Induction heating device with an induction heating coil and electrical device with an induction heating device

Abstract

An induction heating device comprises an induction heating coil having windings with a coil conductor in a substantially spiral shape, wherein the coil conductor is made of an electrically conductive material such as copper. The induction heating device comprises a receptacle for the induction heating coil, wherein the induction heating coil and its windings are arranged in the receptacle. The receptacle contains electrically insulating, ultrapure water so that the coil conductor is completely surrounded by this water. The ultrapure water can thus replace conventional electrically insulating varnish. At the same time, it can cool the induction heating coil and its coil conductor due to its higher heat capacity. The water can either be permanently in the receptacle or replaced at intervals or permanently.

Description

FIELD OF APPLICATION AND STATE OF THE ART

[0001] The invention relates to an induction heating device with an induction heating coil, such as can generally be installed in electrical appliances, and in particular in water-conducting household appliances such as dishwashers or washing machines. Furthermore, the invention relates to such an electrical appliance or water-conducting household appliance. The induction heating device has an induction heating coil with windings of a coil conductor in a substantially helical and / or spiral shape, wherein the coil conductor is made of electrically conductive material and / or metal. Furthermore, the induction heating device has a receptacle for the induction heating coil.

[0002] Such an induction heating device is known from German patent application DE 10 2023 123 893.0, filed on September 5, 2023, by the same applicant. It heats water inductively. To do so, it heats metal that contains or carries water. TASK AND SOLUTION

[0003] The invention is based on the object of creating an induction heating device as mentioned above and an electrical device provided therewith, with which problems of the prior art can be solved and in particular it is possible to heat an electrical device efficiently and in an energy-saving manner.

[0004] This object is achieved by an induction heating device having the features of claim 1 and by an electrical device provided therewith having the features of claim 18. Advantageous and preferred embodiments of the invention are the subject of the further claims and are explained in more detail below. Some of the features are described only for the induction heating device or only for an electrical device provided with such an induction heating device. However, they are intended to be able to apply independently and independently of one another both to such an induction heating device and to such an electrical device provided therewith. The wording of the claims is incorporated into the content of the description by express reference.

[0005] The induction heating device has an induction heating coil, which in turn has turns with a coil conductor, so that the induction heating coil is wound from the coil conductor in the turns. These turns can run essentially in a helical and / or spiral shape, preferably in a plane and in a spiral shape. The coil conductor consists of electrically conductive material and / or metal, preferably as a stranded wire, i.e., of several thin strands or wires, preferably 5 to 100 strands, which run alongside one another and thus together form the coil conductor. Alternatively, the coil conductor can also be formed from a single wire, i.e., as a single or solid coil conductor. The coil conductor can advantageously consist largely or entirely of copper, or alternatively of other good electrically conductive materials.

[0006] The induction heating device has a receptacle for the induction heating coil, wherein the induction heating coil or its windings are arranged in this receptacle. They are thus protected from the outside, in particular electrically insulated. Electrically insulating liquid is located in the receptacle such that the windings or the coil conductor are at least partially surrounded by the electrically insulating liquid, preferably also in direct contact, for example at least 20% or at least 50%. This can relate to the vertical height or the diameter or to the length of the entire windings or the coil conductor. Preferably, the windings or the coil conductor are completely surrounded by the electrically insulating liquid. This electrically insulating liquid forms, on the one hand, electrical insulation for the coil conductor orIts windings, especially outward and especially relative to each other, i.e., between adjacent coil conductors or windings. This allows for a simpler design or even complete elimination of the previously common electrical insulation of individual strands or individual wires, usually with so-called insulating varnish. The coil conductor or a corresponding strand or individual wires can be bare or without any surface treatment or similar. This reduces effort and costs and is more environmentally friendly.

[0007] Secondly, the coil conductor or its windings can be cooled by the liquid directly surrounding it, which can reduce other cooling requirements, for example, using fans or similar. Above all, liquid cooling is generally much more efficient due to the direct contact between the coil conductor and the liquid, as inventive. This can be achieved with a liquid circulating in a cooling circuit, or with a liquid that can simply absorb a large amount of heat due to its high heat storage capacity relative to its own heating.

