A combined heating device and method of use thereof

Abstract

The application provides a combined heating device and a use method thereof. In the application, the combined heating device comprises a circumferential heating device and an axial heating device arranged on one side of the circumferential heating device. The circumferential heating device can compensate for the problem that the tobacco substrate at a high position is difficult to heat. In addition, the axial heating device comprises a foamed ceramic body, and an infrared coating is arranged on the side of the foamed ceramic body in contact with the circumferential heating device. The infrared coating can simultaneously serve as the only heat source for airflow heating and infrared radiation heating, so that the two heating modes of airflow and infrared radiation are adopted for axial combined heating. In this way, the heat value of the infrared radiation can be fully utilized, the energy consumption is low, the airflow heating can be used, the distance of heat transfer in the axial direction is relatively long, the heat transfer contact area is sufficient, and the heat transfer space is uniformly distributed.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of cigarettes, and particularly relates to a combined heating device and a use method thereof. BACKGROUND

[0002] At present, low-temperature cigarette heating appliances mainly adopt inner core heating or circumferential heating. Heat transfer of the two heating methods is dependent on contact heat conduction and is transmitted along the radial direction of the cigarette. Since the radius of the cigarette is shorter than the length of the cigarette, the radial transmission distance of heat is shorter than the axial transmission distance, the heat conduction path is short, and the heat transfer efficiency is high. However, both the circumferential heating and the inner core heating are heat conduction by contact of the heating element, and the contact area will affect the efficiency of heat conduction. In addition, the temperature of the heating element is generally above 300 DEG C, and the tobacco substrate close to the heating element is prone to pasting phenomenon. Moreover, for the circumferential heating, heat needs to pass through the cigarette paper of the cigarette first, which not only blocks the heat conduction, but also causes paper taste difficult to cover due to heat absorption.

[0003] In comparison, the axial heating in the form of radiation and convection can solve the above problems. The axial heating method is along the axial heating path, does not need to pass through the cigarette paper, avoids heating of the cigarette paper, solves the problem of paper taste in the smoke, and the heat transfer in the radial direction (cigarette cross section) of the axial heating method is uniform. However, the heating path of the axial heating method is longer than that of the circumferential heating method, and there is a greater temperature gradient in the axial direction.

[0004] It can be seen that the single circumferential heating method or the axial heating method has certain problems. SUMMARY

[0005] Therefore, the purpose of the present application is to provide a combined heating device and a use method thereof. The combined heating device can make full use of heat energy and make the tobacco substrate of the cigarette more uniform.

[0006] To achieve the purpose, the present application adopts the following technical solutions:

[0007] In a first aspect, the present application provides a combined heating device, comprising:

[0008] a circumferential heating device;

[0009] an axial heating device arranged on one side of the circumferential heating device;

[0010] The axial heating device comprises a foamed ceramic body, and an infrared coating is arranged on the side of the foamed ceramic body in contact with the circumferential heating device.

[0011] Preferably, the infrared coating is composed of conductive material and infrared radiation material.

[0012] Preferably, the electrically conductive material is selected from any one or more of tin oxide, zinc oxide, silver oxide or copper oxide.

[0013] Preferably, the infrared radiation material is selected from any one or more of a carbon material, a zirconium-titanium oxide, an iron oxide, an iron nitride or an iron carbide.

[0014] Preferably, the infrared coating has a resistance of 0.4 to 5 Ω.

[0015] Preferably, the infrared coating has a thickness of 0.3 to 250 μm.

[0016] Preferably, the infrared coating has an infrared radiation wavelength of 2 to 20 μm at 150 to 300 °C. .

[0017] Preferably, the cross-section of the foam ceramic body is circular; the length of the foam ceramic body is 5 to 10 cm.

[0018] Preferably, the porosity of the foam ceramic body is 80 to 95%.

[0019] Preferably, the circumferential heating device comprises a heating cylinder, and a heating element is arranged on the outer side of the heating cylinder.

[0020] Preferably, the length of the heating cylinder is 5 to 10 cm.

[0021] Preferably, the length of the heating element is less than the length of the heating cylinder.

