AIR-HEATING TYPE HEAT NOT BURN HEATING DEVICE, CERAMIC HEATING ELEMENT AND PREPARATION METHOD THEREOF

Abstract

An air-heating type heat not burn heating device, a ceramic heating element and a preparation method thereof are provided. The ceramic heating element includes a honeycomb ceramic body and a heating printed circuit. Porous channels are arranged in the honeycomb ceramic body, and the porous channels are circular holes or polygonal holes. The heating printed circuit is arranged around an outer surface of the honeycomb ceramic body to heat the air passing through the porous channels. According to the ceramic heating element, the surface made of high purity alumina honeycomb ceramic has high compactness, it is able to effectively prevent absorption of smoke dust particles, thus to effectively preventing odd smell; the high-purity alumina honeycomb ceramic has good thermal conductivity, with a thermal conductivity of 33 W/mk; the wall thickness and pore diameter in the honeycomb ceramic structure are both very small, and the thermal conductivity is extremely excellent.

Claims

1. A ceramic heating element, comprising: a honeycomb ceramic body, wherein porous channels are arranged in the honeycomb ceramic body, and the porous channels are circular holes or polygonal holes; and a heating printed circuit, wherein the heating printed circuit is arranged around an outer surface of the honeycomb ceramic body to heat air passing through the porous channels.

2. The ceramic heating element of claim 1, wherein the alumina ceramic tube body is an alumina honeycomb ceramic body, and the alumina honeycomb ceramic body has a density being larger than or equal to 3.86 g/cm.sup.3.

3. The ceramic heating element of claim 1, wherein the porous channels are uniformly distributed in the honeycomb ceramic body.

4. The ceramic heating element of claim 1, wherein the porous channels are arranged in a center of the honeycomb ceramic body.

5. An air-heating type heat not burn heating device, comprising: the ceramic heating element of claim 1; and a preheating device, wherein the ceramic heating element is arranged below the preheating device.

6. The air-heating type heat not burn heating device of claim 5, wherein the preheating device comprises a preheating tube, a deflector is arranged between the preheating tube and the ceramic heating element, and a plurality of guide holes are arranged on the deflector.

7. The air-heating type heat not burn heating device of claim 5, wherein the ceramic heating element and the preheating device are arranged in a sealing sleeve.

8. The air-heating type heat not burn heating device of claim 5, wherein the preheating device comprises a thin-wall alumina ceramic tube for preheating; a cavity in a center of the thin-wall alumina ceramic tube is used for placing smoking product; an opening at one end of the thin-wall alumina ceramic tube and a base plate forms a cup body; and a plurality of hot air flow holes are arranged on the base plate.

9. The air-heating type heat not burn heating device of claim 8, wherein the thin-wall alumina ceramic tube has a density being larger than or equal to 3.86 g/cm.sup.3.

10. The air-heating type heat not burn heating device of claim 8, wherein the plurality of hot air flow holes are uniformly arranged around a virtual circle in a center of the base plate, and the plurality of hot air flow holes are circular holes with a diameter ranging from 0.1 mm to 2 mm.

11. The air-heating type heat not burn heating device of claim 8, wherein the base plate is made of high-purity alumina ceramics.

12. A preparation method of the ceramic heating element of claim 1, comprising: step 1: preparation of alumina honeycomb ceramic sludge: adding 0.01-0.05 parts (by weight) of magnesium nitrate, 0.01-0.05 parts of zirconium oxychloride, 0.01-0.05 parts of yttrium nitrate, 1.5-2.5 parts of oleic acid, 1-2 parts of lubricant, 3-15 parts of binder and 10-30 parts of deionized water into 100 parts of nano alumina powder, putting the 0.01-0.05 parts (by weight) of magnesium nitrate, the 0.01-0.05 parts of zirconium oxychloride, the 0.01-0.05 parts of yttrium nitrate, the 1.5-2.5 parts of oleic acid, the 1-2 parts of lubricant, the 3-15 parts of binder, the 10-30 parts of deionized water and the 100 parts of nano alumina powder into a mixing machine to be mixed for 1-5 h at a temperature below 30° C., thus to prepare the alumina honeycomb ceramic sludge with uniform distribution and a solid content of 75-85% for later use; step 2: molding of alumina honeycomb ceramics: adding the alumina honeycomb ceramic sludge prepared in step 1 into a screw-type ceramic extrusion molding machine with a vacuum degassing device, and extruding hollow and thin-wall alumina honeycomb ceramic blanks out of the alumina honeycomb ceramic sludge through a die head as pushed by a screw; step 3: drying of the hollow and thin-wall alumina honeycomb ceramic blanks: moving the hollow and thin-wall alumina honeycomb ceramic blanks prepared in step 2 to an oven, make the hollow and thin-wall alumina honeycomb ceramic blanks dry and dehydrate for 5-10 minutes under 40-50° C. hot air, thus to obtain an alumina ceramic green body with satisfactory appearance and straightness; step 4: debinding of the alumina ceramic green body: biscuiting the alumina ceramic green body prepared in step 3 at 1100-1200° C. to obtain a biscuit ceramic; step 5: firing of an alumina honeycomb ceramic: placing the biscuit ceramic prepared in step 4 in a high-temperature molybdenum tube and firing the biscuit ceramic in a hydrogen atmosphere or directly in the air at 1600-1800° C. to obtain the alumina honeycomb ceramic; and step 6: preparation of an alumina honeycomb ceramic surface heating printed circuit and a wire of the alumina honeycomb ceramic surface heating printed circuit: printing a thick-film electric heating wire on an outer surface of the alumina honeycomb ceramic prepared in step 5 using screen printing technology; after the alumina honeycomb ceramic surface heating printed circuit is dried up, applying silver solder on a bonding pad to stick the wire, drying up the alumina honeycomb ceramic surface heating printed circuit with the silver solder in the oven again, and then moving the alumina honeycomb ceramic surface heating printed circuit with the silver solder to a furnace for sintering at 800° C.-1500° C., thus to obtain an integrally sintered wire and printed circuit, and simultaneously, complete silver soldering of the wire in the furnace.

