Device for heating liquids

Abstract

A device (10) for heating liquids, comprising: at least one longitudinally extending hollow body (12) made of an electrically insulating material, an electrical winding (18) arranged around the hollow body (12) and made of electrically conductive metal material, and a longitudinally extending coil (20) running inside the hollow body (12) and traversed internally by a liquid flow and comprising electrically conductive metal material, wherein the electrical winding (18) is configured to generate an electromagnetic field configured to induce an electric current in the coil (20) for electromagnetic inductive heating of the coil (20), wherein the coil (20) is in thermal contact with the liquid flow; wherein the hollow body (12) comprises a first end (14) and a second end (16), wherein the cavity of the hollow body (12) comprises a first opening arranged at the first end (14) and a second opening arranged at the second end (16); and the first opening of the cavity of the hollow body (12) is at least partially closed by a first closing plate (25) and the second opening of the cavity of the hollow body (12) is at least partially closed by a second closing plate, wherein the coil (20) is enclosed in the hollow body (12) by means of the first and second closing plates characterized by the fact that the heating device (10) further comprises an electric valve (28) which is designed to convey the liquid into the coil (20) before the electromagnetic inductive heating and to drain the remaining liquid present in the coil (20) after the electromagnetic inductive heating.

Description

[0001] The present invention relates to a device for heating liquids, which is particularly, but not exclusively, useful and practical for heating water, milk or oils, which are to be used for countless purposes in the private or industrial sector, for example for heating residential buildings (i.e., warm running water).

[0002] Nowadays, the use of electric boilers or gas boilers - typically methane boilers - is well known, which are specifically suitable for heating liquids, mainly water, but also other substances.

[0003] However, these known solutions are not without disadvantages, for example due to the fact that they have a very high energy loss and are consequently highly inefficient from an energy and operational point of view.

[0004] An electric boiler must indeed be switched on constantly to ensure that the liquid inside it reaches a temperature – typically set by the user – that remains constant over time.

[0005] Similarly, a gas boiler must heat a quantity of liquid that is greater than the quantity required by the user in order to ensure the delivery of the liquid at a temperature that remains constant over time.

[0006] Furthermore, as mentioned above, these boilers are operated with methane and perform their function by burning this gas; therefore, there are risks of leakage of both methane and carbon monoxide, as well as accidents due to the high flammability of methane itself.

[0007] EP2868242A1 describes a device for heating water in a beverage preparation and dispensing machine, consisting essentially of a hollow coil, an electromagnetic induction winding around the hollow coil and a channel arranged inside the hollow coil through which a stream of water passes.

[0008] The aim of the present invention is to overcome the limitations of the prior art described above by providing a device for heating liquids with which better effects can be achieved than with known solutions and / or similar effects at lower costs and with better performance.

[0009] Within the scope of this objective, it is an object of the present invention to provide a device for heating liquids with which a liquid can be heated from an initial temperature to a selected final temperature up to the gaseous state.

[0010] Another objective of the present invention is to provide a device for heating liquids that ensures a high level of safety, in particular for the person - whether a user or a person skilled in the art - who handles the device, for example during installation or maintenance work on the device or during maintenance work on the machine or on the equipment in which the device is installed.

[0011] Another objective of the present invention is to provide a device for heating liquids that enables energy savings compared to the prior art.

[0012] Another objective of the present invention is to provide a device for heating liquids that does not need to be in constant operation in order to heat the liquid adequately.

[0013] Another objective of the present invention is to provide a device for heating liquids that makes it possible to heat a quantity of liquid that is essentially limited to the actual needs of the user.

[0014] Another objective of the present invention is to provide a device for heating liquids that makes it possible to do without a gas boiler - typically without a methane boiler - and thus reduce the risks resulting from the use of this extremely flammable gas.

[0015] It is also an objective of the present invention to provide a device for heating liquids that eliminates the need for an electric boiler.

[0016] Another objective of the present invention is to provide a device for heating liquids that has reduced dimensions and thus reduces the space requirement.

[0017] Another objective of the present invention is to provide a device for heating liquids that is highly reliable, relatively easy to manufacture and install, and economically competitive compared to the prior art.