[0022] Preferably, the heating element is arranged on the side of the circumferential heating device that is away from the side of the heating cylinder that is in contact with the foam ceramic body.

[0023] Preferably, the combined heating device further comprises a filtering element.

[0024] Preferably, the filtering element is arranged on the other side of the circumferential heating device that is away from the axial heating device.

[0025] In a second aspect, the present application provides a method for using the combined heating device described above, comprising the following steps:

[0026] The cigarette tobacco substrate is placed in the circumferential heating device, and at the same time, one side of the cigarette tobacco substrate is in contact with the axial heating device, and the circumferential heating device and the axial heating device are started to heat the tobacco substrate.

[0027] Compared with the prior art, the present application has the following beneficial effects:

[0028] The application provides a combined heating device, which comprises a circumferential heating device and an axial heating device arranged on one side of the circumferential heating device. In the application, the axial heating device comprises a foamed ceramic body, and an infrared coating is arranged on the side of the foamed ceramic body in contact with the circumferential heating device. The infrared coating serves as a heat source of the foamed ceramic body, can radiate infrared rays and heat the foamed ceramic body, and the foamed ceramic body can heat the air therein. Therefore, the infrared coating can simultaneously serve as the only heat source for airflow heating and infrared radiation heating. The axial combined heating by using the two heating modes of airflow and infrared radiation can ensure that the heat value of infrared radiation can be fully utilized, the energy consumption is low, the airflow heating can be used, the distance of heat transfer in the axial direction is relatively long, the heat transfer contact area is sufficient, and the heat transfer space is uniformly distributed.

[0029] Further, the heating path of the axial heating is long, and a greater temperature gradient exists in the axial direction. Therefore, the circumferential heating is arranged to compensate for the heat of the tobacco substrate in the distal axial direction, so as to solve the problem that the tobacco substrate in the distal axial direction is difficult to be heated. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 It is a schematic view of the combined heating device in the application;

[0031] In the figure, 1 is a heating cylinder, 2 is a foamed ceramic body, 3 is a heating element, 4 is an infrared coating, 5 is a tobacco substrate, and 6 is a filter.

[0032] Figure 2 It is a surface plan view of the upper end of the foamed ceramic body;

[0033] In the figure, 21 is a pore.

[0034] Figure 3 It is a front view and a sectional view of a tobacco column sample with different thicknesses;

[0035] Figure 4 It is a reflectivity data graph of a tobacco column sample with different thicknesses;

[0036] In the figure, Figure 4 a) in the figure is a reflectivity data graph (wavelength: 700-1500 nm) of a tobacco column sample with different thicknesses; Figure 4 b) in the figure is an enlarged view of the reflectivity data (wavelength: 750-1000 nm) of a tobacco column sample with different thicknesses;

[0037] Figure 5 It is a transmittance data graph of a tobacco column sample with a thickness of 5 mm;

[0038] In the figure, Figure 5a) is the transmittance data graph (wavelength: 700~1500nm) of the tobacco plug sample with a thickness of 5 mm in b) is the enlarged view of the transmittance data (wavelength: 750~1000nm) of the tobacco plug sample with a thickness of 5 mm. Figure 5 a) is the transmittance data graph (wavelength: 700~1500nm) of the tobacco plug sample with a thickness of 5 mm in b) is the enlarged view of the transmittance data (wavelength: 750~1000nm) of the tobacco plug sample with a thickness of 5 mm. DETAILED DESCRIPTION

[0039] The technical solutions of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0040] The present application provides a combined heating device, comprising:

[0041] a circumferential heating device;

[0042] an axial heating device arranged on one side of the circumferential heating device. In some embodiments of the present application, the structural schematic diagram of the combined heating device is as shown in Figure 1 , wherein the circumferential heating device is designed as a heating cylinder 1, the axial heating device is designed as a foam ceramic body 2, and the side of the foam ceramic body 2 in contact with the heating cylinder 1 is further provided with an infrared coating 4. According to the present application, when the above combined heating device is used to heat cigarette tobacco, the tobacco is preferably inserted into the heating cylinder 1, and the bottom of the tobacco is made to contact the infrared coating 4.