13. The preparation method of the ceramic heating element of claim 12, wherein the nano alumina powder used in step 1 has a purity of 99.99% or above, a particle size of 350 nm, and a specific surface area of 7 m.sup.2/g.

14. The air-heating type heat not burn heating device of claim 5, wherein the alumina ceramic tube body is an alumina honeycomb ceramic body, and the alumina honeycomb ceramic body has a density being larger than or equal to 3.86 g/cm.sup.3.

15. The air-heating type heat not burn heating device of claim 5, wherein the porous channels are uniformly distributed in the honeycomb ceramic body.

16. The air-heating type heat not burn heating device of claim 5, wherein the porous channels are arranged in a center of the honeycomb ceramic body.

17. The preparation method of claim 12, wherein the alumina ceramic tube body is an alumina honeycomb ceramic body, and the alumina honeycomb ceramic body has a density being larger than or equal to 3.86 g/cm.sup.3.

18. The preparation method of claim 12, wherein the porous channels are uniformly distributed in the honeycomb ceramic body.

19. The preparation method of claim 12, wherein the porous channels are arranged in a center of the honeycomb ceramic body.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0069] FIG. 1 is a structural diagram of a heating element according to an embodiment of the present invention;

[0070] FIG. 2 is a plane expansion diagram of a heating printed circuit on the surface of the alumina honeycomb ceramic heating element according to an embodiment of the present invention;

[0071] FIG. 3 is a structural diagram of an air-heating type heat not burn heating device according to an embodiment of the present invention;

[0072] FIG. 4 is a structural diagram of an air-heating type heat not burn heating device according to another embodiment of the present invention;

[0073] FIG. 5 is a structural diagram of an air-heating type heat not burn heating device according to a third embodiment of the present invention;

[0074] FIG. 6 is a structural diagram of a deflector according to an embodiment of the present invention;

[0075] FIG. 7 is a structural diagram of a preheating device according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0076] To make the purpose, technical scheme and advantages of the embodiments of the present invention more clear, in combination with the attached drawings given in the embodiments of the present invention, the technical scheme described in embodiments of the present invention are described explicitly and completely below. Apparently, the embodiments described only represent a part but not all of the embodiments of the present invention. Based on the embodiments quoted in the detailed description of the present invention, all other embodiments obtained by ordinary technicians skilled in the art without creative work should be included in the scope of protection of the present invention. Therefore, the following detailed descriptions of the embodiments of the present invention provided in the attached drawings are not intended to limit the scope of the present invention to be protected, but only represent the selected embodiments of the present invention. Based on the embodiments quoted in the detailed description of the present invention, all other embodiments obtained by ordinary technicians skilled in the art without creative work should be included in the scope of protection of the present invention.

[0077] In the description of the present invention, it should be understood that the terms “above”, “below”, “inner”, “outer”, “front end”, “rear end”, “one end”, “the other end”, etc. refer to the direction or position based on the attached drawings. The terms are provided only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred therein must have a specific direction, must be constructed or operated in a specific direction, they can not be construed as a limitation on the present invention. The terms “first” and “second” are for illustrative purpose only, which may not to construed as indicating or implying relative importance.

[0078] In the description of the present invention, it should be noted that, unless otherwise expressly specified and defined, the terms “install”, “arrange”, “connect”, etc. should be understood in a broad sense. For example, “connect” may be fixed connection or detachable connection or integral connection; it may be mechanical connection or electrical connection; it may be also direct connection or indirection connection through a medium, or it may be internal communication of two components. For those ordinary technicians skilled in the art, the specific meanings of the above terms quoted in the present invention can be understood according to specific situations.

[0079] With reference to the attached drawings, a ceramic heating element, an air-heating type heat not burn heating device with the ceramic heating element, and a preparation method of the ceramic heating element proposed by the embodiments of the present invention are illustrated in detailed below.

