WO2012090091A1 - Boiler for a machine for the production of an infused drink - Google Patents

Abstract

A boiler (30) for a machine for the production of an infused drink, preferably coffee, comprises at least one heat exchanger (46) suitable for containing a fluid to be heated by the boiler (30), at least one outlet junction (10) and one inlet junction (1) connected to said exchanger (46) respectively for the exit and entrance of said fluid from the latter. The outlet junction identifies a transit duct (14) of the fluid which extends from an entrance intake and comprises a fluid mixing device (16) applied to said entrance intake and jutting inside the exchanger (46) so as to be at least partially immersed in the fluid contained in said exchanger (46). Said fluid mixing device (16) comprises a plurality of entrance passages (20, 22) suitable for identifying respective sub-flows of the fluid in the duct (14) in different directions in such a way as to reduce the heat gradients of the fluid entering the outlet junction.

Description

DESCRIPTION

"Boiler for a machine for the production of an infused drink"

[0001] The present invention relates to a boiler for a machine for the production of an infused drink, preferably coffee, an inlet junction and an outlet junction of a fluid, and a coffee machine comprising such boiler or at least one of such junctions.

[0002] Traditionally, a machine for the production of an infused drink comprises a boiler for heating the fluid which will later be used for the infusion of such drink with an aromatic substance, for example coffee-flavoured.

[0003] The boilers of the prior art, which comprise connector junctions used indiscriminately in a plurality of applications, receive the fluid from suitable supply means and channel the heated fluid to the infusion chamber with the aforesaid substance.

[0004] Such devices however are not without drawbacks.

[0005] In particular, adjustment of the exchanger to obtain a determined temperature of the fluid coming out of the boiler, regardless of the speed of flow of the fluid and the number of times the machine is used, proves an extremely complex operation.

[0006] In fact it happens that when turning on the machine the first infused drinks are dispensed at an insufficiently high temperature so that the infusion is not completed; conversely, in the case of intensive use of the machine, for the subsequent drinks an excessively high temperature is reached so that the flavour of the drink is jeopardised. For example, in the case of coffee- flavoured drinks, an infusion temperature close to the boiling temperature of the water (at approx. 98°) leads to a tannin aroma manifesting itself in the drink, displeasing to most palates on account of its typically astringent taste.

[0007] It is the object of the present invention therefore to provide a boiler able to supply water to the infusion group at the most correct temperature for making coffee, that is at a temperature of 88°C to 92°C, preferably around 90°C, maintaining such correct temperature for as long as possible and thereby ensuring that all the drinks dispensed from the moment of turning on the machine to turning it off, have the same pleasant organoleptic characteristic .

[0008] Such object is achieved by a boiler according to claim 1, by means of the junctions according to claims 14 and 15, and by means of a coffee machine according to claim 16. The dependent claims show preferred embodiment variations .

[0009] The object of the present invention will now be described in detail, with the help of the attached drawings, wherein:

[0010] - figures 1 and 2 respectively show a perspective view and a lateral view of a boiler, which the present invention relates to, according to a possible embodiment;

[0011] - figures 3 and 4 respectively show perspective views of an outlet junction and an inlet junction used in the boiler in figure 1; and

[0012] - figure 5 shows a schematised longitudinal cross- section of the boiler in figures 1 and 2.

[0013] With reference to the aforesaid drawings, reference numeral 30 globally denotes a boiler for a machine for the production of an infused drink, in particular for the production of coffee, preferably espresso coffee.

[0014] The boiler 30 comprises at least one heat exchanger 46 suitable for containing a fluid to be heated by the boiler 30, e.g. water, at least one outlet junction 10 and at least one inlet junction 1 connected to such exchanger 46 respectively for the exit and entrance of said fluid from the latter.

[0015] As a result, the inlet junction is supplied by fluidic supply means to fill the exchanger, while the outlet junction is responsible for withdrawing the heated fluid from the exchanger to conduct it to an infusion chamber (not shown), preferably of a coffee machine. [0016] In the embodiment shown for example in figure 5, the boiler 30 comprises a boiler compartment 40 in which a heat exchange fluid is contained for heating the fluid which passes through the exchanger.

