Heating element assembly, preparation method and application thereof

Abstract

This invention discloses a heating element assembly, its preparation method, and its application. The heating element assembly includes a first inorganic layer and a second inorganic layer, with a heating layer disposed between the first and second inorganic layers. The heat generated by the heating layer is transferred to the first inorganic layer at a different rate than it is transferred to the second inorganic layer. In this heating element assembly, the heat generated by the heating layer under the action of an alternating magnetic field is transferred through the first and second inorganic layers at different rates, thus creating a favorable heat transfer direction, making it easier for heat to be transferred to the inorganic layer with the faster transfer rate. Simultaneously, this heating element assembly also reduces noise generated when heating materials.

Description

Technical Field

[0001] This invention belongs to the field of cooking utensil technology, specifically relating to a heating element component, its preparation method, and its application. Background Technology

[0002] Many inorganic materials, such as ceramics and glass, are used in cooking utensils. Examples include the ceramic inner pot of electric slow cookers, the glass inner pot of glass health pots, and the microcrystalline and ceramic pots used in induction cookers. Glass and ceramic materials have excellent chemical stability and are considered healthy and environmentally friendly. However, these inorganic materials also have many drawbacks, such as low heat transfer efficiency, poor toughness, and fragility.

[0003] For glass heating vessels, the existing conventional application scheme mainly uses heating components such as heating tubes and heating plates. The glass vessel contacts the heating plate and heating tubes for heat transfer. The feature of this scheme is that the overall components are simple, but there are significant problems, such as small contact area, difficulty in close contact, and low heat transfer efficiency. When applied to kettles, heating 1L of water takes more than 15 minutes. Existing technologies have improved the thermal efficiency, but the benefits are small.

[0004] Existing technologies also include thick-film heating, which involves printing thick-film circuits on a glass plate for heating. This method has high thermal efficiency and uniform heating, but it has high requirements for the glass, such as using heat-resistant quartz glass. It also has safety issues, as the large current in the event of glass breakage poses a significant safety hazard to consumers.

[0005] In addition, existing technologies also include a method of printing or heat transfer to place a metal magnetic film on the outside of a glass plate and heating it by electromagnetic heating. This method has high heating efficiency of the metal film and no safety issues, but it has problems such as high stress during the heating process of glassware, high thermal resistance of glass, low heat transfer efficiency, and high stress making the glass prone to breakage. Summary of the Invention

[0006] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, one object of this invention is to provide a heating element assembly, its preparation method, and its application. In this heating element assembly, the heat generated by the heating layer under the action of an alternating magnetic field is transferred at different rates through the first and second inorganic layers, thereby creating a favorable heat transfer direction, with heat more easily transferred to the inorganic layer where the transfer rate is faster. Simultaneously, this heating element assembly also reduces noise generated when heating materials.

[0007] In one aspect of the invention, a heating element assembly is provided. According to an embodiment of the invention, the heating element assembly includes: a first inorganic layer and a second inorganic layer, with a heating layer disposed between the first inorganic layer and the second inorganic layer, wherein the rate at which heat generated by the heating layer is transferred to the first inorganic layer is different from the rate at which it is transferred to the second inorganic layer.

[0008] According to the heating element assembly of the present invention, the heat generated by the heating layer under the action of an alternating magnetic field is transferred at different speeds through the first inorganic layer and the second inorganic layer, thereby creating a favorable heat transfer direction, with heat more easily transferred to the inorganic layer where the transfer speed is faster. Simultaneously, the heating element assembly of the present invention also reduces noise generated when heating materials. Specifically, if a single inorganic layer is provided on one side of the heating layer, when the heating layer generates heat, the heat is transferred at a greater speed to the direction without an inorganic layer, thus generating more noise. The present invention, by providing inorganic layers on both sides of the heating layer, although reducing heat transfer efficiency to some extent, reduces noise while simultaneously ensuring high heat transfer efficiency.

[0009] In addition, the heating element assembly according to the above embodiments of the present invention may also have the following additional technical features:

[0010] In some embodiments of the present invention, the rate at which heat is transferred to the first inorganic layer is greater than the rate at which heat is transferred to the second inorganic layer.

[0011] In some embodiments of the present invention, the thickness of the second inorganic layer is not less than the thickness of the first inorganic layer.

[0012] In some embodiments of the present invention, the thickness difference between the second inorganic layer and the first inorganic layer is no greater than 4.5 mm.

[0013] In some embodiments of the present invention, the thickness difference between the second inorganic layer and the first inorganic layer is 0.5-3 mm.

[0014] In some embodiments of the present invention, the thickness ratio of the second inorganic layer to the first inorganic layer is greater than 1 and less than or equal to 15.

[0015] In some embodiments of the present invention, the thickness ratio of the second inorganic layer to the first inorganic layer is greater than 1 and less than or equal to 10.

[0016] In some embodiments of the present invention, the thickness of the second inorganic layer is not less than 2 mm, and the thickness of the first inorganic layer is not greater than 2 mm.

[0017] In some embodiments of the present invention, the thickness of the first inorganic layer is 0.3-2 mm, and the thickness of the second inorganic layer is 2-4 mm.

[0018] In some embodiments of the present invention, at least one of the following conditions is met: the thickness of the heating layer is 10-25 μm; the heating layer comprises a weakly magnetic metal material and a glass phase.

[0019] In some embodiments of the present invention, at least one of the following conditions is met: the content of the weakly magnetic metal material in the heating layer is 70-90 wt%; the weakly magnetic metal material is selected from at least one of silver, aluminum and copper; the glass phase material includes at least one of SiO2, Al2O3, Bi2O, Ti2O, K2O and B2O3.

[0020] In some embodiments of the present invention, the first inorganic layer is connected to the heating layer through a first adhesive glaze layer, and the second inorganic layer is connected to the heating layer through a second adhesive glaze layer; or the first inorganic layer is connected to the heating layer through a first adhesive glaze layer, and the second inorganic layer is directly connected to the heating layer; or the second inorganic layer is connected to the heating layer through a second adhesive glaze layer, and the first inorganic layer is directly connected to the heating layer; or the first inorganic layer and the second inorganic layer are respectively directly connected to the heating layer.

[0021] In some embodiments of the present invention, the thicknesses of the first adhesive glaze layer and the second adhesive glaze layer are each independently greater than the thickness of the heating layer.

[0022] In some embodiments of the present invention, the thicknesses of the first adhesive glaze layer and the second adhesive glaze layer are each independently 5-30 μm.

[0023] In some embodiments of the present invention, at least a portion of the first adhesive glaze layer and / or the second adhesive glaze layer is embedded in the heating layer.

[0024] In some embodiments of the present invention, the glazes in the first adhesive glaze layer and the second adhesive glaze layer each independently include at least one of SiO2, Al2O3, Bi2O, Ti2O, K2O and B2O3.

[0025] In some embodiments of the present invention, the heating layer is directly connected to the first inorganic layer and / or the second inorganic layer, the weakly magnetic metal material in the heating layer is disposed away from the first inorganic layer and / or the second inorganic layer, and the glass phase in the heating layer is disposed close to the first inorganic layer and / or the second inorganic layer.

[0026] In some embodiments of the present invention, the heating layer is connected to the first inorganic layer and / or the second inorganic layer via a concave-convex structure, wherein the glass phase in the heating layer is at least partially embedded in the first inorganic layer and / or the second inorganic layer to form the concave-convex structure.

[0027] In some embodiments of the present invention, the heating layer includes a heating layer and a transition connection layer. The heating layer is connected to the first inorganic layer and / or the second inorganic layer through the transition connection layer. The heating layer includes a weakly magnetic metal material and a glass phase. The transition connection layer includes a glass phase. The glass phase in the heating layer is connected to the glass phase in the transition connection layer.

[0028] In some embodiments of the present invention, at least one of the following conditions is met: the composition of the glass phase in the transition connection layer is the same as the composition of the glass phase in the heating layer; the transition connection layer does not contain weakly magnetic metal material; and the thickness of the transition connection layer is 0.1-5 micrometers.

[0029] In some embodiments of the present invention, the weakly magnetic metal material in the heating layer is at least partially embedded in the transition connection layer.

[0030] In some embodiments of the present invention, the first inorganic layer and the second inorganic layer are independently glass layers or ceramic layers.

[0031] In another aspect of the invention, a method for preparing the above-described heating element assembly is provided. According to an embodiment of the invention, the method includes:

[0032] (1) Provide a first inorganic layer and a second inorganic layer;

[0033] (2) A heating layer is formed between the first inorganic layer and the second inorganic layer to obtain a heating element assembly.

