Beverage preparation apparatus comprising a mixing chamber

Abstract

The invention concerns a beverage preparation apparatus (100), said apparatus comprising at least one chamber (1) for receiving and mixing an aqueous liquid and at least one soluble beverage ingredient, said chamber comprising: —a lateral side wall (11) comprising a liquid inlet (2), —a bottom wall (12) comprising a beverage outlet (3), and wherein the liquid inlet is positioned close to the bottom of the chamber, and wherein the liquid inlet is configured so that the liquid is introduced in the chamber as a straight jet of liquid, said introduced straight jet extending transversely through the internal volume of the chamber along a line L, said line L being offset relative to the longitudinal central axis (XX′) of the chamber, wherein, at the area of the cylindrical lateral side wall opposed to the liquid inlet and crossed by the line L, the chamber comprises a bump (4) extending from the cylindrical lateral side wall inside the chamber, said bump presenting a shape designed: —to convert the introduced straight jet of liquid extending transversely through the internal volume of the chamber into a swirl flowing along the lateral side wall off the chamber, and —to reduce the diameter of the swirl rotating back to the bump and to guide said swirl in direction of the liquid inlet.

Claims

1. A beverage preparation apparatus comprising: at least one chamber for receiving and mixing an aqueous liquid and at least one soluble beverage ingredient, the at least one chamber comprising: a lateral side wall, a lower part of the lateral side wall being essentially cylindrical, and the lateral side wall comprising a liquid inlet, a bottom wall comprising a beverage outlet, the liquid inlet is positioned close to a bottom of the at least one chamber, the liquid inlet is configured so that the aqueous liquid is introduced in the at least one chamber as a straight jet of liquid, the straight jet of liquid extending transversely through an internal volume of the at least one chamber along a line L, the line L being offset relative to a longitudinal central axis of the at least one chamber, at an area of the lateral side wall opposed to the liquid inlet and crossed by the line L, the at least one chamber comprises a bump extending from the lateral side wall inside the at least one chamber, the bump having a shape designed: to convert the straight jet of liquid extending transversely through the internal volume of the at least one chamber into a swirl flowing along the lateral side wall off the at least chamber, and to reduce a diameter of the swirl rotating back to the bump and to guide the swirl in a direction of the liquid inlet, the bump comprises a first side and a second side, the first side and the second side are lateral and at least partially curved, each extending gradually from a cylinder defined by the lateral side wall inside the inner volume of the at least one chamber and converging at a central common essentially vertical edge, the first side is crossed by the line L and comprises: a curved trailing part end tangent to the lateral side wall, and a leading part end oriented so that an angle between the leading part end and the line L is of at most 45°, the second side comprises: a curved leading part end tangent to the lateral side wall, and a trailing part end oriented so that an angle between the trailing part end and the line L is of at most 90°, and a trailing edge positioned at a distance d.sub.2 from a centre O of the lateral side wall of the at least one chamber inferior to a radius r.sub.0 of the lateral side wall of the at least one chamber.

2. The beverage preparation apparatus according to claim 1, wherein the first side is positioned relatively to the line L so that line L crosses the first side at a middle distance between two edges of the first side.

3. The beverage preparation apparatus according to claim 1, wherein the first side is an archaving a radius r.sub.1 equal to a radius r.sub.2 of an arc of the second side of the bump.

4. The beverage preparation apparatus according to claim 1, wherein the first side is a combination of an arc at the curved trailing part end and a flat surface at the leading part end, a radius r.sub.11 of the arc being inferior to a radius r.sub.2 of an arc of the second side of the bump.

5. The beverage preparation apparatus according to claim 1, wherein the second side is an arc, the arc presenting having a radius r.sub.2 inferior to the radius r.sub.0 of the lateral side wall of the at least one chamber.

6. The beverage preparation apparatus according to claim 5, wherein a centre O.sub.2 of the arc forming the second side is positioned at a distance d.sub.O2 from a central axis of the lateral side wall of the at least one chamber equal to the distance d.sub.2 between the trailing edge of the second side and the centre O of the lateral side wall of the at least one chamber.

