STEAM PLATE FOR A COFFEE MACHINE

Description

Technical field

[0001] The description concerns a steam wand for a coffee machine, a coffee machine with such a steam wand, and a system consisting of a coffee machine and a liquid container. Technical background

[0002] Coffee machines come in various forms and categories. They are typically used to brew coffee. After brewing, the coffee beverage is a drink in which aroma and flavor have been extracted from ground coffee using hot water. The coffee can then be consumed as is, or it can be enhanced with additional ingredients such as sugar or other sweeteners, flavored additives, and milk or milk substitutes.

[0003] Milk or milk substitutes can be added to the coffee beverage in their original form. However, it is often done using a milk frother to create a foam, which is then added to the coffee beverage, or the coffee beverage is added to the frothed milk.

[0004] In this context, milk of animal origin is frequently used. However, it is also conceivable to use milk substitutes of plant origin. Such milk substitutes can be made, for example, from peas, lupins, oats, hemp, almonds, rice, soy, etc. For the sake of readability, milk is often mentioned in this description. However, it should be understood that the reference to milk always refers to a frothy liquid of animal or plant origin that can be used as a coffee additive.

[0005] Several techniques exist for producing milk foam. For example, an element with an irregular surface structure can be set in motion or rotation within the milk, causing it to foam due to its composition (especially its fat and protein content). Alternatively, the milk can be foamed with a pressurized fluid or gas, such as steam or a steam-air mixture, by introducing this fluid or gas into the milk in a container at appropriate pressure. This second approach uses a steam wand to introduce the fluid or gas into the milk. Producing high-quality milk foam with a steam wand sometimes requires skill and experience on the part of the person operating it.The production of milk foam with a steam wand usually takes place in two phases: in a first phase, the steam wand or the container with milk is held so that the steam wand is close to the surface of the milk, thereby drawing in some air from the surface and introducing it into the milk; from a certain milk temperature, the steam wand is immersed deeper into the milk, so that in this second phase the milk is essentially swirled without the addition of further air.

[0006] US 2018 / 353001 A1 describes a steam lance with steam outlet openings on a lateral surface. The steam lance has a substantially cylindrical body. At one end are inlet openings, each connected via a pipe to one of the steam outlet openings. A step with two mutually perpendicular surfaces is provided at the end face. The steam outlet openings are arranged on these surfaces in the form of nozzles, so that the two exiting steam jets intersect.

[0007] WO 2021 / 074829 A1 describes a steam lance with steam outlet openings. The steam outlet openings are arranged in a conical end section of the steam lance, so that the steam outlet openings release the steam in a star-shaped and straight line away from the steam lance. Description

[0008] It can be considered a task to improve the production of high-quality milk foam using a steam wand.

[0009] This problem is solved by the subject matter of the independent claim. Further embodiments are described in the dependent claims and in the following description.

[0010] According to the invention, a steam wand for a coffee machine comprises a rod-shaped lance body and an outlet area for releasing steam and / or air from the interior of the lance body into its surroundings. The outlet area is arranged on a circumferential surface of the lance body and is configured to release the steam and / or air in such a way that the steam and / or air forms a flow that has a tangential direction with respect to the lance body and flows tangentially out of the lance body. The circumferential surface is curved in the circumferential direction of the lance body. The outlet area is configured such that the flow direction of the steam and / or air runs perpendicular to a longitudinal axis or direction of extension in the longitudinal direction of the lance body, at least section by section, along the circumferential surface.The outlet area is designed in such a way that the flow formed by the steam and / or the air flows at least section by section around the lance body and at least partially and section by section follows a curvature of the outer surface in the circumferential direction.

[0011] The steam wand is typically connected to the coffee machine or a source of a pressurized fluid (steam and / or air). For this purpose, the coffee machine or the source has a water reservoir with a heating element and a pump. The pump transports the fluid to the steam wand, where it is dispensed at a specific velocity.

[0012] The steam wand is designed, for example, as a tube or rod. It typically has an elongated or linear end section, which is immersed in the milk to be frothed. The steam wand may be mounted on the coffee machine housing in a way that allows it to be moved, swiveled, or rotated, enabling a container of milk to be placed underneath and the wand to be immersed in the milk.

[0013] In the steam lance described here, the outlet for steam and / or air is located on a surface of the lance body. The outlet is designed such that the steam and / or air exits in a tangential flow direction. The steam and / or air is therefore neither expelled from an end face of the steam lance in the longitudinal direction nor radially from the surface. Rather, the outlet guides the steam and / or air in a direction with a tangential component of motion relative to the lance body.

