WO2006066622A1

WO2006066622A1 - Apparatus for preparing a beverage

Info

Publication number: WO2006066622A1
Application number: PCT/EP2004/053643
Authority: WO
Inventors: Marcel Hendrikus Simon Weijers
Original assignee: Martex Holland B.V.; Electrical & Electronics Ltd.; Coval Art Tec Limited
Priority date: 2004-12-21
Filing date: 2004-12-21
Publication date: 2006-06-29

Abstract

The invention relates to an apparatus for preparing a beverage with a froth layer comprising at least one liquid inlet (5) arranged to provide pressurized liquid to a container (11) with a soluble or extractable product to obtain a flow (F) of brewed beverage. The apparatus is adapted to split said flow of brewed beverage into separate flows (S) and to guide said separate flows such that at least two of said flows interfere with each other. By arranging the apparatus such that an interference or collision between the separate beverage flows occurs, a froth layer with smaller bubbles and higher stability is obtained. The invention further relates to a frothing device and a method for preparing a beverage with a froth layer.

Description

Apparatus for preparing a beverage

The invention relates to an apparatus for preparing a beverage fit for consumption, such as coffee, tea, chocolate and cappuccino . More specifically, the invention relates to an appa- ratus for preparing such a beverage with a fine-bubble froth layer comprising at least one liquid inlet arranged to provide liquid to a container with a soluble or extractable product to obtain a flow of brewed beverage .

WO 03/105644 discloses an apparatus for preparing a beverage fit for consumption, such as coffee or milk, with a fine-bubble froth layer provided with a beverage unit for dispensing under pressure a beverage to be processed, at least one nozzle (8) , which is in fluid communication with the beverage unit for feeding the beverage to the nozzle to generate a j et of the beverage by means of the nozzle, and a collecting unit , into which the jet squirts to obtain the beverage with the fine- bubble froth layer. The collecting unit is provided with a tubular chamber with at least one open end for dispensing the beverage with the fine-bubble froth layer, the nozzle and the collecting unit being in fluid communication with each other such that the j et squirts against an inner wall of the tubular chamber for beating, in the tubular chamber, air into the beverage to obtain the beverage with the fine-bubble froth layer, which, in use, leaves the tubular chamber via the at least one open end.

The kinetic energy of the liquid jet is used to create a forced mixture with air due to the impact and the sudden decrease of speed of the liquid j et , caused by the impact with the inner wall . In the prior art , it is therefore important to have a small and stable j et with sufficient kinetic energy to create a stable and fine-bubbled froth layer. If the velocity of the liquid j et varies slightly, e .g . because of differences in pressure or some blockage in the apparatus resulting e . g . from calcification, the quality of the froth layer is detrimentally influenced . It is an object of the invention to provide an apparatus which has an alternative way of mixing air with the beverage in order to obtain a fine-bubble froth layer for said beverage . This object is accomplished by providing an apparatus for preparing a beverage with a fine-bubble froth layer comprising at least one liquid inlet arranged to provide pressurized liquid to a container with a soluble or extractable product to obtain a flow of brewed beverage, wherein said apparatus is adapted to split said flow of brewed beverage into separate flows and to guide said separate flows such that at least two of said flows interfere with each other .

By arranging the apparatus such that an interference or collision between the separate beverage flows occurs, the kinetic energy involved in this process is increased without increasing the pressure for the initial liquid and, consequently, a froth layer with smaller bubbles and higher stability is obtained.

The embodiment of the invention defined in claim 2 has the advantage that the holder for the container or pad can be adapted to position the frothing device in the beverage flow path beneath the container .

The embodiment of the invention defined in claim 3 has the advantage that a collision of the separate beverage flows in the open air results in a more efficient mixing between air and the beverage .

The embodiment of the invention as defined in claim 4 has the advantage that the frothing device can be removed for cleaning purposes .

The embodiment of the device as defined in claim 5 has the advantage that silicon material enables a tight fit for the frothing device in the apparatus . Further, silicon can be cleaned easily.

The embodiment of the device as defined in claims 6 and 7 has the advantage that control of the degree of interference of the separated flows influences the thickness of the fine- bubble froth layer. Further, the redirection device may prevent interference between the separated flows and accordingly the user is provided with the possibility to obtain a beverage without a froth layer . It is noted that the above defined embodiments, or aspects thereof , may be combined.

The invention also relates to a frothing device for an apparatus for preparing a beverage with a fine-bubbled froth layer, wherein said frothing device is adapted to have at least two separate flows of brewed beverage interfere with each other . The frothing device may be further arranged to split at least one flow of brewed beverage into separate flows of brewed beverage . The invention also relates to a method for preparing a beverage with a fine-bubble froth layer comprising the steps of :

- providing a pressurized liquid to a container with a soluble or extractable product to obtain a flow of brewed beverage; - splitting said flow of brewed beverage into separate flows , and

- guiding said separate flows in a direction such that at least two of said flows interfere with each other.