7. The beverage preparation apparatus according to claim 5, wherein the radius r.sub.2 of the arc of the second side is inferior to the distance d.sub.2 between the trailing edge of the second side and the centre O of the lateral side wall of the at least one chamber.

8. The beverage preparation apparatus according to claim 1, wherein the line L is offset relative to the longitudinal central axis of the at least one chamber by a distance d measured orthogonally from a direction of orientation of the liquid inlet to the longitudinal central axis of the at least one chamber, and the ratio d/r.sub.0 is between 0,2 and 0,4.

9. The beverage preparation apparatus according to claim 1, wherein the line L is inclined downwardly.

10. The beverage preparation apparatus according to claim 1, wherein the beverage outlet is a straight conduit subdivided in at least four straight sub-conduits.

11. The beverage preparation apparatus according to claim 10, wherein the length L.sub.0 of the conduit of the beverage outlet is greater than the hydraulic diameter D.sub.0 of the beverage outlet.

12. The beverage preparation apparatus according to claim 10, wherein the at least one chamber has an internal volume of between 40 and 100 ml, and a hydraulic diameter D.sub.0 of the straight conduit of the beverage outlet is of at least 2 mm.

13. The beverage preparation apparatus according to claim 1, wherein the position of the beverage outlet is offset the longitudinal central axis of the lateral side wall of the at least one chamber.

14. The beverage preparation apparatus according to claim 1 comprising a liquid supply system connectable to the liquid inlet.

15. The beverage preparation apparatus according to claim 1 comprising a dosing device configured for dispensing a dose of soluble beverage ingredient in the at least one chamber.

16. A method for producing a beverage in a beverage preparation apparatus, the method comprising: providing the beverage preparation apparatus, the beverage preparation apparatus comprising at least one chamber for receiving and mixing an aqueous liquid and at least one soluble beverage ingredient, the at least one chamber comprising: a lateral side wall, a lower part of the wall being essentially cylindrical, and the lateral side wall comprising a liquid inlet, a bottom wall comprising a beverage outlet, the liquid inlet is positioned close to a bottom of the at least one chamber, the liquid inlet is configured so that the aqueous liquid is introduced in the at least one chamber as a straight jet of liquid, the straight jet of liquid extending transversely through an internal volume of the at least one chamber along a line L, the line L being offset relative to a longitudinal central axis of the at least one chamber, at an area of the lateral side wall opposed to the liquid inlet and crossed by the line L, the at least one chamber comprises a bump extending from the lateral side wall inside the at least one chamber, the bump having a shape designed: to convert the straight jet of liquid extending transversely through the internal volume of the at least one chamber into a swirl flowing along the lateral side wall off the at least one chamber, and to reduce a diameter of the swirl rotating back to the bump and to guide the swirl in a direction of the liquid inlet, the bump comprises a first side and a second side, the first side and the second side are lateral and at least partially curved, each extending gradually from a cylinder defined by the lateral side wall inside the inner volume of the at least one chamber and converging at a central common essentially vertical edge, the first side is crossed by the line L and comprises: a curved trailing part end tangent to the lateral side wall, and a leading part end oriented so that an angle between the leading part end and the line L is of at most 45°, the second side comprises: a curved leading part end tangent to the lateral side wall, and a trailing part end oriented so that an angle between the trailing part end and the line L is of at most 90°, and a trailing edge positioned at a distance d.sub.2 from a centre O of the lateral side wall of the at least one chamber inferior to a radius r.sub.0 of the lateral side wall of the at least one chamber; dosing the at least one chamber with the at least one soluble beverage ingredient, and introducing the aqueous liquid through the liquid inlet.

17. The method of claim 16, wherein the first side is positioned relatively to the line L so that line L crosses the first side at a middle distance between two edges of the first side.

18. The method of claim 16, wherein the first side is an arc having a radius r.sub.1 equal to a radius r.sub.2 of an arc of the second side of the bump.

19. The method of claim 16, wherein the first side is a combination of an arc at the curved trailing part end and a flat surface at the leading part end, a radius r.sub.11 of the arc being inferior to a radius r.sub.2 of an arc of the second side of the bump.