[0014] The fact that steam and / or air flows tangentially from the lance body means that the flow direction of the steam and / or air is perpendicular to a longitudinal axis or extension direction of the lance body. The flow then flows at least section by section along the surface of the lance body to indicate or create a circular or spiral flow.

[0015] The flow exiting the outlet area has a tangential flow direction and flows tangentially out of the lance body and at least partially around the lance body. This means that the exiting flow has at least one directional component that extends tangentially around the lance body.

[0016] With this steam wand design, the fluid exiting the outlet typically does not move in a completely linear fashion after leaving the outlet. Instead, the curved or convex surface of the wand body causes the fluid to at least partially and section by section follow the curvature of the surface. This advantageously promotes a swirl or rotation within the milk container, enabling the production of high-quality milk foam.

[0017] Such a swirl or rotation cannot be generated to the same degree if the fluid exits the outlet area in a straight line (either longitudinally or radially along the lance body). To create a swirl in the milk container with a straight-flowing fluid, it is necessary to manually adjust the container's position relative to the steam wand. In the steam wand described here, the outlet area is positioned so that the exiting fluid, due to the predetermined tangential flow direction and the fact that it follows the contour of the curved / convex surface in the circumferential direction, inherently generates a swirl in the milk container.

[0018] According to one embodiment, the outlet area includes an opening, the opening being arranged such that the steam and / or air flowing from it flows at least section by section in the circumferential direction along the outer surface.

[0019] According to another embodiment, the opening is a slot or a nozzle.

[0020] The outlet area can also contain several such openings. For example, the outlet area may contain several slots, each extending longitudinally along the lance body. These slots can be arranged side by side circumferentially. It is also conceivable that two or more slots are arranged longitudinally side by side and separated from each other by a thin rib. The outlet area can also contain several nozzles, which are distributed regularly or irregularly across the outer surface of the lance body. It is also conceivable that both slots and nozzles are used in the outlet area. For example, the nozzles can be designed to release steam, and the slots can be designed to introduce air.

[0021] According to another embodiment, the lance body has a circular cross-section and the outlet area extends along the longitudinal direction of the lance body on the outer surface.

[0022] Typically, the outlet area on the surface of the steam wand extends further longitudinally than circumferentially. This design allows for the creation of a circular flow around the wand at various depths within the milk. A steam wand with this design creates a circular flow in a liquid container when it is immersed and steam and / or air is expelled from the outlet area.

[0023] According to a further embodiment, the steam lance also has a closing slide which is movable in the longitudinal direction of the lance body and is arranged so that the closing slide covers or releases a variable area of ​​the outlet area.

[0024] The sealing slide is arranged on or within the lance body. For example, the sealing slide may be slidably held within the lance body, such as in a sliding bearing or similar mechanism. The sealing slide can be moved longitudinally along the lance body, thereby covering part of the outlet area. This reduces the effective cross-section or the number of free openings in the outlet area. This occurs particularly when the sealing slide is moved towards an end face of the lance body. By moving the sealing slide towards the end face, it covers part of the outlet area and the openings within it, thus reducing the area of ​​the outlet from which steam and / or air escapes. In this way, the outlet area can be adjusted to a fill level in a container, so that steam and / or air preferably escape only from the portion of the outlet area that is submerged in the liquid.

[0025] According to another embodiment, the steam lance further comprises an actuating device, wherein the actuating device is mechanically coupled to the closing slide so that the closing slide can be moved by means of the actuating device.

[0026] The actuating device serves to move the sealing slide into the desired position so that no steam and / or air escapes from the outlet area above the liquid. This ensures that all the steam and / or air is introduced into the milk.

[0027] According to another embodiment, the actuating device is a lever or a float.

[0028] The actuating device allows the shut-off valve to be moved into a desired position. This can be done, for example, using a manually operated lever. Alternatively, a float is mounted on the steam lance and mechanically coupled to the shut-off valve. The float is designed to float on the surface of a liquid, so that it moves relative to the lance body when the lance body is immersed to a greater or lesser depth. This relative movement of the float to the lance body also moves the shut-off valve within the lance body, covering a larger or smaller area of ​​the outlet. Thus, the shut-off valve can be positioned within the outlet area according to the fill level or the relative position of the outlet area to the liquid.