[0008] The electrically insulating fluid, especially ultrapure water, can replace conventional electrically insulating varnish. At the same time, it can cool the induction heating coil or its coil conductors due to its higher heat capacity. The fluid can be either permanently in the holder or replaced at intervals or permanently.

[0009] In an embodiment of the invention, the electrically insulating liquid can have an electrical conductivity between 50 nS / cm and 100 µS / cm, preferably between 0.1 µS / cm and 50 µS / cm. Thus, the electrically insulating liquid does not have to be completely electrically insulating, but the electrical conductivity should be low or very low.

[0010] In a further development of the invention, the coil conductor can be a single conductor or a single conductor along the windings of the induction heating coil. In this case, it can preferably be made of solid material with a continuous cross-section, either solid throughout or tubular, i.e., hollow inside.

[0011] In an advantageous embodiment, the coil conductor can consist of wire that has been bent into the shape of the windings of the induction heating coil. The wire is advantageously bent from a straight initial state into the bent shape of the induction heating coil, since wire is usually manufactured in a straight form and then wound.

[0012] Alternatively, the coil conductor with the intended windings can be machined, in particular punched, from a flat solid material. It can preferably be machined in the shape of the finished induction heating coil, so that it does not require further processing or bending of the material. For this purpose, the induction heating coil can advantageously have a spiral shape.

[0013] In a first basic embodiment of the invention, the receptacle can be elongated, corresponding to the shape of the individual windings of the induction heating coil or its entirety, with only a single coil conductor running in a cross-section perpendicular to the longitudinal extension of each winding, whether a single coil conductor or a bundle of strands. The receptacle can advantageously be a flexible hose or a rigid tube through which the single coil conductor runs. The hose or tube contains the coil conductor and the electrically insulating fluid, advantageously only the coil conductor and the fluid.

[0014] In a second, different, basic embodiment of the invention, the receptacle can be a housing which contains most or all of the induction heating coil within its interior. Advantageously, the receptacle can have a single chamber for the entire induction heating coil. The outer shape of the receptacle is advantageously independent of the shape of the individual turns of the induction heating coil, i.e., whether these are spiral or helical. The outer shape is preferably dependent on the shape of the wound induction heating coil, for example, flat and round if the induction heating coil is also flat and round, only slightly higher and wider. Preferably, the turns in the receptacle are completely surrounded by the electrically insulating liquid. In particular, no outer wall of the receptacle runs between adjacent turns, preferably between adjacent turns of the same induction heating coil.

[0015] In an advantageous development of the invention, the receptacle can be made of an electrically insulating material to additionally provide electrical insulation for the induction heating coil or its individual windings. Advantageously, the receptacle can be made of plastic. In the aforementioned first basic embodiment, it can and should be a flexible and / or elastic plastic, for example, rubber or silicone.

[0016] Preferably, it is possible to provide a PTC effect for the coil conductor material or to select a material with a PTC effect. This can be a simple and inexpensive material, for example, copper. With R(T)=Ro*(1+beta Delta T) and beta = 3.9 / 1000, a current I=50 A, and a room temperature resistance of 0.02 ohms, the loss in an induction heating coil at room temperature is approximately 50 watts. At a temperature 200°C higher, however, this rises to 89 watts. Cooling with the liquid prevents any significant heating of the coil conductors, so the PTC effect cannot have a significant impact.

[0017] In a further embodiment of the invention, the electrically insulating fluid can be replaceable, with the receptacle having an inlet and an outlet for this purpose. The inlet is advantageously connected to or connected to a source of electrically insulating fluid. The outlet, in turn, is either connected to an outlet from the corresponding electrical device or, advantageously, also to the source. Furthermore, the outlet and / or the inlet can be connected to a heat exchanger in the induction heating device for cooling the electrically insulating fluid and thus the induction heating coil, as well as for recovering heat from the possibly heated fluid, which could improve the energy balance.