WO 97/39668 discloses an assembly comprising a filter holder and a coffee filter which, in use, is filled with ground coffee for preparing a cup of coffee with a small-bubble foam layer . Located between the lower side of the coffee filter and the bottom of the filter holder is a separation plate provided with at least one j et opening. Through the presence of the sepa- ration plate a pressure is built up so that coffee extract will be forced out of the jet openings into a space with great velocity. The assembly however does not use a pressurized liquid and is not arranged to provide interference between separate flows of beverage flows . The invention will be further illustrated with reference to the attached drawings , which schematically show a preferred embodiment according to the invention. It will be understood that the invention is not in any way restricted to this specific and preferred embodiment . In the drawings :

Fig . 1 is a schematic illustration of an apparatus according to an embodiment of the invention;

Fig . 2 depicts a frothing device according to an embodiment of the invention; Figs . 3 and 4 respectively show the frothing device of Fig . 2 accommodated in a holder in top view and bottom view according to an embodiment of the invention;

Figs . 5 and 6 show a cross-section, respectively a de- tailed part thereof, of a frothing device in a holder,-

Figs . 7A and 7B show a frothing device with a redirection device according to an embodiment of the invention, and

Fig . 8 shows a frothing device in a holder arranged to prevent interference of separate beverage flows according to an embodiment of the invention.

Fig . 1 is a schematic illustration of an apparatus 1 for preparing a beverage 2 suitable for consumption in a cup 3 with a fine-bubble froth layer 4. The apparatus 1 is capable of producing beverages 2 , such as coffee, tea, chocolate or cappuc- cino, in a predetermined volume , typically one or two cups . The apparatus comprises a liquid inlet 5 , a water container 6 for fresh water for the preparation of the beverage 2 , a pump 7 , a valve system 8 and a heating chamber 9 from which heated water is provided into a brew chamber 10. The brew chamber 10 involves the volume available for a container 11 with a filter, also referred to as pad, pod or pouch, pre-packed with a soluble or extractable product to obtain the brewed beverage 2 after the pressurized liquid has passed through the product . The brew chamber 10 has a brew chamber lid 12 , a closing seal 13 and a holder 14 enclosing the container 11. The apparatus 1 has a frothing device 15 for providing the fine-bubble froth layer 4 for the beverage 2.

In operation, water from the water container 6 is fed to the pump 7 to inject the water under pressure via the valve system 8 into the heating chamber 9. The pressure from the pump for the liquid is in the range of 1.2-3 bar, preferably 1.4 - 2.5 bar. In the heating chamber 9, the water is heated till it has a temperature just below the boiling point . Expansion water during heating is guided through the valve system 8 back into the water container 6. Subsequently, the heated and pressurized water is provided via the inlet 5 into the brew chamber 10 where it passes through the container 11 to obtain a flow F, shown in Figs . 6-8 , of brewed beverage . After the flow F of brewed beverage is output from the container 11, it passes the frothing device 15 that adds the fine-bubble froth layer 4 to the beverage 2 in the cup 3.

Figs . 2 -6 illustrate the frothing device 15 , its accommodation in the holder 14 and its operation according to an embodiment of the invention. The holder 14 is the subject of a co-pending patent application of the applicants , titled "Apparatus for preparing a beverage" , filed at the same day as the present application and is herewith incorporated in the present application by reference with respect to the structural charac- teristics of the holder 14. The frothing device 15 has a separating structure 16 to separate the flow F of brewed beverage from the container 11 into at least two separate flows S . It should be appreciated that the splitting of the flow F of brewed beverage may also be accomplished by another component of the apparatus 1 , i . e . the flow F of brewed beverage is provided at the frothing device 15 in a separated state . The separation structure 16 determines at least two chambers 17 and has a height H such that the bottom of the container 11 substantially abuts to the upper surface of the separation structure 16 , as shown in Figs . 3 , 5 and 6. For a replaceable frothing device 15 , the height H is preferably such that the separating structure provides grip to manually remove the frothing device 15 from its holder 14. Accordingly, the flow F of brewed beverage is almost immediately split into the separate flows S of brewed beverage . From the bottom of the chambers 17 a guiding channel 18 for each separate flow S of brewed beverage is formed in the surface of the frothing device and extends downstream to direct the separate flows S such that these flows interfere with or influence each other in an open space 19. The dimensions of the guiding channel are preferably in the sub-millimeter range, such as a channel width of 0 , 7 or 0 , 8 mm. It should be appreciated that these dimensions may vary within reasonable ranges and depend on the characteristics of the pump 7 , such as the pressure and/or the flow rate of the pump. The open space 19 is provided by the recess 20 in the frothing device 15. In the open space

19 , the frontal collision of the separated flows S with high impact velocity provided by the pressure of the pump 7 results in the fine-bubble froth layer 4. While both flows S have a high velocity, a high velocity impact will occur and a good mixture with air is obtained. The kinetic energy for the collision may be up to four times higher than known and comparable methods , while maintaining the same pressure from the pump 7. This results in a froth layer 4 with smaller bubbles and a higher stability.

