Method for preparing a very hot beverage in a container by a beverage dispensing machine

Abstract

The invention relates to a method for preparing a very hot beverage in a container from a beverage dispensing machine comprising a control circuit, a hot water and / or steam generator and a rotary stirring device comprising a rotary tool around an axis A and intended to cooperate with the beverage contained in the container. The rotary stirring device comprises a delivery conduit for delivering hot water and / or steam to the rotary tool. The method comprises the following steps: a) placing the container on a support under the rotary stirring device, then placing the rotary tool in the container; b) selecting and starting, by the control circuit, a preparation based on very hot water, c) injecting a volume V of hot water through the delivery conduit, d) injecting steam through the delivery conduit to bring the water to a temperature higher than 80°C; d1) during step d): operating the rotary tool to stir the preparation and break the bubbles formed in the preparation under the action of the steam, thereby avoiding splashing outside the container.

Description

Technical Field

[0001] This invention relates to the preparation of very hot beverages in containers using a beverage dispensing machine. Very hot beverages are understood to be beverages with a temperature of at least 80°C. For example, the beverage could be based on black tea, requiring very hot water of approximately 85°C to 95°C, or any other beverage requiring water at a temperature of at least 80°C, to effectively process one or more ingredients incorporated into the beverage's composition, thereby extracting all flavors. Background Technology

[0002] Hot water-based beverage dispensers are common. Some of these dispensers include control circuitry, a hot water and / or steam generator, and a rotary stirring device comprising a rotating tool about a vertical axis and used to interact with a beverage contained in a container to prepare the beverage. The rotary stirring device also includes a delivery conduit for conveying hot water and / or steam to the rotating tool.

[0003] Some one-ingredient-based beverages, such as tea or coffee, require very hot water (at least 80°C) to brew properly and release all their aromas during the brewing process. Traditionally, very hot water is poured into a container placed on the base of a dispenser, with the ingredient placed inside. The ingredient may be in bulk and placed in a basket or brewing ball type filter, or pre-packaged in a filter bag. During the pouring of very hot water into the container, it quickly loses several degrees of temperature; as a result, the water in the container is often not hot enough to properly brew the ingredient.

[0004] In European patent EP2667756B1, a beverage dispenser includes a heated base on which a container rests when hot water is poured. The heated base allows for reheating of the bottom of the container and the liquid contained therein during the brewing process. A rotary stirring device may optionally be immersed in the container and activated to mix the liquid and, appropriately, extract the aroma of the ingredients. Summary of the Invention

[0005] The first objective of this invention is to extract all the aromas of the ingredients during the brewing process by using very hot water, i.e., water at a temperature of at least 80°C, so as to meet all recommended water temperatures depending on the different ingredients to be brewed, such as green tea, black tea, or coffee, and even for substances to be diluted, such as milk powder or chocolate powder. Therefore, this method allows for the convenient preparation of a wide variety of beverages using a beverage dispenser.

[0006] A second objective of this invention is to prevent very hot beverages from splashing during their preparation. The applicant has observed that the preparation of very hot beverages, reaching or exceeding 80°C, during the reheating of the liquid contained in the container, generates bubbles in the container. These bubbles can eject from the container and potentially soil the surface on which the beverage dispenser is placed, or even burn people during beverage preparation.

[0007] The third objective is to reduce beverage preparation time by brewing the ingredients in the container more quickly.

[0008] Therefore, the present invention relates to a method for preparing a very hot beverage in a container by a beverage dispensing machine. The beverage dispensing machine includes a control circuit, a hot water and / or steam generator, and a rotary stirring device comprising a rotating tool about an axis A and for engaging with the beverage contained in the container during its preparation. The rotary stirring device includes a delivery conduit for conveying hot water and / or steam to the rotating tool.

[0009] According to the present invention, the method includes the following steps:

[0010] a) Place the container on the support below the rotary stirring device, and then put the rotating tool into the container;

[0011] b) Select and initiate beverage preparation based on very hot water from the control circuit.

[0012] c) Inject a volume V of hot water into the container via hot water and / or steam delivery pipes.

[0013] According to the invention, the method includes step d) after step c), which includes injecting steam through a delivery conduit to bring the water to a temperature of 80°C or higher. Then, during step d), step d1) includes operating a rotating tool to agitate the article and break any air bubbles formed in the article under the action of steam, thereby preventing splashing outside the container.

