GB2642318A - A gas infusion device for a beverage dispense system - Google Patents

Abstract

A gas infusion device 19 comprises a liquid inlet 18, a gas inlet 20 and an elongate blending chamber 28 for mixing liquid and gas, i.e. to create a gas infused beverage flow stream with reduced bubble sizes. At least one constriction feature 29 is arranged within the chamber 28 downstream of gas injection; the feature including an aerodynamic body, e.g. teardrop shape (30, fig 4), for directing the gas-infused liquid flow toward a wall of the chamber 28. An orifice/opening (31, fig 4) which may be downstream of the body (30, fig 4) is provided for directing liquid flow back toward a centre of the chamber 28. The aerodynamic body (30, fig 4) and orifice (31, fig 4) of the construction 29 have the effect of reducing the bubble size of gas infused into the beverage. The tail end of the aerodynamic body (30, fig 4) may overlap with the orifice (31, fig 4) and be supported by at least one radial leg (32, fig 4) which extends forwardly from the orifice (31, fig 4).

Description

[0001] A gas infusion device for a beverage dispense system

[0002] Technical field

[0003] The present invention relates to a gas infusion device for a beverage dispense system. The infusion device is particularly suited for use in the delivery of pre-mixed cocktails.

[0004] Background to the invention

[0005] Draught dispensing systems in a commercial environment can take many different forms. A common solution is to pump beverage from a large container such as a keg, e.g. located in a basement, to a bar-top dispense tap via a supply line. For the dispense of smaller volumes of beverage, so-called "Bag-in-Box" (BiB) containers may be used, i.e. a type of container for the storage and transportation of liquids consisting of a bladder, often made of several layers of metallised film or other plastics, housed inside a box of corrugated fibreboard or the like. The bag may feature a simple plastic tap or coupler that, for commercial use, may be connected to a supply line of a dispenser, via a pump, which drains the contents (deflating the bag) when the dispenser is activated, until empty. A replacement BIB is then connected to the supply line while the empty container is removed and separated for recycling, disposal, etc. A particular form of draught system, suited for dispense of cocktails that are also required to be infused with a gas (i.e. carbon dioxide or nitrogen) which imparts bubbles/fizz into the beverage to form a foamy head, is disclosed by GB2584736. Such a system is effective, but is comprised of many parts requiring complicated assembly and instructions for use.

[0006] Infusing gas into beverages, primarily nitrogen and carbon dioxide, can elevate the flavour and texture of the beverage, creating a desirable product that looks and tastes more appealing. For CO2 infusion there are various methods, such as a carbonator bowl (being a large appliance that forces CO2 into the liquid under high pressure) but this is an expensive option. Another option is to hold CO2 and the beverage in a sealed vessel under pressure for multiple hours to allow it to absorb into the liquid, but this method is time consuming.

[0007] Inline infusion is common for nitrogen infused beverages to create a crema/head that enhances the flavour, texture and visual appeal of the beverage. Such infusers have a smaller footprint than the options above, are generally quicker to produce results, and are used for nitro coffee to give a silky crema or in cocktails to replace the use of egg whites in producing a crema. However, an issue with many nitrogen inline infusers is that the quality of the crema produced is inconsistent and can breakdown quickly (e.g. due to large bubbles), resulting in a pitted and undesirable crema. Further, when used in a carbonation context, inline infusers typically do not achieve the same level of carbonation and will produce a beverage with a lower resultant concentration (g/L) of CO2.

[0008] Examples of prior patent publications that disclose gas infuser devices include U59227161, EP3505487A1 and US5863128.

[0009] Summary of the invention

[0010] The invention seeks to provide an improved gas infusion device, particularly suited for specialty drinks such as cocktails. At the least, the invention provides an alternative for users of such infusers and associated systems.

[0011] In one aspect as outlined in claim 1, a novel gas infusion device is described. It may broadly comprise a beverage inlet for connection to the beverage/product line, a gas inlet for connection to a gas line supplied with gas from at least one gas source, and an outlet for the gas-infused beverage. The beverage inlet communicates with a Venturi section where a beverage flow channel narrows to a constricted portion and subsequently, downstream thereof, widens to a widened portion. The gas inlet communicates to supply gas to the Venturi section, for mixture of the gas with the beverage at the constricted portion thereof.