[0080] As shown in FIG. 1, a ceramic heating element proposed in an embodiment of the present invention includes a honeycomb ceramic body 1 and a heating printed circuit 2. Wherein, porous channels 11 are arranged in the honeycomb ceramic body, and porous channels 11 are circular or polygonal holes; the heating printed circuit 2 is arranged around the outer surface of the honeycomb ceramic body 1 to heat the air passing through the porous channels 11.

[0081] Optionally, as one embodiment, the alumina ceramic tube body is an alumina honeycomb ceramic body, and the alumina honeycomb ceramic body has a density being not less than 3.86 g/cm.sup.3.

[0082] Optionally, as one embodiment, the porous channels are uniformly distributed in the honeycomb ceramic body.

[0083] Optionally, as one embodiment, the porous channels are arranged in the center of the honeycomb ceramic body.

[0084] Optionally, as one embodiment, the honeycomb ceramic body is a cylinder with a circular or polygonal cross section.

[0085] With reference to the attached drawings, detailed description of embodiments of the present invention is described in details.

Embodiment 1

[0086] As shown in FIG. 1-2, an alumina honeycomb ceramic heating element disclosed by the present invention, includes an alumina honeycomb ceramic body 1, a heating printed circuit 2, and a wire 3; porous channels 11 are arranged in the center of the alumina honeycomb ceramic body 1; and the porous channels 11 are evenly arranged square holes; the heating printed circuit 2 is arranged around the outer surface of the alumina honeycomb ceramic body 1; and a wire 3 is arranged at a first end of the heating printed circuit 2.

[0087] Further, the density of the alumina honeycomb ceramic body 1 is 3.9 g/cm.sup.3.

[0088] Further, the resistance of the alumina honeycomb ceramic body 1 is 0.6Ω.

[0089] Further, the alumina honeycomb ceramic body 1 is a cylinder with a circular cross section.

[0090] Further, the square hole diameter of the porous channels 11 is 1.5 mm, that is, the side length of the square hole is 1.5 mm; the wall thickness of the porous channels 11 is 0.2 mm; as shown in FIG. 1, distance between the corresponding sides of two adjacent square holes is the wall thickness of the porous channels 11.

[0091] Further, the heating printed circuit 2 is made of silver.

[0092] Further, the printing thickness of the heating printed circuit 2 is 0.015 mm.

[0093] Further, the wire 3 is a silver wire, with a diameter of 0.2 mm.

Embodiment 2

[0094] As shown in FIG. 1-2, an alumina honeycomb ceramic heating element disclosed by the present invention, includes an alumina honeycomb ceramic body 1, a heating printed circuit 2, and a wire 3; porous channels 11 are arranged in the center of the alumina honeycomb ceramic body 1; and the porous channels 11 are evenly arranged circular holes; the heating printed circuit 2 is arranged around the outer surface of the alumina honeycomb ceramic body 1; and a wire 3 is arranged at a first end of the heating printed circuit 2.

[0095] Further, the density of the alumina honeycomb ceramic body 1 is 3.9 g/cm.sup.3.

[0096] Further, the resistance of the alumina honeycomb ceramic body 1 is 0.8Ω.

[0097] Further, the alumina honeycomb ceramic body 1 is a cylinder with a circular cross section, and the porous channels 11 in the center thereof are square holes.

[0098] Further, the circular pore diameter of the porous channels 11 mm is 1.5 mm; the wall thickness of the porous channels 11 is 0.2 mm, and the minimum distance between two adjacent circular holes is the wall thickness of the porous channels 11.

[0099] Further, the heating printed circuit 2 is made of silver.

[0100] Further, the printing thickness of the heating printed circuit 2 is 0.02 mm.

[0101] Further, the wire 3 is a silver wire, with a diameter of 0.2 mm.

[0102] In this embodiment, the porous channels 11 are circular holes, in comparison with the embodiment 1, the utilization rate of the center of the alumina honeycomb ceramic body 1 is obviously lower than that of the embodiment 1, and its specific surface area is smaller than that of the embodiment 1, and the heating efficiency is lower than that of the embodiment 1.

[0103] In the present invention, the purity of the alumina honeycomb ceramics is more than 99%, so that the honeycomb ceramic surface has high compactness, which can effectively prevent adsorption of smoke and dust particles, thus to exert the effect of preventing odd smell. The high-purity alumina honeycomb ceramic has good thermal conductivity, with a thermal conductivity of 33 W/mk; the wall thickness and pore diameter in the honeycomb ceramic structure are both very small, and the thermal conductivity is extremely excellent; the shape of the honeycomb porous can greatly increase the contact area with air, the alumina honeycomb ceramics has large specific area, and high heating efficiency, which is favorable for quickly heating the air.