[0029] The valve slide can be coupled to the float in such a way that the outlet area on the lance body is only opened at a certain distance below the liquid's surface. In other words, the valve slide has an offset along the longitudinal direction of the lance body relative to the float, such that a lower edge of the valve slide is closer to the end face of the lance body than a lower edge of the float.

[0030] According to a further embodiment, the steam lance has a first line and a second line, which are located inside the steam lance and extend to the outlet area. The first line is designed to carry steam to the outlet area. The second line is designed to carry air to the outlet area.

[0031] A steam-air mixture can be generated using the first and second lines, which escapes from the outlet area into the surrounding milk.

[0032] It is also conceivable that a vapor-air mixture is generated in front of the outlet area and is led to the outlet area by means of a single pipe.

[0033] According to another aspect, a coffee machine is specified which is designed to brew a coffee beverage. The coffee machine has a steam wand as described herein.

[0034] According to another aspect, a system with a coffee machine as described herein and a container is specified. The steam wand is designed to be immersed in a liquid located in the container and to froth the liquid using steam and / or air exiting the steam wand's outlet.

[0035] The steam wand described here, both on its own and in conjunction with a coffee machine or system, improves the frothing and heating of milk by setting steam and / or air into circumferential flow around the wand body at the outlet. The resulting swirl ensures an even distribution of the introduced air in the milk and improves the quality of the frothed milk. With the steam wand geometry described here, the production of milk foam is virtually independent of the wand's position within the milk. The outlet is preferably designed so that all openings within it expel the fluid in the same tangential flow direction. Brief description of the characters

[0036] The following section describes exemplary embodiments with reference to the accompanying drawings. The illustrations are schematic and not to scale. Identical reference numerals refer to identical or similar elements. The drawings show: Fig. 1 is a schematic representation of a system with a coffee machine and a milk container. Fig. 2 is a schematic representation of a steam wand in a milk container. Fig. 3 is a schematic representation of the cross-section of a steam wand. Fig. 4 is a schematic representation of the cross-section of a steam wand. Fig. 5 is a schematic representation of a steam wand in a milk container. Fig. 6 is a schematic representation of a steam wand. Fig. 7 is a schematic representation of a steam wand. Fig. 8 is a schematic representation of a steam wand. Fig. 9 is a schematic representation of a steam wand. Fig. 10 is a schematic representation of a steam wand. Fig. 11 is a schematic representation of the cross-section of a steam wand. Detailed description of implementation examples

[0037] Fig. 1 Figure 1 shows a system 1 with a coffee machine 10 and a container 200. The container 200 can be called a milk container, for example, and contains a liquid 210, which is usually milk. The liquid 210 is filled in the container 200 to a fill level 220, where the fill level 220 also corresponds to the surface area of ​​the liquid 210. Not all technical elements of the coffee machine 10 for the brewing process of a coffee beverage are shown here. Rather, only some of those elements are shown that are directly or indirectly functionally related to the steam wand 100.

[0038] The coffee machine 10 has a water tank 12, a boiler 14, and a pump 16. The water tank 12 holds water for brewing a coffee beverage and for generating steam. The boiler 14 heats the water. The pump 16 transports the water or steam to the steam wand 100.

[0039] The steam wand 100 is rigidly or movably attached to the coffee machine 10. The steam wand 100 can, in principle, be shaped in any way. The steam wand 100 has a lance body 101. The steam wand 100 as a whole, or the lance body, is preferably made of metal, for example, stainless steel. Other materials can be used, for example, plastic or ceramic, whereby the type of material has no direct influence on the design of the steam wand 100 and the outlet area described below.

[0040] Fig. 2 Figure 1 shows a steam lance 100 with a surface area 102 and an outlet area 110 located on the surface area 102. The steam lance is immersed in the liquid 210 of the container 200. The outlet area 110 is completely immersed in the liquid 210 and is located below the surface of the liquid 210.

[0041] Fig. 3 Figure 1 shows a schematic representation of the cross-section of the steam lance 100 in the area where the outlet section 110 is located on the outer surface 102 of the lance body. This representation shows that the cross-section of the steam lance is essentially circular and has a circumferentially curved or convex outer surface. The steam lance 100 may have a radial constriction 104. The outlet section 110 is arranged in this radial constriction, so that steam and / or air exiting the outlet section 110 creates a flow 180, which has a flow component in the circumferential or tangential direction of the steam lance.