[0018] This objective is achieved, and these and other tasks, which will become clearer below, are fulfilled by a device for heating liquids, comprising: at least one longitudinally extending hollow body, an electrical winding made of electrically conductive metal material arranged around the hollow body, and a longitudinally extending coil which runs inside the hollow body and is traversed in its interior by a liquid stream and comprises electrically conductive metal material, wherein the electrical winding is configured to generate an electromagnetic field, which is configured to induce an electric current in the coil for electromagnetic induction heating of the coil, wherein the coil is in thermal contact with the liquid stream; characterized by the fact that the hollow body comprises a first end and a second end, wherein the cavity of the hollow body comprises a first opening located at the first end and a second opening located at the second end; and the first opening of the cavity of the hollow body is at least partially closed by a first closing plate and the second opening of the cavity of the hollow body is at least partially closed by a second closing plate, wherein the coil is enclosed in the hollow body by first and second closing plates.

[0019] Further features and advantages of the invention will become clearer by describing some preferred, but not exclusive, embodiments of the device for heating liquids according to the invention, illustrated as non-limiting examples with the aid of the accompanying drawings, wherein Fig. 1 a perspective view of an embodiment of the device for heating liquids according to the present invention; the Fig. 2a and Fig. 2b a perspective view and a section view, along a vertical plane, of a first variant of an embodiment of the device for heating liquids according to the present invention; the Fig. 3a and Fig. 3b a perspective view and a section view, along a vertical plane, of a second variant of an embodiment of the device for heating liquids according to the present invention; the Fig. 4a and Fig. 4b a perspective view and a section view, along a vertical plane, of a third variant of an embodiment of the device for heating liquids according to the present invention; Fig. 5 is a top view of an embodiment of the device for heating liquids according to the present invention.

[0020] With reference to the figures: The device for heating liquids according to the invention, generally characterized by reference numeral 10, essentially comprises at least one longitudinally extending hollow body 12, an electrical winding 18 arranged around the hollow body 12, in particular around its outer wall, and a longitudinally extending coil 20 extending in the hollow body 12, in particular through the cavity of the hollow body 12. Like the hollow body 12, the cavity of the hollow body 12 also extends longitudinally.

[0021] The hollow body 12 is the supporting element of the heating device 10 and comprises a first end 14 and a second end 16. The cavity of the hollow body 12 comprises a first opening, arranged at the first end 14, and a second opening, arranged at the second end 16. The cavity of the hollow body 12 is bounded by its inner wall.

[0022] For practical purposes, as in Fig. As shown in Figure 1, the first opening of the cavity of the hollow body 12 is partially or completely closed by a first closing plate 25, which is arranged and attached at the first end 14. Similarly, the second opening of the cavity of the hollow body 12 is partially or completely closed by a second closing plate (not shown), which is arranged and attached at the second end 16.

[0023] For example, the first closure plate 25 and the second closure plate can be fastened to the first end 14 and the second end 16 of the hollow body 12 using locking couplings or threaded pins.

[0024] In practice, the coil 20 is essentially enclosed within the hollow body 12 by means of the aforementioned sealing plates, thereby forming a single body. In some embodiments, the end sections of the coil 20, in particular an inlet section and an outlet section, may protrude from the hollow body 12 and thus from the single body.

[0025] The essentially complete enclosure of the coil 20 in the hollow body 12 by means of the sealing plates ensures both correct and safe operation of the device 10 according to the invention, in particular according to the working specifications, and correct and safe installation of the device 10 in a machine or device, without any room for errors during installation.

[0026] Regarding correct and safe operation, it should be noted that if the coil 20 were a through-coil but not completely enclosed in the hollow body 12, the overall inductance value of the device 10 according to the invention would change, which would lead to malfunctions in the electronic circuit board 30, for example, the failure of the corresponding components as well as to abnormal absorption from the power grid.