[0104] The honeycomb ceramic heating body of the present invention is arranged below a heat not burn product to be baked without contacting; when the user smokes the heat not burn, air flows through the holes in the honeycomb of the heating element and is heated to a certain temperature, and then the hot air flows through the heat not burn to rapidly heat the heat not burn to 320° C. This method can improve the heating area and heating efficiency of heat not burn product, achieve even heating, carbonize tobacco more completely, avoid wasting of tobacco, improve the smoking experience of users, and it is not limited by the type of cartridge. Due to the honeycomb porous structure, the air flow rate is restricted to some extent, and the contact time between the hot air and the heat not burn is prolonged, which slows the heat loss and saves energy. When there is no smoking action, the porous honeycomb ceramic can lock the hot air while reducing the outflow of hot air, which will further save energy.

[0105] The embodiment of the present invention further discloses an air-heating type heat not burn heating device, as shown in FIG. 3, the air-heating type heat not burn heating device includes the ceramic heating element described in the embodiment 10 and the preheating device 20.

[0106] A ceramic heating element 10 is arranged below the preheating device 20.

[0107] Optionally, as one embodiment, the preheating device includes a preheating tube, a deflector is arranged between the preheating tube and the ceramic heating element, and a plurality of guide holes are arranged on the deflector.

[0108] According one embodiment of the present invention, the ceramic heating element and the preheating device are arranged in a sealing sleeve.

[0109] Optionally, as one embodiment, the preheating device includes a thin-wall alumina ceramic tube for preheating, a cavity in the center of the thin-wall alumina ceramic tube is used for placing a smoking product, and an opening at one end of the thin-wall alumina ceramic tube and a base plate forms a cup body, and a plurality of hot air flow holes are arranged on the base plate.

[0110] Wherein, the thin-wall alumina ceramic tube has a density not less than 3.86 g/cm.sup.3.

[0111] Optionally, as one embodiment, a plurality of hot air flow holes are uniformly arranged around a virtual circle in the center of the base plate, and the hot air flow holes are circular holes with a diameter ranging from 0.1 mm to 2 mm.

[0112] The base plate is made of high-purity alumina ceramics.

[0113] Specifically, as one embodiment, as shown in FIGS. 1-3, the air-heating heat not burn heating device includes a preheating tube 21 and a ceramic heating element 10, and the ceramic heating element 10 is arranged under the preheating tube 21; the ceramic heating element 10 includes a honeycomb ceramic body 1 and a heating printed circuit 2 arranged on the honeycomb ceramic body 1, a wire 3 is arranged at an end of the heating printed circuit 2, and honeycomb porous channels 11 are arranged in the ceramic heating body 1.

[0114] Further, a deflector 22 is arranged between the preheating tube 21 and the ceramic heating element 10, and a plurality of guide holes 31 are arranged on the deflector 22.

[0115] Further, the preheating tube 21 and the ceramic heating element 10 are arranged in a sealing sleeve 4.

[0116] Further, the preheating tube 21, ceramic heating element 10 and deflector 22 are all made of high-purity alumina ceramics.

[0117] Further, printing materials of the heating printed circuit 2 include but are not limited to silver, tungsten, and MoMn.

[0118] Further, the wire 2 material includes but is not limited to silver, copper, and nickel.

[0119] Further, the honeycomb porous channels 11 are uniformly arranged circular holes or polygonal holes, with a pore diameter ranging from 0.1 mm to 2 mm, and the minimum distance between two adjacent holes within 0.1 mm-0.5 mm.

[0120] Optionally, as one embodiment, as shown in FIG. 3, a ceramic heating element 10 is arranged under the preheating tube 21, and a deflector 22 is arranged between the preheating tube 21 and the ceramic heating element 10, the preheating tube 21 and the ceramic heating element 10 are arranged inside a sealing sleeve 4; as shown in FIG. 1, the ceramic heating element 10 includes a honeycomb ceramic body 1, and a heating printed circuit 2 arranged on the honeycomb ceramic body 1, a wire 3 is arranged at an end of the heating printed circuit 2. When a smoker desires to smoke, he/she may put a cartridge into the preheating tube 21 to prevent the cartridge from falling; after powering on, the heating printed circuit 2 starts to heat, because the effective ingredients such as nicotine can only be heated to generate the smoke to smoke only when the cartridge is baked at 280° C.-320° C., so it is necessary to preheat the device, and preheating is deemed as completed when the temperature of the preheating tube 21 and the deflector 22 reaches 200° C., the preheating is completed. Since the preheating is completed, at the time of a first and second puffs during the first heating, the cartridge only needs to be heated from 200° C. to 320° C., which is faster than rising from the room temperature, and can better guarantee the smoke volume produced by the first and second puffs. To speed up heating, a honeycomb porous channel 11 is arranged in the honeycomb ceramic body 1 and the porous channels are uniformly arranged square holes or other polygonal holes, with the pore diameter ranging from 0.1 mm to 2 mm, and the minimum distance between two adjacent holes within 0.1 mm-0.5 mm, and the expanded area is large, the air-heating efficiency is very high, and the heated air flows from the center of the honeycomb without contacting the heating printed circuit 2, so it will not cause pollution. As the preheating tube 21, the ceramic heating element 10 and the deflector 22 are all made of high-purity alumina ceramics featuring good electrical insulation, high strength, and good thermal conductivity, so the ceramic heating element 10 will not leak when being heated, and the preheating tube 21 and the deflector 22 will be heated up because of the good thermal conductivity of high-purity alumina ceramics, the user can smoke the cartridge soon; during smoking the airflow is heated to 320° C. by the ceramic heating element 10, then further homogenized and diverted through the diversion holes 31 on the deflector 22 and finally flows into the cartridge more evenly to heat the tobacco, so as to increase the smoke volume, improve the smoking taste, and provide good user experience. During smoking, some fluid contaminants emitted from the cartridge may inevitably remain in the device. As the high-purity alumina ceramics feature high compactness and almost have no pores in microstructure, so penetration of contaminants in fluid is impossible, and no pollution and odd smell will be left on the surface; In the working process, the sealing sleeve 4 serves as a seal, which ensures that the heated air will not flow to other places.