[0042] Fig. 4 shows a schematic representation of the cross-section of the steam lance 100, similar to Fig. 3 , however, with a differently designed outlet area 110. While the outlet area 110 in Fig. 3 A slot that extends into the drawing plane is the outlet area 110 in Fig. 4 A nozzle located on the outer surface 102 of the steam lance 100. The nozzle can be oriented so that it also generates a flow 180° in the circumferential direction of the steam lance 100.

[0043] Both in Fig. 3 as well as in Fig. 4 Steam and / or air exiting from the outlet area 110 follows the convex outer surface 102 of the steam wand 100 and creates a swirl in the container that is advantageous for the formation of milk foam.

[0044] Fig. 5 Figure 1 shows a steam lance 100 in the liquid 210 of the container 200. The outlet area 110 is located completely in the liquid 210, i.e., below the surface of the liquid 210. Steam and / or air exits from the outlet area 110 and is guided circumferentially around the steam lance 100, as shown by the arrows for the flow 180.

[0045] Fig. 6 Figure 1 shows a steam lance 100 with an outlet area 110 for steam and / or air and a shut-off slide 120. The shut-off slide 120 can be moved along the direction of movement 122, thereby covering or uncovering part of the outlet area 110, depending on the direction in which the shut-off slide 120 is moved. The direction of movement 122 of the shut-off slide 120 preferably corresponds to the longitudinal direction 105 of the steam lance 100.

[0046] In an initial state, the shut-off slide 120 is positioned such that there is no overlap between the shut-off slide 120 and the outlet area 110. In this initial state, the shut-off slide 120 is further away from the end face 103 of the steam lance 100 than is the case in Fig. 6 is shown. Fig. 6 An intermediate state is shown in which the closing slide 120 partially covers the outlet area 110. In a state of maximum coverage, the closing slide 120 can cover the entire outlet area or a large part of it. The closing slide 120 can be designed and arranged such that, in the state of maximum coverage, it covers a desired section of the outlet area 110.

[0047] In its initial state, the sealing slide 120 is at its maximum distance from the end face 103 of the steam lance 100. In the state of maximum overlap, the sealing slide 120 is closer to the end face 103.

[0048] Furthermore, the Fig. 6 It can be deduced that steam and / or air exits from the outer surface 102 of the steam lance 100 described here and not from the end face 103.

[0049] In Fig. 6 The shut-off slide 120 is shown with dashed lines because, in this example, it is located inside the steam lance 100. For example, the shut-off slide 120 may be located in or on the inner surface of the steam lance 102. The shut-off slide 120 may be slidably mounted in or on the surface 102 to allow movement 122 in the longitudinal direction 105 of the steam lance. The shut-off slide 120 may be sealed against the surface 102 by a gasket (not shown).

[0050] Fig. 7 Figure 1 shows an example of how the slide valve 120 can be moved along direction 122 with respect to the steam lance 100 to cover or uncover a covered area 125 of the outlet area 110. The further the slide valve 120 is moved relative to the outer surface 102 towards the end face 103, the larger the covered area 125 becomes and the smaller the effective cross-section of the opening of the outlet area 110 from which steam and / or air can escape.

[0051] The shut-off valve 120 is connected to an actuating device 130 via a linkage 140. The actuating device 130 is located outside the outer surface 102 of the steam lance 100. The actuating device 130 can be moved along the outer surface 102 as indicated by the direction of movement 132. The actuating device 130 is mechanically coupled to the shut-off valve 120. As soon as the actuating device 130 is moved, the shut-off valve 120 moves relative to the outlet area 130.

[0052] The actuating device 130 can be designed as a manually operated lever or as a float. The size of the outlet area 110 can be adjusted to the liquid level in the container by means of the actuating device 130. If the actuating device 130 is designed as a float, it floats on the surface of the liquid in the container and moves the closing slide 120 to a corresponding position relative to the outlet area 110, depending on the liquid level.

[0053] Fig. 8 Figure 1 shows an exemplary design of the outlet area 110 of the steam lance 100. In this variant, the outlet area 110 contains two slots 112 which extend in the longitudinal direction of the steam lance 100. Fig. 9 Figure 1 shows an alternative embodiment of the outlet area 110, in which the outlet area 110 has several nozzles 114. The slots 112 and the nozzles 114 are arranged and designed such that they create a flow 180 (see Figure 1). Fig. 3 and Fig. 4 ) cause.