20. The method of claim 16, wherein the second side is an arc having a radius r.sub.2 inferior to the radius r.sub.0 of the lateral side wall of the at least one chamber.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The characteristics and advantages of the invention will be better understood in relation to the following figures:

(2) FIG. 1 is a schematic view of a beverage preparation apparatus according to the present invention,

(3) FIG. 2 is a perspective view of a chamber used in the apparatus of the present invention

(4) FIG. 3 is a top view of the chamber of FIG. 2,

(5) FIG. 4 is a vertical cross section of the chamber of FIG. 2 along the plane traversing the liquid inlet

(6) FIG. 5a corresponds to FIG. 4, the divider of the beverage outlet being removed,

(7) FIG. 5b is a perspective view of the divider,

(8) FIG. 6 is an illustration of two chambers positioned aside,

(9) FIG. 7 is a magnified view of the bump of the chamber illustrated in FIG. 2,

(10) FIGS. 8a-e are schematic illustrations of the chamber according to the invention,

(11) FIGS. 9a-d are schematic illustrations of the chamber according to the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

(12) FIG. 1 illustrates a beverage preparation apparatus 100. The apparatus includes a mixing chamber 1 for producing a beverage from a soluble beverage ingredient and liquid, preferably water, entering the chamber.

(13) The beverage ingredient is stored in a container 107. The container can be a hopper which is permanent or a disposable package containing the beverage ingredient.

(14) A dose of beverage ingredient is metered and dispensed by a dosing device 108. The dosing device has the primary function to meter upon request doses of ingredient into the mixing chamber 1. The dosing device dispenses the dose of beverage ingredient in mixing chamber 1, generally by gravity fall in a top opening of the chamber.

(15) The dosing device can be any suitable system such as a dosing screw, a reciprocating dosing piston or a rotating disc. The dosing technology is also of course dependent on the nature of the soluble ingredient. The soluble ingredient is typically a dry beverage powder, preferably mild powder. However, it could also be a liquid concentrate such as milk concentrate. The device is fed upon request with ingredient manually or automatically as prompted by a controller 111 and command 112.

(16) When the beverage ingredient is a powder, this dosing device can be a rotating device such as described in WO 2009/144239.

(17) According to a particular embodiment (not illustrated), the beverage preparation apparatus can be deprived of reservoir and dosing device. Accordingly, the user can introduce a dose of ingredient in the chamber manually using a spoon or a stick of powder.

(18) A liquid, preferably water, supplying system 105 is provided in the machine to be able to feed water in the mixing chamber 1, more particularly, hot water.

(19) The water supplying system comprises: a tank 101 that can be replenished with fresh water, or eventually connected to tap water, a water pump 102 for pumping water from the tank 101. The pump can be any type of pump such as a piston pump, diaphragm pump or a peristaltic pump. a water heater 103 such as a thermoblock or a cartridge type heater to heat the pumped water, alternatively or in addition to, the machine can comprise a water cooler in a line bypassing the heater, a non-return valve 104.

(20) Finally water is fed into the mixing chamber by a tube 106. In a variant, not illustrated, water can be fed by two tubes 106 in two different inlets of the chamber.

(21) As illustrated in FIG. 1, the mixing chamber 1 can be placed directly above a service tray 109 onto which is placed a drinking receptacle 113 to receive the beverage. Generally, the mixing chamber 1 is removable from the machine for cleaning and optionally for dosing. Usually the machine comprises a mixing chamber receiving area to removably fix the chamber inside and provide cooperation between the mixing chamber liquid inlet(s) and the liquid supply tube(s) 106.

(22) Usually, the chamber 2 is immobile within the apparatus. Yet, in a less preferred embodiment, the mixing chamber 1 can be movable to a position placed under the dosing device 108 as described in WO 2009/153157.

(23) The controller 12 can coordinate dosing of the soluble beverage ingredient by the dosing device 108 and dosing of liquid by the pump 102 upon the user actuating or being prompted to press the command 112 on the apparatus.