[0014] Therefore, unlike the aforementioned European patent EP2667756B1, the reheating of the water in the container is achieved by directly injecting steam into the water during beverage preparation, rather than by reheating the bottom of the container with a heating base on the machine. Thus, the method according to the invention allows for similar results to be achieved using a simpler beverage preparation machine—without a heating base. Direct reheating of the water in the container with steam makes it easy to reach a temperature of 95°C, which is necessary for perfect brewing of certain ingredients (especially certain black teas). The agitation of the very hot water in the container during steam heating breaks up any air bubbles formed within the container, thereby preventing very hot beverage products from splashing out of the container.

[0015] According to a preferred embodiment of the method for preparing a very hot beverage, which is the subject of this invention, in step d), steam is injected through a delivery conduit to bring the water to a temperature above 90°C. The steam injection time is proportional to the amount of water poured into the container to achieve a temperature above 90°C, and the control circuit is programmed for this purpose.

[0016] According to the method for preparing a very hot beverage, which is the subject of this invention, during step d1), a rotating tool is continuously operated at a speed v1. Preferably, the duration of step d) is equal to the duration of step d1). However, a variation of the method may be provided, according to which step d1) begins a period of time after the start of step d), which is programmed on the control circuit and corresponds to an estimated time for bubbles to begin forming in the container after steam release, and depends on the volume V of hot water poured into the container.

[0017] According to one embodiment of a method for preparing a very hot beverage, the beverage comprises ingredients to be brewed, which may be introduced into a container during or after step a). Furthermore, the method includes step c1) at the end of step c), which includes operating a rotating tool during ingredient brewing, such that the ingredients to be brewed can be brewed more quickly by stirring.

[0018] Preferably, during step c1), the rotating tool is operated intermittently at a rotational speed v2, the rotating tool operating during time T1 and stopping during time T2. Preferably, the ratio of time T1 to time T2 is greater than 0.1.

[0019] Preferably, during step d1), the rotating tool operates continuously at a rotational speed v1. Furthermore, the ratio of speed v1 to speed v2 is greater than 0.5.

[0020] Preferably, the ingredients to be brewed, particularly tea leaves, are placed in a receiving basket included in the container. The receiving basket is detachably placed in the container and receives the ingredients to be brewed.

[0021] According to one embodiment of a method for preparing a very hot beverage, the ingredient to be brewed is black tea. Furthermore, in step d), steam is injected through a delivery conduit to bring the water to a temperature above 90°C.

[0022] According to methods used for preparing very hot beverages, a rotating tool with peripheral fins is used for stirring. This allows the material to be brewed to avoid getting stuck in the rotating tool during stirring, especially when ingredients such as loose tea leaves are involved. Attached Figure Description

[0023] The following description presents the features and advantages of the invention. This description is based on figures, in which:

[0024] Figure 1 A perspective view shows one embodiment of a beverage dispensing machine having a container placed on the machine and a rotating stirring device including a rotating tool immersed in the container;

[0025] Figure 2 The beverage dispenser is shown from the front, without a container, with the rotating stirring device in a lowered position;

[0026] Figure 3 The illustration schematically shows the interior of a beverage dispenser according to one embodiment, particularly the system for generating hot water and steam;

[0027] Figure 4 The design of a rotary stirring device according to a preferred embodiment is shown in more detail;

[0028] Figure 5 A rotating tool on a rotary stirring apparatus according to a preferred embodiment is shown in more detail;

[0029] Figure 6 A basket filter is shown, designed to be placed directly in the container and receive the ingredients to be brewed, especially loose tea;

[0030] Figure 7 The filter is shown placed directly in the container, with the rotating tool submerged in the filter;

[0031] Figure 8 The steps of a method for preparing a very hot beverage according to a first embodiment are illustrated schematically.

[0032] Figure 9 The steps of a method for preparing a very hot beverage according to a second embodiment are illustrated schematically.

[0033] Figure 10 The steps of a method for preparing a very hot beverage according to a third embodiment are illustrated schematically. Detailed Implementation

[0034] In the following description, the term "machine" is used to refer to a beverage dispensing machine. Similarly, the term "method" is used to refer to a method according to the invention for preparing a very hot beverage.