[0012] In this way, as the liquid flows into the Venturi constriction it experiences negative pressure due to the Bernoulli effect and draws in/mixes with gas from the gas inlet. In one form, the gas inlet is positioned at an angle to the constricted portion/beverage flow channel, e.g. at least 40 degrees up to perpendicular, preferably 40 to 75 degrees, most preferably 45 degrees. Such a configuration reduces the footprint of the device. Beverage is prevented from backflow into the gas line by the one-way valve as described above. An orifice or other flow-regulating element may be incorporated into the gas inlet. Beverage may also be prevented from backflow into the product line by placement of a one-way valve at or upstream of the beverage inlet to the gas infusion device.

[0013] Downstream of the widened portion of the Venturi section, according to the invention, a blending chamber comprises at least one, preferably two, constriction feature(s) (e.g. in series) that facilitate further mixing of the liquid and gas. The widened portion of the Venturi section and the blending chamber may be continuous and/or of the same cross-sectional area. The constriction feature(s) function to reduce the bubble size (smaller bubble size being associated with achieving a longer-lasting and more visually appealing crema) and aid mixing. A constriction feature preferably includes a leading aero/hydrodynamic surface (such as a spherical/half-spherical face) at an upstream end thereof. In one form, the aerodynamic constriction includes a body arranged concentrically, within the flow path, at a longitudinal axis of the blending chamber.

[0014] For the avoidance of doubt, the terms "aerodynamic" and "hydrodynamic" herein are used interchangeably to refer to the general property of the feature having a shape which reduces/mitigates the drag from fluid moving past said feature.

[0015] According to the configuration described above, as the liquid and gas (preliminarily mixed within the Venturi section which produces relatively large bubbles) flows into the blending chamber, the mixture encounters an aerodynamic constriction which is configured to reduce the bubble size, resulting in an improved mixture for subsequent head formation of the delivered beverage in a drinking vessel.

[0016] The aerodynamic feature may be a solid body suspended in the flow path (i.e. concentrically at the centre thereof to effectively form a ring-shaped cross section for the flow path). The feature is preferably as aerodynamically efficient as possible, e.g. a teardrop shape, that directs fluid between itself and a cylindrical wall of the blending chamber to reduce average bubble size in the mixture. An annular gap for accommodating the mixed flow therethrough, i.e. between the aerodynamic body and wall, may be between 0.3 to 1.2mm. In one form, the constriction feature has radial legs at its trailing/downstream end that attach/suspend the body centrally within the liquid path, i.e. to form a symmetrical ring-shaped/annular restricted/constricted opening (when viewed in cross section).

[0017] A surface of the body may comprise concave dimples, spaced about the teardrop, e.g. where its circumference is largest. Such features are similar to dimples on a golf ball, and serve to reduce turbulence and allow the mixture to maintain speed as it flows over the surface of the body. As the mixture of liquid and gas bubbles is forced around the annular constriction, the bubbles in the liquid are reduced in size.

[0018] In one form of the constriction feature, a secondary cylindrical/ring-like constriction is provided at the tail/downstream end of the aerodynamic constriction portion. The secondary constriction may have an angled/smoothly curved face around its entrance to aid flow and reduce turbulence, allowing the liquid to pass through at high speed. A downstream portion of the cylindrical constriction may have a 90-degree face where the blending chamber immediately expands/returns to its full circumference. This dramatic change in channel diameter causes the liquid pressure to drop resulting in turbulence which further infuses the liquid with gas while maintaining the smaller bubble size.

[0019] In broad terms, the constriction feature of the blending chamber may be comprised of an aerodynamic portion and an orifice portion, downstream thereof. The aerodynamic portion may be a smooth walled body supported centrally within the blending chamber. A tail end of the body may overlap into the orifice.

[0020] In a preferred form, the mixture may then pass serially through a second constriction feature in the flow path of the blending chamber, having the same features described above. Alternative constriction features and/or a third or further constriction features as described above may be arranged in series within the flow path of the blending chamber.

[0021] An infuser according to the foregoing disclosure has resulted in carbonation levels within water that are between 6g/L and 7 g/L, a marked improvement over existing inline infusers that are generally capable of achieving carbonation levels of up to 5.5g/L (significantly below which may give the liquid a "flat" mouthfeel).

[0022] The relatively small size of an infuser device as described herein (aided by the angle of the gas inlet at its connection to the constricted portion/beverage flow channel) is particularly suited to inline infusion since it can be easily incorporated into liquid lines without having to modify the lines or add extra / bespoke insulation. It is significantly smaller than existing inline infusion devices making it more versatile and offering a cost saving in terms of less material and parts used to manufacture it. It also contributes to a reduced footprint for the dispense system as a whole, which enables the components to be accommodated within a smaller casing or container. This increases the ease installation and improves mobility for the dispense system, allowing the entire system (and not just the dispense tap) to be located on, and moved around, e.g., a bar-top.