(24) FIG. 2 is a perspective view of a chamber 1 according to the invention used in a beverage preparation apparatus such as described in FIG. 1, but not limited to. FIG. 3 is a top view of this chamber

(25) The chamber 1 comprises a lateral side wall 11 and a bottom wall 12. These walls define an internal volume able to contain a liquid. The lower part 111 of the lateral side wall is cylindrical. This lower part comprises the diluent inlet 2 and the bump 4 as described later. The upper part of the lateral side changes progressively to the cross section of a square with rounded corners. This upper shape enables an increase of the internal volume of the chamber. It does not affect the preparation of the beverage that essentially happens in the lower part of the chamber.

(26) Preferably, the cylindrical lateral side wall 11 is such that its longitudinal distance (height) is close to its cross section dimension (diameter). Consequently, the internal volume of the chamber sufficiently large without increasing the height of the chamber and, as a result. the height of the apparatus. The diameter can be comprised between 40 and 70 mm and the height between 40 and 80 mm. The internal volume is generally set so as to be able to hold a volume of liquid comprised between 40 and 100 ml.

(27) The cylindrical lateral side wall 11 comprises a liquid inlet 2. This liquid inlet 2 is positioned close to the bottom wall 12 of the chamber. Generally, the distance between the bottom of the chamber and the central axis of the liquid inlet is comprised between 5 and 20 mm.

(28) This liquid inlet 2 is configured so that the liquid is introduced in the chamber as a straight jet of liquid. Preferably, this straight jet is produced by and emerges from a nozzle 6 positioned in the liquid inlet of the chamber as illustrated in FIG. 4 that is a vertical cross section of the chamber traversing the liquid inlet.

(29) The liquid inlet is also configured so that the straight jet of liquid extends transversely through the internal volume of the chamber along a line L, said line L being offset relative to the longitudinal central axis XX′ of the chamber, as illustrated in the top view of the chamber in FIG. 3.

(30) More specifically, the line L is oriented in a direction so that a ratio d/r.sub.0 is comprised between 0.2 and 0.4, preferably of about 0.3, where r.sub.0 is the radius of the cylindrical lateral side wall 11 and d is the distance measured orthogonally from the line L to the central longitudinal axis XX′ of the chamber.

(31) The nozzle 6 positioned in the liquid inlet 2 is designed for producing a straight jet of liquid. According to another embodiment, the nozzle can be moulded in the liquid inlet that is in the chamber lateral side wall.

(32) Generally, the nozzle presents an outlet section with a surface area equivalent to the surface of a circular surface of diameter comprised between 0.2 and 0.8 mm, preferably between 0.3 and 0.5 mm and even more preferably of about 0.4 mm. With such a dimension, the delivery of water at a pressure comprised between 2 and 10 bar, preferably of at least 6 bar, in the nozzle enables the production of a jet of high velocity.

(33) In the illustrated embodiment, the liquid inlet is also configured so that the straight jet of liquid is inclined downwardly in direction of the opposed surface of the lateral cylindrical wall. When the soluble beverage ingredient is a powder and the beverage preparation requires a certain amount of powder, the powder is usually dosed before the liquid is introduced in the chamber. In that case, the inclined jet of liquid flows directly down the heap of powder which reduces the risk of powder flowing through the whole chamber and the creation of lumps. This is particular critical when the flow rate of the pump of the beverage preparation apparatus cannot be controlled. In the case where the pump can control this flow rate, the flow can be progressively increased at the beginning of the introduction of the liquid in order to avoid powder hitting. In that case, the inclination of the liquid inlet is not necessary and the jet can be oriented horizontally.

(34) The chamber comprises an optional second liquid inlet 21 at the top of the chamber. This second liquid inlet can be used to rinse the chamber or to prepare a non-frothed beverage.

(35) The chamber comprises a beverage outlet 3. This outlet is a conduit positioned at the lowest position of the bottom wall 12 of the chamber. The bottom wall 12 presents the shape of a funnel inclined in direction of the conduit.