[0018] Preferably, directly adjacent turns do not lie directly against each other, but are spaced apart, which can particularly preferably be between 1 mm and 10 mm, preferably between 2 mm and 6 mm. Such a spacing helps with electrical insulation from each other, especially when, according to the second basic embodiment, several or all turns of the induction heating coil are arranged in a common receptacle.

[0019] By combining the aforementioned low conductivity of the liquid, the insulating properties of the receptacle, and the aforementioned spacing, it is possible to achieve a very high electrical resistance between directly adjacent windings. This electrical resistance can be between 1 kΩ and 50 MΩ, i.e., very high, preferably between 50 kΩ and 1 MΩ.

[0020] In a further development of the invention, the induction heating device can have a heating surface that can be heated inductively by the induction heating coil. This is therefore the location or area that can be primarily heated by the induction heating coil or where its heating energy is directed. This can then be used to heat water, for example, either in a tank, i.e. largely static, or in a pipe as a continuous-flow heater or the like, i.e. in continuous flow. Advantageously, the heating surface is metallic or can be heated inductively, for example ferrous or largely made of iron. This heating surface can preferably run adjacent to the receptacle with the induction heating coil therein, particularly preferably at a distance of 0.5 mm to 20 mm, preferably 2 mm to 10 mm. In particular, the receptacle with the induction heating coil therein can directly border the heating surface, preferably adjoin it.However, the holder should have its own wall and its wall thickness in between, especially for electrical insulation.

[0021] In a further embodiment of the invention, a thermal coupling is provided between the electrically insulating liquid or the induction heating coil on the one hand and the heating surface on the other, preferably to cool the induction heating coil. This is particularly advantageous when the heating surface is not yet very hot or is cooled significantly by water flowing past it, so that it is cooler than the induction heating coil during heating operation.

[0022] Preferably, ferritic material or ferrites are provided on the receptacle for magnetic field guidance, with this ferritic material preferably being in the form of rods, bars, or powder in a sheath. Ferrite rods, in particular, are frequently provided on induction heating coils for magnetic field guidance, both for focusing in one direction and for shielding against another direction. Particularly preferably, the ferritic material can be attached to the outside of the aforementioned receptacle.

[0023] In a further development, the ferritic material for guiding the magnetic field can be arranged within the receptacle, preferably around the coil conductor or between the coil conductor and the receptacle. This is particularly suitable if the receptacle is a housing in which the coil conductor is arranged directly within the electrically insulating liquid, i.e. is surrounded by it. The ferritic material can then also be arranged in this electrically insulating liquid or at least in a heat-conducting connection with it in order to be cooled by it. During operation of the induction heating coil, this ferritic material for guiding the magnetic field usually also becomes warm or even hot. Under certain circumstances, it can also be provided that predominantly or even only the ferritic material or ferrites for guiding the magnetic field can be cooled. The ferritic material does not have to be continuous or in larger pieces orIt can be present in solid pieces that are, for example, longer than 2 cm or 3 cm. It can also be present in significantly smaller sizes and be sufficiently effective, for example, as granules with diameters between 3 mm and 0.2 mm, or as powder with diameters between 0.2 mm and 0.01 mm.

[0024] An electrical appliance equipped with at least one of the above-described induction heating devices may comprise a source of distilled water, particularly as or with a heat exchanger or condenser, if the electrical appliance is a washing machine, a tumble dryer, a washer-dryer, or a dishwasher. This source of distilled water may be connected to an aforementioned inlet into the receptacle, and the distilled water may form the electrically insulating liquid. Advantageously, the electrical appliance may comprise a waste water tank, and an outlet from the receptacle may be led to the waste water tank. Alternatively, the electrically insulating liquid may generally also circulate in a closed circuit, flowing through the receptacle on the one hand, primarily for cooling the induction heating coil, and flowing past a heat sink, heat exchanger, or the like, thereby being cooled.

[0025] Furthermore, said electrical appliance may be a washing machine and include said condenser as a source for the distilled water or electrically insulating liquid. An outlet from the coil winding receptacle may lead into a drum or drum receptacle of the washing machine.