[0034] According to an embodiment of the present invention, a method for preparing the above-mentioned heating element assembly involves providing a heating layer between a first inorganic layer and a second inorganic layer. The heat generated by this heating layer under the action of an alternating magnetic field is transferred at different rates through the first and second inorganic layers, resulting in a favorable heat transfer direction, with heat more easily transferred to the inorganic layer where the transfer rate is faster. Simultaneously, the heating element assembly of the present invention also reduces noise generated when heating materials. Specifically, if a single inorganic layer is provided on one side of the heating layer, when the heating layer generates heat, the heat is transferred at a higher rate to the direction without an inorganic layer, thus generating more noise. The present invention, by providing inorganic layers on both sides of the heating layer, although reducing heat transfer efficiency to some extent, reduces noise while simultaneously ensuring high heat transfer efficiency.

[0035] In addition, the method for preparing the heating element assembly according to the above embodiments of the present invention may also have the following additional technical features:

[0036] In some embodiments of the present invention, the step of forming a heating layer between the first inorganic layer and the second inorganic layer to obtain a heating element assembly further includes: forming a first adhesive glaze layer on the side of the first inorganic layer near the heating layer; and / or forming a second adhesive glaze layer on the side of the second inorganic layer near the heating layer.

[0037] In a third aspect, the present invention provides a heatable appliance. According to an embodiment of the invention, the heatable appliance includes a heating element assembly as described in the above embodiments or a heating element assembly manufactured using the methods described in the above embodiments, wherein the first inorganic layer constitutes at least a portion of the cavity of the heatable appliance. Thus, the first inorganic layer, with a higher heat transfer rate, constitutes at least a portion of the cavity of the heatable appliance, and the heat generated by the heating layer is transferred to the first inorganic layer at a greater rate than to the second inorganic layer. Therefore, heat is more easily transferred in the direction of the first inorganic layer, i.e., more easily transferred in the direction of the cavity of the heatable appliance, thereby giving the heatable appliance higher heat transfer efficiency; simultaneously, the noise generated when heating materials using this heatable appliance is lower.

[0038] In addition, the heatable appliance according to the above embodiments of the present invention may also have the following additional technical features:

[0039] In some embodiments of the present invention, the heating element assembly is disposed at the bottom of the heatable appliance;

[0040] And / or, negative pressure air is provided between the heating layer and the edges of the first inorganic layer and the second inorganic layer.

[0041] In some embodiments of the present invention, the heatable appliance includes a sealed sidewall and a bottom wall, at least a portion of the bottom wall being the heating element assembly;

[0042] And / or, the heating element assembly is connected to the sidewall by welding or by adhesive.

[0043] In a fourth aspect, the present invention provides a cooking appliance. According to an embodiment of the invention, the cooking appliance has the heatable appliance described in the above embodiments. Therefore, the cooking appliance has high heat transfer efficiency and generates less noise when heating materials, further meeting consumer needs and improving the user experience.

[0044] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. Attached Figure Description

[0045] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0046] Figure 1 This is a schematic diagram of the structure of a heating element assembly according to an embodiment of the present invention.

[0047] Figure 2 This is a schematic diagram of the heating element assembly according to another embodiment of the present invention.

[0048] Figure 3 This is a schematic diagram of the heating element assembly according to another embodiment of the present invention.

[0049] Figure 4 This is a schematic diagram of the heating element assembly according to another embodiment of the present invention.

[0050] Figure 5 This is a partially enlarged view of the heating element assembly according to another embodiment of the present invention.

[0051] Figure 6 This is a schematic diagram of an electric kettle with a heating element assembly according to an embodiment of the present invention.

[0052] Figure 7 This is a schematic diagram of an electric kettle with a heating element assembly according to another embodiment of the present invention.

[0053] Figure 8 This is a schematic diagram of a cookware with a heating element assembly according to an embodiment of the present invention. Detailed Implementation

[0054] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0055] In one aspect of the invention, a heating element assembly 100 is provided. According to an embodiment of the invention, refer to the accompanying drawings. Figure 1The aforementioned heating element assembly 100 includes a first inorganic layer 1 and a second inorganic layer 2, with a heating layer 3 disposed between the first inorganic layer 1 and the second inorganic layer 2. The heat generated by the heating layer is transferred through the first and second inorganic layers, and the rate at which heat is transferred to the first inorganic layer differs from the rate at which it is transferred to the second inorganic layer. Therefore, the heat generated by the heating layer under the action of an alternating magnetic field is transferred at different rates through the first and second inorganic layers, resulting in a favorable heat transfer direction, with heat more easily transferred to the inorganic layer where the transfer speed is faster. Simultaneously, the heating element assembly of this invention also reduces noise generated when heating materials. Specifically, if a single inorganic layer is disposed on one side of the heating layer, when the heating layer generates heat, the heat is transferred at a higher rate to the direction without an inorganic layer, resulting in greater noise. This invention, by distributing inorganic layers on both sides of the heating layer, reduces noise to some extent while maintaining high heat transfer efficiency.

[0056] According to a specific embodiment of the present invention, the heat is transferred to the first inorganic layer at a greater rate than it is transferred to the second inorganic layer, thereby creating a favorable heat transfer direction, and the heat generated by the heating layer is more easily transferred to the direction where the first inorganic layer is located.

[0057] According to another specific embodiment of the present invention, the thickness of the second inorganic layer is not less than the thickness of the first inorganic layer. Thus, under the same conditions, the heat transfer efficiency of the first inorganic layer is not less than the heat transfer efficiency of the second inorganic layer, which further promotes the speed at which the heat generated by the heating layer is transferred to the first inorganic layer greater than the speed at which it is transferred to the second inorganic layer, thereby creating a favorable heat transfer direction, and the heat generated by the heating layer is more easily transferred to the direction where the first inorganic layer is located.

[0058] According to another specific embodiment of the present invention, the thickness difference between the second inorganic layer 2 and the first inorganic layer 1 is no greater than 4.5 mm, and more preferably, the thickness difference between the second inorganic layer 2 and the first inorganic layer 1 is 0.5-3 mm. This further ensures that heat is more easily transferred towards the thinner first inorganic layer 1, with the majority of heat transferred to the first inorganic layer 1, thereby heating the material in contact with the first inorganic layer 1, thus achieving high heat transfer efficiency. At the same time, it avoids problems such as the second inorganic layer being prone to cracking, the heating element generating excessive noise when heating materials, and the first inorganic layer being prone to cracking due to poor mechanical strength, which can result from an excessively large thickness difference between the second and first inorganic layers. The inventors discovered that if the thickness difference between the second inorganic layer and the first inorganic layer is too large, it will cause the following problems: First, it indirectly leads to an excessively large thickness of the second inorganic layer, resulting in excessive thermal resistance. Heat generated by the heating layer is difficult to transfer from the second inorganic layer, causing a large amount of heat to accumulate there. Excessive heat can easily generate thermal stress in the second inorganic layer, increasing the risk of cracking. Second, given a fixed thickness difference between the second and first inorganic layers, to ensure the second inorganic layer is not too thick, the thickness of the first inorganic layer must be significantly reduced, resulting in an excessively thin first inorganic layer. This reduces the mechanical strength of the first inorganic layer, increases the manufacturing difficulty, and also increases the efficiency of heat transfer to the first inorganic layer, thus increasing the noise generated by the heating element when heating materials. Third, if the thickness difference between the first and second inorganic layers is large, it further increases the rate of heat transfer to the first inorganic layer, resulting in greater noise generated by the heating element when heating materials, and also increases the risk of cracking of the thinner first inorganic layer.

[0059] According to another specific embodiment of the present invention, the thickness ratio of the second inorganic layer to the first inorganic layer is greater than 1 and less than or equal to 15, preferably greater than 1 and less than or equal to 10. This further ensures that heat is more easily transferred to the direction where the thinner first inorganic layer 1 is located, and most of the heat is transferred to the first inorganic layer 1, thereby heating the material in contact with the first inorganic layer 1, thus achieving the purpose of high heat transfer efficiency. At the same time, it avoids the problems caused by the second inorganic layer being prone to cracking, the heating element generating more noise when heating the material, and the first inorganic layer being prone to cracking due to poor mechanical strength, which are caused by the second inorganic layer being too large in thickness ratio to the first inorganic layer. The inventors discovered that if the thickness ratio of the second inorganic layer to the first inorganic layer is too large, it will cause the following problems: First, it indirectly leads to an excessively large thickness of the second inorganic layer, resulting in excessive thermal resistance. Heat generated by the heating layer is difficult to transfer from the second inorganic layer, causing a large amount of heat to accumulate there. Excessive heat can easily generate thermal stress in the second inorganic layer, increasing the risk of cracking. Second, given a fixed thickness ratio, to ensure the second inorganic layer is not too thick, the thickness of the first inorganic layer must be significantly reduced, resulting in an excessively thin first inorganic layer. This reduces the mechanical strength of the first inorganic layer, increases the manufacturing difficulty, and also increases the efficiency of heat transfer to the first inorganic layer, thus increasing the noise generated by the heating element when heating materials. Third, if the thickness ratio of the first and second inorganic layers is large, it further increases the rate of heat transfer to the first inorganic layer, resulting in greater noise generated by the heating element when heating materials, and also increases the risk of cracking of the thinner first inorganic layer.