(36) The conduit is not centred on the longitudinal central axis XX′ of the cylindrical lateral side wall chamber but is offset. This illustrated embodiment enables the dispensing of the beverage in a receptacle 113 positioned to receive a beverage from a beverage dispensed from the outlet 3′ of another chamber 1′ positioned aside the chamber 1 as illustrated in FIG. 6.

(37) In another embodiment wherein there is no such constraint, the chamber the conduit of the beverage outlet can be centred on the longitudinal central axis XX′ of the chamber.

(38) The diameter of the conduit of the beverage outlet is sufficiently large to enable the rapid dispensing of a large quantity of the beverage. Preferably, the hydraulic diameter of the conduit of the beverage outlet is of at least 2 mm.

(39) As illustrated in FIGS. 3 and 4, the conduit is subdivided in four straight sub-conduits 30 by means of a divider 31. This divider prevents the rotation of the swirling beverage inside the beverage conduit which has the effects of slowing down the dispensing and not enabling the dispensing of the beverage as a straight flow in the drinking receptacle. The divider is removable from the chamber for cleaning.

(40) In that configuration of the divider, preferably, the length Lo of the conduit of the beverage outlet is greater than the hydraulic diameter D.sub.0 of the beverage outlet, preferably greater than two times the hydraulic diameter of the beverage outlet. In the illustrated embodiment, the length of the conduit is of at about 5 mm and the hydraulic diameter D.sub.0 of the conduit is of about 2 mm. By hydraulic diameter, it is meant the diameter of a conduit with round section presenting the same cross section area as a conduit with a section of a different shape.

(41) Coming back to the embodiment illustrated in FIG. 6, it is noticeable that the two chambers present the same external height. This feature is particularly interesting when the apparatus comprises dosing devices to feed soluble beverage ingredient through the tops of the chamber. Actually these dosing devices can be positioned at the same height and the global footprint and height of the apparatus can be reduced. Eventually a common actuator can be used and the general architecture optimised. Specifically, when the apparatus is configured for preparing coffee and milk beverages with the chamber 1 dedicated to milk and the chamber 1′ dedicated to coffee, this requires that the milk chamber 1′ is larger than the coffee chamber 1 to be able to produce bigger volume of beverage with a chamber of fixed height H. The particular internal design of the chamber 1 reaches this objective.

(42) As illustrated in FIGS. 3, 4, 5a and in FIG. 7 the chamber comprises a bump 4 extending from the lateral surface of the chamber inside the volume of the chamber. This bump 4 is positioned at the area of the cylindrical lateral side wall 111 opposed to the liquid inlet.

(43) The bump 4 presents two lateral at least partially curved sides 41, 42. Each side extend gradually from the surface cylinder in opposite directions and converge at a central common essentially vertical edge 43.

(44) According to the preferred embodiment, the bump presents two lateral curved parts 412, 421, each curved sides extending gradually from the cylinder defined by cylindrical lateral side wall (in opposed directions) inside the volume of the chamber and converging at a central common essentially vertical edge 423.

(45) FIGS. 8a-c are top views of the chamber used to schematically illustrate the features and functions of the first side 41.

(46) The first side guides the liquid in a direction starting from the leading part end 411—corresponding to the part where the jet enters in contact with the first side—to a trailing part end—corresponding to the part where the liquid leaves the first side 41.

(47) As illustrated in FIG. 8b, the first side 41 is crossed by the line L meaning that the straight jet of liquid hits the first side 41 and in particular the leading part end 411.

(48) Preferably, the first side 41 is positioned relatively to the line L so that line L crosses the first side at the middle distance between the trailing edge 412 and the leading edge 411 of the first side. The distance d.sub.1 between the line L and the edge of the leading part end 411 is essentially identical to the distance d.sub.2 between the line L and the edge of the trailing part end 142. Accordingly, depending on the shape of the jet (e.g. conical shape of the jet), the first side is positioned to hold and guide the whole cross section of the jet. Generally the cross section surface of the jet when it impacts the first side 41 is linked to the liquid inlet cross section, the flow rate of the liquid and the distance between the diluent inlet and the bump. Based on these features, the distances d.sub.1 and d.sub.2 are preferably defined so that each of these distances are superior to three times the diameter of the jet at the point of impact. Similarly the height of the bump and the vertical position of the pump in the chamber relatively to the line L are set so that the whole cross section of the jet hits the bump.