[0017] According to a preferred embodiment, the boiler compartment 40 is in thermic contact with an electric resistor 56 which heats the heat exchange fluid standing in the compartment, so as to increase the temperature of the fluid transitorily contained in the aforesaid exchanger.

[0018] For example, the electric resistor 56 is immersed in the heat exchange fluid.

[0019] According to a further embodiment, the heat exchange fluid is flowing, that is it is supplied to the boiler compartment 40 by means of a first pipe, and withdrawn from said compartment by means of a second pipe, such pipes (not shown) being for example opposite.

[0020] In any case, the fluid enters the inlet junction through the wall 32 of the boiler and is received in the exchanger 46 in thermic contact with the boiler compartment 40 and with the heat exchange fluid in a fluidically insulated manner from the latter.

[0021] In one embodiment, the heat exchanger 46 comprises a hollow body, for example prism-shaped, preferably cylindrical, preferably longer in length than the maximum diameter of the boiler, advantageously it too cylindrical, so as to traverse it fully.

[0022] In such way the coupling portions 12, 42 of the exchanger to the junctions 1, 10 lie outside the boiler compartment 40.

[0023] According to one advantageous embodiment, the at least one heat exchanger 46 extends in an inclined manner in relation to an imaginary vertical plane Y of the boiler. Such inclination is shown for example in figures 1 and 2.

[0024] The outlet junction identifies a transit duct 14 of the fluid which extends from an entrance intake, and comprises a fluid mixing device 16 applied to the entrance intake and jutting inside the exchanger 46 so as to be at least partially immersed in the fluid contained in said exchanger 46.

[0025] In other words, the mixing device is joined to the entrance intake of the duct 14 in such a way as to be at least partially submerged by the level of the fluid to be heated in the exchanger.

[0026] Such fluid mixing device 16 comprises a plurality of entrance passages 20, 22 suitable for identifying respective sub-flows of the fluid in the duct 14 in different directions in such a way as to reduce the heat gradients of the fluid entering the outlet junction. [0027] Since the fluid to be heated, entering the boiler, has a macroscopically homogenous but locally non- homogenous outlet temperature, for example in that a part of the fluid will proceed directly to the exit of the inlet junction, while other portions will come into contact with the heat exchanger 46, the fluid mixing device 16 permits the separation of the flow into a plurality of sub-flows, each entering from a different entrance passage 20 , 22 ; this way even the local heat difference are reduced, if not eliminated entirely, by the mixing of said sub-flows at different temperatures inside the device.

[0028] In other words, the flow of fluid entering the outlet junction is not formed exclusively of the pressurised fluid coming from the inlet junction with a flow which follows the main direction coinciding with the axis of the exchanger, but also comprises a plurality of sub-flows coming from secondary directions. This way the standing fluid also enters the outlet junction, at least next to the outlet junction, in the peripheral volume of the exchanger around said exchanger axis.

[0029] Advantageously, to obtain the desired temperature of the fluid coming out of the boiler, the exchanger can be heated to a lesser degree, thanks to the fact that the temperature of the sub-flows coming from zones peripheral to the main axis are at a higher temperature than that of the main flow coming from the inlet junction.

[0030] By avoiding overheating of the heat exchanger therefore the organoleptic characteristics of the drink are considerably improved.

[0031] According to one embodiment, the mixing device 16 is joined to the junction 10 for example by welding or screwing, preferably proximally to a second portion 54 coupling to the boiler 30.

[0032] According to a preferred embodiment, the mixing device 16 is positioned upstream of said duct 14 in the flow direction 18 of the fluid, or is positioned at least partially externally to the duct 14 or internally to the exchanger .

[0033] This way, the aforesaid mixing takes place before the fluid enters the duct.

[0034] Preferably, the mixing device 16 comprises a bottom, which extends around an incoming intake axis Z and in which a plurality of radial passages 20, 22 is performed flowing into the duct.

[0035] This way, the radial passages 20, 22 reciprocally converge so that the sub-flows restore a single flow of fluid in the duct 14, that is after the fluid has crossed the bottom.

[0036] Advantageously, the bottom comprises a plurality of passages 20, 22 distributed circumferentially and comprising at least one longitudinal fissure 22 which extends parallel to the intake axis Z.