[0043] In the present application, the length of the heating cylinder, i.e. the depth of the tobacco entering during subsequent heating of the cigarette tobacco, is generally controlled to be 5~10 cm, preferably 6~8 cm. It can be understood that the tobacco above the height of 5~10 cm is heated by the heating cylinder.

[0044] In the present application, the inner wall of the heating cylinder is covered with a peripheral heating element 3 for providing heat transfer in the circumferential direction, and the heating mode of the heating element includes but is not limited to resistance wire heating mode and / or infrared radiation heating mode. It should be noted that in the present application, the heating element 3 does not completely cover the inner wall of the heating cylinder, and the length of the heating element is generally less than the length of the heating cylinder. Meanwhile, referring to Figure 1 , the heating element is preferably arranged on the side away from the side of the heating cylinder in contact with the foam ceramic body. In this way, the bottom of the tobacco can be heated by the axial heating device, and the tobacco that cannot be heated by the axial heating device can be heated by the circumferential heating device.

[0045] Referring to Figure 1In the present application, the axial heating device is a ceramic foam body 2, which is preferably circular in cross-section, considering the subsequent heating of tobacco shreds, and can be specifically referred to the attached Figure 2 In the present application, the axial heating device is a ceramic foam body 2, which is preferably circular in cross-section, considering the subsequent heating of tobacco shreds, and can be specifically referred to the attached

[0046] In the present application, the axial heating device is preferably a combination of infrared radiation heating and airflow heating, and the two types of heating can be in a non-contact mode.

[0047] It should be noted that the infrared radiation heating has a high electric-to-thermal conversion efficiency, which can be above 90%. The infrared radiation is generally thermal radiation or temperature radiation. Once the infrared radiation is absorbed by an object, the energy of the infrared radiation is converted into heat energy, which heats the object to increase its temperature. When the infrared radiation directly propagates to the surface of the object at the speed of light, the emission frequency thereof matches the inherent frequency of the molecular motion of the object, which causes strong vibration of the molecules of the object and generates heat in the object due to intense friction.

[0048] The generation of infrared radiation is closely related to temperature, and the radiation energy and the distribution of wavelengths are determined by the surface temperature of the object. The radiation energy of the surface of the object is proportional to the fourth power of the surface temperature of the object; the higher the temperature of the object, the more the near-infrared radiation with shorter wavelength can be radiated, and the lower the temperature, the more the infrared radiation with longer wavelength can be radiated.

[0049] As a heating method for low-temperature cigarettes, if the direction of the infrared radiation is set at the radial position of the cigarette, it is easy to be intercepted by the aluminum foil cigarette paper which is impermeable. The transmittance of the infrared radiation through the aluminum foil cigarette paper is very low, and the reflectance is high, which causes other components to be heated. If the energy of the infrared radiation is increased, the temperature of the infrared radiation generating device must be increased, and a heat insulation device must be designed, and the energy is inevitably lost.

[0050] Since the infrared radiation has reflection and transmission in the axial direction of the cigarette, there are two technical indexes of reflectance and transmittance. It can be seen that the two technical indexes of the space point at the axial position of the cigarette are of great significance for whether the infrared radiation method can be used as a heat source. Therefore, the present application investigates the transmittance and reflectance of the infrared radiation with respect to the axial depth of the cigarette.

[0051] The specific experiment is as follows:

[0052] The tobacco mound sample obtained by reconstruction according to the apparent bulk density of the low-temperature cigarette is shown in FIG. 1. The cylindrical samples with thicknesses of 5 mm and 10 mm are respectively denoted as 1# sample and 2# sample (the apparent bulk density of the tobacco leaf is 0.22 g / cm3). Figure 3 The apparent bulk density of the low-temperature cigarette is 0.22 g / cm3.3 ).

[0053] The transmittance and reflectance data of samples 1# and 2# were measured using a UV / Vis / NIR diffuse reflectance meter (Perkin Elmer, Lambda 1050).

[0054] The reflectance data of the two samples in the 700-1500 nm infrared band are as follows: Figure 4 As shown. From Figure 4 a) and enlarged view ( Figure 4 As shown in b), samples #1 and #2 with different thicknesses have comparable reflectivity, indicating that the apparent morphology and apparent bulk density of the two samples are comparable.

