of flow restrlctlon design and performance is most acute in "short-run" appllcations, such as those that arise In such beer dispense appliances. Short-run in this sense refers to the physical distance over which the beer makes Its way from the beer reservoir (typically a keg of some descriptlon or another), and the dispensing tap. The shorter the distance, the less the inherent moderation in changes In the pressure to which the beer Is exposed, and hence the greater the need for pressure management by way of flow constrictions such as that of the present invention, A short run in this sense would be less than a meter or so, and typically half a meter or $

less, down to as short as a third of a meter or even slightly less - say In. the range of as little as four to six Inches in length.

Tntroduction to the Drawings:
In the foiiowing detailed description of various aspects of the present Inventlon, reference will be made to the appended drawings, In which:
Figure 1 of the drawings depicts an exploded elevated perspective view of the top side of trough and cap sections;
Flgure 2 of the drawings deplcts an exploded elevated perspective view of the underside of the trough and cap sections; and;
Flgure 3 of the drawings Is a cross-sectional view of the assembly of the trough and cap sectlons, exposing the interior of the interior fiuld conducting surfaces of the conduit, and the venturi features thereof.

Referring now to the drawings In general, there is illustrated a condult 1, adapted to pass a fluid there-through and providing at least one flow restriction, (e.g. F'i), across an operational pressure drop between a fluid outlet 2 from and an inlet 3 into conduit 1.

Condult icomprises a cooperative plurality of mutually Inter-fltting longitudinal sections 4 adapted to enclose a Iongitudinally-extending passage 5 for the fluid, between respective mutually opposed surfaces (4a and 4b) which are conformed so that, with sections 4 arranged In mutually conjoined relation, flow restriction i;1 is defined between surfaces 4a and 4b.

Sections 4 include:
m a trough section 6 originating from a well body 7 which defines an inlet passage 8 extending transversely from a junction 9 between iniet passage 8 and longitudinally-extending passage S. Inlet passage 8 originates at inlet 3 In an opening Into well body 7.

and, ~ a cap section 10 Is adapted to overlay trough section 6 and well body 7 (adjacent junction 9), so as to enclose passages 5 and 8 as a contiguous channel In which fluid can be conducted through said conduit 1.

zn the preferred embodiment deplcted In the drawings, flow restrlction Fl includes a flow restricting venturi-type constriction within longitudinally extending passage S.

A valve actuating pin with a downstream flow relaxing extension F2 is provided at inlet 3. The actuating pin operates a valve when the inlet is engaged with a dispense system. Extenslon F2 is a conical shaped body arranged centrally within the inlet opening 3, and Is supported there on a bridge 11 (see Figure 2) extending across the opEning Inlet 3.

Trough section 6 comprises a beam structure Including a pair of generally parallel rails 12a and 12b, between which a web 13 is supported. Surface 4a Is formed In the upper side of web 13.

5-Cap section 10 comprlses a pair of generally parallel guides 14a and 14b, that are adapted to be Interfittingly recelved within trough 15 In trough section 6, and to thereby not only form at least a portion of longitudinally extending passage's (5) side walls, but to facllitate aligned assembly of the trough and cap sections 6 and 10.
A peripheral groove 16 surrounds trough 15 on trough section 6, and a complementary and coextensive tongue 14c, is provided on cap section 10 - and their cooperation facilitates the joining of the two sections together.
In additlon, radiused tab 17 on cap section 10 is adapted to engage in fitted relatlon Into a correspondingly radiused tab receiving slot 18 In trough section 6. The radius affords a rotational degree of freedom when the tab is first engaged In the slot and provides a polnt of contact around which the two sections can be rotated relative to one another, until guides 14 a and 14b can be allgned with and inserted into the trough 15. This greatly facilitates the assembly operation.
The conduit according to the present lnvention is particularly well suited to applicatlon In dispensing systems such as that described In the aforesaid WO 2004 050535. Moreover, the present invention provides for fewer parts and a simplified assembly relative to the conduit described In that patent document, and at about one half of 1]

the materials cost. All together, this results in a substantial per hectoliter costs savings In the aforesaid appllcation

Claims (2)

1. A conduit, adapted to pass a fluid there-through and providing a flow restriction across an operational pressure drop between a fluid inlet into and an outlet from that restriction:
~ said conduit comprising a cooperative plurality of mutually inter-fitting longitudinal sections adapted to enclose a longitudinally-extending passage for the fluid, between respective mutually opposed surfaces conformed so that, with the sections arranged in mutually conjoined relation, the flow restriction is defined between said surfaces;
~ said sections comprising:
~ a trough section originating at a well body which defines a inlet passage extending transversely from a junction between said inlet passage and said longitudinally-extending passage, from its origins at an inlet opening into said well body; and, ~ a cap section adapted to overlay said trough section and said well body adjacent said junction to enclose said passages as a contiguous channel for said fluid to be conducted through said conduit.

2. The conduit according to claim 1, wherein said flow restriction is a flow restricting venturi-type constriction within said longitudinally extending passage.