[0060] According to another specific embodiment of the present invention, the thickness of the second inorganic layer is not less than 2 mm, and the thickness of the first inorganic layer is not greater than 2 mm. This further ensures that heat is more easily transferred to the direction where the thinner first inorganic layer 1 is located, and most of the heat is transferred to the first inorganic layer 1, thereby heating the material in contact with the first inorganic layer 1, thus achieving the purpose of high heat transfer efficiency and reduced noise. The inventors discovered that, due to the high heat transfer rate in the first inorganic layer, if the thickness of the first inorganic layer is greater than 2 mm, on the one hand, it will cause excessive thermal stress inside the first inorganic layer. In the case of microcracks in the first inorganic layer, the probability of breakage will increase significantly. On the other hand, it may also reduce the heat transfer rate on the first inorganic layer side, reducing the dominant heat transfer trend. If the thickness of the second inorganic layer is less than 2 mm, on the one hand, it will reduce the mechanical strength of the second inorganic layer, making it prone to problems such as impact breakage. On the other hand, it may also increase the heat transfer rate on the second inorganic layer side, reducing the dominant heat transfer trend. At the same time, since the second inorganic layer itself has a slow rate of heat transfer to the outside, but the rate of heat transfer from the heating layer to the second inorganic layer is relatively fast, and the second inorganic layer is in contact with air, heat is prone to accumulate in the second inorganic layer, thereby increasing its risk of breakage.

[0061] According to another specific embodiment of the present invention, the thickness of the first inorganic layer 1 is 0.3-2 mm, and the thickness of the second inorganic layer 2 is 2-4 mm. Therefore, firstly, the aforementioned thickness range ensures a suitable thickness difference between the second and first inorganic layers, further guaranteeing that the rate at which heat generated by the heating layer is transferred to the first inorganic layer is greater than the rate at which it is transferred to the second inorganic layer, thereby creating a favorable heat transfer direction, making it easier for heat generated by the heating layer to be transferred towards the first inorganic layer; secondly, it ensures that the thickness of the first inorganic layer is within a suitable range, avoiding a decrease in the strength and noise reduction of the first inorganic layer due to excessively small thickness. The risks include: 1) Insignificant effects; 2) Ensuring the thickness of the second inorganic layer is within a suitable range, avoiding the risk of low heat transfer efficiency due to excessive thickness, and 3) Excessive internal stress causing cracking of the second inorganic layer; 4) Matching the thicknesses of the first and second inorganic layers ensures that the thickness difference or ratio between them is not too high or too low, thereby improving the overall mechanical properties, heat transfer efficiency, and noise reduction of the heating element assembly. It also enhances the ability to withstand welding stress during subsequent welding of the heating element assembly to the container body, ensuring the overall mechanical properties of the heating element assembly.

[0062] According to another specific embodiment of the present invention, the heating layer 3 includes a weakly magnetic metal material and a glass phase. The heating layer is formed by heating and sintering a slurry including a weakly magnetic metal material and an inorganic glaze. The inorganic glaze forms a glass phase after sintering. The role of weakly magnetic metal materials is to generate eddy currents under the action of an alternating magnetic field, thereby generating heat. It can be understood that the weakly magnetic metal materials in the heating layer generate heat under the action of an alternating magnetic field, which can easily lead to heat concentration within the heating layer. If a glass phase is not provided to directly transfer heat to the first or second inorganic layer, hot spots can easily form in the first or second inorganic layer due to their poor thermal conductivity, creating thermal stress. Excessive thermal stress can easily cause the first or second inorganic layer to crack. Therefore, the heating layer of this invention connects the first or second inorganic layer through a glass phase, thereby providing a transitional glass phase between the weakly magnetic metal material and the inorganic layer (first or second inorganic layer). This increases the thermal resistance between the two, preventing heat from forming hot spots in the first or second inorganic layer, thus allowing for more uniform heat distribution and transfer. It also avoids thermal stress in the inorganic layer caused by hot spots, improving the bonding force between the heating layer and the inorganic layer, thereby increasing the overall mechanical strength of the heating element assembly.

[0063] According to another specific embodiment of the present invention, the mass proportion of the weakly magnetic metal material in the heating layer 3 is 70-90%. Thus, the weight content of the weakly magnetic metal material in the heating layer 3 is limited to the above range, which further enables the heating layer 3 to achieve high heating efficiency. At the same time, the heat generated by the weakly magnetic metal material is transferred to the first inorganic layer or the second inorganic layer more evenly through the appropriate content of glass phase, avoiding the formation of hot spots in the first inorganic layer or the second inorganic layer. This further enables the heat to be distributed and transferred more evenly, and also avoids the thermal stress formed in the inorganic layer due to hot spots, improving the bonding force between the heating layer and the inorganic layer, thereby improving the overall mechanical strength of the heating element assembly.

[0064] In the embodiments of the present invention, the specific types of the weak magnetic metal materials are not particularly limited, and those skilled in the art can choose them at will according to actual needs. As a preferred option, the weak magnetic metal materials are selected from at least one of silver, aluminum and copper, thereby the heating layer 3 formed by the above materials has high heating efficiency.

[0065] In embodiments of the present invention, the glass phase is sintered from an inorganic glaze. The specific type of inorganic glaze is not particularly limited, and those skilled in the art can choose it arbitrarily according to actual needs. As a preferred embodiment, the inorganic glaze is selected from at least one of SiO2, Al2O3, Bi2O, Ti2O, K2O, and B2O3. Therefore, the glass phase formed by the above material can provide suitable thermal resistance between the weakly magnetic metal material and the inorganic layer (first inorganic layer or second inorganic layer), preventing heat from forming hot spots in the first or second inorganic layer, thereby allowing heat to be distributed and transferred more uniformly.

[0066] According to another specific embodiment of the present invention, the thickness of the heating layer 3 is in the range of 10-25 μm, thereby the heating layer 3 in this thickness range has a high heating efficiency.

[0067] According to another specific embodiment of the present invention, the heating layer is directly connected to the first inorganic layer and / or the second inorganic layer. The weakly magnetic metal material in the heating layer is disposed away from the first inorganic layer and / or the second inorganic layer, and the glass phase in the heating layer is disposed close to the first inorganic layer and / or the second inorganic layer. Thus, by disposing the weakly magnetic metal material away from the inorganic layer (i.e., the first inorganic layer and / or the second inorganic layer), the risk of direct contact between the weakly magnetic metal material and the inorganic layer is further reduced. This ensures that the heat generated by the weakly magnetic metal material is not directly transferred to the inorganic layer, but is transferred to the inorganic layer through the glass phase. This increases the thermal resistance of heat transfer, while the low thermal conductivity of the glass phase increases the uniformity of heat transfer, avoids the formation of hot spots in the inorganic layer, and improves the bonding force between the heating layer and the inorganic layer, thereby improving the overall mechanical strength of the heating element assembly.

[0068] According to another specific embodiment of the present invention, the heating layer is connected to the first inorganic layer and / or the second inorganic layer through a concave-convex structure. The glass phase in the heating layer is embedded in the matrix of the first inorganic layer and / or the second inorganic layer to form the concave-convex structure. Thus, on the one hand, by setting the concave-convex structure, the contact area between the heating layer and the inorganic layer (i.e., the first inorganic layer and / or the second inorganic layer) is increased, that is, the area for heat transfer is increased, thereby improving the uniformity of heat transfer, avoiding the formation of hot spots in the inorganic layer, and reducing the risk of inorganic layer breakage. Simultaneously, the bonding force between the heating layer and the inorganic layer is also improved. On the other hand, by embedding the glass phase in the heating layer into the inorganic layer matrix, the risk of direct contact between the weakly magnetic metal material and the inorganic layer is further reduced. This ensures that the heat generated by the weakly magnetic metal material is not directly transferred to the inorganic layer, but is transferred through the glass phase, increasing the thermal resistance of heat transfer. Furthermore, the low thermal conductivity of the glass phase increases the uniformity of heat transfer, avoids the formation of hot spots in the inorganic layer, reduces the risk of inorganic layer breakage, and improves the bonding force between the heating layer and the inorganic layer.