[0055] Transmittance data of the two samples in the 700–1500 nm infrared band, such as Figure 5 As shown. Among them, the transmittance of sample #2, which is 10 mm thick, is 0, and the instrument cannot detect it. Therefore... Figure 5 Only transmittance data for a 5 mm thick sample (sample #1) in the 700–1500 nm infrared band are shown. From... Figure 5 As shown in a), the infrared transmittance of sample #1 (5 mm thick) is only 1-5%. (Magnified image) Figure 5 As shown in b), sharp infrared transmission peaks can be observed at wavelengths of 800 nm, 820 nm and 863 nm, indicating that sample #1 has preferential transmission performance for infrared light of certain wavelengths.

[0056] Therefore, the present invention draws the following conclusions: In the infrared radiation heating method, about 15% of the energy is reflected, a 5 mm thick sample can transmit 5% of the energy, and 80% of the energy is absorbed.

[0057] In this invention, infrared radiation heating can make full use of the heat source and has low energy consumption, but the heating path of infrared radiation heating is short.

[0058] Airflow heating is a method of generating smoke by heating tobacco matrix with high-temperature air heated by heating elements. This heating method allows for long-distance heat transfer, sufficient heat transfer contact area, and uniform heat distribution. However, airflow heating requires high power to heat the heat storage body, which needs to heat the air to 280~300℃. The high temperature of the components brings a series of problems, such as heat insulation and energy loss.

[0059] Therefore, the present invention employs both infrared radiation heating and airflow heating as heating methods for the axial heating device, with the advantages and disadvantages of the two complementing each other.

[0060] In summary, please refer to the appendix. Figure 1In the present application, the side of the foam ceramic body 2 in contact with the heating cylinder 1 is further provided with an infrared coating 4, which is a composite infrared radiation coating formed by spraying an electrically conductive material and an infrared radiation material on the end face of the foam ceramic body in a mass ratio of (3-6):(7-4), preferably (4-5):(5-6), to form the infrared coating 4. The infrared coating 4 generates heat after being electrified and radiates infrared rays. The electrically conductive material is any one or more of tin oxide, zinc oxide, silver oxide or copper oxide. The infrared radiation material is any one or more of carbon material, zirconium-titanium oxide, iron oxide, iron nitride or iron carbide.

[0061] In the present application, the resistance of the infrared coating 4 is 0.4-5 Ω, preferably 1-3 Ω; the thickness is 0.3-250 μm, preferably 10-200 μm; and the infrared radiation wavelength is 2-20 μm at 150-300 °C.

[0062] In the present application, the infrared coating 4 serves as a heat source for the foam ceramic body 2, can radiate infrared rays and heat the foam ceramic body 2, and the foam ceramic body 2 can heat the air therein. Therefore, the infrared coating 4 can simultaneously serve as a heat source for airflow heating and infrared radiation heating, thereby ensuring the simultaneous existence of airflow heating and infrared radiation heating in the axial direction. The infrared radiation heating can fully utilize the heat source and has low energy consumption, but the heating path is short. The airflow heating has a long heat transfer distance, sufficient heat transfer contact area and uniform heat transfer space distribution, which can effectively compensate for the shortcomings of infrared radiation.

[0063] In addition, as described above, a 5 mm thick sample can transmit 5% of the energy and absorb 80% of the energy. Therefore, the present application selects a position at a distance of 5 mm or more from the infrared coating 4 to perform circumferential heating of the tobacco substrate for heat compensation.

[0064] In some embodiments of the present application, the combined heating device further comprises a filter element arranged on the other side of the circumferential heating device away from the axial heating device, with reference to the accompanying drawings Figure 1 The filter element is a filter tip 6.

[0065] In one embodiment of the present application, the combined heating device is specifically that the foam ceramic body 2 is placed at the bottom of the cigarette containing cavity, the upper end face of the foam ceramic body 2 is covered with the infrared coating 4 (with air holes 21), and the heating cylinder 1 with a heating element 3 (such as a resistance) is covered at the position 5 mm or more above the bottom of the cigarette containing cavity, which performs temperature compensation on the distal end of the cigarette in the axial direction in a circumferential heating manner.