(49) As shown in FIG. 8c, this leading part end 411 is oriented so that the angle α between said part end and the line L is of at most 45°, preferably at least 10°. This orientation avoids the splashing of the jet against the cylindrical lateral side wall 11 of the chamber; the jet of liquid slides more gently along the leading part end.

(50) After hitting the leading part end 411, the flow of liquid is guided by the curved trailing part end 412 that is tangent to the cylindrical lateral side wall 11. Accordingly, there is perfect control of the flow of liquid from a straight jet to a swirl.

(51) This curved trailing part end 412 initiates the creation of the swirl although the chamber is larger compared to usual ones: as a result, a nozzle and a pump comparable to those used in the state of the art can be used and the cost of manufacturing of the apparatus can remain low.

(52) According to one first mode illustrated in FIG. 8d, the first side 41 can be an arc. This arc can present a radius r.sub.1 equal to the radius r.sub.2 of the arc of the second side of the bump (illustrated in FIG. 8d).

(53) According to one second mode illustrated in FIG. 8e, the first side 41 can be the combination of an arc at the trailing part end and a flat surface at the leading part end.

(54) Preferably the radius r.sub.4 of the arc is inferior to the radius r.sub.2 of the arc of the second side of the bump.

(55) Once the flow of liquid leaves the first side 41, this flow swirls along the cylindrical surface 11 of the lateral wall of the chamber. When the swirl 92 flows in front of the liquid inlet 2 (see FIG. 8a), it is hit by the entering straight jet 91 of liquid inducing a strong agitation and aeration of the liquid in the swirl with the effect of increasing dissolution and foaming.

(56) FIGS. 9a-d are top views of the chamber used to schematically illustrate the features and functions of the second side 42.

(57) The second side guides the swirl in a direction starting from the leading part end 421—corresponding to the part where the swirl enters in contact with the first side—to a trailing part end 422—corresponding to the part where the swirl leaves the second side 42.

(58) After the swirl 92 has flown in front of the liquid inlet 2, the swirl 92 reaches the second side 42 of the bump as illustrated in FIG. 9a. This second side 42 comprises a curved leading part end 421 tangent to the cylindrical lateral side wall 11, as a result, the curvature guides the swirl of liquid gently away from the cylindrical wall 11. Simultaneously, the curved leading part end 421 reduces the diameter of the swirl.

(59) Following the leading part end, the flow reaches the edge 423 of the trailing end part of the second side—at the common edge of the two curved surfaces of the bump. As illustrated in FIG. 9b, this edge 423 is positioned at a distance d.sub.2 from the longitudinal central axis of the chamber that is inferior to the radius r.sub.0 of the cylindrical side wall of the chamber, preferably comprised between 0.5 r.sub.0 and 0.9 r.sub.0. As a result, the swirl is induced to get closer to the liquid inlet 2. Specifically, the position of this edge 423 guarantees that the diameter of the swirl decreases while it passes through the jet of liquid still entering inside the chamber. The effect is that the swirl is reached again by the jet of liquid 91 still entering the chamber and is agitated and aerated again. Although the chamber is rather large to enable the preparation of a large volume of beverage, the second side of the bump is configured to bring closer the swirl 92 to the jet of liquid 91 entering the chamber. At the point where they cross, that is at the edge 423, the strength of the entering jet remains high since this position at the edge 423 is closer to the liquid inlet 2 than the part of the cylindrical lateral wall opposed to the liquid inlet, then the shearing of the swirl is more efficient.

(60) In addition, as illustrated in FIG. 9c, the trailing part end 422 is oriented so that the angle β between said trailing part end and the line L is of at most 90°, preferably at least 30°. This specific orientation provides an impulsion to the swirl and straighten up the swirl in direction of the entering jet 91 of liquid as illustrated in FIG. 9a. The result is an increased shearing of the swirl by the jet again.