[0023] In a particular form, the relative dimensions of the gas infusion device and its constriction feature may be as follows: 1. Gas inlet: 0.8 to 1.6mm at point of injection, preferably 1.2mm; 2. Venturi section constricted portion: 1.8 to 2.8mm, preferably 2mm; 3. Beverage inlet diameter, prior to constricted portion: 3 to 6mm, preferably 5mm; 4. Blending chamber diameter (CD): 3 to 6mm, preferably 4 to 5mm; 5. Tear drop body diameter maximum (TBD) = CD minus 1 to 2mm (i.e. annular opening of 0.5 to 1mm clearance between the tear drop body and blending chamber wall), or, preferably, a maximum diameter of TBD is 3.25mm; 6. Tear drop body longitudinal length (TBL) = 5 to 15mm, and there may be different lengths thereof, e.g. a first tear drop of 7.25mm and a second one of 8.75mm; 7. Secondary downstream constriction (of the same constriction feature), e.g. orifice, diameter (SCD) = TBD minus 2 to 3mm (i.e. the downstream constriction/orifice is a round centred opening measuring less across than the maximum diameter of the tear drop body in front of it. The teardrop may overlap into the constriction at its narrow end). The SCD may be, by way of example, 2.7mm.

[0024] It has been found that an infuser according to the foregoing disclosure, tuned for use with a carbon dioxide gas input, will generally also perform for infusion of nitrogen gas/air.

[0025] The infuser device may be positioned in any orientation (e.g. vertical, horizontal or angled) and is preferably positioned in-line close to (or incorporated with) the dispense fount where it maximises the effectiveness of the infusion technology (due to shorter distance travelled to dispense), maintaining consistency of both delivery and temperature.

[0026] An example of draught beverage dispense system is also described herein, as useful to understand a use case of the gas infusion device. The system broadly comprises: a beverage/product line for connection at an upstream end to a beverage storage container, a liquid pump configured to pump beverage through the product line, optionally via a cooler, a gas infusion device for connection to the product line at a downstream end, and a dispenser device (e.g. a lever operated tap) for dispense of gas infused beverage provided from an outlet of the gas infusion device.

[0027] As it relates to the system, the gas infusion device comprises a beverage inlet, for connection to the product line, and a gas inlet for connection to a gas line supplied with gas from at least one gas source. The gas inlet or gas line comprises a restrictor/regulator (i.e. a gas flow-regulating constriction) and a one-way valve configured to permit gas into the gas infusion device while preventing backflow of beverage into the gas line. In this way, the constriction (e.g. in the form of a single orifice through which gas flows, that is from 0.2 to 0.6 mm, preferably 0.4 mm, in diameter) may regulate the gas flowing through the gas line to maintain pressure at a constant value into the infusion device. Flow rate may be varied by control of the at least one gas source while the proportion of gas mixed into the beverage may be controlled by pressure and flow of the beverage, via the liquid pump. Use of a fixed restriction/orifice replaces the need for a needle valve that would need to be manually adjusted and set to a required aperture to adjust the gas flow rate, and is prone to error or loss of calibration (affecting the quality of the dispensed beverage). Notably, the beverage supplied from the storage container preferably has no dissolved gas in solution, i.e. is flat, suitable for a bag-in-box solution.

[0028] In embodiments, a controller is provided for control of signals/power to the liquid pump (e.g. being an electric pump), configuring same for variable flow rate of the beverage flowing in the product line and into the gas infusion device. The controller may also be configured to control gas flow rate in the gas line (e.g. via an electric air pump or control of a release valve on a gas cylinder) and into the gas infusion device. In this way, gas infusion to the beverage is electronically controllable for accurately determining a height/depth of a creamy head formed upon a dispensed beverage. The motive form of energy for the liquid pump may be electricity, but alternatives may be possible -so long as accurately controllable by the controller to determine flow rate therethrough. The controller is preferably configured to detect or cause actuation of the dispenser, thereby activating the liquid pump to deliver beverage through the system at a (pre)determined flow rate. Infused beverage flow rate through a nozzle of the dispenser will be dependent on pressure in the system; i.e. product delivery to a drinking vessel may be faster for a carbonated beverage than a nitrogenated beverage.

[0029] The system may generally incorporate a plurality of sensors for assisting controller function. For example, flow sensors and temperature sensors installed within the product line for monitoring performance of the liquid pump (and optionally an electric air pump) and cooler.