The frothing device 15 is preferably made of a flexible material , such as silicon . The holder 14 has a chamber formed by- walls 21 to receive the frothing device 15. The walls 21 of the chamber leave an opening at the bottom and hold the frothing de- vice 15. The dimensions of the chamber are such that the insertion of the frothing device 15 , that is flexible and slightly oversized in comparison with the dimensions of the chamber, results in a tight fit . This tight fit is enhanced in operation of the apparatus 1 due to the pressure of the pump 7. The frothing device 15 preferably can be removed from the holder 14 and a cleaned or new device can be subsequently inserted.

In an embodiment of the invention, the separate flows S can be redirected to control the degree of interference between said flows . Figs . 7A, 7B and 8 show three embodiments to redi- rect the separate flows S . The redirection of the flows S in these embodiments may result in the absence of any interference between the separate flows S in which case no froth layer 4 is formed on the beverage 2. Alternatively, the interference can be reduced to influence the thickness of the froth layer 4. A redirection device 25 is provided to control the degree of interference between the separated flows S . In Fig . 7A the redirection device can be introduced from the recess 20 into the open space 19 of the frothing device 15 as indicated by the arrow A. Consequently, the redirection device 25 prevents the collision of the separated flows S of brewed beverage by redirection of said flows S and thus the formation of the fine- bubble froth layer 4 on the beverage 2 in the cup 3. The redi rection device 25 can be introduced at the option of a user of the apparatus 1. Instead of translation of the redirection device 25 in the direction indicated by the arrow T, the redirection device 25 may be permanently present in the open space 19. In this embodiment , the redirection device 25 is rotatably arranged, indicated by the arrow R, in the open space 19 and comprises a hole 26 as shown in Fig . 7B . If the redirection device 25 is rotated such that the hole 26 is aligned with the flows S , these flows of brewed beverage are able to collide with each other to form a froth layer . If the redirection device 25 is rotated such that the flows S cannot meet each other in the open space 19 due to the orientation of the hole, no interference of the separated flows S of brewed beverage will occur . In this situation, formation of the froth layer 4 is substantially prevented . Small rotations of the redirection device may reduce the interference between the separated flows S of brewed beverage to obtain a froth layer 4 of reduced thickness .

Fig . 8 illustrates another option by providing a valve system 27 , that prevents the separated flows S of brewed beverage to be guided towards each other . The holder 14 is adapted to allow passage of the separated flows S without interference resulting in a beverage 2 without a froth layer .

It should be acknowledged that the present invention is not limited to the above-described embodiment ; the frothing device 15 may e . g . be an integral part of the holder 14. Further, the separation of the flow or flows F of brewed beverage may be performed by another component of the apparatus 1. Still further, the flow F of brewed beverage may be split in more than two separate flows S that may e . g . influence each other in pairs or all together to obtain the froth layer 4.

Claims

1. An apparatus (1) for preparing a beverage (2 ) with a froth layer (4 ) comprising at least one liquid inlet (5) arranged to provide pressurized liquid to a container (11) with a soluble or extractable product to obtain a flow (F) of brewed beverage, wherein said apparatus is adapted to split said flow of brewed beverage into separate flows (S) and to guide said separate flows such that at least two of said flows interfere with each other.

2. The apparatus (1) according to claim 1 , wherein said container (11) is provided in a holder (14 ) and said holder has or is adapted to receive a frothing device (15) for guiding said separate flows (S) .

3. The apparatus (1) according to claim 1 , wherein said apparatus comprises a frothing device (15) for guiding said separate flows (S) such that said flows interfere in an open space (19) .

4. The apparatus (1) according to claim 1 , wherein said apparatus comprises a removable frothing device for guiding said separate flows .

5. The apparatus (1) according to claim 1 , wherein said apparatus comprises a frothing device (15) of silicon material for guiding said separate flows (15) .

6. The apparatus (1) according to claim 1 , wherein said apparatus is adapted to redirect said separate flows (S) to con- trol the degree of interference between said flows .

7. The apparatus (1) according to claim 1 , wherein said apparatus comprises a controllable redirection device (25) for redirecting said separate flows (S) .

8. The apparatus (1) according to claim 7 , wherein said apparatus comprises a frothing device ( 15) for guiding said separate flows (S) such that said flows interfere in an open space (19) and said redirection device (25) is arranged to be positioned or is positioned in said open space .

9. A frothing device (15) for an apparatus for prepar- ing a beverage with a froth layer, wherein said frothing device is adapted to have at least two separate flows (S) of brewed beverage interfere with each other.

10. The frothing device (15) according to claim 9 , wherein said frothing device is further arranged to split at least one flow (F) of brewed beverage into separate flows (S) of brewed beverage .

11. A method for preparing a beverage (2 ) with a froth layer (4) comprising the steps of : providing a pressurized liquid to a container (11) with a soluble or extractable product to obtain a flow (F) of brewed beverage ; splitting said flow (F) of brewed beverage into separate flows (S) , and guiding said separate flows (S) in a direction such that at least two of said flows interfere with each other .

12. The method according to claim 11 , wherein said method comprises the step of guiding said separate flows (S) such that said flows interfere in an open space (19) .

13. The method according to claim 11 , wherein said method further comprises the step of redirecting said separate flows (S) to determine the degree of interference between said flows .