[0121] Optionally, as another embodiment, as shown in FIG. 4, a ceramic heating element 10 is arranged under the preheating tube 21, and the preheating tube 21 and the ceramic heating element 10 are arranged inside a sealing sleeve 4; as shown in FIG. 1, the ceramic heating element 10 includes a honeycomb ceramic body 1, and a heating printed circuit 2 arranged on the honeycomb ceramic body 1, a wire 3 is arranged at an end of the heating printed circuit 2. When a smoker desires to smoke, he/she may put a cartridge into the preheating tube 21 to prevent the cartridge from falling; after powering on, the heating printed circuit 2 starts to heat, because the effective ingredients such as nicotine can only be heated to generate the smoke to smoke only when the cartridge is baked at 280° C.-320° C., so it is necessary to preheat the device, and preheating is deemed as completed when the temperature of the preheating tube 21 reaches 200° C., the preheating is completed. Since the preheating is completed, at the time of a first and second puffs during the first heating, the cartridge only needs to be heated from 200° C. to 320° C., which is faster than rising from the room temperature, and can better guarantee the smoke volume produced by the first and second puffs. To speed up heating, a honeycomb porous channel 11 is arranged in the honeycomb ceramic body 1 and the porous channels are uniformly arranged square holes or other polygonal holes, with the pore diameter ranging from 0.1 mm to 2 mm, and the minimum distance between two adjacent holes within 0.1 mm-0.5 mm, and the expanded area is large, the air-heating efficiency is very high, and the heated air flows from the center of the honeycomb without contacting the heating printed circuit 2, so it will not cause pollution. As the preheating tube 21 and the ceramic heating element 10 are made of high-purity alumina ceramics featuring good electrical insulation, high strength, and good thermal conductivity, so the ceramic heating element 10 will not leak when being heated, and the preheating tube 21 will be heated up because of the good thermal conductivity of high-purity alumina ceramics, the user can smoke the cartridge soon; during smoking the airflow is heated to 320° C. by the ceramic heating element 10, when the smoker starts to smoke, the heated air flows to the preheating tube 21 through the ceramic heating element 10, and the heated air flows into the cartridge to evenly heat the tobacco then further homogenized and diverted through the diversion holes 10 on the deflector 22 and finally flows into the cartridge more evenly to heat the tobacco, so as to increase the smoke volume, improve the smoking taste, and provide good user experience. During smoking, some fluid contaminants emitted from the cartridge may inevitably remain in the device. As the high-purity alumina ceramics feature high compactness and almost have no pores in microstructure, so penetration of contaminants in fluid is impossible, and no pollution and odd smell will be left on the surface; In the working process, the sealing sleeve 4 serves as a seal, which ensures that the heated air will not flow to other places.

[0122] Optionally, as one embodiment, as shown in FIG. 5, a ceramic heating element 10 is arranged under the preheating tube 21, and a deflector 22 is arranged on the preheating tube 21 and the ceramic heating element 10; as shown in FIG. 1, the ceramic heating element 10 includes a honeycomb ceramic body 1, and a heating printed circuit 2 arranged on the honeycomb ceramic body 1, a wire 3 is arranged at an end of the heating printed circuit 2. When a smoker desires to smoke, he/she may put a cartridge into the preheating tube 21 to prevent the cartridge from falling; after powering on, the heating printed circuit 2 starts to heat, because the effective ingredients such as nicotine can only be heated to generate the smoke to smoke only when the cartridge is baked at 280° C.-320° C., so it is necessary to preheat the device, and preheating is deemed as completed when the temperature of the preheating tube 21 and the deflector 22 reaches 200° C., the preheating is completed. Since the preheating is completed, at the time of a first and second puffs during the first heating, the cartridge only needs to be heated from 200° C. to 320° C., which is faster than rising from the room temperature, and can better guarantee the smoke volume produced by the first and second puffs. To speed up heating, a honeycomb porous channel 11 is arranged in the honeycomb ceramic body 1 and the porous channels are uniformly arranged square holes or other polygonal holes, with the pore diameter ranging from 0.1 mm to 2 mm, and the minimum distance between two adjacent holes within 0.1 mm-0.5 mm, and the expanded area is large, the air-heating efficiency is very high, and the heated air flows from the center of the honeycomb without contacting the heating printed circuit 2, so it will not cause pollution. As the preheating tube 21, the ceramic heating element 10 and the deflector 22 are all made of high-purity alumina ceramics featuring good electrical insulation, high strength, and good thermal conductivity, so the ceramic heating element 10 will not leak when being heated, and the preheating tube 21 and the deflector 22 will be heated up because of the good thermal conductivity of high-purity alumina ceramics, the user can smoke the cartridge soon; during smoking the airflow is heated to 320° C. by the ceramic heating element 10, then further homogenized and diverted through the diversion holes 31 on the deflector 22 and finally flows into the cartridge more evenly to heat the tobacco, so as to increase the smoke volume, improve the smoking taste, and provide good user experience. During smoking, some fluid contaminants emitted from the cartridge may inevitably remain in the device. As the high-purity alumina ceramics feature high compactness and almost have no pores in microstructure, so penetration of contaminants in fluid is impossible, and no pollution and odd smell will be left on the surface;