[0035] In the following description, terms related to spatial location, such as “horizontal,” “vertical,” “low,” “up,” “high,” “low,” “left,” “right,” etc., may be used to consider the position of the machine on the work surface when in use, with the rotating agitator facing the user.

[0036] See Figures 1 to 3The machine 1 includes a frame 2, a support 3 on which a container 4 can be placed during beverage preparation, a dispensing device 5, a rotary stirring device 6 that allows stirring of the product contained in the container 4, and a nozzle 7 that allows dispensing of beverages based on, for example, coffee and / or chocolate. The dispensing device 5 includes a reservoir 8 that contains cold water and allows the supply of hot water and / or steam to the rotary stirring device 6, as well as the supply of brewed or non-brewing beverages (coffee, chocolate, etc.) to the nozzle 7.

[0037] The rotary stirring device 6 includes a rotating tool 9 about axis A and for engaging with a beverage product contained in container 4. This axis A is vertically defined on machine 1. The rotary stirring device 6 is translatably mounted along axis A within a guide 10 disposed on frame 2, allowing it to adjust according to its raised position (not shown) and... Figure 1 , Figure 2 and Figure 6 The lowering position is shown, in which the rotating tool 9 is disengaged from the container 4 to allow the container 4 to be disengaged, in which the rotating tool 9 is inserted into the container 4, and the container 4 is placed on the support 3 below the rotating stirring device 6.

[0038] like Figure 3 and Figure 4 The implementation of the rotary stirring device 6 shown is known in the beverage dispensing machine developed by the applicant, and those skilled in the art can refer to it. Figure 4 As shown, the rotary stirring device 6 includes a main body 11, which is translatably mounted within a guide member 10 along axis A. An electric motor 12 and a steam chamber 13 are disposed within the main body 11. The electric motor 12 rotates a drive shaft 14 along axis A. The drive shaft 14 is pivotally mounted relative to the steam chamber 13 at axis A via two sealed rolling bearings 15 and 16, creating a seal between the steam chamber 13, the bearings 15 and 16, and the drive shaft 14, thus defining a chamber 17. Radial channel 18 ( Figure 3 (As shown) Passing through the steam box 13 and leading to the chamber 17, the radial channel 18 is connected to the flexible conduit 19 ( Figure 3 As shown), the flexible conduit 19 allows for unimpeded translational movement relative to the guide member 10 along the axis A of the rotating stirring device 6 between raised and lowered positions. The flexible conduit 19 supplies hot water and / or steam to the chamber 17. The drive shaft 14 has a hollow portion 20 extending along axis A, which opens into the chamber 17 on one side via a hole 21 passing through the hollow portion 20 and onto the lower end 22 of the drive shaft 14 on the other side. Figure 3 and Figure 4As shown, the rotary stirring device 6 includes a tubular portion 23 extending along axis A. The lower end 24 of the tubular portion 23 is assembled with the rotary tool 9, preferably by fitting or by a bayonet assembly. The upper end 25 of the tubular portion 23 is detachably connected to the drive shaft 14. Thus, the flexible conduit 19, the radial channel 18, the chamber 17, the hollow portion 20 of the drive shaft 14, and the tubular portion 23 define a delivery conduit 26 for conveying hot water and / or steam to the rotary tool 9.

[0039] like Figure 3 As schematically shown, the dispensing device 5 of machine 1 includes a supply circuit 27, which includes a pump 28 and a boiler 29 containing a heating element 30. The supply circuit 27 is connected upstream to a water reservoir 8 and downstream to a solenoid valve 31, allowing hot water and / or steam to be supplied to the delivery conduit 26 of the rotary stirring device 6, or to hot water to the brewing chamber 32, which is itself connected to a nozzle 7. A control circuit 33 allows the pump 28, the heating element 30 of the boiler 29, and the solenoid valve 31 to be actuated according to the beverage preparation program selected on machine 1; machine 1 includes a control keyboard 34 for this purpose. Figure 1 and Figure 2 This allows for the selection of beverage products.

[0040] For example, when the machine 1 is running in the mode of preparing coffee-type beverages, the control circuit 33 starts the pump 28 and the heating element 30 to produce hot water at a temperature of about 80°C to 96°C according to the beverage, and controls the solenoid valve 31 to supply to the brewing chamber 32. The brewed beverage is discharged through the nozzle 7 to be poured into the container 4 placed on the support 3 below the nozzle 7.