(61) Usually, the second side 42 is an arc and this arc presents a radius r.sub.2 inferior to the radius r.sub.0 of the cylindrical side wall of the chamber.

(62) Preferably the centre O.sub.2 of the arc forming the second side 42 is positioned at a distance doe from the central axis XX′ of the cylindrical side wall of the chamber equal to the distance d.sub.2 between the edge 423 of the trailing part end of said second side and the central axis XX′ of cylindrical side wall of the chamber.

(63) Preferably, the radius r.sub.2 of the arc of the second side is inferior to the distance d.sub.2 between the trailing end of said second side and the central axis of the cylindrical side wall of the chamber.

(64) The apparatus with the above described chamber enables the rapid preparation of an important volume of frothed beverage such as foamed milk.

(65) Once the beverage ingredient has been dosed in the chamber, the liquid is injected in the chamber too. In the first period of the liquid injection, the bump 4 enables the creation of the swirl 92 of liquid, that is agitated and aerated by the entering jet 91 of liquid. In addition, although the chamber is designed with dimensions large enough in order to prepare an important volume of beverage, the swirl 92 can still be hit again with force by the entering jet 91 of liquid a second time providing again an efficient agitation. Consequently, the chamber design enables the efficient dissolution of the ingredient and the frothing of the beverage from the beginning of the process. That provides the advantage of immediately producing an important quantity of foam in the beverage.

(66) Very rapidly, all the beverage ingredient is dissolved in the liquid and the rest of the process is only a matter of dissolution with liquid that is still being introduced and of frothing. As liquid goes on entering the chamber, the swirl raises inside the chamber and above the diluent inlet. Above the diluent inlet, the swirl enables the mixing of the beverage in preparation. At the diluent inlet, the strength of the jet goes on agitating and aerating the swirl, yet the generation of new foam becomes less important because the surface air/liquid is above the diluent inlet.

(67) After a certain time, the volume of liquid in the chamber is such that the bottom of the swirl reaches the beverage outlet and the dispensing in the drinking receptacle starts. From this time, the dispensing of beverage happens simultaneously to the introduction of liquid until the volume of liquid set for the recipe is reached. Once the liquid stops entering the chamber, the rotation of the swirl decreases and the beverage is fully evacuated.

(68) The design of the chamber enables the preparation of a large volume of frothed beverage.

(69) The apparatus presents the advantage of presenting a compact aspect in particular a small height although it comprises a chamber with larger internal volume.

(70) The apparatus presents the advantage of not comprising costly internal devices such as whipping motors to strongly agitate the beverage or a high pressure pump to supply a high pressure jet. The particular shape of the chamber is enough to guide efficiently the jet, produced by a currently available and low cost pump, inside the chamber to get an optimal dissolution in a short preparation time.

(71) Although the invention has been described with reference to the above illustrated embodiments, it will be appreciated that the invention as claimed is not limited in any way by these illustrated embodiments.

(72) Variations and modifications may be made without departing from the scope of the invention as defined in the claims. Furthermore, where known equivalents exist to specific features, such equivalents are incorporated as if specifically referred in this specification.

(73) As used in this specification, the words “comprises”, “comprising”, and similar words, are not to be interpreted in an exclusive or exhaustive sense. In other words, they are intended to mean “including, but not limited to”.

LIST OF REFERENCES IN THE DRAWINGS

(74) chamber 1, 1′ lateral side wall 11 top edge 110 lower part 111 bottom wall 12 liquid inlet 2 beverage outlet 3, 3′ sub-conduit 30 divider 31 bump 4 first side 41 leading part end 411 trailing part end 412 second side 42 leading part end 421 trailing part end 422 trailing edge 423 central edge 43 nozzle 6 conduit 9 beverage preparation apparatus 100 tank 101 pump 102 heater 103 valve 104 liquid supplying system 105 pipe 106 container 107 dosing device 108 service tray 109 controller 111 command 112 drinking receptacle 113 liquid 90 straight jet of liquid 91 swirl of liquid 92