[0026] In a further development of the invention, the aforementioned electrical appliance, particularly a washing machine, can have a heat exchanger with two circuits. A water supply into the drum or into the drum container can be connected to one of the heat exchanger circuits. A second circuit of the heat exchanger can be connected to the induction heating device or connected to the induction heating coil for heating.

[0027] In a further development of the invention, the induction heating device can have a heating surface, preferably metallic, that can be heated inductively by the induction heating coil. The electrical device can then have a water guide on this heating surface for flowing water to heat it and cool the heating surface or to remove heat from it.

[0028] These and other features emerge not only from the claims but also from the description and the drawings. The individual features may be implemented individually or in combination in an embodiment of the invention and in other fields, and may represent advantageous and individually protectable embodiments for which protection is claimed here. The division of the application into individual sections and subheadings does not limit the generality of the statements made therein. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Further advantages and aspects of the invention emerge from the claims and from the description of exemplary embodiments of the invention, which are explained below with reference to the figures. In the figures: Fig. 1 a front view of a washing machine according to the invention as an electrical appliance with a drawer for detergent and an induction heating device according to the invention for a detergent dispenser arranged above it, Fig. 2 a plan view of the induction heating device from Fig. 1 with spiral coil conductor in a housing, Fig. 3 a side sectional view through the induction heating device from Fig. 2, wherein the coil conductor is arranged together with distilled water in a correspondingly extending receiving tube, Fig. 4 a modification of the induction heating device from Fig. 3 with water channels at the bottom of the housing, Fig. 5 a further modification of the induction heating device from Fig. 3, in which ferrites are arranged around the coil conductor within the receiving tube, Fig. 6 an enlarged sectional view through the receiving tube from Fig. 5 with coil conductor and ferrite pieces in it, and Fig. 7 a further modification of the induction heating device from Fig. 3, in which the spiral coil conductor in the housing is surrounded only by distilled water and has no receiving hose or the like around it. Detailed description of the implementation examples

[0030] In the Fig. 1 schematically shows a front view of a washing machine 11 according to the invention as an electrical appliance according to the invention. The washing machine 11 has a housing 12 and therein a drum receptacle 14 with a door 15, wherein a conventional drum 16 for washing laundry is provided in the drum receptacle 14. In order to apply water and detergent into the drum 16 or onto the laundry contained therein, an inlet 18 runs from above, branching off from an inlet funnel 19 at the bottom. Above the inlet funnel 19, a drawer 20 is arranged, in which detergent and other additives for washing are present, either added manually or dosed automatically. For this purpose, a flat detergent distributor 30 can be provided above the drawer 20. An induction heating device 32 according to the invention is arranged above the detergent distributor 30 or directly on it. With this induction heating device 32, water and, if applicable,Detergents or other additives can also be heated in the detergent dispenser 30 before being applied to the laundry. This can improve their effectiveness or the washing process in general. For a more precise description of the function of the detergent dispenser 30 in particular, reference is made to German patent application DE 10 2023 128 918.7, filed on October 20, 2023, by the same applicant.

[0031] The detergent dispenser 30 and, above all, the induction heating device 32 are controlled in their function by a washing machine control unit 26. If necessary, the induction heating device 32 is also supplied with power, advantageously controlled by a converter. The washing machine control unit 26 is also connected to an operating device 28 of the washing machine 11, which advantageously has a display and operating elements such as buttons or the like.

[0032] Inductive heating of water is generally known and possible—not of the water itself, of course, but of a container or a guide for the water, which can be heated inductively. Reference is made to the aforementioned German patent application, as well as to the German patent application DE 10 2023 123 893.0, filed on September 5, 2023, by the same applicant. One advantage of using an induction heating device 32 or an induction heating coil to heat water or other substances in the washing machine 11 is that harmful high temperatures at the heating device itself and in its surroundings, especially in its immediate vicinity, can be avoided. This enables a robust and practical heating device design.