[0030] Head height or carbonation may be adjusted (e.g. set) by control of the liquid (and optionally gas) flow rate as controlled by the liquid pump (and optionally the electric air pump or release valve on a gas cylinder) via the controller, e.g. triggered by actuation of the dispenser, while the gas pressure remains constant. Liquid flow rate and/or pressure is adjustable by control of voltage (and/or current) to the liquid pump, while gas flow rate is adjustable by control of voltage (and/or current) to the electric air pump. Liquid flow rate and/or pressure, and gas flow rate, may need to be varied in order to optimise infusion for the type of gas that is being infused. Different pumps will require the system to be calibrated for use therewith, to ensure consistent results. In some forms, a signal from a controller may activate the liquid pump to deliver a preset volume of beverage or time period of pour to a drinking vessel, infused with gas according to a required head height.

[0031] In embodiments, there are two gas sources selectably connectable to the gas line, e.g. via a valve at a y-connector, being a junction valve between the two gas sources and gas line to the infuser. In this way, a branch to a desired gas source can be selected for connection to the gas line and, subsequently, the gas infusion device. In a particular example, a first gas source is carbon dioxide (e.g. delivered from a pressurised canister) and a second gas source is air (e.g. predominantly nitrogen delivered by an air pump from the atmosphere).

[0032] Selection between first and second gas sources may be manually or electronically switchable (e.g., by a solenoid) at the y-connector/junction valve with the gas line. In principle a third or further gas source/branch could be selected as a gas feed to the infuser.

[0033] According to the foregoing, a user of the system can select an appropriate gas for infusion which will depend on the guidelines for dispense of the beverage to be delivered from a particular container, which may vary seasonally or geographically.

[0034] In this way, a single dispense tap may be reconfigured for delivery of several beverage types. Preferably, the product line will be cleaned/purged when switched over to a new beverage type. Notably, the system is configurable to operate at different pressures, depending on the gas selected. It is generally known that infusion of CO2 into a liquid requires a higher pressure than the infusion of nitrogen, and, as mentioned above, it is intended that the pressure setting of the gas is maintained at a constant value, via a constriction of known diameter in the gas line, determined during development. The main variable operating parameter, for affecting crema height and quality, is the flow rate/pressure of beverage through the product line. It is noteworthy that the disclosure may seek different effects depending on the gas selected, i.e. the infusion of CO2 is primarily for the purpose of making the beverage fizzy, whereas nitrogen is infused for creating a desirable/aesthetic creamy head.

[0035] A lower pressure is needed to achieve a crema in a nitrogenated beverage where the smaller bubbles float to the top to create the head. In the case of COP, the intent is to produce a fizzy beverage out of the dispenser and a higher pressure is required to do this.

[0036] In embodiments, the product line passes through a cooler device. As such, the beverage is cooled on its way to the dispenser, from an ambient temperature when resident in the storage container (e.g. bag-in-box). The cooler may be a dry block cooler, i.e. a block of metal maintained at a stable temperature through which the beverage is routed (before or after gas infusion). The block receives a coolant through a coolant line isolated from the product line, and thereby serves as a heat-exchanger. It is preferable with CO2 infusion that the liquid is cooled, but less important for Nz.

[0037] It is noteworthy that, at least for N2, it is preferable to have the infusion device located just before the tap, since if infused liquid is left in the line it can affect head quality when it is dispensed.

[0038] In embodiments, the gas infusion device is an inline infuser comprised of a Venturi chamber for mixing gas with beverage passing through the product line. When the liquid path is narrowed by a constriction (at which the gas inlet is located), the flow rate speeds up in this section creating lower pressure and thereby drawing the gas into the gas infusion device and mixing it with the beverage.

[0039] The current disclosure outlines an improvement/optimisation over existing inline infusion methods, preferably resulting in carbon dioxide infused products with a higher g/L CO2 concentration, and nitrogen (the dominant gas in atmospheric air) infused products with a consistent, dense, higher quality crema comprised of micro bubbles that are long lasting and visually appealing.

[0040] In one form there are at least two product lines, each requiring a dispense tap, infuser, liquid pump and beverage container in line therewith. The lines may share a cooler and associated coolant send line and return line.

[0041] In one form the coolant may be driven to a dispense tap (i.e. within a python) by an electric recirculation pump situated in the cooler. The pump may be powered as part of the total cooler unit and also agitates/stirs the coolant in a bath of the cooler to achieve a more even temperature throughout for surrounding the stainless steel coils that hold the product being cooled. However, by virtue of the reduction in the footprint of the system as a whole (including by reducing the size of the gas infusion device), the various components of the system (including the cooler) can be located, for example, in a single casing or container on the bar-top (and therefore closer to the dispense tap). With a reduced distance for the cooled beverage to travel before dispense, the need to cool the dispense tap is reduced.

