METHOD FOR MANUFACTURING A HEATABLE MEDIA LINE

Abstract

The invention relates to a method for manufacturing a heatable media line (100), in particular for conducting and simultaneously reheating brewing water or a freshly brewed hot beverage (1) in a hot-beverage dispensing machine (1000). According to the invention, along a hose line (2), at least one heat transfer foil which homogenizes the heat transfer via the hose line surface and which is composed of a material with a thermal conductivity at 0° C. of λ>10 W/mK, preferably λ>50 W/mK, is wound onto the outside, and an electrical heating medium is applied to the heat transfer foil, which electrical heating medium serves for heating the hose line surface.

Claims

1. A method for manufacturing a heatable media line (100), in particular for carrying and simultaneously reheating brewing water or a freshly brewed hot beverage (1) in a hot beverage machine (1000), characterized in that at least one heat transfer foil is wound along the outside of a hose line (2), evening out the transfer of heat over the hose line surface and made of a material having a thermal conductivity at 0° C. of λ>10 W/mK, preferably λ>50 W/mK, and in that an electric heating medium, which serves to heat the hose line surface, is applied to the heat transfer foil.

2. The method according to claim 1, characterized in that the heat transfer foil consists of a metallic material, preferably aluminum or copper.

3. The method according to claim 1, characterized in that the heat transfer foil has a layer thickness of at most 100 μm, preferably at most 30 μm.

4. The method according to claim 1, characterized in that the application of the heating medium takes place after the winding of the heat transfer foil.

5. The method according to claim 1, characterized in that the heating medium is applied to the heat transfer foil before winding.

6. The method according to claim 1, characterized in that the winding of the heat transfer foil and/or of the heating medium takes place helically along the axis (x) of the hose line (2).

7. The method according to claim 6, characterized in that the heat transfer foil is wound in the opposite direction to the heating medium.

8. The method according to claim 1, characterized in that the individual windings of the at least one heat transfer foil overlap at the edges.

9. The method according to claim 1, characterized in that the hose line contains silicone or consists of silicone.

10. The method according to claim 1, characterized in that the heating medium comprises at least one heating wire (3) having a preferably circular cross-section and/or at least one heating foil (3′).

11. The method according to claim 1, characterized in that the heat transfer foil is self-adhesive on the side facing the hose line surface or on both sides.

12. The method according to claim 1, characterized in that the heat transfer foil is provided on the outside with a coating, preferably made of a polymer, which enables the heating medium to be welded onto the heat transfer foil.

13. The method according to claim 1, characterized in that a preferably polymeric protective layer (4) is applied to the outside of the heating medium (3, 3′).

14. A media line (100, 200), manufactured by a method according to claim 1.

Description

[0016] The invention is explained in detail below by reference to a drawing that represents just one exemplary embodiment. In the schematic figures:

[0017] FIG. 1 shows a schematic representation of a fully automatic coffee machine with a media line manufactured in accordance with the invention

[0018] FIG. 2 shows a media line manufactured in accordance with the invention in a partial longitudinal view

[0019] FIG. 3 shows a cross-sectional representation of the hose line shown in FIG. 2, and

[0020] FIGS. 4, 5 show an alternative embodiment of the invention in a representation corresponding to FIG. 2 or 3

[0021] FIG. 1 shows a schematic representation of a machine for the preparation of hot beverages, in particular a fully automatic coffee machine 1000, with a media line 100 manufactured in accordance with the invention. The machine 1000 comprises, in addition to the media line 100, an electric heater 300 for producing boiling hot brewing water 1, which is carried through a transport line 200 to a brewing unit 400 of the machine 1000, in which ground coffee is brewed with the brewing water 1 to prepare hot coffee. This freshly prepared coffee 1 then flows from the brewing unit 400 through the media line 100 to the coffee dispensing unit 500 of the machine 1000, during which process it is reheated. In addition (or alternatively) to the line 100, the transport line 200 for transporting the brewing water 1 from the heater 300 to the brewing unit 400 can also be designed as a media line according to the invention.

