Heating assembly and baking device

Abstract

The utility model provides a heating assembly and a baking device, the heating assembly comprises a heating base body and a heat conduction layer, the heat conduction layer comprises a first heat conduction layer arranged above the heating base body, the thickness of the first heat conduction layer is 0.5-50mm, or the first heat conduction layer is a precision coating film with the thickness D1 = lambda / (4 * n1), wherein lambda represents a preset central wavelength for emitting far infrared rays, the value range is 4-1000 [mu] m, and n1 represents the refractive index of the first heat conduction layer. According to the utility model, the radiation effect of the whole far-infrared wave band is optimized and improved by controlling the thickness and the number of layers of the heat conduction layer of the material to the wavelength interference of heat radiation; therefore, the following baking advantages of heating or heat conduction are realized: direct conduction of heat convection energy is reduced, burns are reduced, and heat radiation energy of the whole far infrared wave band is optimized and improved to mildly penetrate into baked products to reduce burns.

Description

Technical Field

[0001] This utility model relates to the field of baking technology, and more specifically, to a heating element and a baking device. Background Technology

[0002] Baking is a crucial step in product preparation, allowing moisture to evaporate. Methods include charcoal baking and electric oven baking. Charcoal baking, however, requires highly experienced operators and is often time-consuming, labor-intensive, and inefficient. Electric oven baking, on the other hand, involves placing the product in a preheated oven and using hot air for baking, making it easier to industrialize. When using an electric oven, heat is primarily transferred through conduction and convection. Existing heating elements, such as stainless steel heating tubes, mainly utilize these methods. Low baking temperatures result in excessively long drying times, hindering large-scale production; conversely, excessively high temperatures can cause scorching, severely impacting product quality.

[0003] To address this, Chinese Patent Application No. 201910548890.2 discloses a far-infrared heating element comprising tin tetrachloride, tin oxide, antimony trichloride, titanium tetrachloride, copper sulfate pentahydrate, germanium chloride, hydrochloric acid, and a solvent. This design utilizes the interactive transitions between the outermost electrons of metal elements, mutually promoting each other, thereby improving the conversion efficiency of electrical energy to heat energy, reducing energy consumption, and providing excellent heating effect; however, this design has high production costs and is mainly targeted at health and physiotherapy products, making it unsuitable for product baking.

[0004] Chinese Patent Application No. 03138038.7 discloses a high-temperature far-infrared radiating electric heating element made of carbon material and its preparation method. The heating element is composed of one of the following: carbon felt, carbon cloth, graphite felt, graphite cloth, carbon / carbon composite material plate, or carbon / graphite composite material plate. The heating element has a carbon content greater than 95%, an oxygen content less than 0.005%, and a resistivity between (0.001-100)² cm. This technical solution can be applied to civilian, health care, and industrial fields, and features a long service life, high heat output, and high efficiency. However, it cannot be used for product baking.

[0005] In view of the above, this utility model is hereby proposed. Utility Model Content

[0006] The problem solved by this invention is that existing products using ordinary electric heating baking devices rely mainly on heat convection conduction, which easily leads to surface scorching and results in unsatisfactory final product quality.

[0007] To address the aforementioned issues, this utility model provides a heating component, comprising a heating substrate and a thermally conductive layer. The thermally conductive layer includes a first thermally conductive layer disposed above the heating substrate. The thickness of the first thermally conductive layer is 0.5-50 mm, or the thickness of the precision-coated film is D1 = λ / (4*n1), where λ represents the preset center wavelength for emitting far-infrared radiation, ranging from 4-1000 μm, and n1 represents the refractive index of the first thermally conductive layer.

[0008] This solution optimizes and enhances the radiation effect across the entire far-infrared band by controlling the thickness and number of thermally conductive layers of the material to influence the wavelength interference of thermal radiation. This achieves the following advantages in baking: reducing direct heat convection energy to minimize burns; and optimizing and enhancing the thermal radiation energy across the entire far-infrared band to gently penetrate the interior of the baked product, further reducing burns. Preferably, the preset wavelength can be in the range of 4-500 μm, 4-100 μm, 4-50 μm, or 4-15.4 μm.