[0123] As one embodiment, as shown in FIG. 7, the preheating device includes a thin-wall alumina ceramic tube for preheating, a cavity 210 in the center of the thin-wall alumina ceramic tube 21 is used for placing a tobacco product such as cartridge, and an opening at one end of the thin-wall alumina ceramic tube 21 and a base plate 23 forms a cup body, and a plurality of hot air flow holes 32 are arranged on the base plate 23; the thin-wall alumina ceramic tube 21 has a density that is not less than 3.86 g/cm.sup.3; the thin-wall alumina ceramic tube 21 is a thin-wall alumina ceramic hollow circular tube, with the wall thickness of 0.2 mm; the shape of the base plate 23 matches with that of an opening section of the thin-wall alumina ceramic tube 21; 8 hot air flow holes 32 are uniformly arranged around a virtual circle in the center of the base plate 23, and the hot air flow holes 32 are circular holes with a diameter of 1.5 mm; and the base plate 23 has a thickness of 0.2 mm; and the base plate 23 is made of high-purity alumina ceramics.

[0124] Wherein, the purity of the ultra-thin high-purity alumina ceramics is more than 99%, so that the ceramic surface has high compactness, which can effectively prevent adsorption of smoke and dust particles, thus to exert the effect of preventing odd smell. Ultra-thin high-purity alumina ceramics have good thermal conductivity (thermal conductivity up to 33 W/m.Math.k), and high heating efficiency, so it can quickly achieve the purpose of preheating the air in cavity 210.

[0125] The preheating device is installed above the air heating element such as a ceramic heating element 10, when the heating element is heated, it can be quickly heated up to preheat the cavity 210 as the base plate 23 and the thin-wall alumina ceramic tube 21 are both made of ultra-thin high-purity alumina ceramics. The thin-wall alumina ceramic tube 21 is not used as a traditional heating component, which can reduce heat loss. In a heating scheme in a related art, a ceramic heating tube is used to bake a a smoking product directly, a heating circuit is printed on the outer surface of the ceramic heating tube, when the power is on, the high temperature of the ceramic heating tube itself will bake the smoking product, in this way, the heat utilization rate is low, and a lot of heat is released while baking the tobacco, which does not economic and environmental friendly. In the embodiments of the present invention, heating the smoking product is achieved by the user's smoking action, and hot air is extracted from the heating component under the hot air flow hole 32 to bake the smoking product, the baking effect is good and the baking is uniform. On one hand, the hot air flow hole can facilitate the circulation of hot air; on the other hand, direct diffusion of hot air is prevented when no one smokes, thus to achieve heat preservation. The high-purity alumina ceramic material has good compactness, which will reduce the absorption of smoke dust particles, generate no odd smell, it is therefore safer to use.

[0126] Besides, an embodiment of the present invention further discloses a preparation method of the ceramic heating element, which includes the following steps:

[0127] Step 1: Preparation of alumina ceramic sludge: adding 0.01-0.05 parts (by weight) of magnesium nitrate, 0.01-0.05 parts of zirconium oxychloride, 0.01-0.05 parts of yttrium nitrate, 1.5-2.5 parts of oleic acid, 1-2 parts of lubricant, 3-15 parts of binders and 10-30 parts of deionized water into 100 parts of nano alumina powder, putting them into a mixing machine, and mix them for 1-5 h at a temperature below 30° C., thus to prepare the alumina honeycomb ceramic sludge with uniform distribution and a solid content of 75-85% for later use;

[0128] Step 2: Molding of alumina honeycomb ceramics: adding the alumina honeycomb ceramic sludge prepared in step 1 into a screw-type ceramic extrusion molding machine with a vacuum degassing device, and extruding hollow, thin-wall honeycomb ceramic blanks out of the ceramic sludge through the die head as pushed by the screw.