[0033] In the Fig. 2, the flat induction heating device 32 is shown in plan view. It has a substantially rectangular shape and is formed by a housing 34, which, according to the side sectional view of the Fig. 3 has an upper housing cover 36a and a lower housing base 36b. Arranged in the interior 38 is a single-layer wound induction heating coil 40, which is specially designed according to the invention. The induction heating coil 40 has a receiving tube 42, in which a coil conductor 44 runs, specifically over most of the length of the receiving tube 42. The diameter of the receiving tube 42 is generally between 10% and 100% larger than that of the coil conductor 44, in the present example approximately 60%. Distilled water 43 is located inside the receiving tube 42, which thus surrounds the coil conductor 44 and electrically insulates it from the outside. The water 43 completely surrounds the coil conductor 44 here, but it could also only partially surround it, for example up to 50% of its vertical height. In this case, good heat dissipation would still be possible. The receiving tube 42 is elastic and flexible.It is advantageously made of rubber or silicone. Silicone is preferred due to its good electrical insulation properties and high thermal resistance. Distilled water can also be present in the interior space 38 to further improve the electrical insulation and also to increase the heat capacity of the induction heating device 32, i.e., to absorb heat, particularly from the coil conductor 44 or to cool it.

[0034] The receiving hose 42 has a hose inlet 46 and a hose outlet 47. In one embodiment of the invention, distilled water can be admitted and discharged here, i.e., flow through the receiving hose 42, for example, continuously or at least when the coil conductor 44 becomes warm due to inductive heating or exceeds a certain predetermined first limit temperature, above which cooling becomes advantageous or necessary. Such a water flow F is represented by the arrows, i.e., in to the hose inlet 46 and out through the hose outlet 47. Furthermore, an external connection 49 leads from the coil conductor 44 in the receiving hose 42 to the outside, advantageously near the hose inlet 46.If no distilled water is to flow through the receiving hose 42, the external connection 49 can simply be led out through the hose inlet 46, thereby sealing the receiving hose 42 in a watertight manner. In a corresponding manner, an internal connection 50 of the coil conductor 44 can be led out inside the hose outlet 47.

[0035] If distilled water 43 is to flow or be pumped through the receiving hose 42 as water flow F, it is recommended that the external connection 49 be laterally routed out at the hose inlet 46. The internal connection 50 should be similarly routed out at the hose outlet 47. This is easily envisioned with appropriate openings in the receiving hose 42, or alternatively with appropriate connectors made of plastic or the like.

[0036] Either the upper housing cover 36a and / or the lower housing base 36b are advantageously designed so that they can be heated inductively or by a conventional inductive alternating field generated by the induction heating coil 40 or the coil conductor 44. For example, one of the two parts can be ferrous, in particular the lower housing base 36b, in order to heat water or detergent in the detergent distributor 30 arranged underneath. Temperature sensors or the like are advantageously provided here for precise temperature adjustment, for example on the lower housing base 36b. These are easily implemented by a person skilled in the art and are therefore not shown here. In a further embodiment, the lower housing base 36b could, for example, be a wall of a water tank or a water guide such as a channel or the like for the most direct heating of water therein.

[0037] Because the coil conductor 44 is surrounded by distilled water 43 within the receiving tube 42, electrical insulation is provided around it. In abstract terms, this electrical insulation can correspond to a conventional insulating varnish on a coil conductor for an induction heating coil. The insulating effect of the distilled water 43 adds to the electrically insulating properties of the receiving tube 42, which it advantageously exhibits. This eliminates the need for the costly and chemically harmful insulating varnish, or more environmentally friendly varnishes can be used for lower temperatures. Furthermore, the induction heating coil 40, including the coil conductor 44, can then easily be arranged close to an electrically conductive housing wall 36 or even between two such housing walls 36 without the risk of a short circuit.The distilled water should preferably be very pure to ensure the best possible electrical insulation. One possible use is purified or low-salt water with a conductivity of 1 µS / cm to 50 µS / cm. Another possibility is the use of pure water or ultrapure water, whose conductivity is 0.1 µS / cm to 1 µS / cm. Particularly good insulation properties are achieved with ultrapure water, whose conductivity is between 0.055 µS / cm and 0.1 µS / cm. For the first option, the water can be generated in the washing machine 11 itself, for example by evaporation or by means of a condenser. Such water can then also flow through the receiving hose 42 in the aforementioned passage, whereby particularly good cooling of the induction heating coil 40 or the coil conductor 44 is possible.However, the requirements for the electrical insulation of the water for the other two options are so high, and thus the costs for such pure or ultrapure water are so high, that it should remain stationary and permanent in the receiving tube 42 around the coil conductor 43. An electrical resistance between two adjacent turns of the induction heating coil 40 or between two adjacent coil conductors 44 can be between 1 kΩ and 1 MΩ, especially in the design of the . Fig. 7 without receiving hose, which will be explained in detail later.