[0042] Brief description of the drawings

[0043] Figure 1 illustrates a schematic view of a draught dispense system; Figures 2 and 3 illustrate side and perspective longitudinal section views of a gas infusion device; Figure 4 illustrates a detailed perspective view of a constriction feature incorporated into the gas infusion device; and Figure 5 illustrates a further side section view of a gas infusion device.

[0044] Detailed description of the invention

[0045] Advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings that illustrate various embodiments of the invention. However, the scope of the disclosure is not intended to be limited to the precise details of the embodiments, with variations apparent to a skilled person deemed

[0046] also to be covered by the description.

[0047] Furthermore, terms for components and materials used herein should be given a broad interpretation that also encompasses equivalent functions and features. Descriptive terms should also be given the broadest possible interpretation; e.g. the term "comprising" as used in this specification means "consisting at least in part of" such that interpreting each statement in this specification that includes the term "comprising", features other than that or those prefaced by the term may also be present. Related terms such as "comprise" and "comprises" are to be interpreted in the same manner. Any directional terms such as "vertical", "horizontal", "up", "down", "upper" and "lower" are used for convenience of explanation and are not intended to be ultimately limiting if an equivalent function can be achieved with an alternative dimension and/or direction as broadly interpreted according to a doctrine of equivalents. Furthermore, the present description refers to embodiments with particular combinations of features, however, it is envisaged that additional combinations and cross-combinations of compatible features between embodiments will be possible. Indeed, isolated features may function independently from other features and not necessarily be implemented as a complete combination.

[0048] Figure 1 illustrates a draught dispense system 10, e.g. of a scale to be positioned on top of a bar/countertop or similar location. In use, the system is configured to supply a pre-mixed beverage supplied in a specific volume, e.g. from a Bag-in-Box (BIB), container 11. In the illustrated embodiment there is one beverage type deliverable by the system at any one time. A second container (not shown) could be connected/switchable in parallel into the system or, more likely, used to replace the first container 11 when empty. In other words, the system can be configured to accept different beverage types and/or replacements of the same type, determined by the contents of the container 11. Figure 1 shows a single line system, but there can be multiple isolated lines on the system all using the same cooler.

[0049] Beverage is supplied from container 11 through a beverage line 12, motivated by a liquid pump 13, e.g. an electric pump suitable for pumping liquid such as a peristaltic or diaphragm pump. For the purposes of explanation, beverage line 12 is a continuous conduit for enabling flow of beverage between an origin (e.g. the container 11 stored out of sight of a customer) and destination (e.g. ultimately a dispenser tap 14 located on a bar top or the like and/or attached to a casing containing the draught dispense system), however, it may in practice be divided into multiple sections, such as a first length connected from the container 11 to liquid pump 13 and a second length connected from liquid pump 13 to a cooler 15, etc. Cooler 15 may be a block cooler supplied with coolant through a send/return coolant line(s) 16 from a compressor 17, however, alternative configurations are possible. Preferably, the cooling device is located toward a dispense end of the line/system, so that the cooled beverage does not have far to travel from being cooled to being delivered to a vessel V. There is less opportunity for temperature to change if the distance between cooler 15 and dispenser 14 is relatively short. Cooling particularly improves the carbonation process.

[0050] Up until and throughout the cooling stage, the beverage is still/flat (i.e. containing no significant dissolved gas/fizz) as stored in and supplied from the container 11 (in a pre-mixed state as opposed to concentrate form, although alternative forms may feature a concentrate that is rehydrated within the system). The beverage/product line leaves the cooler 15 (driven by pressure in the line from liquid pump 13) carrying a cooled still/flat beverage and communicates with a beverage inlet 18 end (which may include or be proximate to a one-way valve preventing backflow of beverage into the product line 12; see Figure 5) of an infuser 19 that functions to carbonate or nitrogenate the beverage dependent on a selected operation as will be described below. Details of the infuser 19 are also outlined further below.

[0051] A gas inlet 20 of infuser 19 is coupled by a gas line 21 to at least one gas source, e.g. a pressurised canister of carbon dioxide 22 and/or an air pump 23, via a y-connector / junction valve 24. Connector 24 is configured, manually or electronically, to switch gas line 21 to a branch associated with either carbon dioxide source 22 or air source 23 (i.e. predominantly nitrogen). In alternative forms, the gas source may comprise pure nitrogen from a tank, or possibly a blend of nitrogen and carbon dioxide.