[0009] Preferably, the heating component further includes a second thermally conductive layer, which is attached above the first thermally conductive layer. The thickness of the second thermally conductive layer is 0.5-50 mm, or the thickness of the precision coating is D2 = λ / (4*n2). Where λ represents the preset center wavelength of the far-infrared emission and its value ranges from 4-1000 μm, and n2 represents the refractive index of the second thermally conductive layer material (103).

[0010] Preferably, the first thermally conductive layer is a single layer, or the first thermally conductive layer is multi-layered and alternately arranged with the second thermally conductive layer, or the first thermally conductive layer is a precision-coated film. The heating component further includes a second thermally conductive layer, and both the first and second thermally conductive layers are multi-layered and alternately arranged. This multi-layered alternating arrangement allows for focusing on the center wavelength, resulting in an overall enhancement of the far-infrared band near the center wavelength.

[0011] Preferably, the material of the first thermally conductive layer is graphite or zirconium oxide ceramic.

[0012] Preferably, the first thermally conductive layer and / or the second thermally conductive layer are prepared by any one of plasma thermal spraying, PVD physical vapor deposition, CVD chemical vapor deposition, and ALD atomic layer deposition.

[0013] Preferably, the material of the first thermally conductive layer is a material with a high far-infrared emissivity of 4 micrometers or more, including at least one of aluminum oxide, zirconium oxide, metal oxide materials, tourmaline, volcanic rock, jade, ore powder materials, silicon dioxide, silicon nitride, silicon-based composite materials, silicon carbide, graphite alloy, carbon alloy, and carbon-based composite materials.

[0014] Preferably, the material of the heating substrate is a heating material with insulation and high thermal conductivity, including metals and metal alloys, ceramics, carbon-based materials, semiconductors, and composite materials.

[0015] Preferably, a first thermally conductive layer with a thickness of 0.5-50 mm is used for single-layer thermal conduction, and a second thermally conductive layer with a thickness of 0.5-50 mm is stacked for thermal conduction; or a single-layer, double-layer or multi-layer precision coating is applied to the first thermally conductive layer with a thickness of 0.5-50 mm.

[0016] Compared with the prior art, the heating component of this utility model has the following beneficial effects: 1) It significantly improves the emissivity of the overall far-infrared band, thereby significantly improving the transfer of thermal radiation energy, while reducing the heat transferred by thermal convection. Far-infrared rays can penetrate and enter the interior of the product, resulting in more uniform drying; 2) Through double or multiple alternating heat-conducting layers, the center wavelength can be focused, thereby improving the overall far-infrared band near the center wavelength.

[0017] This invention also provides a baking apparatus, including the aforementioned heating element. The baking apparatus has the same beneficial effects as the heating element, and will not be described in detail here.

[0018] The above-mentioned baking device is used in product baking. The products are tea, food, and medicinal materials. This invention generates far-infrared rays through a heating element. The penetrating power of far-infrared rays can penetrate the product surface, which is beneficial for internal drying. At the same time, based on the traditional heat conduction method of heat convection, it increases the proportion of far-infrared heat radiation in the overall wavelength band, which better promotes the internal reaction of the product and effectively avoids scorching caused by high and uneven heating of the product surface or long baking time.

[0019] This utility model provides a heating component, including a heating substrate, on the surface of which a first thermally conductive layer is disposed. The thickness of the first thermally conductive layer is D1=λ / (4*n1), where λ represents a preset wavelength for emitting far-infrared radiation, and the value range is 4-15μm, and n1 represents the refractive index of the first thermally conductive layer.

[0020] Preferably, the heating component further includes a second thermally conductive layer, which is located on the side of the first thermally conductive layer away from the heating substrate. The thickness of the second thermally conductive layer is D2 = λ / (4*n2), where n2 represents the refractive index of the second thermally conductive layer.