[0054] Fig. 10 Figure 1 schematically shows the supply of steam and / or air to the outlet area 110 of the steam lance 100. Inside the steam lance 100, a first line 150 and a second line 160 are arranged. The first line 150 is, for example, an air line, and the second line 160 is, for example, a steam line. Steam and / or air is selectively supplied to the outlet area 110 via these two lines 150 and 160.

[0055] The type, quantity and pressure of the fluid (steam and / or air) supplied to the outlet area 110 can be controlled via input elements (not shown) on the coffee machine 10 (see Fig. 1 ) are set or specified.

[0056] Fig. 11 shows a cross-sectional view of the steam lance 100 from Fig. 10 In Fig. 11 It can be seen that the first line 150 and the second line 160 are led to the outlet area 110, where steam and / or air are released into the environment.

[0057] Even if in the Fig. 10 und 11 Since the first line 150 and the second line 160 are depicted as separate lines within the interior of the steam lance 100, it is understood that steam and / or air can be routed to separate areas within the interior volume of the steam lance 100 and that separate lines are not required for this purpose. It is also conceivable that a steam-air mixture is routed to the outlet area 110 via a single line if this mixture is generated before being fed into the individual line. Reference symbol list

[0058] 1 System 10 Coffee machine 12 Water tank 14 Boiler 16 Pump 100 Steam wand 101 Lance body 102 Casing surface 103 End face 104 Radial constriction 105 Longitudinal direction 110 Outlet area 112 Slot 114 Nozzle 120 Shut-off slide 122 Direction of movement 125 Covered area 130 Actuating device (lever, float) 132 Direction of movement 140 Linkage 150 First line, steam line 160 Second line, air line 180 Flow 200 Container 210 Liquid 220 Fill level

Claims

1. A steam distributor (100) for a coffee machine (10), comprising: a rod-like lance body (101); an outlet region (110) for discharging steam and / or air from an interior of the lance body (101) into an environment of the lance body (101); wherein the outlet region (110) is arranged on a lateral surface (102) of the lance body (101) and is configured to discharge the steam and / or the air such that the steam and / or the air forms a flow (180) which has a tangential flow direction with respect to the lance body and flows tangentially out of the lance body (101); characterized in that the lateral surface (102) is curved in the circumferential direction of the lance body (101); the outlet region (110) is configured such that the flow direction of the steam and / or of the air runs perpendicular to a longitudinal axis or direction of extent in the longitudinal direction (105) of the lance body (101) at least in sections along the lateral surface (102); the outlet region (110) is configured such that the flow (180) formed by the steam and / or the air flows at least in sections around the lance body (180) and follows at least partially and in sections a curvature profile of the lateral surface (102) in the circumferential direction.

2. The steam distributor (100) according to claim 1, wherein the outlet region (110) contains an opening; wherein the opening is arranged such that steam and / or air flowing therefrom flows at least in sections in the circumferential direction along the lateral surface.

3. The steam distributor (100) according to claim 2, wherein the opening is a slot (112) or a nozzle (114).

4. The steam distributor (100) according to any one of the preceding claims, wherein the lance body (101) has a circular cross section and the outlet region (110) extends on the lateral surface (102) of the lance body (101) in the longitudinal direction (105) of the lance body (101).

5. The steam distributor (100) according to any one of the preceding claims, wherein the steam distributor (100) further comprises a closure slide (120) which is movable in the longitudinal direction (105) of the lance body (101) and is arranged such that the closure slide (120) covers or releases a variable region (125) of the outlet region (110).

6. The steam distributor (100) according to claim 5, wherein the steam distributor (100) further comprises an actuating device (130); wherein the actuating device (130) is mechanically coupled to the closure slide (120) so that the closure slide (120) can be displaced by means of the actuating device (130).

7. The steam distributor (100) according to claim 6, wherein the actuating device (130) is a lever or a float.

8. The steam distributor (100) according to any one of the preceding claims, wherein the steam distributor (100) comprises a first conduit (150) and a second conduit (160) which are located in an interior of the steam distributor and extend to the outlet region (110); wherein the first conduit (150) is configured to guide steam to the outlet region (110); wherein the second conduit (160) is configured to guide air to the outlet region (110).

9. A coffee machine (10) configured to brew a coffee beverage; wherein the coffee machine comprises a steam distributor (100) according to any one of claims 1 to 8.

10. A system (1), comprising: a coffee machine (10) according to claim 9, and a container (200); wherein the steam distributor (100) is configured to be immersed in a liquid (210) located in the container (200) and to foam the one liquid (210) by means of steam and / or air exiting from the outlet region (110) of the steam distributor (100).