[0027] In particular, since the coil 20 preferably comprises ferromagnetic, electrically conductive metal material, the overall inductance value of the coil 20 would change if it were not completely enclosed in the hollow body 12. The coil 20 is indeed magnetically coupled to the electrical winding 18 arranged around the hollow body 12. The device 10 according to the invention is designed such that the coil 20 and the electrical winding 18 of the hollow body 12 operate within certain limits or ranges of magnetic coupling. If this magnetic coupling between the coil 20 and the electrical winding 18 were not within the aforementioned limits or ranges, malfunctions would occur in the device 10 according to the invention.

[0028] If even one-third of the length of the coil 20 were not enclosed within the hollow body 12, the power consumption from the mains would be up to two and a half times higher than that required during normal operation. For example, in a normal operating state of the device 10 according to the invention, a power consumption of 1 kW from the mains may be present for a specific application; if the coil 20 were enclosed within the hollow body 12 for two-thirds of its length, the power consumption from the mains would be greater than 2.3 kW and would lead to the failure of the circuit board 30.

[0029] Regarding the correct and safe installation, it should be noted that the fact that the hollow body 12 and the coil 20 are essentially part of a single body speeds up the installation of the device 10 according to the invention by the operator, who only has to connect the two ends of the device 10, for example with the help of the inlet distributor 24 and the outlet distributor 26, and the electrical connections 32.

[0030] Another advantage of the monolithic solution, which comprises the hollow body 12, the coil 20, the first sealing plate 25 and the second sealing plate, is that the cavity of the hollow body 12, in which the coil 20 heated by electromagnetic induction is arranged, is not accessible during the operation of the device 10 according to the invention.

[0031] The hollow body 12 can have any geometry, cross-section, and length, which in each case must be defined according to the requirements. In the preferred and illustrated embodiments, the hollow body 12 has a circular cross-section. Accordingly, both the outer and inner walls of the hollow body 12 also have a circular cross-section. In the preferred and illustrated embodiments, the hollow body 12 is tubular, i.e., it is a cylindrical hollow body of variable length. In other embodiments, which differ from the preferred and illustrated ones, the hollow body 12 is obtuse. In further embodiments, which differ from the preferred and illustrated ones, the hollow body 12 has a simple, preferably regular, polygonal cross-section, for example, a square, rectangular, hexagonal, or similar cross-section.

[0032] The hollow body 12 can be made of any heat-resistant material, for example, a plastic material (e.g., polyamide 66). Preferably, the hollow body 12 is made of an electrically insulating material.

[0033] The electrical winding 18 of the heating device 10, which, as mentioned above, is arranged around the hollow body 12, consists of electrically conductive metal material, e.g., copper or aluminum of the fine-stranded type or of the solid wick type. In a preferred embodiment of the invention, the electrical winding 18 is arranged in contact with the outer wall of the hollow body 12. In another embodiment, the electrical winding 18 is arranged near the outer wall of the hollow body 12. In the preferred and illustrated embodiments, in which the hollow body 12 has a circular cross-section, the electrical winding 18 has a cylindrical helical shape with a pitch that can vary depending on the requirements.

[0034] Conveniently, the electrical winding is 18, as in the Fig. 1 and Fig. Figure 4 shows the outer surface covered with an insulating layer 22. Generally, the insulating layer 22 consists of an electrically and thermally insulating material, e.g., an epoxy resin, a silicone resin, or a thermoplastic resin. Preferably, the insulating layer 22 consists of a thermoplastic resin, for example, polyethylene terephthalate (e.g., Mylar®).

[0035] The electrical winding 18 is designed to transmit the energy required for the electromagnetic heating of the coil 20 by induction. Specifically, the electrical winding 18 is designed to generate an electromagnetic field suitable for inducing an electric current in the coil 20, thereby heating it electromagnetically. In practice, the electrical winding 18 functions as an inductor or coil.

[0036] In general, electromagnetic inductive heating is a method developed to heat electrically conductive materials, specifically ferromagnetic materials. Electromagnetic inductive heating involves an alternating electric current flowing through the electrical winding 18, which, by generating an electromagnetic field, induces the same alternating current in the coil 20, thus heating it. This physical process is known as electromagnetic induction or Faraday's law.