[0069] According to another specific embodiment of the present invention, the heating layer includes a heating layer and a transition connection layer. The heating layer is connected to the first inorganic layer and / or the second inorganic layer through the transition connection layer. The heating layer includes a weakly magnetic metal material and a glass phase. The transition connection layer includes a glass phase, and the glass phase in the heating layer is interconnected with the glass phase in the transition connection layer. Therefore, firstly, by including a weakly magnetic metal material and a glass phase in the heating layer, the distribution of the weakly magnetic metal material in the heating layer is more uniform, thus preventing the heat generated by the weakly magnetic metal material from concentrating excessively and resulting in more uniform heat generation. This reduces the formation of hot spots in the heating layer and the inorganic layer, reduces the risk of inorganic layer cracking, and improves efficiency. The inorganic layer has a longer service life and the bonding strength between it and the heating layer is improved. Secondly, the transition layer includes a glass phase. Since there is also interfacial thermal resistance between the transition layer and the first inorganic layer, the rate at which heat generated by the weakly magnetic metal material is transferred to the first inorganic layer is further reduced, thus reducing the noise generated by the heating component when heating materials. Thirdly, the glass phase in the transition layer is interconnected with the glass phase in the heating layer, reducing the thermal resistance between the heating layer and the transition layer. This reduces the risk of microcracks forming inside the heating layer and promotes the uniform distribution of heat in the transition layer, reducing the formation of hot spots in the heating layer. It also improves the bonding strength between the transition layer and the heating layer.

[0070] According to another specific embodiment of the present invention, the composition of the glass phase in the transition connection layer is the same as that of the glass phase in the heating layer. Thus, the interconnection of the two glass phases with the same composition further reduces the thermal resistance between the heating layer and the transition connection layer, thereby further reducing the risk of microcracks forming inside the heating layer, and promoting the uniform distribution of heat in the transition connection layer, further reducing the formation of hot spots in the heating layer, and further improving the bonding force between the transition connection layer and the heating layer.

[0071] According to another specific embodiment of the present invention, the transition connection layer does not contain weakly magnetic metal material, thereby further promoting the formation of thermal resistance in this part, avoiding direct contact between the weakly magnetic metal material and the inorganic layer, so that the heat generated by the weakly magnetic metal material is not directly transferred to the inorganic layer, but is transferred to the inorganic layer through the transition connection layer, increasing the thermal resistance of heat transfer, increasing the uniformity of heat transfer, avoiding the formation of hot spots in the heating layer and the inorganic layer, improving the bonding force between the heating layer and the inorganic layer, and also reducing noise.

[0072] According to another specific embodiment of the present invention, the thickness of the transition connection layer is 0.1-5 micrometers. Thus, limiting the thickness of the transition connection layer within the above range further promotes the formation of thermal resistance in this part, avoids direct contact between the weakly magnetic metal material and the inorganic layer, avoids the formation of hot spots in the heating layer and the inorganic layer, improves the bonding force between the heating layer and the inorganic layer, and also reduces noise. If the thickness of the transition connection layer is too large, it may reduce the efficiency of heat transfer.

[0073] According to another specific embodiment of the present invention, the weakly magnetic metal material in the heating layer is embedded in the transition connection layer, thereby further increasing the contact area between the weakly magnetic metal material and the transition connection layer, increasing the area of ​​heat transfer, thereby improving the uniformity of heat transfer, avoiding the formation of hot spots in the heating layer, and further reducing the risk of microcracks forming inside the heating layer.

[0074] According to yet another specific embodiment of the present invention, refer to the appendix. Figure 2 The first inorganic layer 1 is connected to one side of the heating layer 3 through the first adhesive glaze layer 4, while the other side of the heating layer 3 is directly connected to the second inorganic layer 2. Thus, by setting the first adhesive glaze layer between the first inorganic layer and the heating layer, the thermal resistance between the heating layer and the first inorganic layer is increased, reducing the formation of hot spots in the first inorganic layer. This allows the heat to be distributed and transferred more evenly, avoiding the formation of thermal stress in the first inorganic layer due to hot spots, reducing the risk of cracking of the first inorganic layer, reducing noise, and also improving the bonding force between the heating layer and the first inorganic layer.

[0075] According to yet another specific embodiment of the present invention, refer to the appendix. Figure 3 and 5 The second inorganic layer 2 is connected to one side of the heating layer 3 via the second adhesive glaze layer 5, while the other side of the heating layer 3 is directly connected to the first inorganic layer 1. Thus, the thinner first inorganic layer is directly connected to the heating layer, which can promote heat transfer to the first inorganic layer and further promote the advantageous heat conduction direction. The thicker second inorganic layer is connected to the heating layer via the adhesive glaze layer. On the one hand, this increases the thermal resistance between the heating layer and the second inorganic layer, further promoting heat transfer to the first inorganic layer. On the other hand, it also reduces the efficiency of heat transfer to the second inorganic layer, reducing heat loss and the formation of hot spots in the second inorganic layer. This allows the heat to be distributed more evenly, reducing the thermal stress formed in the second inorganic layer due to hot spot accumulation, reducing the risk of cracking of the second inorganic layer. At the same time, it also increases the bonding force between the heating layer and the second inorganic layer, thereby improving the overall mechanical strength of the heating element assembly.

[0076] According to yet another specific embodiment of the present invention, refer to the appendix. Figure 4 The first inorganic layer 1 is connected to one side of the heating layer 3 via the first adhesive glaze layer 4, and the second inorganic layer 2 is connected to the other side of the heating layer 3 via the second adhesive glaze layer 5. Thus, by providing the first adhesive glaze layer between the first inorganic layer and the heating layer, the thermal resistance between the heating layer and the first inorganic layer is increased, reducing the formation of hot spots in the first inorganic layer. This allows for more uniform heat distribution and transfer, avoiding thermal stress in the first inorganic layer due to hot spots, reducing the risk of cracking of the first inorganic layer, reducing noise, and simultaneously improving the bonding strength between the heating layer and the first inorganic layer. By setting a second adhesive glaze layer between the second inorganic layer and the heating layer, on the one hand, the thermal resistance between the heating layer and the second inorganic layer is increased, further promoting the transfer of heat to the first inorganic layer. On the other hand, it also reduces the efficiency of heat transfer to the second inorganic layer, reducing heat loss and the formation of hot spots in the second inorganic layer. This allows the heat to be distributed and transferred more evenly, reducing the thermal stress formed in the second inorganic layer due to hot spot accumulation and lowering the risk of cracking of the second inorganic layer. At the same time, it also improves the bonding force between the heating layer and the second inorganic layer, thereby improving the overall mechanical strength of the heating element assembly.

[0077] According to another specific embodiment of the present invention, the glaze in the first adhesive glaze layer and / or the second adhesive glaze layer is embedded in the heating layer, thereby increasing the contact area between the adhesive glaze layer (i.e., the first adhesive glaze layer and / or the second adhesive glaze layer) and the heating layer, improving the uniformity of heat distribution in the adhesive glaze layer, thereby reducing the formation of hot spots in the adhesive glaze layer, thereby reducing the formation of microcracks between the adhesive glaze layer and the heating layer, and also improving the bonding force between the adhesive glaze layer and the heating layer.

[0078] According to another specific embodiment of the present invention, the thickness of the first adhesive glaze layer 4 is 5-30 μm. Thus, limiting the thickness of the first adhesive glaze layer 4 to the above range can further reduce the risk of cracking of the first inorganic layer, reduce noise, and improve the bonding force between the heating layer and the first inorganic layer. It can also avoid the first adhesive glaze layer 4 having excessively large thickness, which would result in excessive thermal resistance of the first adhesive glaze layer 4 and weaken the dominant heat transfer direction.

[0079] In the embodiments of the present invention, the material of the first adhesive glaze layer 4 is not particularly limited, and those skilled in the art can choose it at will according to the actual situation. As a preferred option, the material of the first adhesive glaze layer includes at least one selected from SiO2, Al2O3, Bi2O, Ti2O, K2O and B2O3.

[0080] According to another specific embodiment of the present invention, the thickness of the second adhesive glaze layer 5 is 5-30 μm. Thus, limiting the thickness of the second adhesive glaze layer 5 to the above range can further reduce the risk of cracking of the second inorganic layer, improve the bonding force between the heating layer and the second inorganic layer, and also avoid excessive thermal resistance of the second adhesive glaze layer due to excessive thickness, resulting in low heat transfer efficiency in the second adhesive glaze layer, which would lead to heat accumulation in the second adhesive glaze layer, forming thermal stress, and causing the formation of microcracks in the second adhesive glaze layer.