[0041] When the machine 1 is running in the tea preparation mode, which requires a longer brewing time of about three to four minutes, the control circuit 33 activates the pump 28 and the heating element 30 to generate hot water at a temperature of 70°C to 95°C, depending on the type of tea, and controls the solenoid valve 31 to supply hot water discharged through the lower end 24 of the tubular portion 23 to the delivery conduit 26. The tubular portion 23 is attached to the rotating tool 9 and immersed in the product contained in the container 4 located below the rotating stirring device 6.

[0042] In the same manner, machine 1 allows the generation of steam for the preparation of certain beverages based on milk foam or whipped cream, and also for the preparation of certain very hot beverages, particularly tea-based, as will be explained later. In this case, control circuit 33 activates pump 28 and heating element 30 to generate hot water at a temperature above 100°C to produce steam, and controls solenoid valve 31 to supply the steam discharged through the lower end 24 of tubular portion 23 to delivery conduit 26, which is attached to rotating tool 9 and immersed in the contents contained in container 4.

[0043] exist Figure 3The diagram shows a vent valve 35 developed by the applicant, which functions to prevent blockage of the tubular portion 23. In practice, the cessation of the heating element 30 of the boiler 29 causes cooling of residual steam in the delivery conduit 26. This residual steam condenses, creating suction through the delivery conduit 26; this causes the beverage product contained in the container 4 to rise within the tubular portion 23, which is submerged in the beverage product, resulting in blockage. The vent valve 35 allows the beverage product in the container to be prevented from rising too high within the tubular portion 23, sufficiently preventing it from reaching the lower end 22 of the drive shaft 14 and rising from the delivery conduit 26 into the chamber 17, which is inaccessible to the user and therefore potentially difficult to clean. This ventilation of the delivery conduit 26 also allows for a reduction in the temperature of the boiler 29 after steam generation. This advantageously allows for the avoidance of overheated water when the user immediately brews coffee after using the rotary stirrer 6; overheated water from the boiler 29 and injected into the brewing chamber 32 would have the effect of burning the coffee.

[0044] See Figure 1 , Figure 6 and Figure 7 The machine 1 includes a receiving basket 36, which allows for the receipt of ingredients to be brewed, particularly tea. The receiving basket 36 preferably has a cylindrical or slightly conical profile 37, sized to allow insertion into a container 4. A flange 38 is defined at the upper end 37a of the profile 37, resting on the upper edge 39 of the container 4 when the receiving basket 36 is introduced into the container 4. When the rotating stirring device 6 is in the position as... Figure 1 and Figure 7 When the container 4, which is in the lowered position and contains the receiving basket 36, is placed on the support 3 below the rotating stirring device 6, the tubular portion 23 is submerged in the receiving basket 36, and the rotating tool 9 is placed near the bottom 40 of the receiving basket 36, while the receiving basket itself is placed near the bottom 41 of the container 4. Figure 7 As shown. The receiving basket 36 has perforations 42 on its outline 37 and preferably on its bottom 40 to filter the beverage product when it is removed from the container 4 when the beverage is ready.

[0045] Receiving basket 36, in particular, allows for the acceptance of loose tea leaves. When preparing tea beverages, the water should be hot, even very hot, but not boiling, depending on the type of tea. In fact, depending on the type of tea, the water temperature can be between 60°C and 96°C. Similarly, the steeping time varies depending on the type of tea. Therefore, generally speaking, white tea will be steeped at 60°C for 5 to 6 minutes; green tea will be steeped at 75-80°C for 3 minutes; black tea will be steeped at a temperature between 85°C and 95°C, preferably between 90°C and 95°C, for 4 minutes; oolong tea will be steeped at around 95°C for 4 to 5 minutes; and infused tea will be steeped at a temperature close to 100°C for 5 to 10 minutes. Therefore, the conditions for preparing the beverage vary greatly depending on the type of tea being prepared.