[0037] After heating by electromagnetic induction, the coil 20 conducts heat to the liquid flowing in it, in particular through contact between the coil 20 and the liquid.

[0038] In practice, the alternating current induced in the coil 20 heats it to a desired temperature, so that the liquid flowing in the coil 20 is in turn heated.

[0039] The heating device 10 according to the invention further comprises at least one circuit board 30, which is connected to the electrical winding 18, in particular to its ends, via power cables 32, e.g., of the fine-stranded type or of the solid wick type. Conveniently, the electrical connections 32 from the circuit board 30 to the electrical winding 18 have a length of one meter or less. Of course, it is also possible to use electrical connections 32 that are longer than one meter, but in this case the output power decreases considerably.

[0040] The circuit board 30 is powered by the mains electricity supply. The circuit board 30 is designed to supply the alternating current to the electrical winding 18, which is required to generate the electromagnetic field for the electromagnetic inductive heating of the coil 20. In practice, the circuit board 30 functions as a high-frequency current generator.

[0041] The operating frequency value or range of the printed circuit board 30 depends exclusively on the desired temperature, the amount of liquid to be heated flowing in the coil 20, and the heat dissipation coefficient of the liquid in question.

[0042] The coil 20 of the heating device 10, which, as mentioned above, runs inside the hollow body 12, is a tube or conduit through which the liquid flow to be heated passes internally. In one embodiment, the coil 20 consists of a preferably ferromagnetic, electrically conductive metal material. In another embodiment, the coil 20 consists of a silicone material, i.e., a silicone-based material, covered with a braid of electrically conductive, preferably ferromagnetic, metal material. This combination of silicone material and metal braid allows for a simpler construction of the coil 20 and expands the possible uses of the device 10 according to the invention, for example, in the food sector.

[0043] The coil 20 is in thermal contact with the flow of liquid. Specifically, the coil 20 is designed to transfer heat to the liquid flowing within it. The liquid flow exiting the coil 20 can reach any desired temperature, even down to a gaseous state.

[0044] Furthermore, the coil 20 is designed to receive the liquid flow to be heated and to direct its flow from an inlet section of the coil 20, e.g. near the first end 14 of the hollow body 12 and / or near the first opening of the cavity of the hollow body 12, to an outlet section of the coil 20, which is located, for example, near the second end 16 of the hollow body 12 and / or near the second opening of the cavity of the hollow body 12.

[0045] The coil 20 can have any geometry, cross-section, and length, which in each case must be defined depending on the requirements of the application. In the preferred and illustrated embodiments, the coil 20 has a circular cross-section. In one embodiment of the invention, e.g., as in the Fig. 2a, Fig. 2b, Fig. 3a and Fig. As shown in 3b, the coil 20 has a spiral, preferably cylindrical shape with a pitch that can vary depending on the requirements.

[0046] With particular reference to the Fig. 2a and Fig. 2b: In one embodiment, the coil 20 has a helical shape, preferably a cylindrical shape, and at least part of its windings, preferably all, is in contact with the inner wall of the hollow body 12.

[0047] With particular reference to the Fig. 3a and Fig. 3b In another embodiment, the coil 20 has a helical shape, preferably a cylindrical shape, and at least some, preferably all, of its windings are connected to the hollow body 12. In practice, in this embodiment, the coil 20 and the hollow body 12 are monolithically connected.

[0048] In another embodiment (not shown), the coil 20 has a helical shape, preferably a cylindrical shape, and at least some of its windings, preferably all, are arranged near the inner wall of the hollow body 12.

[0049] With particular reference to the Fig. 4a and Fig. 4b: In another embodiment of the invention, the coil 20 is parallel to the central longitudinal axis of the hollow body 12 and preferably coincides with it.

[0050] The shape and / or size of some components of the heating device 10 according to the invention, such as the diameter of the hollow body 12 or the curvatures and diameter of the coil 20, depend exclusively on the desired temperature, the amount of liquid to be heated flowing inside the coil 20, and the heat transfer coefficient of the liquid in question.