[0021] Preferably, the heating component further includes a second heat-conducting layer, wherein the first heat-conducting layer and the second heat-conducting layer are both provided in multiple layers and are arranged alternately.

[0022] Preferably, the thickness of the first thermally conductive layer is 0.1-1 mm and the material is graphite or zirconium oxide ceramic.

[0023] Preferably, the thickness of the first thermally conductive layer is 1-5 mm, and the material is at least one of aluminum oxide, zirconium oxide, metal oxide materials, tourmaline, volcanic rock, jade, ore powder materials, silicon dioxide, silicon nitride, silicon-based composite materials, silicon carbide, graphite alloy, carbon alloy, and carbon-based composite materials.

[0024] Preferably, the material of the heating substrate is a metal or metal alloy, a ceramic material, a carbon-based material, a semiconductor material, or a composite material. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a structure of the heating component described in an embodiment of the present utility model;

[0026] Figure 2 This is another structural schematic diagram of the heating component described in an embodiment of the present utility model;

[0027] Figure 3 The far-infrared emissivity of the heating element at room temperature was prepared for embodiments 1-4 of this utility model;

[0028] Figure 4 The far-infrared emissivity of the heating element at 85°C was prepared for embodiments 1-4 of this utility model;

[0029] Figure 5 The far-infrared emissivity of the heating element at room temperature was prepared for embodiments 5-6 of this utility model;

[0030] Figure 6 The far-infrared emissivity of the heating element at 85°C was prepared for embodiments 5-6 of this utility model;

[0031] Figure 7 The far-infrared emissivity of the heating component at 85°C was prepared for Embodiments 7-8 of this utility model.

[0032] Explanation of reference numerals in the attached figures:

[0033] 101-Heating substrate; 102-First heat-conducting layer; 102-Second heat-conducting layer. Detailed Implementation

[0034] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Without conflict, the technical features of the embodiments of this utility model can be combined with each other.

[0035] As a beverage with a long history, tea not only has a profound cultural heritage in China, but also enjoys a high reputation worldwide. As an indispensable part of the tea processing, roasting plays an important role in improving tea quality, removing moisture, promoting tea transformation, sterilizing and disinfecting, shaping tea characteristics, and enhancing tea value. It has a significant impact on the final quality and market value of tea.

[0036] The high temperature and humidity changes during the roasting process facilitate chemical reactions within the tea leaves, such as the oxidation of polyphenols and the reduction of enzyme activity. These reactions promote the transformation and maturation of the tea leaves, resulting in a more stable taste and quality. Existing ovens mainly heat tea leaves through conduction and convection, typically dehydrating the surface first while requiring a long drying time to remove internal moisture. During this process, tea leaves near the heating element are prone to scorching, affecting their flavor and color. Although some excellent far-infrared materials are used to improve the conduction of heat radiation energy, comprehensive optimization considerations are often lacking in terms of heat conductivity and far-infrared radiation bands.

[0037] Existing microwave ovens can rapidly heat food using microwaves with a frequency of around 2.45 GHz and penetrating power. When microwaves are absorbed by the moisture in the food, they cause it to vibrate. As the vibration of water molecules intensifies, the internal temperature of the food gradually rises, achieving rapid heating. However, this rapid penetrating heating method cannot be used for traditional baked goods. For optimal baking of products such as food, medicinal herbs, and tea, a gentle far-infrared wavelength is required to minimize the loss of beneficial components during baking. For example, carbon fiber heating elements emit orange visible light, which, while having a high far-infrared emissivity, also emits high-energy visible light, which is not conducive to gentle baking. Therefore, the applicant proposes the following technical solution:

[0038] A heating element includes a heating substrate 101, the outer surface of which is coated with a first thermally conductive layer 102. The thickness of the first thermally conductive layer is D1 = λ / (4*n), where λ represents the wavelength of far-infrared emission, ranging from 4 to 1000 μm, and n represents the refractive index of the first thermally conductive layer 102. This design utilizes the first thermally conductive layer 102 to specifically enhance the radiation effect in the far-infrared band, penetrating and conducting heat into the tea leaves, reducing scorching caused by direct heat convection energy conduction and minimizing burning. Simultaneously, it utilizes existing heat conduction to maintain a relatively high temperature. Furthermore, infrared radiation, being a type of electromagnetic wave, can induce vibrations in molecules, atoms, and ions, thereby increasing their chemical reaction rates. This allows chemical reactions to occur at lower temperatures, ensuring that the final tea's taste and color are essentially consistent with traditional processing methods.