[0066] The application also provides a method for using the combination heating device, comprising the following steps:

[0067] The cigarette tobacco substrate is placed in the circumferential heating device, and the bottom of the cigarette tobacco substrate contacts the axial heating device, and the circumferential heating device and the axial heating device are started to heat the tobacco substrate.

[0068] In summary, the combination heating device provided by the application adopts airflow heating and infrared radiation heating, and combines axial heating and circumferential heating at a certain height of the cigarette above the heating element (such as a resistor), and has the following advantages:

[0069] (1) The infrared coating serves as a heat source of the foam ceramic body, plays a role in radiating infrared rays and heating the foam ceramic body, and the foam ceramic body can heat the air passing through it. The infrared coating can simultaneously serve as the only heat source for airflow heating and infrared radiation heating;

[0070] (2) Since the infrared radiation energy is related to temperature, increasing the infrared radiation energy leads to an increase in the temperature of the foam ceramic body, and in addition, the energy reflected back by the tobacco substrate is also utilized by the foam ceramic, and the heat of the ceramic body is transferred to the inflowing air, and the high-temperature air heats the tobacco substrate, and the energy can be fully utilized. Only the length of the ceramic body needs to be optimized, and the heat insulation problem of the heat source can be effectively solved;

[0071] (3) The airflow heating mode can make up for the short heating path of the infrared radiation heating mode, and the circumferential resistance heating at a high position can further make up for the problem that the tobacco substrate at a high position is difficult to heat;

[0072] (4) The heat energy in the technical solution is fully utilized, and the difficulty of heat insulation design is reduced to a certain extent.

[0073] The above description of the disclosed embodiments enables one skilled in the art to make or use the application. Various modifications to these embodiments will be obvious to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Therefore, the application will not be limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A combination heating device, characterized in that, It comprises: a circumferential heating device; the circumferential heating device comprises a heating cylinder, the outer side of the heating cylinder is provided with a heating element; the length of the heating cylinder is 5-10 cm; the length of the heating element is less than the length of the heating cylinder; an axial heating device arranged on one side of the circumferential heating device; the axial heating device comprises a foamed ceramic body, the foamed ceramic body is arranged at the bottom of a cigarette accommodating cavity, and the side of the foamed ceramic body in contact with the circumferential heating device is provided with an infrared coating; the infrared coating simultaneously serves as the only heat source for airflow heating and infrared radiation heating; the infrared coating is provided with air holes; wherein the heating element is arranged on the side away from the side of the heating cylinder in contact with the foamed ceramic body; the heating element is arranged at a position more than 5 mm away from the infrared coating; the circumferential heating device compensates heat in the distal end axial direction of the tobacco substrate.

2. The combination heating device of claim 1, wherein, The infrared coating is composed of a conductive material and an infrared radiation material; the conductive material is selected from any one or more of tin oxide, zinc oxide, silver oxide or copper oxide; the infrared radiation material is selected from any one or more of carbon material, zirconium-titanium-based oxide, iron-based oxide, iron-based nitride or iron-based carbide.

3. The combined heating device according to claim 1 or 2, characterized in that The resistance of the infrared coating is 0.4-5 Ω, and the thickness is 0.3-250 μm; the infrared radiation wavelength of the infrared coating is 2-20 μm at 150-300 ℃.

4. The combination heating device according to any one of claims 1 to 3, wherein The cross section of the foamed ceramic body is circular; the length of the foamed ceramic body is 5-10 cm; The porosity of the foamed ceramic body is 80-95%.

5. The combination heating device according to any one of claims 1 to 4, wherein, The combined heating device further comprises a filter element; the filter element is arranged on the other side of the circumferential heating device away from the axial heating device.

6. A method of using the combination heating device of any one of claims 1-5, wherein, It comprises the following steps: put the cigarette tobacco substrate into the circumferential heating device, at the same time, one side of the cigarette tobacco substrate contacts the axial heating device, and start the circumferential heating device and the axial heating device to heat the tobacco substrate.

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