[0051] In one embodiment of the invention, which is in Fig. As shown in Figure 1, the heating device 10 further comprises an inlet distributor 24 and an outlet distributor 26, which are configured to connect the coil 20 to a system of conduits for the flow of the liquid. The inlet distributor 24 is connected to the inlet of the coil 20, e.g., near the first end 14 of the hollow body 12 and / or near the first opening of the cavity of the hollow body 12. The outlet distributor 26 is connected to the outlet of the coil 20, e.g., near the first end 14 of the hollow body 12 and / or near the first opening of the cavity of the hollow body 12. B. near the second end 16 of the hollow body 12 and / or near the second opening of the cavity of the hollow body 12. Optionally, the inlet distributor 24 is coupled to the first closing plate 25, which, as already mentioned, is arranged at the first end 14 of the hollow body 12, and the outlet distributor 26 is coupled to the second closing plate, which, as already mentioned, is arranged at the second end 16 of the hollow body 12.

[0052] In one embodiment of the invention, which is in Fig. As shown in Figure 1, the heating device 10 further comprises a three-way electric valve 28 configured to allow the liquid to enter and exit the coil 20.

[0053] Preferably the electric valve 28 is connected to the outlet distributor 26.

[0054] The electric valve 28 is designed to transfer the heating fluid to be heated into the hydraulic circuit, specifically into the coil 20, during operation, prior to the heating processes (and subsequent discharge), i.e., prior to the electromagnetic inductive heating of the coil 20. The flow of fluid in the coil 20 can be initiated by gravity, a pump, or the pressure of a water system. In practice, the electric valve 28 activates the circulation of fluid in the coil 20 before the device 10 according to the invention is switched on. Once the electric valve 28 activates the circulation of fluid in the coil 20, the device 10 according to the invention can begin the heating processes. This is necessary to prevent the device 10 from operating "dry," i.e., without fluid flow within it, particularly in the coil 20.This is necessary because the "dry" operation of the device 10 can lead to very high temperatures and subsequent damage to the device 10 within a few seconds.

[0055] The electric valve 28 is designed to drain any remaining fluid in the hydraulic circuit, particularly in the coil 20, after the heating (and subsequent discharge) processes, i.e., after the electromagnetic inductive heating of the coil 20. In practice, the electric valve 28 prevents any fluid from remaining in the coil 20 after the device 10 according to the invention has been switched off. This draining process performed by the electric valve 28 is useful to prevent the fluid in the hydraulic circuit, particularly in the coil 20, from stagnating and, in the case of low temperatures, freezing.

[0056] In an alternative embodiment, the electric three-way valve 28 can be replaced by an electric holding valve, preferably connected to the inlet distributor 24, and an electric drain valve, preferably connected to the drain distributor 26.

[0057] In one embodiment of the invention, the device 10 for heating liquids according to the invention comprises a plurality of hollow bodies 12 connected to one another in series, in a number that can vary according to requirements; wherein the coil 20 passes through the plurality of hollow bodies 12. Preferably, all hollow bodies 12 of the plurality of hollow bodies have the same cross-section.

[0058] In general, the heating device 10 according to the invention is controlled and operated by one or more printed circuit boards (including the printed circuit board 30), which may have different hardware and / or software configurations, which in each case are defined according to the respective requirements, for example on the basis of the length of the hollow body 12 and the coil 20 or on the basis of the desired temperature that must be reached by the liquid which exits from the coil 20.

[0059] Thus, the temperature of the liquid exiting coil 20 is adjusted using a suitable hardware and / or software configuration of the aforementioned circuit boards. For example, it is possible to define different temperature thresholds for the liquid exiting coil 20 using these configurations.

[0060] In one embodiment of the invention, the heating device 10 for indirectly measuring the liquid temperature and subsequently adjusting it further comprises a thermistor, which is arranged in thermal contact with the coil 20, preferably with an end section of the coil 20, and is functionally connected to a control unit of the heating device 10 according to the invention and optionally also to the circuit board 30. The thermistor can be in contact with the outer wall or with the inner wall of the coil 20. The thermistor can be arranged on any of the sealing plates for the openings of the cavity of the hollow body 12.