[0039] Preferably, the material of the first thermally conductive layer 102 is at least one of aluminum oxide, zirconium oxide, metal oxide materials, tourmaline, volcanic rock, jade, ore powder materials, silicon dioxide, silicon nitride, silicon-based composite materials, silicon carbide, graphite alloy, carbon alloy, and carbon-based composite materials.

[0040] As an example of this utility model, the first thermally conductive layer 102 is aluminum oxide and is prepared using the following process:

[0041] S1. Take 50 mL of deionized water and 50 mL of α-Al2O3 hydrosol with a solid content of 10 w / w%, add 5 g of pseudoboehmite, stir with a magnetic stir bar for 5 min, then add 1 mL of concentrated HNO3 solution, stir thoroughly for 0.5 h, then add 2 g of polyvinylpyrrolidone, stir for 0.5 h to obtain the precursor solution.

[0042] S2. Clean the heating substrate 101 sequentially with deionized water, acetone and ethanol, sonicating for 20 minutes each time, and then dry it for later use. Place the clean heating substrate 101 in the above precursor solution for 5-50 minutes, then remove it with the thermally conductive layer perpendicular to the horizontal plane and air dry at room temperature.

[0043] S3. Place the stainless steel plate with aluminum oxide sol precursor deposited on its surface in a high-temperature furnace and hold it at 600℃ for 30 minutes; then raise it to 800℃ and age it for 10 minutes.

[0044] As an example of this utility model, the first thermally conductive layer 102 or the second thermally conductive layer 103 is made of zirconium oxide and is prepared by plasma spraying. The specific method is as follows:

[0045] S1. Add polyethylene glycol as a dispersant to a 0.1 mol / L zirconium oxychloride solution to achieve a final mass concentration of 1%. Under stirring conditions at 80°C, add oxalic acid solution dropwise to the zirconium oxychloride solution at a molar ratio of 1:5 for oxalic acid to zirconium oxychloride. After reacting for 3 hours, zirconium oxychloride sol (pH=2) is obtained.

[0046] S2. The zirconium oxalate sol obtained in step S1 is placed in a hydrothermal reactor with a filling degree of 60%. The reactor is kept at 150°C for 12 hours. The hydrothermal reactor is then removed and allowed to cool naturally. The mixture is then sheared or ultrasonically treated to ensure uniform mixing and to obtain zirconium oxide nano-solution.

[0047] S3. Add plasticizer polyvinyl alcohol and binder hydroxyethyl cellulose to the zirconium oxide nano solution obtained in step S2, and make the final mass concentrations of polyvinyl alcohol and hydroxyethyl cellulose 2% and 0.1% respectively. After mixing, add organosilicon defoamer and make its final mass concentration 0.01%. Mix well to obtain the coating liquid.

[0048] S4. Apply the coating liquid to the surface of the first heat-conducting layer 102 or the heating substrate 101 by dip coating, heat it to 120°C at a heating rate of 3°C / min, dry it for 5 hours, then heat it to 650°C at a heating rate of 3°C / min, keep it at that temperature for 3 hours, and then cool it to obtain the coating.

[0049] As an example of this utility model, the first thermally conductive layer 102 or the second thermally conductive layer 103 is made of aluminum oxide and is prepared by the following method:

[0050] S1: Purification treatment: The surface of the wheel hub to be sprayed is sequentially washed with hot water, alkaline water, water, acid, water, passivated, water, deionized water, and dried.