[0046] Figures 8 to 10 This allows understanding of the different preparation steps for a very hot beverage to be brewed, which requires a water temperature of at least 80°C. When preparing a hot beverage using the rotary stirring device 6, in the first step (step a), the user places the container 4 on the support 3, below the rotary stirring device 6, and then inserts the rotating tool 9 into the container 4. When the beverage is tea-based, the user can pre-place the tea leaves in the receiving basket 36 and then insert the receiving basket 36 into the container 4. In the second step (step b), the user selects their beverage on the keyboard 34 and then initiates beverage preparation via the interface between the keyboard 34 and the control circuit 33. Information regarding beverage selection and preparation initiation is transmitted to the control circuit 33. In the third step (step c), the control circuit 33 acts on the pump 28, the heating element 30, and the solenoid valve 31 to deliver a volume V of hot water through the delivery conduit 26. The hot water flows through the lower end 24 of the tubular portion 23, at the height of the rotating tool 9 placed in the container 4, through or not through the receiving basket 36, which is pre-positioned in the container 4 and contains the ingredients to be brewed, particularly tea. The ingredients to be brewed can be added to container 4 or to receiving basket 36 placed in container 4 at the end of the third step (step c). Once the control circuit 33 has completed the delivery of hot water of volume V, the rotating tool 9 exits container 4 by moving the rotating stirring device 6 to the raised position to enter container 4 containing hot water of volume V.

[0047] Some beverages require very hot water, i.e., water at a temperature of 80°C or higher, especially those based on black tea, green tea, or infused leaves. When very hot water is poured into container 4, whether or not it passes through receiving basket 36, the water cools rapidly upon leaving the rotating tool 9, dropping by about 7°C. The temperature of the hot water in container 4 is no longer optimal for the perfect brewing of the ingredients contained in container 4 or in receiving basket 36 placed within it. For this type of beverage preparation, machine 1 performs a fourth step (step d), in which control circuit 33 drives pump 28 and heating element 30 to generate hot water at a temperature above 100°C and produce steam. Control of solenoid valve 31 allows supply to delivery conduit 26, whereby steam exits through the lower end 24 of the tubular portion 23 attached to rotating tool 9 and submerged in the contents of container 4 or receiving basket 36. Injecting steam into the volume V of hot water contained in container 4 allows for reheating of that volume of water or the beverage product during the brewing process, restoring it to the ideal temperature for brewing the ingredients, at least 80°C. According to one embodiment, particularly when the ingredient is black tea, steam is injected into container 4 or into receiving basket 36 contained in said container 4 to raise the water temperature above 90°C. Control circuit 33 is programmed to determine the duration of steam injection into the beverage product contained in container 4 based on the volume V of hot water poured into said container 4.

[0048] Reheating the water in container 4 or the beverage product during the brewing process to a temperature exceeding 80°C will cause the formation of bubbles, which can lead to splashing. To overcome this drawback, in step 5 (step d1) performed during step 4 (step d), as... Figures 8 to 10 As shown, control circuit 33 actuates motor 12 to rotate rotating tool 9 and agitate the hot water or beverage preparation in container 4, thereby breaking the bubbles and preventing splashing outside container 4. Preferably, during this fifth step (step d1), control circuit 33 continuously operates motor 12 to rotate rotating tool 9 continuously at speed v1. Preferably, control circuit 33 is programmed such that the duration of the fourth step (step d) and the duration of the fifth step (step d1) are equal, and the injection of steam and the rotation of rotating tool 9 in the container containing the beverage preparation in the brewing process are synchronized. However, as a variation, it is conceivable that the fourth step (step d) begins first, and then the fifth step (step d1) begins with a delay, with steps (steps d and d1) ending simultaneously.

[0049] When the beverage being prepared includes ingredients to be brewed that can be introduced into the container in the first step (step a) or after the third step (step c), the control circuit 33 specifies the start of the motor 12 in the sixth step (step c1) to rotate the rotating tool 9 during the brewing process of the ingredients. This sixth step (step c1) can be initiated after the third step (step c) when the ingredients are introduced into the container 4 or contained in the receiving basket 36 within the container 4 in the first step (step a), as... Figure 9 As shown, or initiated during the third step (step c), as Figure 10 As shown. This sixth step (step c1) is initiated after the third step (step c) when the ingredients are introduced into container 4 or contained in receiving basket 36 within container 4 in the third step (step c), as... Figure 9 As shown. The activation of the rotating tool 9 during the preparation of the ingredients facilitates this preparation. Preferably, during this sixth step (step c1), the control circuit 33 activates the motor 12 to intermittently rotate the rotating tool 9 at a rotational speed v2, the motor 12 running for a period T1 and stopping for a period T2. Preferably, the ratio of time T1 to time T2 is greater than 0.1. In the fifth step (step d1), as previously described, the control circuit 33 causes the rotating tool 9 to rotate continuously at a speed v1; preferably, the control circuit 33 is programmed such that the ratio of v1 to v2 is greater than 0.5.