[0129] Step 3: Drying of alumina honeycomb ceramic blanks: moving the ceramic blanks prepared in step 2 to an oven, make them dry and dehydrate for 5 minutes to 10 minutes under 40° C.-50° C. hot air, thus to obtain a ceramic green body with satisfactory appearance and straightness.

[0130] Step 4: Debinding of the alumina ceramic green body: biscuiting the ceramic green body prepared in step 3 at 1100-1200° C. to obtain a biscuit ceramic;

[0131] Step 5: Firing of alumina honeycomb ceramic: placing the biscuit ceramic prepared in step 4 in a high-temperature molybdenum tube and firing it in a hydrogen atmosphere or directly in the air at 1600-1800° C. to obtain an alumina honeycomb ceramic;

[0132] Step 6: Preparation of alumina honeycomb ceramic surface heating printed circuit and its wire: print a thick-film electric heating wire on the outer surface of the alumina honeycomb ceramic prepared in step 5 using screen printing technology, after the printed circuit is dried up, apply silver solder on a bonding pad to stick the wire, dry them up in the oven again, and then move them to a furnace for sintering at 800° C.-1500° C., thus to obtain an integrally sintered wire and printed circuit, and simultaneously, complete silver soldering of the wire in the furnace.

[0133] Optionally, the nano alumina powder used in step 1 has a purity of 99.99% or above, a particle size of 350 nm, and a specific surface area of 7 m.sup.2/g.

[0134] According to one embodiment of the present invention, the preparation method of the said alumina honeycomb ceramic heating element includes the following steps:

[0135] Step 1. Preparation of alumina ceramic sludge: adding 0.04 parts (by weight) of Mg(NO.sub.3).sub.2.6H.sub.2O, 0.04 parts of ZrOCl.sub.2.8H.sub.2O, 0.01 part of Y(NO.sub.3).sub.3.6H.sub.2O, 2.4 parts of oleic acid, 1.2 parts of polyethylene glycol 600, 14 parts of high-purity ethyl cellulose ether and 12 parts of deionized water in 100 parts of nano alumina powder, and then placing the mixture in a mixing machine, and mix them for 5 h at a temperature below 30° C., thus to prepare the alumina honeycomb ceramic sludge with uniform distribution and a solid content of 75% for later use;

[0136] Step 2: Molding of alumina honeycomb ceramics: adding the alumina honeycomb ceramic sludge prepared in step 1 into a screw-type ceramic extrusion molding machine with a vacuum degassing device, and extruding hollow, thin-wall honeycomb ceramic blanks out of the ceramic sludge through the die head as pushed by the screw.

[0137] Step 3: Drying of alumina honeycomb ceramic blanks: moving the ceramic blanks prepared in step 2 to an oven, make them dry and dehydrate for 10 minutes under 49° C. hot air, thus to obtain a ceramic green body with satisfactory appearance and straightness.

[0138] Step 4: Debinding of the alumina ceramic tube green: biscuiting the ceramic green body prepared in step 3 at 1190° C. to obtain a biscuit ceramic;

[0139] Step 5: Firing of alumina ceramic: placing the biscuit ceramic prepared in step 4 in a high-temperature molybdenum tube and firing it in a hydrogen atmosphere or directly in the air at 1650° C. to obtain an alumina honeycomb ceramic;

[0140] Step 6: Preparation of heating a printed circuit and its wire on alumina ceramic tube surface: print a thick-film electric heating wire on the outer surface of the alumina honeycomb ceramic prepared in step 5 using screen printing technology, after the printed circuit is dried up, apply silver solder on a bonding pad to stick the wire, dry them up in the oven again, and then move them to an atmospheric hydrogen furnace for sintering at 800° C., thus to obtain the heating component of an integrally sintered alumina honeycomb ceramic body, and simultaneously, complete silver soldering of the wire in the furnace.

[0141] Further, the nano alumina powder used in step 1 has a purity of 99.99% or above, a particle size of 350 nm, and a specific surface area of 7 m.sup.2/g.

[0142] Further, the density of the alumina honeycomb ceramic body is 3.9 g/cm.sup.3.

[0143] Further, the resistance of the alumina honeycomb ceramic body is 0.6Ω.

[0144] Further, the alumina honeycomb ceramic body is a cylinder with a circular cross section, and the porous channels in the center thereof are evenly distributed square holes.

[0145] Further, the square hole diameter of the porous channels is 1.5 mm, that is, the side length of the square hole is 1.5 mm; the wall thickness of the porous channels is 0.2 mm; as shown in FIG. 1, distance between the corresponding sides of two adjacent square holes is the wall thickness of the porous channels.

[0146] Further, the heating printed circuit is made of silver.

[0147] Further, the printing thickness of the heating printed circuit is 0.015 mm.

[0148] Further, the wire is a silver wire, with a diameter of 0.2 mm.