[0081] In the embodiments of the present invention, the material of the second adhesive glaze layer 4 is not particularly limited, and those skilled in the art can choose it at will according to the actual situation. As a preferred option, the material of the second adhesive glaze layer includes at least one selected from SiO2, Al2O3, Bi2O, Ti2O, K2O and B2O3.

[0082] According to another specific embodiment of the present invention, the first inorganic layer 1 is a glass layer or a ceramic layer, and / or the second inorganic layer 2 is a glass layer or a ceramic layer, preferably a glass layer, so that magnetic lines of force can more easily pass through the glass layer to reach the heating layer 3, thereby not affecting the eddy current heating effect of the heating layer 3. In addition, the glass plate on the upper surface is in direct contact with water or food. Due to the high chemical stability of glass itself, there is no risk of glass falling off or discoloration during food cooking.

[0083] In the embodiments of the present invention, the specific type of the glass layer is not particularly limited, and those skilled in the art can choose it at will according to actual needs. As a preferred option, the glass layer is a high borosilicate glass layer, a tempered glass layer, a soda-lime glass layer, an alkali-free glass layer, or a microcrystalline glass layer. Thus, magnetic lines of force can more easily pass through the glass layers of the above types to reach the heating layer 3, thereby not affecting the eddy current heating effect of the heating layer 3.

[0084] In another aspect of the invention, a method for preparing the above-described heating element assembly is provided. According to an embodiment of the invention, the method includes:

[0085] S100: Provides a first inorganic layer and a second inorganic layer.

[0086] S200: A heating layer is formed between the first inorganic layer and the second inorganic layer to obtain a heating element assembly.

[0087] As a specific example, step S200 above includes the following steps:

[0088] S210: Prepare a heating layer on the first inorganic layer or the second inorganic layer, and bond the heating layer to the first inorganic layer or the second inorganic layer.

[0089] In the embodiments of the present invention, the specific method for preparing the heating layer is not particularly limited, and those skilled in the art can choose any method according to actual needs, as long as the heating layer can be bonded to the first inorganic layer or the second inorganic layer. As a specific example, the specific method for preparing the heating layer is as follows: printing a heating layer paste on the first inorganic layer (or the second inorganic layer), drying it, and then firing it to bond the heating layer to the first inorganic layer (or the second inorganic layer).

[0090] In embodiments of the present invention, the drying temperature is not particularly limited during the preparation of the heating layer, and those skilled in the art can select it according to actual needs. As a preferred embodiment, the drying temperature range is 120–160°C. In embodiments of the present invention, the firing temperature is not particularly limited during the preparation of the heating layer, and those skilled in the art can select it according to actual needs. As a preferred embodiment, the firing temperature range is 550–650°C, thereby ensuring that the inorganic glaze in the heating layer slurry can form a glassy phase, ensuring its bonding strength with the inorganic layer, such as the glass layer.

[0091] According to another specific embodiment of the present invention, the heating layer slurry comprises a weakly magnetic metal material, an organic solvent, and an inorganic glaze. The weakly magnetic metal material generates eddy currents under the action of an alternating magnetic field, thereby generating heat. Preferably, the weakly magnetic metal material is selected from at least one of silver, aluminum, and copper. The inorganic glaze forms a glassy phase during the sintering process of the heating layer. The inorganic glaze is selected from at least one of SiO2, Al2O3, Bi2O, Ti2O, K2O, and B2O3. The heating layer is connected to the first inorganic layer and / or the second inorganic layer through this glassy phase, thereby serving to connect the first inorganic layer and / or the second inorganic layer. The organic solvent is used to uniformly disperse the weakly magnetic metal material and the inorganic glaze in the organic solvent, forming a uniform and stable heating layer slurry.

[0092] In the embodiments of the present invention, the specific types of organic solvents are not particularly limited. Those skilled in the art can choose them arbitrarily according to actual needs, as long as the weakly magnetic metal materials and inorganic glazes are uniformly dispersed in the organic solvents to form a uniform and stable heating layer slurry.

[0093] According to another specific embodiment of the present invention, the above-mentioned organic solvent is an alcohol solvent, such as ethanol, methanol, and propanol, etc. Alcohol solvents have the advantage of being easily volatile.

[0094] According to another specific embodiment of the present invention, the solid content of the heating layer slurry is in the range of 60 to 90 wt%. Therefore, the heating layer prepared by the heating layer slurry with the solid content in the above range has better uniformity, thereby further improving the heating efficiency of the heating layer.

[0095] According to another specific embodiment of the present invention, the heating layer includes a heating layer and a transition connection layer. The first inorganic layer (and / or the second inorganic layer) and the heating layer are bonded together through the transition connection layer. The preparation method is as follows: a transition connection layer paste is printed on the first inorganic layer (and / or the second inorganic layer), dried and fired to form the transition connection layer; a heating layer paste is printed on the transition connection layer, dried, and sintered at high temperature to form the heating layer. The aforementioned transition layer slurry includes an organic solvent and an inorganic glaze, with the inorganic glaze forming a glass phase after sintering. Simultaneously, the aforementioned heating layer slurry includes a weakly magnetic metal material, an organic solvent, and an inorganic glaze, with the inorganic glaze forming a glass phase after sintering. Thus, the glass phase in the heating layer is interconnected with the glass phase in the transition layer, and the glass phase in the transition layer is interpenetrating with the first inorganic layer (or second inorganic layer) matrix. Consequently, the content of the glass phase in the heating layer closer to the first inorganic layer (or second inorganic layer) is greater than the content of the glass phase in the heating layer farther from the first inorganic layer (or second inorganic layer), and the content of the weakly magnetic metal material in the heating layer closer to the first inorganic layer (or second inorganic layer) is less than the content of the weakly magnetic metal material in the heating layer farther from the first inorganic layer (or second inorganic layer).

[0096] In embodiments of the present invention, the requirements for drying temperature and sintering temperature during the preparation of the heating layer are the same as those for the heating layer, and will not be repeated here. Similarly, the requirements for drying temperature and sintering temperature during the preparation of the transition connection layer are the same as those for the heating layer, and will not be repeated here.

[0097] According to another specific embodiment of the present invention, the heating layer slurry comprises a weakly magnetic metal material, an organic solvent, and an inorganic glaze, and the transition bonding layer slurry comprises an organic solvent, an inorganic glaze, and a weakly magnetic metal material with a content greater than or equal to 0. The weakly magnetic metal material generates eddy currents under the action of an alternating magnetic field, thereby generating heat. Preferably, the weakly magnetic metal material is selected from at least one of silver, aluminum, and copper. The inorganic glaze forms a glassy phase during the sintering process of the heating layer, and the inorganic glaze is selected from at least one of SiO2, Al2O3, Bi2O, Ti2O, K2O, and B2O3. The heating layer is connected to the first inorganic layer and / or the second inorganic layer through this glassy phase, thereby serving to connect the first inorganic layer and / or the second inorganic layer. The organic solvent uniformly disperses the weakly magnetic metal material and the inorganic glaze in the organic solvent, forming a uniform and stable heating layer slurry and transition bonding layer slurry.

[0098] In the embodiments of the present invention, the specific types of organic solvents are not particularly limited. Those skilled in the art can choose them arbitrarily according to actual needs. The goal is to uniformly disperse the weakly magnetic metal material and inorganic glaze in the organic solvent to form a uniform and stable heating layer slurry and transition bonding layer slurry.

[0099] According to another specific embodiment of the present invention, the above-mentioned organic solvent is an alcohol solvent, such as ethanol, methanol, and propanol, etc. Alcohol solvents have the advantage of being easily volatile.

[0100] According to another specific embodiment of the present invention, the solid content of the heating layer slurry is in the range of 60 to 90 wt%. Therefore, the heating layer prepared by the heating layer slurry with the solid content in the above range has better uniformity, thereby further improving the heating efficiency of the heating layer.

[0101] According to another specific embodiment of the present invention, before preparing the heating layer on the first inorganic layer, the method further includes: preparing a first adhesive glaze layer on the side of the first inorganic layer near the heating layer. By preparing the first adhesive glaze layer between the first inorganic layer and the heating layer, the thermal resistance between the heating layer and the first inorganic layer is increased, the formation of hot spots in the first inorganic layer is reduced, and the heat can be more evenly distributed and transferred. This avoids the formation of thermal stress in the first inorganic layer due to hot spots, reduces the risk of cracking of the first inorganic layer, reduces noise, and also improves the bonding force between the heating layer and the first inorganic layer.