[0038] On the housing 34 of the induction heating device 32 according to Fig. 3, ferrite rods 53 are arranged on top of the upper housing cover 36a and on the bottom of the lower housing base 36b. Corresponding ferrite material can also be formed in another suitable shape. These ferrite rods 53 serve in a known manner to guide the magnetic field of the induction heating coil 40, in particular for external shielding and thus also for concentration in parts to be heated, for example, the lower housing base 36b as previously explained. They can also be designed as usual for induction heating coils, for example, for cooktops.

[0039] When considering the Fig. 2, it should be noted that the coil conductor 44 of the induction heating coil 40 could also be wound much more tightly, allowing for more or even many more turns. This allows the heating effect to be optimized.

[0040] In the modified induction heating device 132 of the Fig. 4, three water channels 55a, 55b and 55c are arranged at the bottom of the lower housing base 36b. These are advantageously formed in separate walls or channels, for example as part of the detergent distributor 30 according to Fig. 1. This prevents any water contained therein from reaching the lower housing base 136b or the ferrite rods 153 arranged below. The water channels 55a to 55c are connected in series, but this may also be different. They may also be separate from each other. Normal water, in particular domestic water to be heated, is pumped through it by means of water pipes and a pump 57 and, if necessary, a three-way valve 58. This can be done with the three-way valve 58 in direct circulation for a certain time, or with connections 56b and 56c into the washing machine 11, in particular via the drawer 20. The distilled water 143 within the receiving hose 142, i.e. around the coil conductor 144, cools, if necessary as water flow F, the coil conductor 144 and, if necessary, also the ferrite rods 153. The induction heating coil 140, in turn, heats the lower housing base 136b and thus the water in the water channels 55a to 55c.This allows water to be heated or warmed in the washing machine 11. This can be done continuously or in a batch mode, i.e., if a specific amount of water needs to be heated to a specific temperature.

[0041] A further alternative embodiment of an induction heating device 232 is shown in Fig. 5. Here, too, a housing 234 is provided with an upper housing cover 236a and a lower housing base 236b. The induction heating coil 240 is arranged in the interior space 238 formed therebetween, again as a coil conductor 244 that is not electrically insulated on its outside, in a receiving tube 242. Due to the larger diameter of the receiving tube 242, a layer of distilled water 243 can surround the coil conductor 244, in this case completely, in order to electrically insulate it and, above all, to remove and absorb heat from it. Such distilled water can also be provided in the interior space 238 for further improved electrical insulation, or at least to remove even more heat from the coil conductor 244. This, in turn, allows the use of insulating varnishes for lower temperatures.

[0042] A special feature here is the receiving tube 242, as the enlarged sectional view of the Fig. 6 shows, a certain amount of ferrite 253 is provided around the coil conductor 244. This ferritic material 253 can be provided in the form of ferrite powder or ferrite grains. Alternatively, it can also be arranged in a wall of the receiving tube 242. In yet another alternative, the receiving tube 242 can be double-walled with the ferrite material 253 in between. Thus, the large and continuous ferrites at the top and bottom of the housing 34, as shown in Fig. 3 and Fig. 4 is shown.