[0051] S2: Local roughening treatment: The surface of the heating substrate 101 treated by S1 is roughened by shot blasting machine to achieve a surface roughness of Ra6.3-12.5μm;

[0052] S3: Preheating: The heating substrate 101 treated by S2 is preheated using a heating furnace, and the furnace gas temperature is set to 200-250℃;

[0053] S4: Plasma spraying: 200-300 mesh alumina ceramic powder is selected as the coating material. The plasma jet generated by the plasma spray gun heats and accelerates the alumina ceramic powder of several micrometers to tens of micrometers. The powder is sprayed onto the surface of the heating substrate 101 treated by S3 in a molten or near-molten state to form a coating. During the spraying process, compressed air is used to force-cool the heating substrate 101. The spraying distance is 100-120mm, the coating thickness is 0.1-0.2mm, the powder feed rate is 8g / s, and the particle velocity is 250-280m / s.

[0054] Preferably, the material of the heating substrate 101 is a metal or metal alloy, a ceramic material, a carbon-based material, a semiconductor material, or a composite material.

[0055] Preferably, the heating component further includes a second heat-conducting layer 103, which is located outside the first heat-conducting layer 102. The thickness of the second heat-conducting layer 102 is D2 = λ / (4*n), where λ represents the wavelength of the emitted far-infrared radiation and n represents the refractive index of the second heat-conducting layer 102. This configuration can further improve the wavelength interference of thermal radiation to optimize and enhance the radiation effect of the entire far-infrared band, further reduce burns caused by direct conduction of heat convection energy, and optimize and enhance the thermal radiation energy of the entire far-infrared band to gently penetrate into the interior of the baked goods to reduce burns.

[0056] As an example of this utility model, the material of the second heat-conducting layer 103 is any one of aluminum oxide, zirconium oxide, metal oxide materials, tourmaline, volcanic rock, jade, mineral powder materials, silicon dioxide, silicon nitride, silicon-based composite materials, silicon carbide, graphite alloy, carbon alloy, and carbon-based composite materials, and the materials of the first heat-conducting layer 102 and the second heat-conducting layer 103 are different.

[0057] Preferably, the first thermally conductive layer 102 and the second thermally conductive layer 103 are multiple and alternately distributed. This arrangement can further improve the emissivity of the heating component in the 4-1000μm range, thereby reducing the direct heat conduction during the baking process. The first thermally conductive layer 102 and the second thermally conductive layer 103 are prepared using methods such as plasma thermal spraying, PVD physical vapor deposition, CVD chemical vapor deposition, and ALD atomic layer deposition.

[0058] Example 1

[0059] like Figure 1 As shown, a heating component includes a heating substrate 101, with a first thermally conductive layer 102 disposed around the heating substrate 101. The heating substrate 101 is a stainless steel heating tube, and the first thermally conductive layer 102 is 1μm aluminum oxide.

[0060] Example 2

[0061] A heating component includes a heating substrate 101, with a first thermally conductive layer 102 disposed around the heating substrate 101. The heating substrate 101 is a stainless steel heating tube, and the first thermally conductive layer 102 is 5μm aluminum oxide.

[0062] Example 3

[0063] like Figure 2 As shown, a heating component includes a heating substrate 101. A first thermally conductive layer 102 and a second thermally conductive layer 103 are sequentially disposed around the heating substrate 101. The heating substrate 101 is a stainless steel heating tube. The first thermally conductive layer 102 is 1.18 μm aluminum oxide with a refractive index of 1.7. The second thermally conductive layer 103 is 0.78 μm silicon carbide with a refractive index of 2.6. The λ is preset to 8 μm.

[0064] Example 4

[0065] A heating element includes a heating substrate 101. A first thermally conductive layer 102 and a second thermally conductive layer 103 are sequentially disposed around the heating substrate 101. The first thermally conductive layer 102 and the second thermally conductive layer 103 each have four layers and are arranged alternately. The heating substrate 101 is a stainless steel heating tube. The first thermally conductive layer 102 is 1.07 μm silicon dioxide with a refractive index of 1.4. The second thermally conductive layer 103 is 0.91 μm tourmaline with a refractive index of 1.65. The λ is preset to 6 μm.