[0102] According to another specific embodiment of the present invention, before preparing the heating layer on the second inorganic layer, the method further includes: preparing a second adhesive glaze layer on the side of the second inorganic layer near the heating layer. By preparing the second adhesive glaze layer between the second inorganic layer and the heating layer, on the one hand, the thermal resistance between the heating layer and the second inorganic layer is increased, further promoting the transfer of heat to the first inorganic layer; on the other hand, the efficiency of heat transfer to the second inorganic layer is reduced, heat loss is reduced, and the formation of hot spots in the second inorganic layer is reduced, thereby enabling the heat to be distributed and transferred more evenly, reducing the thermal stress formed in the second inorganic layer due to hot spot accumulation, reducing the risk of cracking of the second inorganic layer, and also improving the bonding force between the heating layer and the second inorganic layer, thereby improving the overall mechanical strength of the heating element assembly.

[0103] According to another specific embodiment of the present invention, after preparing the heating layer on the first inorganic layer, the method further includes: preparing the second adhesive glaze layer on the side of the second inorganic layer near the heating layer. According to another specific embodiment of the present invention, after preparing the heating layer on the first inorganic layer, the method further includes: preparing the second adhesive glaze layer on the side of the heating layer near the second inorganic layer. Thus, by preparing the second adhesive glaze layer between the second inorganic layer and the heating layer, on the one hand, the thermal resistance between the heating layer and the second inorganic layer is increased, further promoting heat transfer to the first inorganic layer; on the other hand, the efficiency of heat transfer to the second inorganic layer is reduced, reducing heat loss, and also reducing the formation of hot spots in the second inorganic layer. This allows for more uniform heat distribution and transfer, reducing thermal stress in the second inorganic layer due to hot spot accumulation, reducing the risk of cracking of the second inorganic layer, and simultaneously improving the bonding force between the heating layer and the second inorganic layer, thereby improving the overall mechanical strength of the heating element assembly.

[0104] In the embodiments of the present invention, the specific method for preparing the first adhesive glaze layer (or the second adhesive glaze layer) is not particularly limited, and those skilled in the art can choose arbitrarily according to actual needs. As a specific example, the specific method for preparing the first adhesive glaze layer is as follows: printing the first adhesive glaze layer slurry onto the first inorganic layer, drying it, and then firing it to bond the first adhesive glaze layer onto the first inorganic layer. The second adhesive glaze layer is prepared using the same method, and will not be described in detail here.

[0105] In embodiments of the present invention, the drying temperature is not particularly limited during the preparation of the first adhesive glaze layer (or the second adhesive glaze layer). Those skilled in the art can select the appropriate temperature based on actual needs. As a preferred embodiment, the drying temperature range is 120–160°C. In embodiments of the present invention, the firing temperature is not particularly limited during the preparation of the first adhesive glaze layer (or the second adhesive glaze layer). Those skilled in the art can select the appropriate temperature based on actual needs. As a preferred embodiment, the firing temperature range is 550–650°C. This ensures that the inorganic glaze in the first adhesive glaze slurry (or the second adhesive glaze slurry) can form a glassy phase, guaranteeing its bonding strength with the inorganic layer or the heating layer.

[0106] According to another specific embodiment of the present invention, the first adhesive glaze slurry comprises an inorganic glaze and an organic solvent, wherein the inorganic glaze is selected from at least one of SiO2, Al2O3, Bi2O, Ti2O, K2O, and B2O3. In the embodiments of the present invention, the specific type of the organic solvent is not particularly limited, and those skilled in the art can choose it arbitrarily according to actual needs, as long as the inorganic glaze is uniformly dispersed in the organic solvent to form a uniform and stable first adhesive glaze slurry. The organic solvent used to form the first adhesive glaze slurry is generally an alcohol solvent, which is characterized by easy volatility.

[0107] According to another specific embodiment of the present invention, the solid content of the first adhesive glaze slurry is in the range of 60-90 wt%, thereby resulting in better uniformity of the first adhesive glaze layer prepared from the first adhesive glaze slurry with a solid content within the above range. The requirements for the second adhesive glaze slurry of the present invention are the same as those for the first adhesive glaze slurry, and will not be repeated here.

[0108] In an embodiment of the present invention, after a first adhesive glaze layer is prepared on the first inorganic layer, a heating layer is then prepared on the first adhesive glaze layer, thereby connecting the first inorganic layer and the heating layer through the first adhesive glaze layer. The method for preparing the heating layer on the first adhesive glaze layer is the same as the method for preparing the heating layer on the first inorganic layer, and will not be described again here.

[0109] S220: The first inorganic layer and the second inorganic layer on which the heating layer is formed are sintered, or the second inorganic layer on which the heating layer is formed is sintered with the first inorganic layer, so that the heating layer is bonded to the first inorganic layer and the second inorganic layer respectively, so as to obtain the heating element assembly.

[0110] According to another specific embodiment of the present invention, the sintering temperature is 550 to 650°C, thereby improving the bonding force between the first inorganic layer and the second inorganic layer in the heating element assembly sintered within this temperature range.

[0111] It should be noted that those skilled in the art can first prepare a first adhesive glaze layer on a first inorganic layer, then prepare a heating layer on the first adhesive glaze layer, and finally fire and bond the first inorganic layer, which has the first adhesive glaze layer and the heating layer bonded together, to a second inorganic layer to obtain the above-mentioned heating element assembly. Alternatively, a second adhesive glaze layer can be prepared first on a second inorganic layer, then a heating layer can be prepared on the second adhesive glaze layer, and finally the second inorganic layer, which has the second adhesive glaze layer and the heating layer bonded together, can be fire and bonded to the first inorganic layer to obtain the above-mentioned heating element assembly. Alternatively, a heating layer can be prepared first on a first inorganic layer, then a second adhesive glaze layer can be prepared on the heating layer, and finally the first inorganic layer, which has the second adhesive glaze layer and the heating layer bonded together, can be fire and bonded to the second inorganic layer to obtain the above-mentioned heating element assembly. Alternatively, a heating layer can be prepared first on a first inorganic layer, a second adhesive glaze layer can be prepared on a second inorganic layer, and finally the first inorganic layer with the heating layer bonded together and the second inorganic layer with the second adhesive glaze layer bonded together can be fire and bonded to obtain the above-mentioned heating element assembly. The specific process is not subject to any particular restrictions, and those in the field can choose freely according to actual needs.

[0112] Furthermore, when preparing the first adhesive glaze layer and the heating layer on the aforementioned first inorganic layer, the first adhesive glaze layer paste can be printed on the first inorganic layer first, dried, and then fired to bond the first adhesive glaze layer to the first inorganic layer. Then, the heating layer paste can be printed on the first adhesive glaze layer, dried, and then fired to bond the heating layer to the first adhesive glaze layer. Alternatively, the first adhesive glaze layer paste can be printed on the first inorganic layer first and dried, then the heating layer paste can be printed on the dried first adhesive glaze layer and dried, and finally sintered together to bond the first inorganic layer and the heating layer together through the first adhesive glaze layer.

[0113] Furthermore, when preparing the heating layer and the second adhesive glaze layer on the aforementioned first inorganic layer, the heating layer paste can be printed onto the first inorganic layer first, dried, and then fired to adhere the heating layer to the first inorganic layer. Then, the second adhesive glaze layer paste can be printed onto the heating layer, dried, and then fired again to adhere the second adhesive glaze layer to the heating layer. Alternatively, the heating layer paste can be printed onto the first inorganic layer first and dried, then the second adhesive glaze layer paste can be printed onto the dried heating layer and dried, and finally sintered together to bond the first inorganic layer, the heating layer, and the second adhesive glaze layer together.

[0114] Furthermore, when preparing the second glaze layer on the second inorganic layer, a heating layer paste can be printed onto the first inorganic layer first, dried, and then fired to adhere the heating layer to the first inorganic layer. Then, a second adhesive glaze layer paste can be printed onto the second inorganic layer, dried, and then fired to adhere the second adhesive glaze layer to the second inorganic layer. Alternatively, a heating layer paste can be printed onto the first inorganic layer first and dried, followed by the printing and drying of the second adhesive glaze layer paste on the second inorganic layer. Finally, all layers are sintered together to bond the first inorganic layer, heating layer, second adhesive glaze layer, and second inorganic layer together.