[0022] FIG. 2 shows a partial longitudinal view of the electrically heatable media line 100 shown in FIG. 1, which serves to transport and simultaneously reheat the freshly brewed coffee 1 in the fully automatic coffee machine 1000. In the method according to the invention for the manufacture of such a media line 100, in the exemplary embodiment, an electric heating medium in the form of two electric heating wires 3 is wound helically onto the outside of a silicone hose line 2 along the longitudinal axis x of the hose line 2. Viewed in the axial direction, the heating wires 3 are arranged spaced evenly apart by length a. It can also be seen that, in order to manufacture the media line 100, two aluminum heat transfer foils 20 (thermal conductivity λ>200 W/mK at 0° C.) are wound helically along the outside of the hose line 2, a heating wire 3 being arranged on each foil 20. The heating wires 3 serve to heat the hose line 2 and hence the fluid 1 transported through the hose line 2, the transfer of heat from the heating wires 3 to the hose line surface by the heat transfer foils 20 being evened out over this surface. Each heat transfer foil 20 has a layer thickness s.sub.w of 10 to 40 μm. It can be seen that the windings of the heat transfer foils 20 overlap at the edges, the width ü.sub.w of the overlap regions Ü being 1 to 3 mm.

[0023] The winding of the heating wires 3 onto the heat transfer foils 20 can be carried out by way of a separate manufacturing operation after the foils have been wound onto the hose line surface. Alternatively, however, it is also possible for each heating wire 3 to be applied to a heat transfer foil 20, e.g. by gluing or welding, before a composite structure of the heating wire 3 and foil 20 is wound onto the hose line 2. In the exemplary embodiment, the heating wires 3 and the heat transfer foils 20 are wound in the same direction. If the heating wires 3 are applied only after the foils 20 have been wound onto the hose line 2, it is also possible in principle for the helical windings of wires 3 and foils 20 to run in opposite directions and to cross one another accordingly (not shown).

[0024] As can be seen in particular from the enlarged section on the right in FIG. 3, the heating wires 3 have a circular cross-section with a diameter do of 0.5 to 1.5 mm. The heat transfer foils 20 are designed such that the side facing the hose line surface is self-adhesive, and accordingly they have an adhesive layer 30 on that side, thereby improving the adhesion of the foils 20 to the hose line surface. Alternatively, a layer of glue can also be applied to the hose line 2 before the foils 20 are wound. Moreover, the heat transfer foils 20 have a polymeric coating 40 on the outside, which allows the heating wires 3 to be welded to the foils 20 (either before the foils 20 are wound onto the hose line 2 or afterwards), for example by ultrasonic heating of the heating wires 3 or by heating the heating wires 3 by passing an electric current through them. The welding of the heating wires 3 causes the material of the coating 40 to melt locally, such that an indentation 50 matching the contour of the heating wire 3 is formed in the coating 40 in the contact region of a heating wire 3. Alternatively, the layer 40 can also be formed as an adhesive layer.

[0025] A polymeric protective layer 4, made of polyamide for example, is applied to the outside of the heating wires 3, serving both for mechanical protection of the wires 3 and for thermal insulation, and having a layer thickness s.sub.a of 0.2 to 0.8 mm, for example. The hose line 2 itself has an outside diameter d.sub.A of 5 to 15 mm, preferably 7 to 12 mm. The wall thickness s.sub.i of the hose line 2 is preferably 0.5 to 2 mm, in particular 0.8 to 1.5 mm. The hose line 2 is relatively short and has a maximum length of 30 cm.

[0026] In the exemplary embodiment according to FIGS. 4 and 5, the heating medium is designed as an electric heating foil 3′, which is likewise wound helically onto the hose line 2 along the hose line axis x. The width b.sub.F of the heating foil 3′ viewed in cross-section is over 20 times greater than its thickness s.sub.F, which is 0.2 to 0.8 mm. In the exemplary embodiment, only one heating foil 3′ is wound onto the hose line 2. In this case, viewed in the axial direction, the individual windings of the heating foil 3′ are arranged spaced evenly apart by length a′. The heating foil 3′ in turn is applied to an aluminum heat transfer foil 20 which evens out the transfer of heat over the hose line surface. In this exemplary embodiment, the windings of the foil 20 are spaced apart from one another at the edges by length b′, such that there are no overlap regions in this case.

[0027] If the media line is used to transport brewing water 1 to the brewing unit 400 of the fully automatic coffee machine 1000 (represented by the transport line 200 in FIG. 1), said media line, because of the high pressure prevailing there, is additionally provided with a reinforcing layer made of wound or braided filaments (not shown in the figure), which is in turn surrounded by a polymeric, preferably extruded outer layer, made of PA for example.

[0028] As an alternative to using the media line 100 manufactured in accordance with the invention in a fully automatic coffee machine 1000, it can also be used for example in simple coffee machines and in machines for preparing tea or other hot beverages.