[0066] Heating components prepared in Examples 1-4 were designated A1, A2, B, and C, respectively, each with a length of 1 cm. A stainless steel heating tube was used as a control. The far-infrared emissivity of each sample at room temperature and 85°C was measured using a Fourier transform infrared spectrometer with a blackbody source as the light source. The results are shown in [Figure number missing]. Figure 3-4 .

[0067] Depend on Figure 3-4 It is known that coating stainless steel with materials of high far-infrared emissivity, such as aluminum oxide (theoretically far-infrared emissivity of 0.7-0.9), will increase the far-infrared emissivity. At the same time, as the thickness of the first heat-conducting layer 102 increases, the interference effect is enhanced and tends to be similar to the far-infrared emissivity of the heat-conducting layer material itself. For schemes B and C, an emissivity peak will be generated near the preset far-infrared center wavelength, which will significantly increase the emissivity of the overall far-infrared band. The thermal conductivity of the first heat-conducting layer 102 and the second heat-conducting layer 103 is lower than that of the heating substrate 101. With the increase of the overall far-infrared emissivity, the direct heat conduction of heat convection during the baking process is reduced accordingly.

[0068] Example 5

[0069] A heating component includes a heating substrate 101, with a first thermally conductive layer 102 disposed around the heating substrate 101. The first thermally conductive layer 102 is a 3mm graphite thermally conductive plate, and a second thermally conductive layer 102 is a 5μm zirconium oxide precision-coated layer on the first thermally conductive layer 102.

[0070] Example 6

[0071] A heating component includes a heating substrate 101. A first thermally conductive layer 102 is sequentially disposed around the heating substrate 101. The first thermally conductive layer 102 is a 3mm graphite plate with a 5µm coating as described in Example 5. The thermally conductive plate is coated with five layers each of aluminum oxide and zirconium oxide alternately. The aluminum oxide has a thickness of 1.47µm and a refractive index of 1.7. The zirconium oxide has a thickness of 1.14µm and a refractive index of 2.2. λ is preset to 10µm.

[0072] Heating components prepared in Examples 5 and 6 were designated as D and E, respectively, each with a length of 1 cm. A graphite plate was used as a control. Using a Fourier transform infrared spectrometer with a blackbody source as the light source, the far-infrared emissivity of each sample was measured at room temperature and 85°C. The results are shown in [Figure number missing]. Figure 5-6 .

[0073] Depend on Figure 5-6 It is known that the far-infrared emissivity of graphite plates decreases significantly above 10μm. However, after applying zirconium oxide and / or aluminum oxide to the surface through a thermally conductive layer process, the overall far-infrared emissivity increases significantly. This indicates that the technical solutions in Examples 5-6 can effectively improve the far-infrared emissivity at high temperatures. The multi-layer thermally conductive layer process generates a far-infrared emissivity peak near the preset far-infrared center wavelength (see sample E), and optimizes and improves the overall far-infrared emissivity. The thermal conductivity of the thermally conductive layer material is lower than that of the graphite plate thermally conductive material. At the same time, with the increase in the overall far-infrared emissivity, the direct heat conduction during baking is reduced accordingly.

[0074] Example 7

[0075] A heating component includes a heating substrate 101, a first thermally conductive layer 102 disposed on the outer side of the heating substrate 101, the heating substrate 101 being a stainless steel heating tube, and the first thermally conductive layer 102 being a 0.1 mm graphite film disposed on a 5 mm thick zirconium oxide plate.

[0076] Example 8

[0077] A heating component includes a heating substrate 101, a first thermally conductive layer 102 disposed on the outer side of the heating substrate 101, the heating substrate 101 being a stainless steel heating tube, and the first thermally conductive layer 102 being a 3mm graphite plate with a 1mm zirconium oxide ceramic plate disposed thereon.