[0052] According to the illustrated system, a controller 25 may electronically control one or more of the component functions/parameters, e.g. liquid pump 13, compressor 17, gas selector 24. Alternatively, these may be independently controlled by another means, such as a manual switch at selector 24 for a user to choose a gas source. Particularly, controller 25 may control voltage and/or current to liquid pump 13 (and, optionally, gas flow from canister 22 and/or air pump 23) in order to accurately determine the rate of gas infusion into the beverage flowing through the system and, as a function thereof, the head height of a gas infused beverage after delivery to drinking vessel V. It is noteworthy that gas inlet 20 (and/or a section of gas line 21) comprises a one-way valve and a flow-regulating constriction in series (see Figures) which serves to regulate flow of gas from the gas source(s). The pressure may be adjusted by a valve or pump at the gas source, but flow is generally set by the constriction so it is the optimal ratio to mix into the liquid path. The one-way valve serves to permit gas into infuser 19 while preventing backflow of liquid beverage into the gas line 21.

[0053] The infuser 19 may take the form of a commercially available prior art device or comprise unique features developed for complimentary use with the present system.

[0054] An advantageous form of gas infuser 19 is illustrated in more detail with reference to Figures 2 to 5. At a first end (right hand side of Figure 2), the beverage inlet 18 (e.g. of a diameter continuous with the product line 12) communicates with a Venturi section 26 (e.g. a narrowed portion compared to full diameter of the inlet/product line) where the gas inlet intersects to inject gas at a mid-point thereinto. In the illustrated form the inlets converge at about 45 degrees, but the Venturi section may operate at any practical angle between forty and ninety degrees (right angles). In general, an angle of 45 degrees is chosen to reduce the overall footprint of the device, where the gas line 21 and beverage line 12 will be closer together than they would be if the intersection were at right angles. In the illustrated form, threaded connections are shown for coupling of gas line 21 to gas inlet 20 and beverage line 12 to beverage inlet 18, respectively. However, other connections are possible (such as push-fit, bayonet, etc) as will be known to those skilled in the art.

[0055] It will be apparent that gas flowing from gas inlet 20, regulated by the constriction and narrowing toward its injection point, is drawn in to mix directly with beverage from beverage inlet 18 at the narrowed portion of Venturi section 26. Downstream of initial mixing the flow channel walls diverge at a widening portion 27. In the illustrated form, the beverage inlet diameter narrows more abruptly, over a shorter longitudinal distance, to the narrowed Venturi portion 26 than does the widening portion 27 become wider, i.e. that gradually increases/diverges in diameter over a longer longitudinal distance, toward a blending chamber 28, which is generally of a diameter the same or similar to the beverage line 12 and beverage inlet 18. The blending chamber 28 as a whole may be unitary with the Venturi section/inlets or divided into sections that can be coupled in series. The illustrated form shows an infuser 19 with a two-piece construction, e.g. a male and female threaded connection joining the two pieces, for ease of manufacture. The two pieces comprise a Venturi section and substantive blending chamber which includes other internal features that will be described hereinbelow. The construction may comprise one (e.g. if produced through 3D printing), two or more (e.g. for ease of injection moulding) pieces in practice.

[0056] It will be apparent from Figures 2 and 3 that gas infused beverage flowing through the blending chamber 28, denoted by a dashed directional arrow F, encounters a (first) constriction feature 29 that is shown in more detail by Figure 4. Constriction feature 29 functions to force beverage through a narrowed opening that reduces the size of gas bubbles in the beverage that have formed in the Venturi section 26 and upstream length of the blending chamber 28.

[0057] As shown in Figure 4, constriction feature 29 comprises a leading aero/hydrodynamic surface at an upstream end thereof. In the illustrated form, the leading surface is formed by a main body 30 arranged concentrically, within the flow path F, i.e. a longitudinal axis of blending chamber 28.

[0058] The aerodynamic body 30 is preferably of a teardrop shape, with its wider/head end facing frontally toward oncoming beverage flow F, suspended in the blending chamber to create a ring-shaped/annular opening around it for the beverage to flow through. The body 30 is preferably as aerodynamically efficient as possible, e.g. the teardrop shape, for directing fluid between itself and a cylindrical wall of the blending chamber 28 to reduce bubble size in the mixture.

[0059] Body 30 may be supported/mounted by radial legs 31 at its trailing/downstream end that attach the body to hang centrally within the liquid path F, i.e. to form a symmetrical ring-shaped/annular restricted/constricted opening (when viewed in cross section). The legs 31 may extend from a ring-like constriction portion 32 provided at the tail/downstream end of the aerodynamic body 30.