[0149] According to another embodiment of the present invention, the preparation method of the said alumina honeycomb ceramic heating element includes the following steps:

[0150] Step 1: Preparation of alumina ceramic sludge: adding 0.02 parts (by weight) of Mg(NO.sub.3).sub.2.6H.sub.2O, 0.05 parts of ZrOCl.sub.2.8H.sub.2O, 0.015 part of Y(NO.sub.3).sub.3.6H.sub.2O, 2 parts of oleic acid, 1.5 parts of polyethylene glycol 600, 8 parts of high-purity ethyl cellulose ether and 20 parts of deionized water in 100 parts of nano alumina powder, and then placing the mixture in a mixing machine, and mix them for 5 h at a temperature below 30° C., thus to prepare the alumina honeycomb ceramic sludge with uniform distribution and a solid content of 78 for later use;

[0151] Step 2: Molding of alumina honeycomb ceramics: adding the alumina honeycomb ceramic sludge prepared in step 1 into a screw-type ceramic extrusion molding machine with a vacuum degassing device, and extruding hollow, thin-wall honeycomb ceramic blanks out of the ceramic sludge through the die head as pushed by the screw.

[0152] Step 3: Drying of alumina honeycomb ceramic blanks: moving the ceramic blanks prepared in step 2 to an oven, make them dry and dehydrate for 10 minutes under 49° C. hot air, thus to obtain a ceramic green body with satisfactory appearance and straightness.

[0153] Step 4: Debinding of the alumina ceramic tube green: biscuiting the ceramic green body prepared in step 3 at 1190° C. to obtain a biscuit ceramic;

[0154] Step 5: Firing of alumina ceramic: placing the biscuit ceramic prepared in step 4 in a high-temperature molybdenum tube and firing it in a hydrogen atmosphere or directly in the air at 1650° C. to obtain an alumina honeycomb ceramic;

[0155] Step 6: Preparation of heating a printed circuit and its wire on alumina ceramic tube surface: print a thick-film electric heating wire on the outer surface of the alumina honeycomb ceramic prepared in step 5 using screen printing technology, after the printed circuit is dried up, apply silver solder on a bonding pad to stick the wire, dry them up in the oven again, and then move them to an atmospheric hydrogen furnace for sintering at 800° C., thus to obtain the heating component of an integrally sintered alumina honeycomb ceramic body, and simultaneously, complete silver soldering of the wire in the furnace.

[0156] Further, the nano alumina powder used in step 1 has a purity of 99.99% or above, a particle size of 350 nm, and a specific surface area of 7 m.sup.2/g.

[0157] Further, the density of the alumina honeycomb ceramic body is 3.9 g/cm.sup.3.

[0158] Further, the resistance of the alumina honeycomb ceramic body is 0.8Ω.

[0159] Further, the alumina honeycomb ceramic body is a cylinder with a circular cross section, and the porous channels in the center thereof are evenly distributed square holes.

[0160] Further, the square hole diameter of the porous channels is 1.5 mm, that is, the side length of the square hole is 1.5 mm; the wall thickness of the porous channels is 0.2 mm; as shown in FIG. 1, distance between the corresponding sides of two adjacent square holes is the wall thickness of the porous channels.

[0161] Further, the heating printed circuit is made of silver.

[0162] Further, the printing thickness of the heating printed circuit is 0.02 mm.

[0163] Further, the wire is a silver wire, with a diameter of 0.2 mm.

[0164] The purity of the alumina honeycomb ceramics prepared by the preparation method of the present invention is more than 99%, so that the honeycomb ceramic surface has high compactness, which can effectively prevent adsorption of smoke and dust particles, thus to exert the effect of preventing odd smell. The high-purity alumina honeycomb ceramic has good thermal conductivity, with a thermal conductivity of 33 W/mk; the wall thickness and pore diameter in the honeycomb ceramic structure are both very small, and the thermal conductivity is extremely excellent; the shape of the honeycomb porous can greatly increase the contact area with air, the alumina honeycomb ceramics has large specific area, and high heating efficiency, which is favorable for quickly heating the air.

[0165] The honeycomb ceramic heating element of the present invention is arranged below a heat not burn product to be baked without contacting; when the user smokes the heat not burn, air flows through the holes in the honeycomb of the heating element and is heated to a certain temperature, and then the hot air flows through the heat not burn to rapidly heat the heat not burn to 320° C. This method can improve the heating area and heating efficiency of heat not burn product, achieve even heating, carbonize tobacco more completely, avoid wasting of tobacco, improve the smoking experience of users, and it is not limited by the type of cartridge. Due to the honeycomb porous structure, the air flow rate is restricted to some extent, and the contact time between the hot air and the heat not burn is prolonged, which slows the heat loss and saves energy. When there is no smoking action, the porous honeycomb ceramic can lock the hot air while reducing the outflow of hot air, which will further save energy.

[0166] Although the embodiments of the present invention have been shown and described above, it can be understood that the embodiments are exemplary but should not be construed as a limitation on the present invention, the ordinary technician skilled in the art may make changes, modifications, substitutions and variations of the embodiments within the scope of the present invention.