[0043] In the Fig. 7 shows yet another alternative embodiment of an induction heating device 332. A housing 343 with an upper housing cover 336a and a lower housing base 336b is designed as in Fig. 3, ferrite rods 353 are also arranged on top of the housing cover 336a. An interior space 338 of the housing 334 is provided at the top and bottom with an upper electrical insulation 359a and a lower electrical insulation 359b, advantageously made of electrically insulating plastic with a thickness of, for example, 1 mm. An induction heating coil 340, consisting of a coil conductor 344, runs in spiral windings corresponding to Fig. 2. The coil conductor 44 has an external connection 349 on the left and an internal connection 350 in the center. These are led out of the interior space 338 in a watertight manner. What is striking here is that the coil conductor 344 runs freely and without a receiving tube within the housing 334, which, together with the electrical insulation 359, forms a receptacle for the coil conductor. Otherwise, the interior space 338 is filled with distilled water 343 to electrically insulate the coil conductors 344 from each other.

[0044] In the embodiment shown here, the interior space 338 has an inlet 346 to the left and an outlet 347 to the right. This can be Fig. 4 can be connected to water pipes and, for example, to a water guide or a water pump to pump distilled water 343 through it as water flow F. This can achieve improved cooling for the coil conductors 344 or for the induction heating coil 340. Alternatively, if, for example, a cooling effect does not need to be quite as strong, simply stationary distilled water 343 can be present in the interior 338 to be able to remove heat from the coil conductors 344.

[0045] Similar to Fig. 4, water channels or the like could be arranged at the bottom of the lower housing base 336b, which are heated by this as a use for heat generation of the induction heating coil 340.

[0046] In the case of such exposed coil conductors 344 which are not electrically insulated on their outside, according to the Fig. 7, the provision of very good electrically insulating material such as distilled water 343 around them is particularly advantageous or even necessary.

[0047] The coil conductor can be made of a stranded coil wire that is not electrically insulated externally, for example, of copper, particularly bare copper, which eliminates the need for insulation varnish. It can also be a solid round wire or a wire of any cross-section that can be spiraled into the coil. Fig.2 is bent. Depending on the design of the receiving tube 42, it can be inserted into the receiving tube before or after, or the latter can be pushed over it. Alternatively, a coil conductor can also be punched out of a solid material, in particular a sheet metal or thin material of appropriate thickness, in the desired spiral shape. The shape or course of the coil conductor could then be automatically predetermined, allowing the shape to be particularly inherently stable and saving the effort required for bending. Materials such as aluminum are also suitable for this purpose as coil conductor material. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2023 123 893.0 [0002, 0032] DE 10 2023 128 918.7

[0030]