[0115] Furthermore, when preparing the second adhesive glaze layer and the heating layer on the second inorganic layer, the second adhesive glaze layer paste can be printed on the second inorganic layer first, dried, and then fired to bond the second adhesive glaze layer to the second inorganic layer. Then, the heating layer paste can be printed on the second adhesive glaze layer, dried, and then fired again to bond the heating layer to the second adhesive glaze layer. Alternatively, the second adhesive glaze layer paste can be printed on the second inorganic layer first and dried, then the heating layer paste can be printed on the dried second adhesive glaze layer and dried, and finally sintered together to bond the second inorganic layer and the heating layer together through the second adhesive glaze layer.

[0116] According to an embodiment of the present invention, a method for preparing the above-mentioned heating element assembly involves providing a heating layer between a first inorganic layer and a second inorganic layer. The heat generated by this heating layer under the action of an alternating magnetic field is transferred at different rates through the first and second inorganic layers, resulting in a favorable heat transfer direction, with heat more easily transferred to the inorganic layer where the transfer rate is faster. Simultaneously, the heating element assembly of the present invention also reduces noise generated when heating materials. Specifically, if a single inorganic layer is provided on one side of the heating layer, when the heating layer generates heat, the heat is transferred at a higher rate to the direction without an inorganic layer, thus generating more noise. The present invention, by providing inorganic layers on both sides of the heating layer, although reducing heat transfer efficiency to some extent, reduces noise while maintaining high heat transfer efficiency. Furthermore, this preparation method is simple and easy to implement.

[0117] In a third aspect, the present invention provides a heatable appliance. According to an embodiment of the invention, the heatable appliance includes a heating element assembly as described in the above embodiments or a heating element assembly manufactured using the methods described in the above embodiments, wherein the first inorganic layer constitutes at least a portion of the cavity of the heatable appliance. Thus, the first inorganic layer, with a higher heat transfer rate, constitutes at least a portion of the cavity of the heatable appliance, and the heat generated by the heating layer is transferred to the first inorganic layer at a greater rate than to the second inorganic layer. Therefore, heat is more easily transferred in the direction of the first inorganic layer, i.e., more easily transferred in the direction of the cavity of the heatable appliance, thereby giving the heatable appliance higher heat transfer efficiency; simultaneously, the noise generated when heating materials using this heatable appliance is lower.

[0118] According to a specific embodiment of the present invention, the heating element assembly is disposed at the bottom of the heatable appliance.

[0119] According to another specific embodiment of the present invention, the heatable appliance includes a sidewall 200 and a bottom wall that are sealed together, at least a portion of the bottom wall being the heating element assembly 100.

[0120] According to another specific embodiment of the present invention, the sidewall of the heatable appliance is made of microcrystalline glass, borosilicate glass or ceramic.

[0121] According to yet another specific embodiment of the present invention, refer to the appendix. Figure 6 A negative pressure air 300 is provided between the heating layer 3 and the edges of the first inorganic layer 1 and the second inorganic layer 2, thereby preventing the gas expansion during the heating process from causing the first inorganic layer and / or the second inorganic layer to rupture.

[0122] According to another specific embodiment of the present invention, the heating element assembly 100 and the sidewall weld 200 are connected by welding (e.g., fusion welding) (see attached figure). Figure 6 Or through adhesive 400 (see attached document) Figure 7 (connected)

[0123] According to another specific embodiment of the present invention, the specific welding process is as follows: (i) preheating the heating element assembly; (ii) welding the edge of the preheated heating element assembly and the side wall using a heat source; and (iii) annealing the welded vessel.

[0124] According to another specific embodiment of the present invention, the adhesive is an organic silicone, glass glue, or inorganic glass paste.

[0125] According to another specific embodiment of the present invention, the heatable appliance is a pot (see attached drawing). Figure 8 ), the inner pot or body of a cooking utensil.

[0126] In a fourth aspect, the present invention provides a cooking appliance. According to an embodiment of the invention, the cooking appliance has the heatable appliance described in the above embodiments. Therefore, the cooking appliance has high heat transfer efficiency and generates less noise when heating materials, further meeting consumer needs and improving the user experience.

[0127] The embodiments of the present invention are described in detail below. It should be noted that the embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. In addition, unless otherwise specified, all reagents used in the following embodiments are commercially available or can be synthesized according to the methods described herein or known to others. For reaction conditions not listed, they are also readily available to those skilled in the art.

[0128] Example 1

[0129] This embodiment provides an electromagnetic glass kettle, the preparation method of which is as follows:

[0130] (1) A heating layer paste is printed on an upper glass layer with a thickness of 0.3 mm, dried, and then fired. The drying temperature is 140°C and the firing temperature is 600°C. The heating layer paste is a dispersion of ethanol, silver powder, and inorganic glaze (including SiO2, Al2O3, K2O, B2O3, Bi2O, and Ti2O) with a solid content of 75 wt%. Thus, the heating layer is sintered on the first upper glass layer.

[0131] (2) A second adhesive glaze slurry is printed on a lower glass layer with a thickness of 2 mm, dried, and then fired. The drying temperature is 140°C and the firing temperature is 600°C. The second adhesive glaze slurry is a dispersion of ethanol and inorganic glaze (including SiO2, Al2O3, K2O, B2O3, Bi2O, and Ti2O) with a solid content of 75 wt%. After sintering, a second adhesive glaze layer is formed.

[0132] (3) The upper glass with the heating layer bonded to the lower glass with the second adhesive glaze layer bonded to it is fired and bonded at a temperature of 650°C to obtain the heating element assembly.

[0133] (4) The above heating element assembly is fused and welded to the glass sidewall to prepare an electromagnetic glass kettle. The specific process is as follows: (i) the heating element assembly is preheated; (ii) the edge of the preheated heating element assembly and the sidewall are welded together using a heat source; (iii) the welded vessel is annealed.

[0134] (5) Fill the above electromagnetic glass kettle with 1L of water, place it on an induction cooker with a power of 1500W, test and record the time required for the water to be heated to boiling, test and record the highest temperature at the bottom of the electromagnetic glass kettle, and test and record the highest noise generated by the electromagnetic glass kettle during the heating process. The test results are shown in Table 1.

[0135] Example 2

[0136] In this embodiment, the thickness of the upper glass of the heating element assembly at the bottom of the electromagnetic glass kettle is 0.3 mm, and the thickness of the lower glass is 3 mm. All other contents are the same as in Embodiment 1. The test results are shown in Table 1.

[0137] Example 3

[0138] In this embodiment, the thickness of the upper glass of the heating element assembly at the bottom of the electromagnetic glass kettle is 0.3 mm, and the thickness of the lower glass is 4 mm. All other contents are the same as in Embodiment 1. The test results are shown in Table 1.

[0139] Example 4

[0140] In this embodiment, the thickness of the upper glass of the heating element assembly at the bottom of the electromagnetic glass kettle is 0.5 mm, and the thickness of the lower glass is 2 mm. All other contents are the same as in Embodiment 1. The test results are shown in Table 1.

[0141] Example 5

[0142] In this embodiment, the thickness of the upper glass of the heating element assembly at the bottom of the electromagnetic glass kettle is 0.5 mm, and the thickness of the lower glass is 3 mm. All other contents are the same as in Embodiment 1. The test results are shown in Table 1.

[0143] Example 6

[0144] In this embodiment, the thickness of the upper glass of the heating element assembly at the bottom of the electromagnetic glass kettle is 0.5 mm, and the thickness of the lower glass is 4 mm. All other contents are the same as in Embodiment 1. The test results are shown in Table 1.

[0145] Example 7

[0146] In this embodiment, the thickness of the upper glass of the heating element assembly at the bottom of the electromagnetic glass kettle is 1 mm, and the thickness of the lower glass is 2 mm. All other contents are the same as in Embodiment 1. The test results are shown in Table 1.

[0147] Example 8

[0148] In this embodiment, the thickness of the upper glass of the heating element assembly at the bottom of the electromagnetic glass kettle is 1 mm, and the thickness of the lower glass is 3 mm. All other contents are the same as in Embodiment 1. The test results are shown in Table 1.

[0149] Example 9

[0150] In this embodiment, the thickness of the upper glass of the heating element assembly at the bottom of the electromagnetic glass kettle is 1 mm, and the thickness of the lower glass is 4 mm. All other contents are the same as in Embodiment 1. The test results are shown in Table 1.

[0151] Example 10

[0152] In this embodiment, the thickness of the upper glass layer of the heating element assembly at the bottom of the electromagnetic glass kettle is 2mm, the thickness of the lower glass layer is 2mm, and all other contents are the same as in Embodiment 1. The test results are shown in Table 1.