[0061] In this embodiment, the thermistor is characterized according to the temperature detected at coil 20. The thermistor is sensitive to the temperature of the coil. The thermistor is configured to detect the temperature of coil 20 and report this temperature to the control unit, for example, by means of a suitable circuit.

[0062] In this embodiment as well, the control unit is configured to calculate the temperature of the fluid flowing within the coil 20, based on the temperature detected by the thermistor on the coil 20, using a suitable algorithm. The control unit is further configured to control the circuit board 30 and to vary the operating frequency of the circuit board 30 based on the power required to achieve the desired fluid temperature, starting from the current temperature previously calculated by the control unit.

[0063] In an alternative embodiment according to the invention, the heating device 10 further comprises, for the purpose of directly measuring the temperature of the liquid and subsequently adjusting the temperature, a thermistor which is arranged in thermal contact with the flow of liquid flowing within the coil 20 and is functionally connected to the control unit of the heating device 10 according to the invention and optionally also to the circuit board 30. The thermistor can be arranged on any of the sealing plates of the openings of the cavity of the hollow body 12.

[0064] In this embodiment, the thermistor is characterized by the temperature measured in the liquid flow. The thermistor is sensitive to the temperature of the liquid flow. It is configured to detect the temperature of the liquid flowing within coil 20 and transmit it to the control unit, for example, by means of a suitable circuit.

[0065] In this embodiment as well, the control unit is configured to control the circuit board 30 and to change its operating frequency based on the power required to achieve the desired temperature of the liquid from the actual temperature previously detected by the thermistor.

[0066] In a preferred embodiment, the thermistor of the heating device 10 according to the invention is of the NTC type (Negative Temperature Coefficient), in practice with a resistance that decreases as the temperature increases.

[0067] The adjustment of the liquid temperature has an accuracy of less than 0.5°C and enables the minimal use of the current absorbed by the device 10 according to the invention to heat the liquid inside it.

[0068] Consider, for example, a closed hydraulic circuit containing a specific quantity of fluid to be heated, which flows within it. The control unit of the heating device 10 according to the invention is able, by interacting with the thermistor arranged in thermal contact with the coil 20, to adjust the minimum power of the electromagnetic induction required to bring the fluid to the desired temperature or to maintain it there.

[0069] The control unit of the heating device 10 makes it possible to consume only the amount of liquid and electricity that are absolutely necessary by adjusting the liquid temperature and controlling the electric valve 28.

[0070] In one embodiment according to the invention, the heating device 10 further comprises a safety device 45, which is in thermal contact with the coil 20, preferably with an end section of the coil 20, and is functionally connected to the circuit board 30. The safety device 45 can be in contact with the outer wall or the inner wall of the coil 20. It can be arranged on any of the sealing plates for the openings of the cavity of the hollow body 12.

[0071] The safety device 45 is sensitive to the temperature of the coil 20. The safety device 45 is designed to detect the temperature of the coil 20 and trigger a shutdown when the temperature of the coil 20 exceeds a threshold value. Specifically, the safety device 45 is designed to stop the electromagnetic inductive heating of the coil 20 and thus interrupt the power supply to the circuit board 30 when a threshold temperature (e.g., preset to 120°C) is exceeded at the coil 20. In practice, the safety device 45 is designed to stop the heating device 10 according to the invention when its coil 20 reaches a temperature exceeding the threshold value (e.g., 120°C).

[0072] If the temperature of the coil 20 exceeds the threshold value, the safety device 45 is triggered, opens the circuit, thus acting as a switch and interrupting the power supply to the circuit board 30. After the safety device 45 has been triggered, the heating device 10 must cool down according to the invention and be switched on again. The heating device 10 starts again when the temperature of the coil 20 falls below the threshold value again.

[0073] In a preferred embodiment, the safety device 45 of the heating device 10 according to the invention comprises a metal flange arranged in thermal contact with the coil 20 and a temperature controller linked to the flange and functionally connected to the circuit board 30. Conveniently, the temperature controller includes a resettable thermal fuse (e.g., a fuse that can be reset to 120°C), which is also metallic and connected to the flange, e.g., by screws.