[0037] Preferably, the bottom comprises a pair of diametrically opposite longitudinal fissures 22 which, in the assembled configuration, are preferably positioned substantially orthogonal to the intake axis Z.

[0038] Even more preferably, the pair of longitudinal fissures 22 lie in a vertical plane.

[0039] This way, since the hot fluids tend to position themselves at the top while cold fluids mainly at the bottom, and given the fact that the junction described is preferably mounted in an inclined position with respect to an imaginary vertical plane Y (figures 1 and 2), the mixing device is engaged by the sub-flows at different temperatures through special apertures which therefore help to improve the kinetics of the mixing.

[0040] Even more preferably, the radial passages 20, 22 comprise rows of holes, advantageously aligned along the intake axis Z.

[0041] One particularly preferred embodiment variation provides that, between the pair of diametrically opposite longitudinal fissures, three rows of holes circumferentially equidistant from each other are made; for example, in one embodiment the two rows of holes most proximal to the fissures are composed of two holes, while the central row has three holes. Should the mixing device 16 be made from a solid cylinder, for example in brass, all the rows of holes consist of three holes.

[0042] According to one variation, an axial passage is made in the bottom having a smaller transit cross-section than the cross-section of the duct 14 but preferably bigger than the holes forming the radial passages, where provided .

[0043] Preferably, the inlet junction 1 of the fluid in the exchanger 46 comprises an inlet portion 2 ' connectable to fluidic supply means.

[0044] The inlet portion 2 ' is therefore shaped in such a manner as to enable a stable, preferably sealed connection with the fluidic supply means.

[0045] For example, in accordance with figure 2 , the inlet portion 2' comprises an outer threading 28 , that is to say facing the side opposite the crossing chamber 34 defined by the junction, connectable to a duct (not shown) preferably for the supply of water.

[0046] The inlet junction 1 further comprises an outlet portion 2 " communicating with the inlet portion 2 ' , coupling to the boiler 30 and comprising a tubular wall 4.

[0047] As a result, the fluid enters the junction from the inlet portion 2 ' in the direction of the arrow 36, preferably flows through the crossing chamber 34 and comes out from the outlet portion 2 " .

[0048] In addition, such outlet portion is suitable for being connected to the heat exchanger 30, preferably in such a way that the fluid flows into the exchanger itself .

[0049] Preferably, the outlet portion comprises a portion coupling to the boiler and even more preferably a threaded portion 38, preferably externally, suitable for interacting with a complementary portion of the boiler, for example internally threaded.

[0050] According to a preferred variation, the tubular wall 4 extends proximally from the portion coupling to the boiler 30 and, in the case in point, from the threaded portion 38 in the supply direction of the fluid to the exchanger .

[0051] For example, the tubular wall 4 is welded to the threaded portion 38.

[0052] According to one embodiment, the inlet junction 1 comprises an innermost radial section 48 from which the tubular wall 4 extends and an outermost radial section 50, distanced from the innermost radial section 48 in such a way as to create a seat 52 for housing a sealing element, such as an O-ring or a gasket. [0053] The radially innermost section 48 is preferably the part of the inlet junction 1 bearing the threaded portion 38.

[0054] Advantageously, the housing seat 52 is lowered so as to at least partially contain the sealing element (not shown) . This way, when the radially outermost section 50 is brought closer to the wall 32 of the boiler, the sealing element is axially compressed between the aforesaid components.

[0055] In addition, the tubular wall extends along an entrance axis X of the fluid in the exchanger and such wall is of sufficient length to cross the thickness of the wall 32 of the boiler 30.

[0056] In other words, the axial length of the tubular wall is sufficient to completely cross the wall 32, so that the fluid can flow into the exchanger at a certain distance from said wall 32.

[0057] According to a preferred embodiment variation, the entrance axis X and the intake axis Z are parallel and, preferably, coinciding.

[0058] In addition, the tubular wall 4 identifies at least one nozzle 6, suitable for dispensing the fluid in a direction substantially radial to said axis X.

[0059] As a result, the nozzle 6 is positioned in such a way as to direct a jet of fluid in a radial direction, preferably orthogonal to the axis X, so as to improve the efficiency of the heat exchange in the boiler.