[0050] Figure 5 and Figure 7 A preferred embodiment of the rotating tool 9 is shown, which includes peripheral fins 43 that facilitate the entrainment of ingredients during rotation of the rotating tool 9 without the ingredients becoming stuck in the peripheral fins 43. This is particularly advantageous when the ingredients are loose tea leaves or consist of loose tea leaves.

[0051] Therefore, the machine 1 according to the invention implements a method that allows for the reheating of hot water or the product during the brewing process, so as to maintain very hot water at a temperature above or equal to 80°C, depending on the ingredients, to maintain an optimal temperature for brewing or even dilution, depending on the nature of the ingredients. A preferred application of the method according to the invention is for brewing tea, particularly teas requiring a hot water temperature above or equal to 90°C, such as black tea.

Claims

1. A method for preparing a beverage at a temperature of at least 80°C, the beverage being prepared in a container (4) by a beverage dispenser (1), said beverage dispenser (1) including a control circuit (33), a hot water and / or steam generator (29), and a rotary stirring device (6), said rotary stirring device (6) including a rotating tool (9) about an axis A and for engaging with the beverage contained in the container (4), said rotary stirring device (6) including a delivery conduit (26) for delivering hot water and / or steam to the rotating tool (9), said method comprising the steps of: a) Place the container (4) on the support (3) below the rotary stirring device (6), and then place the rotating tool (9) into the container (4). b) Select and initiate the preparation of water at a temperature of at least 80°C from the control circuit (33). c) Inject a volume V of hot water through a hot water and / or steam delivery conduit (26). After step c), step d) includes: d) Inject steam through the delivery conduit (26) to bring the water to a temperature above 80°C. Then, during step d), step d1) includes: d1) Operate the rotating tool (9) to agitate the product and break up any air bubbles formed in the product under the action of steam, thereby preventing splashing outside the container (4). The method is characterized in that the beverage being prepared contains ingredients to be prepared, which can be introduced into the container (4) during or after step a), and the method includes step c1) at the end of step c), which includes: c1) During the preparation of the ingredients, the rotating tool (9) is activated, and the container (4) includes a receiving basket (36) for the ingredients to be prepared.

2. The method for preparing a beverage at a temperature of at least 80°C according to claim 1, characterized in that, The container (4) includes a tea-receiving basket (36).

3. The method for preparing a beverage at a temperature of at least 80°C according to claim 1, characterized in that, In step d), steam is injected through the delivery conduit (26) to bring the water to a temperature above 90°C.

4. The method for preparing a beverage at a temperature of at least 80°C according to any one of claims 1 to 3, characterized in that, During step d1), the rotating tool (9) is continuously operated at a speed v1.

5. The method for preparing a beverage at a temperature of at least 80°C according to claim 4, characterized in that, The duration of step d) is equal to the duration of step d1).

6. The method for preparing a beverage at a temperature of at least 80°C according to claim 1, characterized in that, During step c1), the rotating tool (9) is intermittently operated at a rotational speed v2, and the rotating tool (9) is operated for a period of time T1 and stopped for a period of time T2.

7. The method for preparing a beverage at a temperature of at least 80°C according to claim 6, characterized in that, During step d1), the rotating tool (9) runs continuously at a speed v1, and the ratio of v1 to v2 is greater than 0.

5.

8. The method for preparing a beverage at a temperature of at least 80°C according to claim 6, characterized in that, The ratio of time T1 to time T2 is greater than 0.

1.

9. The method for preparing a beverage at a temperature of at least 80°C according to claim 8, characterized in that, During step d1), the rotating tool (9) runs continuously at a speed v1, and the ratio of v1 to v2 is greater than 0.

5.

10. The method for preparing a beverage at a temperature of at least 80°C according to any one of claims 1 to 3, characterized in that, The ingredient to be brewed is black tea, and in step d), steam is injected through the delivery conduit to bring the water to a temperature above 90°C.

11. The method for preparing a beverage at a temperature of at least 80°C according to any one of claims 1 to 3, characterized in that, The rotating tool (9) includes peripheral fins (43).

Images