[0074] The safety device 45, in the event of a malfunction, allows the heating device 10 according to the invention to be stopped and prevents the coil 20 from melting the hollow body 12 or, even worse, from causing a fire in the components. In any malfunction situation, the safety device 45 ensures that the temperature of the coil 20 remains under control, prevents damage to the circuit board 30, and keeps the operating temperature of the coil 20, and thus of the heating device 10, within the safety limits stipulated by legal regulations and the technical specifications of the materials used.

[0075] In one embodiment of the invention, which is in Fig.As shown in Figure 5, the heating device 10 is enclosed in a box-shaped body 50, which is designed to protect the various components, in particular the hollow body 12, the electrical winding 18, and the circuit board 30. The liquid to be heated enters the coil 20 of the heating device 10 in the following sequence: an inlet opening 36, an inlet line 34, and the inlet distributor 24. The heated liquid exits the coil 20 of the heating device 10 in the following sequence: the outlet distributor 26, an outlet line 38, and an outlet opening 40.

[0076] The operation of an embodiment of the device 10 for heating liquids according to the invention is briefly summarized below.

[0077] First, the liquid to be heated to the desired temperature enters the coil 20 of the heating device 10, which, as already mentioned, passes through the hollow body 12. As the liquid flows through the coil 20, the electrical winding 18 of the heating device 10, which, as already mentioned, is arranged around the hollow body 12, generates an electromagnetic field designed to produce an electric current for the electromagnetic inductive heating of the coil 20. The coil 20 then transfers heat to the flow of liquid within it, particularly by means of thermal contact between the coil 20 and the liquid. Finally, the liquid, heated to the desired temperature, exits the coil 20 of the heating device 10.

[0078] In practice, it has been found that the invention achieves its intended goal and fully fulfills its objectives. In particular, it has been shown that the device designed in this way for heating liquids makes it possible to overcome the qualitative limitations of the prior art, since it achieves better results than known solutions, and / or similar results at lower costs and with better performance.

[0079] An advantage of the device for heating liquids according to the invention is that it makes it possible to heat a liquid from any initial temperature to a desired final temperature, up to the gaseous state, during its passage through the coil.

[0080] Another advantage of the device for heating liquids according to the invention is that it ensures a high level of safety, especially for the person - whether an ordinary user or a specialized technician - who handles the device, for example during installation or during any work to maintain the device or during work to maintain the machine or apparatus in which / which the device is installed.

[0081] Another advantage of the device for heating liquids according to the present invention is that it enables high energy savings compared to the prior art.

[0082] Another advantage of the device for heating liquids according to the present invention is that it does not need to be permanently activated in order to heat the liquid adequately.

[0083] Another advantage of the device for heating liquids according to the present invention is that it makes it possible to heat a quantity of liquid that is essentially limited to the absolutely necessary amount.

[0084] A further advantage of the liquid heating device according to the present invention is that it avoids the use of a gas boiler – typically a methane boiler – and thus reduces the risks resulting from the use of this highly flammable gas. A further advantage of the liquid heating device according to the present invention is that it also eliminates the need for an electric boiler.

[0085] Another advantage of the device for heating liquids according to the present invention is that it has reduced dimensions, which significantly reduces the space required.

[0086] Last but not least, an advantage of the device for heating liquids according to the present invention is that it is highly reliable, relatively easy to provide and install, and economically competitive compared to the prior art.

[0087] Although the device for heating liquids according to the invention was designed in particular for work involving the heating of water, milk or oils for use in countless purposes in the private or industrial field, e.g. for heating living spaces (i.e. warm running water), it can in any case also be used more generally to heat any type of liquid or to generate steam.

[0088] The invention as conceived is suitable for numerous modifications and variations, all of which fall within the scope of protection of the attached claims. Furthermore, all details can be replaced by other, technically equivalent elements.

[0089] In practice, the materials used, provided they are compatible with the specific application, as well as the associated shapes and dimensions, can be arbitrary depending on the requirements and the state of the art.

[0090] Finally, the scope of protection of the claims must not be limited by the representations or preferred embodiments shown by way of example in the description, but the claims must include all features of patentable novelty that are present in the present invention, including all features that would be treated as equivalent by a person skilled in the art.