[0153] Example 11

[0154] In this embodiment, the thickness of the upper glass of the heating element assembly at the bottom of the electromagnetic glass kettle is 2mm, and the thickness of the lower glass is 3mm. All other contents are the same as in Embodiment 1. The test results are shown in Table 1.

[0155] Example 12

[0156] In this embodiment, the thickness of the upper glass of the heating element assembly at the bottom of the electromagnetic glass kettle is 2mm, and the thickness of the lower glass is 4mm. All other contents are the same as in Embodiment 1. The test results are shown in Table 1.

[0157] Comparative Example 1

[0158] In this comparative example, the thickness of the upper glass layer of the heating element assembly at the bottom of the electromagnetic glass kettle is 3 mm, and the thickness of the lower glass layer is 0.3 mm. All other contents are the same as in Example 2. The test results are shown in Table 1.

[0159] Comparative Example 2

[0160] In this comparative example, the thickness of the upper glass layer of the heating element assembly at the bottom of the electromagnetic glass kettle is 3 mm, and the thickness of the lower glass layer is 0.5 mm. All other contents are the same as in Example 5. The test results are shown in Table 1.

[0161] Comparative Example 3

[0162] In this comparative example, the thickness of the upper glass layer of the heating element assembly at the bottom of the electromagnetic glass kettle is 3 mm, and the thickness of the lower glass layer is 1 mm. All other contents are the same as in Example 8. The test results are shown in Table 1.

[0163] Comparative Example 4

[0164] In this comparative example, the thickness of the upper glass layer of the heating element assembly at the bottom of the electromagnetic glass kettle is 3mm, and the thickness of the lower glass layer is 2mm. All other contents are the same as in Example 11. The test results are shown in Table 1.

[0165] Table 1

[0166]

[0167]

[0168] As can be seen from Table 1, in Examples 1-12 of the present invention, the time required to heat 1L of water to 100℃ is relatively short, all controlled below 6.5 minutes, and the noise level is low, all controlled below 65dB. In particular, in Example 5, when the upper glass plate thickness is 0.5mm and the lower plate thickness is 3mm, the operating noise can be reduced to 60dB, and the thermal efficiency is high, with 1L of water boiling in 4 minutes, and the highest temperature at the bottom reaching 160℃. The process is relatively safe, and the internal stress of the glass is low, resulting in a long service life. In contrast, in Comparative Examples 1-4, the time required to heat 1L of water to 100℃ is much longer, all exceeding 14 minutes; and the highest temperature at the bottom reaches over 300℃, making the process more dangerous.

[0169] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0170] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A heating element assembly, characterized in that, include: A first inorganic layer and a second inorganic layer are provided, and a heating layer is provided between the first inorganic layer and the second inorganic layer. The heat generated by the heating layer is transferred to the first inorganic layer at a rate greater than that transferred to the second inorganic layer. The thickness of the second inorganic layer is greater than the thickness of the first inorganic layer, and the thickness difference between the second inorganic layer and the first inorganic layer is 0.5-4.5 mm. The first inorganic layer is used to contact the material, and the heating layer is used to heat the material in contact with the first inorganic layer.

2. The heating element assembly according to claim 1, characterized in that, The thickness difference between the second inorganic layer and the first inorganic layer is 0.5-3 mm.

3. The heating element assembly according to claim 1, characterized in that, The thickness ratio of the second inorganic layer to the first inorganic layer is greater than 1 and less than or equal to 15.

4. The heating element assembly according to claim 3, characterized in that, The thickness ratio of the second inorganic layer to the first inorganic layer is greater than 1 and less than or equal to 10.

5. The heating element assembly according to claim 3, characterized in that, The thickness of the second inorganic layer is not less than 2 mm, and the thickness of the first inorganic layer is not greater than 2 mm.

6. The heating element assembly according to claim 3, characterized in that, The thickness of the first inorganic layer is 0.3-2 mm, and the thickness of the second inorganic layer is 2-4 mm.

7. The heating element assembly according to any one of claims 1-6, characterized in that, At least one of the following conditions must be met: The thickness of the heating layer is 10-25µm; The heating layer comprises a weakly magnetic metallic material and a glass phase.

8. The heating element assembly according to claim 7, characterized in that, At least one of the following conditions must be met: The weakly magnetic metal material in the heating layer contains 70-90 wt%; The weakly magnetic metallic material is selected from at least one of silver, aluminum, and copper; The glass phase material includes at least one of SiO2, Al2O3, Bi2O, Ti2O, K2O, and B2O3.

9. The heating element assembly according to any one of claims 1-6, characterized in that, The first inorganic layer is connected to the heating layer through a first adhesive glaze layer, and the second inorganic layer is connected to the heating layer through a second adhesive glaze layer; Alternatively, the first inorganic layer may be connected to the heating layer via a first adhesive glaze layer, and the second inorganic layer may be directly connected to the heating layer; Alternatively, the second inorganic layer may be connected to the heating layer via a second adhesive glaze layer, and the first inorganic layer may be directly connected to the heating layer. Alternatively, the first inorganic layer and the second inorganic layer may be directly connected to the heating layer.

10. The heating element assembly according to claim 9, characterized in that, The thicknesses of the first adhesive glaze layer and the second adhesive glaze layer are each independently greater than the thickness of the heating layer.

11. The heating element assembly according to claim 10, characterized in that, The thickness of the first adhesive glaze layer and the second adhesive glaze layer are each 5-30 μm.

12. The heating element assembly according to claim 9, characterized in that, At least a portion of the first adhesive glaze layer and / or the second adhesive glaze layer is embedded in the heating layer.

13. The heating element assembly according to claim 12, characterized in that, The glazes in the first adhesive glaze layer and the second adhesive glaze layer each independently include at least one of SiO2, Al2O3, Bi2O, Ti2O, K2O and B2O3.

14. The heating element assembly according to claim 7, characterized in that, The heating layer is directly connected to the first inorganic layer and / or the second inorganic layer. The weakly magnetic metal material in the heating layer is disposed away from the first inorganic layer and / or the second inorganic layer, and the glass phase in the heating layer is disposed close to the first inorganic layer and / or the second inorganic layer.

15. The heating element assembly according to claim 14, characterized in that, The heating layer is connected to the first inorganic layer and / or the second inorganic layer through a concave-convex structure, wherein the glass phase in the heating layer is at least partially embedded in the first inorganic layer and / or the second inorganic layer to form the concave-convex structure.

16. The heating element assembly according to claim 14, characterized in that, The heating layer includes a heating layer and a transition connection layer. The heating layer is connected to the first inorganic layer and / or the second inorganic layer through the transition connection layer. The heating layer includes a weakly magnetic metal material and a glass phase. The transition connection layer includes a glass phase. The glass phase in the heating layer is connected to the glass phase in the transition connection layer.

17. The heating element assembly according to claim 16, characterized in that, At least one of the following conditions must be met: The composition of the glass phase in the transition connection layer is the same as that of the glass phase in the heating layer; The transition connection layer does not contain weakly magnetic metal materials; The thickness of the transition connection layer is 0.1-5 micrometers.

18. The heating element assembly according to claim 16, characterized in that, The weakly magnetic metal material in the heating layer is at least partially embedded in the transition connection layer.

19. The heating element assembly according to any one of claims 1-6, characterized in that, The first inorganic layer and the second inorganic layer are independently glass layers or ceramic layers, respectively.

20. A method for preparing a heating element assembly according to any one of claims 1 to 19, characterized in that, include: (1) Provide a first inorganic layer and a second inorganic layer; (2) A heating layer is formed between the first inorganic layer and the second inorganic layer to obtain a heating element assembly.

21. The method according to claim 20, characterized in that, The step of forming a heating layer between the first inorganic layer and the second inorganic layer to obtain a heating element assembly further includes: forming a first adhesive glaze layer on the side of the first inorganic layer near the heating layer; and / or forming a second adhesive glaze layer on the side of the second inorganic layer near the heating layer.

22. A heatable appliance, characterized in that, The heating element assembly includes any one of claims 1 to 19 or a heating element assembly made by the method of claim 20 or 21, wherein the first inorganic layer is at least a portion of the cavity constituting the heatable appliance.

23. The heatable appliance according to claim 22, characterized in that, The heating element assembly is located at the bottom of the heatable appliance; And / or, negative pressure air is provided between the heating layer and the edges of the first inorganic layer and the second inorganic layer.

24. The heatable appliance according to claim 22, characterized in that, It includes a sealed and connected sidewall and a bottom wall, at least a portion of which is the heating element assembly; And / or, the heating element assembly is connected to the sidewall by welding or by adhesive.

25. A cooking utensil, characterized in that, A heatable appliance having any one of claims 22 to 24.

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