Heating device and water-conducting household appliance with such a heating device

Abstract

Heating device (20) for heating liquid and in particular for generating steam, wherein the heating device (20) comprises: - an internally arranged flow-through water line (24), preferably as a straight pipe, which has inductively heatable material (26) or which consists at least partially of inductively heatable material, - an annular outer water chamber (23) with a distance around the inner flow-through water line (24), which has an inner wall and an outer wall, - a circulating liquid line (31, 32) in the outer water chamber (23), which runs several times around the inner flow-through water line (24) in a helical shape and rests against the flow-through water line (24), characterized in that - an induction heating coil (27, 28) is provided radially outside the circulating liquid line (31, 32) and preferably outside the outer water chamber (23), - the induction heating coil (27,28) runs helically over at least 50% of the length of the heating device (20), - the outer water chamber (23) or its inner wall are sealed against the inner flow water pipe (24) and are thermally conductively connected to each other.,

Claims

[1] Heating device (20) for heating liquid and in particular for generating steam, the heating device (20) comprising: - an internally arranged continuous water pipe (24), preferably as a straight pipe, which has inductively heatable material (26) or which consists at least partially of inductively heatable material, - an annular outer water chamber (23) spaced around the inner flow water pipe (24) and having an inner wall and an outer wall, - a circulating liquid line (31, 32) in the outer water chamber (23), which runs several times around the inner flow water line (24) in a helical shape and rests against the flow water line (24), characterized by , that - an induction heating coil (27, 28) is provided radially outside the circulating liquid line (31, 32) and preferably outside the outer water chamber (23), - the induction heating coil (27, 28) runs helically over at least 50% of the length of the heating device (20), - the outer water chamber (23) or its inner wall is sealed against the inner flow water pipe (24) and is thermally conductively connected to one another. [2] Heating device according to claim 1, characterized by that the flow-through water pipe (24) is in two parts with an inner pipe (25) and an outer pipe (26) running around it, which lie directly against each other. [3] Heating device according to claim 2, characterized by that the inner tube (25) is made of temperature-resistant plastic or stainless steel. [4] Heating device according to claim 2 or 3, characterized by that the outer tube (26) consists of a nickel-iron alloy. [5] Heating device according to one of the preceding claims, characterized bythat the inductively heatable material (26) of the flow-through water pipe (24) has a Curie point with a predetermined temperature between 90°C and 200°C, in particular between 98°C and 150°C, wherein the material preferably comprises iron and nickel. [6] Heating device according to one of the preceding claims, characterized by that the circulating liquid line (31, 32) lies directly on the flow-through water line (24), in particular on an outer pipe (26) according to claim 2. [7] Heating device according to one of the preceding claims, characterized by in that the flow-through water line (24) has a water line inlet, preferably at one end of the heating device (20), and a water line outlet, in particular at the other opposite end of the heating device (20), wherein the water line inlet and / or water line outlet are preferably arranged at opposite outer ends of the heating device (20). [8] Heating device according to one of the preceding claims, characterized by that a liquid inlet into the circulating liquid line (31, 32) and / or a liquid outlet from the circulating liquid line (31, 32) are arranged at opposite end regions of the heating device (20), in particular are provided laterally on the heating device (20), preferably radially outside the flow-through water line (24) and axially above a start and / or axially below an end of the flow-through water line (24) or the heating device (20). [9] Heating device according to one of the preceding claims, characterized by that the flow-through water pipe (24) is cylindrical and elongated or straight, in particular round-cylindrical or circular-cylindrical. [10] Heating device according to one of the preceding claims, characterized bythat the circulating liquid line (31, 32) runs in turns in a helical shape with a constant turn diameter, preferably at least in two longitudinal sections as a uniform helical line. [11] Heating device according to one of the preceding claims, characterized by that the circulating liquid line (31, 32) is interrupted by a free area (34) between two longitudinal sections (31, 32), wherein an axial length of such a free area (34) preferably corresponds to between 50% and 200% of a gradient height of the helical course of the circulating liquid line (31, 32). [12] Heating device according to claim 11, characterized by that one longitudinal section (31) is two to five times longer than the other longitudinal section (32), wherein preferably a lower longitudinal section (31) is longer than an upper longitudinal section (32). [13] Heating device according to one of claims 11 or 12, characterized bythat at least in the two longitudinal sections (31, 32) the turns of the circulating liquid line lie against one another, in particular directly against one another or touching one another. [14] Heating device according to one of the preceding claims, characterized by that the induction heating coil (27, 28) rests against the outer wall of the water chamber (23), in particular is wound onto it, wherein a longitudinal section of the circulating liquid line (31, 32) preferably runs radially within each turn of the induction heating coil (27, 28). [15] Heating device according to claims 8 and 14, characterized byin that in a lower region of the heating device (20), starting at the liquid inlet, a longer first heating section with the circulating liquid line (31) and the induction heating coil (27) is provided, and with an intermediate distance (34) therebetween towards an upper region of the heating device (20) or the liquid outlet, a shorter second heating section with the circulating liquid line (32) and the induction heating coil (28) is provided, wherein the liquid inlet is provided at the lower beginning of the first heating section and the liquid outlet is provided at the upper end of the second heating section. [16] Heating device according to claim 15, characterized byin that the induction heating coil is divided into two partial induction heating coils (27, 28), wherein preferably a first partial induction heating coil (27) is provided at the bottom in the first heating section and a second partial induction heating coil (28) is provided at the top in the second heating section, wherein preferably the first partial induction heating coil (27) is between 50% and 150% longer than the second partial induction heating coil (28). [17] Heating device according to one of the preceding claims, characterized by that an outlet (36) from the outer water chamber (23) is provided near a lower end of the heating device (20), wherein preferably a second outlet (37) from the outer water chamber (23) is provided near the upper end of the heating device (20). [18] Heating device according to one of the preceding claims, characterized by that a casing (29) is provided around the induction heating coil (27, 28). [19] Water-conducting household appliance (11) with a heating device (20) according to one of the preceding claims, characterized by in that the household appliance (11) has a power supply (49) for the induction heating coil (27, 28) of the heating device (20) with a controller, wherein the controller is designed to detect a drop in power at the induction heating coil (27, 28) as soon as it has exceeded a predetermined temperature. [20] Household appliance according to claim 19, characterized by that the induction heating coil (27, 28) consists of a conductor material with PTC effect, and / or that in a heating device according to claim 5 the inductively heatable material (26) of the flow-through water pipe (24) has a Curie point at a predetermined temperature and is no longer inductively heatable at a temperature above the predetermined temperature. [21] Household appliance according to claim 19 or 20, characterized bythat the household appliance (11) has a dosing circuit with water lines (L1), valves and a dosing device (18) for cleaning agents or the like into one of the water lines of the dosing circuit, wherein the heating device (20) or the flow-through water line (24) or the circulating liquid line (31, 32) is connected to one of the water lines (L1) or is looped into this water line.

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