[0091] The disclosures in Italian patent application No. 102019000003373, from which this application claims priority, are included herein by reference.

[0092] If any technical features mentioned in any claim are followed by reference numerals, these reference numerals have been included only for the purpose of increasing the clarity of the claims, and accordingly such reference numerals have no limiting effect on the interpretation of any element which is exemplified by such reference numerals. QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] EP 2868242A1

[0007]

Claims

[1] A device (10) for heating liquids, comprising: at least one longitudinally extending hollow body (12) made of an electrically insulating material, an electrical winding (18) arranged around the hollow body (12) and made of electrically conductive metal material, and a longitudinally extending coil (20) running inside the hollow body (12) and traversed internally by a liquid flow and comprising electrically conductive metal material, wherein the electrical winding (18) is configured to generate an electromagnetic field configured to induce an electric current in the coil (20) for electromagnetic inductive heating of the coil (20), wherein the coil (20) is in thermal contact with the liquid flow; wherein the hollow body (12) comprises a first end (14) and a second end (16), wherein the cavity of the hollow body (12) comprises a first opening arranged at the first end (14) and a second opening arranged at the second end (16); and the first opening of the cavity of the hollow body (12) is at least partially closed by a first closing plate (25) and the second opening of the cavity of the hollow body (12) is at least partially closed by a second closing plate, wherein the coil (20) is enclosed in the hollow body (12) by means of the first and second closing plates characterized by , that the heating device (10) further comprises an electric valve (28) which is designed to convey the liquid into the coil (20) before the electromagnetic inductive heating and to drain the remaining liquid present in the coil (20) after the electromagnetic inductive heating. [2] The heating device (10) according to claim 1, characterized by , that it further comprises at least one printed circuit board (30) which is connected to the electrical winding (18), wherein the printed circuit board (30) is configured to supply an electric current to the electrical winding (18) in order to generate the electromagnetic field for the electromagnetic inductive heating of the coil (20). [3] The heating device (10) according to claim 1 or 2, characterized by , that the electrical winding (18) is covered on the outside with an insulating layer (22). [4] The heating device (10) according to any one of claims 1 to 3, characterized by , that the coil (20) has a spiral shape. [5] The heating device (10) according to claim 4, characterized by , that at least part of the windings of the coil (20) is arranged in contact with the inner wall of the hollow body (12). [6] The heating device (10) according to claim 4, characterized by , that at least part of the windings of the coil (20) is connected to the hollow body (12). [7] The heating device (10) according to claim 4, characterized by , that at least a part of the windings of the coil (20) is arranged near the inner wall of the hollow body (12). [8] The heating device (10) according to any one of claims 1 to 3, characterized by , that the coil (20) is parallel to the central longitudinal axis of the hollow body (12). [9] The heating device (10) according to any one of the above claims, characterized by, that the coil (20) comprises an inlet located near the first end (14) of the hollow body (12) and an outlet located near the second end (16) of the hollow body (12). [10] The heating device (10) according to any one of claims 1 to 9, characterized by , that the hollow body (12) has a circular cross-section. [11] The heating device (10) according to any one of claims 1 to 9, characterized by , that the hollow body (12) has a simple, polygonal, preferably regular, cross-section. [12] The heating device (10) according to any one of claims 2 to 11, characterized by, that it further comprises a safety device (45) arranged in thermal contact with the coil (20) and functionally connected to the circuit board (30), wherein the safety device (45) is configured to detect the temperature of the coil (20), to stop the electromagnetic inductive heating of the coil (20) and to interrupt the power supply to the circuit board (30) when a threshold temperature on the coil (20) is exceeded. [13] The heating device (10) according to any one of the above claims, characterized by , that it further comprises an inlet distributor (24) and an outlet distributor (26), designed to connect the coil (20) to a system of conduits for the fluid flow. [14] The heating device (10) according to any one of the above claims, characterized by, that it comprises a plurality of serially connected hollow bodies (12), wherein the coil (20) runs within the plurality of hollow bodies (12).

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