[0060] The ring-like portion 32 provides a means for the beverage flow to encounter a secondary constriction/orifice, i.e. downstream of the first constriction of body 30. Portion 32 may have an angled/smoothly bevelled face at its entrance to aid flow and reduce turbulence, allowing the liquid to pass through at high speed after it has passed around body 30. A downstream portion of the cylindrical/ring constriction 32 may have a 90-degree face where the blending chamber immediately expands/returns to its full diameter. This dramatic change in flow path/channel diameter causes the liquid pressure to drop resulting in turbulence which further infuses the liquid with gas while maintaining a smaller bubble size.

[0061] A tail end of the teardrop body 30 may overlap into the ring portion 32 as visible in Figure 2.

[0062] A surface of the body may be improved by concave dimples 33, spaced about the teardrop shape, e.g. where its circumference is largest. Such features are similar to dimples on a golf ball, and serve to reduce turbulence and allow the mixture to maintain speed as it flows over the surface of body 30. As the mixture of liquid and gas bubbles is forced around the annular constriction, the bubbles in the liquid are reduced in size. Since fluid flow will tend to "hug" the aerodynamic body, such flow is urged toward a centre of the downstream orifice 32.

[0063] In broad terms, the constriction feature 29 of the blending chamber may be comprised of a first portion forcing flow in a divergent/outward direction toward a constriction in series with a second portion forcing flow in a convergent/inward direction toward a constriction/orifice as indicated by dashed directional arrows shown in Figure 4.

[0064] As shown in Figures 2 and 3, a second complete constriction feature is located in series within the blending chamber, downstream of the first constriction feature 29. In this way, the beverage flow is subjected to a second set of constrictions, further improving the gas infusion and trend towards smaller average bubble size which is important for stable and aesthetic head formation in a drinking vessel V. The dimensions of consecutive constriction features may be different. For example, the first constriction feature/teardrop may have a smaller diameter than the teardrop of the second constriction feature as shown in Figures 2 and 4. In one example, the annular gap for the first in line may be 0.9mm, whereas the second is 0.6mm, i.e. the gap is greater in the first than second. In this way, the bubbles are urged to a smaller size as the infused beverage travels downstream through the device.

[0065] Figure 5 illustrates an infuser 19 with further features of the system shown; namely a (first) one-way valve 34, as previously mentioned, located in the gas path from gas line 21 prior to delivery into the narrowed Venturi section 26. Such a feature prevents backflow of beverage toward the gas source(s). A (second) one-way valve 35, also as previously mentioned, may be located in the beverage path upstream of the narrowed section 26. In the illustrated form, both valves 34 and 35 are flaps converging in the direction of flow and biased to a closed position (as shown), such that pressure from the respective flowing fluids will be permitted through a central opening formed as the flaps are urged apart. By contrast, flow in the reverse direction meets the narrowed end of the convergent flaps and urges same toward a closed position.

[0066] Figure 5 further shows an orifice feature 36 (e.g. installed within the gas line 21) upstream of gas injection to the Venturi section 26. As previously mentioned, orifice 36 provides a uniform narrow passage to regulate gas flow and ensure a constant pressure for delivery to the infuser 19. In the illustrated form, orifice 36 is an elongate passage, but it may be shorter (i.e. as an orifice plate) or longer as required. Furthermore, the flow-regulating restrictor that is orifice 36 may be located integrally with gas inlet 20 or at some other upstream position.

[0067] It will be apparent that the system 10 of Figure 1, as a whole, and infuser 19 may operate independently, however, a system 10 combined with infuser 19 of Figures 2 to 5 provides optimal results.

[0068] The infusion device 19 of Figures 2 to 5 may be supplied for use with other inline gas infusion systems (whether beverage or otherwise). Likewise, the substantive configuration of dispense system 10 according to Figure 1 may substitute other suitable inline gas infusion 25 devices.

[0069] By way of summary, a gas infusion device is described herein which comprises a liquid inlet, a gas inlet and a blending chamber for mixing liquid and gas, i.e. to create a gas infused beverage flow stream. At least one constriction feature is arranged within the chamber downstream of gas injection; the feature including an aerodynamic body (e.g. teardrop shape) for directing the gas-infused liquid flow toward a wall of the chamber. An orifice/opening downstream of the body is provided for directing liquid flow back toward a centre of the chamber. The aerodynamic body of the construction has the effect of reducing the bubble size of gas infused into the beverage.