[0060] Consequently, since the nozzle projects the jet of fluid onto the heat exchanger 46, the temperature of the fluid supplied through the junction 1 is raised rapidly and in an extremely efficient manner.

[0061] The increase of the inlet speed is obtained both by opportunely selecting the diameters of the nozzle and, preferably, by making, in addition, a transit section inside the tubular wall 4 below the cross-section of the crossing chamber 34; this way the incoming fluid undergoes at least two subsequent accelerations caused by the aforesaid reductions of cross-section. As a result the incoming flow becomes turbulent.

[0062] According to one embodiment variation, the nozzle 6 is positioned distally to the entrance portion 2' and, in particular, at a free end 4' of the tubular wall 4.

[0063] Advantageously, the free end 4' of the tubular wall 4 is at least partially closed by an end wall 8, suitable for channelling the fluid towards the nozzle 6.

[0064] In other words, the end wall forms an axial barrier to the exit of the fluid, deviating the flow of the latter radially towards the nozzle.

[0065] According to one embodiment the end wall is made by deformation of the tubular wall 4, for example by radial flattening (and preferably by subsequent welding) of such wall 4. Preferably, the tubular wall 4 comprises a plurality of nozzles 6 positioned circumferentially around the tubular wall 4 so as to create a whirling movement of the fluid.

[0066] Such whirling movement acts in conjunction with the improved heat exchange to homogenise the temperature in the entire mass of fluid crossing the exchanger.

[0067] According to one variation, each of the plurality of nozzles 6 is positioned equidistant in relation to the adjacent nozzle. For example, the use of four nozzles reciprocally positioned at 90° has proven extremely advantageous .

[0068] The present invention relates, in addition, to an outlet junction 10 of a fluid and the inlet junction 1 according to any of the embodiment variations described above .

[0069] Lastly, the present invention relates to a coffee machine comprising at least one boiler 30 according to any of the embodiments shown, at least one inlet junction 1 and /or at least one outlet junction 10 of the type described.

[0070] Innovatively, the boiler and the junctions which the present invention relates to make it possible to lower the temperature curve of the infusion fluid for any infusion of the coffee machine.

[0071] The boiler of the invention in fact permits a reduced dispensing temperature to be reached and maintained, in particular between 88 °C and 92 °C which permits a high degree of constancy in obtaining pleasant taste characteristics of the drink.

[0072] In particular, in the case of coffee infusions, it is possible to prevent such drink from acquiring an unpleasant tannin flavour.

[0073] Advantageously, the junctions which the present invention relates to can be implemented in any existing boiler, given the multiplicity of connections they offer.

[0074] Advantageously, the junction which the present invention relates to is suitable for generating a high speed of flow in the boiler and a high degree of turbulence, so that the heat exchange proves efficient and does not create temperature gradients in the mass of fluid.

[0075] Advantageously, the junctions which the present invention relates to make it possible to achieve a high degree of fluidic tightness and, at the same time, to prevent such seal from being damaged by external factors.

[0076] Advantageously, the characteristics of the mixing device which the present invention relates to, make it possible to homogenise the temperature of the fluid coming out of the boiler, in part thanks to the increase in the transit cross section occurring in some embodiments .

[0077] A person skilled in the art may make variations or substitutions of elements with others functionally equivalent to the aforesaid embodiments of the boiler and of the junctions so as to satisfy specific requirements.

[0078] For example, in the schematisation in figure 5 two heat exchange jackets are shown with two pairs of connectors of the previous type; however alternative variations foresee that the boiler comprises a smaller or greater number of exchanger groups depending on the quantity of infusion chambers to be supplied with the fluid.

[0079] Again, alternatively or in addition to a heat exchange between fluids such as that illustrated above, the boiler according to one variation comprises a heating resistor, preferably in thermic contact with the heat exchanger.

[0080] Such variations are also contained within the scope of protection as defined by the following claims.

[0081] In addition, each of the variations described as belonging to a possible embodiment may be realised independently of the other embodiments described.