Claims

[1] Induction heating device with an induction heating coil, wherein the induction heating coil has turns with a coil conductor substantially in helical form and / or in spiral form, wherein the coil conductor consists of electrically conductive material and / or metal, characterized by , that: - the induction heating device has a receptacle for the induction heating coil, - the induction heating coil or its windings are arranged in the holder, - there is electrically insulating liquid in the receptacle such that the coil conductor is at least partially surrounded by the electrically insulating liquid. [2] Induction heating device according to claim 1, characterized by that the electrically insulating liquid has an electrical conductivity between 50 nS / cm and 100 µS / cm, preferably between 0.1 µS / cm and 50 µS / cm. [3] Induction heating device according to claim 1 or 2, characterized bythat the coil conductor is a single conductor along the turns of the induction heating coil, preferably made of solid material with a continuous cross-section. [4] Induction heating device according to one of the preceding claims, characterized by that the coil conductor consists of wire bent into the shape of the turns of the induction heating coil, wherein preferably the wire is bent from a straight original state into the bent shape of the induction heating coil. [5] Induction heating device according to one of claims 1 to 3, characterized by that the coil conductor with the windings is punched out of a flat solid material, preferably punched out in the shape of the finished induction heating coil, wherein in particular the induction heating coil has a spiral shape. [6] Induction heating device according to one of the preceding claims, characterized bythat the receptacle is elongated corresponding to the shape of the individual turns of the induction heating coil and in a cross-section perpendicular to its longitudinal course only a single coil conductor runs, wherein preferably the receptacle is a flexible hose or a rigid tube in which a single coil conductor runs, wherein only the coil conductor and the electrically insulating liquid are located in the hose or tube. [7] Induction heating device according to one of claims 1 to 5, characterized by that the receptacle is a housing which contains in its interior the essential or the entire induction heating coil, wherein the outer shape of the receptacle is independent of the shape of the windings of the induction heating coil, wherein preferably in the receptacle the windings are completely surrounded by the electrically insulating liquid, wherein in particular no outer wall of the receptacle runs between adjacent windings. [8] Induction heating device according to one of claims 6 or 7, characterized by that the receptacle is made of electrically insulating material, preferably made of plastic. [9] Induction heating device according to one of the preceding claims, characterized by that the material of the coil conductor has a PTC effect. [10] Induction heating device according to one of the preceding claims, characterized by that the electrically insulating liquid is exchangeable and for this purpose the receptacle has an inlet and an outlet, wherein preferably the inlet is connected to a source of electrically insulating liquid, wherein in particular the outlet is in turn connected to the source, wherein preferably the outlet and / or the inlet are connected to a heat exchanger in the induction heating device for cooling the electrically insulating liquid. [11] Induction heating device according to one of the preceding claims, characterized by that directly adjacent turns have a distance between them of between 1 mm and 10 mm, preferably between 2 mm and 6 mm. [12] Induction heating device according to one of the preceding claims, characterized by that directly adjacent turns have an electrical resistance to each other between 1 kΩ and 50 MΩ, preferably between 50 kΩ and 1 MΩ. [13] Induction heating device according to one of the preceding claims, characterized by in that it has a heating surface which can be heated inductively by the induction heating coil, wherein the heating surface preferably runs adjacent to the receptacle with the induction heating coil therein, wherein in particular the receptacle with the induction heating coil therein directly adjoins the heating surface. [14] Induction heating device according to claim 13, characterized bythat a thermal coupling is provided between the induction heating coil and the heating surface, preferably for cooling the induction heating coil. [15] Induction heating device according to one of the preceding claims, characterized by that ferritic material for magnetic field guidance is provided on the receptacle, wherein the ferritic material is preferably in the form of rods or powder in a casing, wherein in particular the ferritic material is fastened externally to the receptacle according to claim 6 or 7. [16] Induction heating device according to claim 15, characterized by that the ferritic material for guiding the magnetic field is arranged within the receptacle, preferably around the coil conductor or between the coil conductor and the receptacle. [17] Induction heating device according to claim 15 or 16, characterized bythat the ferritic material for magnetic field guidance is thermally coupled or connected to the electrically insulating liquid for cooling the ferritic material. [18] Electrical appliance with an induction heating device according to one of the preceding claims, characterized by that it has a source for distilled water, in particular with a heat exchanger or with a condenser of a washing machine, a tumble dryer or washer-dryer or a dishwasher as an electrical appliance, wherein this source for distilled water is connected to an inlet into the receptacle and the distilled water is the electrically insulating liquid, wherein preferably the electrical appliance has a waste water tank and an outlet from the receptacle is led to the waste water tank. [19] Electrical appliance according to claim 18, characterized bythat it is a washing machine and has a condenser as a source for the distilled water or the electrically insulating liquid, with a drain leading from the receptacle into a drum or into a drum receptacle of the washing machine. [20] Electrical appliance according to claim 19, characterized by that the washing machine has a heat exchanger with two circuits, wherein a water supply into the drum or into the drum container is connected to one circuit of the heat exchanger, wherein a second circuit of the heat exchanger is connected to the induction heating device for heating by the induction heating coil. [21] Electrical appliance according to one of claims 18 to 20, characterized bythat the induction heating device has a heating surface which can be heated inductively by the induction heating coil, wherein a water guide of the electrical device is provided on the heating surface for water to flow through it to heat it and to cool the heating surface.

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