[0070] The present disclosure also outlines a dispensing system for a gas infused beverage that comprises a beverage storage container, a liquid pump and product line for sending beverage through an inline gas infuser. The infuser is connected to a switchable choice of gas sources, e.g. carbon dioxide canister for carbonation and air pump for nitrogenation, via a flow-regulating constriction and a one-way valve. The constriction facilitates a maintained pressure and optimal flow of gas into the infuser, while gas/beverage mixing can be controlled by flow & pressure of beverage from the liquid pump. Setting power to the liquid pump (and, optionally, the gas source) via a controller may effectively control, via electronic means, a head height of the gas infused beverage delivered by a dispenser to a drinking vessel. The infuser may further include constriction features within a blending chamber to reduce gas bubble size in the gas infused beverage, so that the beverage head, when settled in a drinking vessel, is creamier, longer-lasting and more aesthetically pleasing.

Claims (25)

1. Claims 1. A gas infuser, comprising: a liquid inlet configured for receiving a liquid flow from a product line; a gas inlet configured for injecting a gas flow from a gas line into the liquid flow; and an elongate chamber for directing a mixed liquid and gas flow therethrough; at least one constriction feature arranged within the elongate chamber downstream of gas injection, the constriction feature being comprised of: an aerodynamic body configured for disposal within the liquid flow and directing the liquid flow toward a wall of the elongate chamber; and/or an orifice configured for disposal within the liquid flow and directing liquid flow toward a central axis of the elongate chamber.

2. The gas infuser of claim 1, wherein the orifice is located downstream of the aerodynamic body, such that mixed flow is first directed outwardly toward a wall of the elongate chamber and then directed inwardly toward a central axis of the elongate chamber.

3. The gas infuser of claim 1 or 2, wherein the aerodynamic body is a teardrop shape.

4. The gas infuser of claim 3, wherein a wide end of the teardrop shape is facing upstream into the mixed flow.

5. The gas infuser of claim 4, wherein a narrow end of the teardrop shape overlaps into the orifice.

6. The gas infuser of any preceding claim, wherein the aerodynamic body is supported centrally within the mixed flow by at least one rib or leg.

7. The gas infuser of claim 6, wherein at least one radial leg, extending forwardly from the orifice, supports the aerodynamic body.

8. The gas infuser of any preceding claim, wherein the gas inlet is positioned for injection of gas at an angle of 40 to 90 degrees relative to the fluid inlet, preferably 40 to 75 degrees, most preferably 45 degrees.

9. The gas infuser of any preceding claim, wherein an annular gap, for accommodating the mixed flow therethrough, between the aerodynamic body and wall is between 0.3 to 1.2mm.

10. The gas infuser of any preceding claim, wherein the aerodynamic body comprises one or more concave dimples upon its surface, for reducing turbulence of mixed flow thereupon.

11. The gas infuser of any preceding claim, wherein the orifice comprises a bevelled edge at its front face for facilitating mixed flow therethrough, and a rear face that is at right angles to the wall of the elongate chamber.

12. The gas infuser of any preceding claim, wherein there are at least two constriction features in series within the chamber.

13. The gas infuser of claim 12, wherein a diameter of the aerodynamic body of a downstream constriction feature is greater than a diameter of the aerodynamic body of an upstream constriction feature.

14. The gas infuser of any preceding claim, comprising a Venturi section configured for receiving the liquid flow from the liquid inlet and injecting gas from the gas inlet into a narrowed portion of the Venturi section.

15. The gas infuser of claim 14, wherein a diameter of the gas inlet, at a point where gas is injected into the Venturi section, is 0.8 to 1.6mm. 30

16. The gas infuser of any preceding claim 14 or 15, wherein a diameter of the narrowed portion of the Venturi section is 1.8 to 2.8mm

17. The gas infuser of any preceding claim, wherein a diameter of the elongate chamber is 3 to 6mm.

18. The gas infuser of any preceding claim, wherein a diameter of the elongate chamber is the same as the beverage inlet.

19. The gas infuser of any preceding claim, wherein a largest diameter of the aerodynamic body is 1 to 2mm less than the diameter of the elongate chamber.

20. The gas infuser of any preceding claim, wherein a length of the aerodynamic body is to 15mm.

21. The gas infuser of any preceding claim, wherein a diameter of the orifice is 2 to 3mm less than a largest diameter of the aerodynamic body.

22. The gas infuser of any preceding claim, wherein the gas inlet comprises a flow-regulating element and/or a one-way valve.

23. The gas infuser of claim 22, wherein the flow-regulating element is an orifice perpendicular to a direction of gas flow.

24. The gas infuser of claim 23, wherein the orifice is preferably 0.2 to 0.6mm in diameter, more preferably 0.4 mm in diameter.

25. Use of a gas infuser according to any preceding claim, in combination with components of a beverage dispense system.