[0078] Heating components prepared in Examples 7-8 were designated F and G, respectively, each with a length of 1 cm. Graphite plates and zirconium oxide were used as controls. The far-infrared emissivity of each sample at 85°C was measured using a Fourier transform infrared spectrometer with a blackbody source as the light source. The results are shown below. Figure 7 Because the thermally conductive layer is relatively thick, heat conduction is not easily observed at room temperature; therefore, experimental testing was conducted at 85℃.

[0079] Depend on Figure 7 It is known that using graphite plates or zirconia plates for heat conduction can significantly improve the emissivity of the far-infrared band; stacking materials with different high far-infrared emissivity on a stainless steel heating tube can also produce a certain wavelength interference effect. Compared with a single-layer heat-conducting plate, the stacked first heat-conducting layer 102 can significantly optimize and improve the emissivity of the far-infrared band, and also has more room for optimization.

[0080] Take a number of fresh green white tea leaves, and select representative examples 3 and 6 from the above implementation cases to bake them in the following manner. The results are shown in Table 1.

[0081] Table 1. Sensory effects of different drying methods on tea leaves

[0082]

[0083] As can be seen from the table above, the technical solutions of Embodiments 3 and 6 of this utility model can significantly improve the roasting effect of tea. Under the same roasting time and temperature, the far-infrared emissivity band of the heating component of Embodiment 6 is also better than that of Embodiment 3. Under long-term mild far-infrared high-temperature radiation, it is not easy to be scorched or charred, and a good complex polymerization reaction of polysaccharides and proteins occurs, making the tea unique in aroma and taste, and the drying effect is also significantly better. It can also be widely used in the fields of food, tea, and medicine.

[0084] This invention also provides a baking apparatus, including the aforementioned heating element. The baking apparatus has the same beneficial effects as the heating element, and will not be described in detail here.

[0085] The above-mentioned baking device is used in product baking. The products are tea, food, and medicinal materials. This invention optimizes the emissivity of the far-infrared spectrum by improving the heating element. The penetrating power of far-infrared radiation can penetrate the surface of the baked product, which is beneficial for drying the interior of the baked product. At the same time, it utilizes the low conductivity of the heat-conducting material to reduce direct heat convection and make more use of combined heat radiation to promote the chemical reaction inside the baked product. This effectively avoids scorching caused by high and uneven heating or long heating time on the surface of the baked product, thereby improving the overall quality of the baked product.

[0086] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A heating element, characterized in that, It includes a heating substrate (101) and a heat-conducting layer. The heat-conducting layer includes a first heat-conducting layer (102) disposed above the heating substrate (101). The thickness of the first heat-conducting layer (102) is 0.5-50 mm, or it is a precision coating layer with a thickness D1=λ / (4*n1), where λ represents the preset center wavelength for emitting far-infrared light and the value range is 4-15 μm, and n1 represents the refractive index of the first heat-conducting layer (102).

2. The heat generating component of claim 1, wherein, The heat-conducting layer includes a second heat-conducting layer (103), which is attached to the top of the first heat-conducting layer (102). The thickness of the second heat-conducting layer (103) is 0.5-50 mm, or it is a precision coating layer with a thickness D2=λ / (4*n2), where λ represents the preset center wavelength for emitting far-infrared rays and the value range is 4-15 μm, and n2 represents the refractive index of the second heat-conducting layer (103).

3. The heat generating assembly of claim 2, wherein, The first thermal conductive layer (102) is a single layer, or it is combined with the second thermal conductive layer (103) in double or multiple layers, or in combination with a precision coating layer.

4. The heat generating assembly of claim 3, wherein, The precision coating of the first thermal conductive layer (102) and / or the second thermal conductive layer (103) is prepared by any one of plasma thermal spraying, PVD physical vapor deposition, CVD chemical vapor deposition, and ALD atomic layer deposition.

5. A toasting apparatus characterised in that, Includes the heating component as described in any one of claims 1-4.

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