Claims

Claims

1. Boiler (30) for a machine for the production of an infused drink, preferably coffee, comprising:

at least one heat exchanger (46) suitable for containing a fluid to be heated by the boiler (30), e.g. water;

at least one outlet junction (10) and one inlet junction (1) connected to said exchanger (46) respectively for the exit and entrance of said fluid from the latter;

where said outlet junction identifies a transit duct (14) of the fluid which extends from an entrance intake and comprises ;

- a fluid mixing device (16) applied to said entrance intake and jutting inside the exchanger (46) so as to be at least partially immersed in the fluid contained in said exchanger (46) ;

said device (16) comprising a plurality of entrance passages (20, 22) suitable for identifying respective sub-flows of the fluid in the duct (14) in different directions in such a way as to reduce the heat gradients of the fluid entering the outlet junction.

2. Boiler according to claim 1, wherein the mixing device (16) comprises a bottom which extends around an incoming intake axis (Z) and in which a plurality of radial passages (20, 22) is provided flowing into the duct .

3. Boiler according to claim 2, wherein the plurality of passages (20, 22), distributed circumferentially, comprise at least one longitudinal fissure (22) which extends parallel to said intake axis (Z) .

4. Boiler according to claim 3, wherein said plurality of radial passages comprise a pair of diametrically opposite longitudinal fissures (22) lying in a vertical plane.

5. Boiler according to any of the claims from 2 to 4, wherein said plurality of radial passages comprise a plurality of hole (20) rows circumferentially equidistant to each other.

6. Boiler according to any of the claims from 2 to 5, wherein an axial passage having a passage cross-section smaller than the cross-section of the duct (14) is performed the bottom.

7. Boiler according to any of the claims from 2 to 6, wherein the rims (24,26) of the bottom which define said radial passage (20,22), optionally said axial passage, are scaled and/or made in a material such as to constitute a preferential accumulation area of solid deposits of said fluid, such as limescale.

8. Boiler according to any of the previous claims, wherein the inlet junction (1) comprises:

- an inlet portion (2' ) connectable to fluidic supply means; and

- an outlet portion (2") communicating with the inlet portion (2' ) , coupling to the boiler (30) and comprising a tubular wall (4), which extends along an entrance axis (X) of the fluid in the boiler (30) and of sufficient length to cross the thickness of a wall (32) of the boiler (30) ;

wherein the tubular wall (4) identifies at least one nozzle (6), suitable for dispensing the fluid in a direction substantially radial to said axis (X) .

9. Boiler according to claim 8, wherein the nozzle (6) is positioned distally to the entrance portion (2' ) .

10. Boiler according to claim 8 or 9, wherein the free end (4') of the tubular wall (4) is at least partially closed by an end wall (8), suitable for channelling the fluid towards the nozzle (6) .

11. Boiler according to claim 10, wherein the end wall (8) is made by deformation of the tubular wall (4).

12. Boiler according to any of the previous claims, comprising a plurality of nozzles (6) positioned circumferentially around the tubular wall (4), e.g. equidistant to each other, so as to create a whirling movement of the fluid.

13. Boiler according to any of the previous claims, wherein the tubular wall extends proximally from a coupling portion (38) to the boiler (30) e.g. a threaded portion .

14. Outlet junction (10) of a heated fluid, e.g. water, from a heat exchanger (46) of a machine for the production of an infused drink, such as coffee, wherein said junction:

- identifies a transit duct (14) of the fluid which extends from an entrance intake; and

- comprises a fluid mixing device (16) applied to said entrance intake and jutting inside the exchanger (46) so as to be at least partially immersed in the fluid contained in said exchanger (46);

said device (16) comprising a plurality of entrance passages (20, 22) suitable for identifying respective sub-flows of the fluid in the duct (14) in different directions in such a way as to reduce the heat gradients of the fluid entering the outlet junction.

15. Inlet junction (1) of a fluid such as water, to a heat exchanger (46) of a boiler (30) for a machine for the production of an infused drink, comprising:

- an inlet portion (2' ) connectable to fluidic supply means ;

- an outlet portion (2") communicating with the inlet portion (2'), coupling to the boiler (46) and comprising a tubular wall (4), which extends along an entrance axis (X) of the fluid in the boiler (30) and of sufficient length to cross the thickness of a wall (32) of the boiler (30);

wherein the tubular wall (4) identifies at least one nozzle (6), suitable for dispensing the fluid in a direction substantially radial to said axis (X) .

16. Coffee machine comprising at least one boiler (30) according to any of the claims from 1 to 13.