Fluidized bed drying system and method for cigarette blast beads

Abstract

The invention discloses a fluidized bed drying system and method for cigarette blast beads, and the fluidized bed drying system for the cigarette blast beads comprises a fluidized bed drying device, a fluidized drying ultraviolet light odor degradation device, a closed-loop total heat recycling heat pump and a fan, a top outlet of the fluidized bed drying device is connected with an inlet of the fluidized drying ultraviolet light smell degradation device through a pipeline, and an outlet of the fluidized drying ultraviolet light smell degradation device is connected with an inlet of the closed-loop total heat recycling heat pump through a pipeline and a fan. And an outlet of the closed-loop total heat recycling heat pump is connected with a lower inlet of the fluidized bed drying device through a pipeline. According to the invention, the cigarette blast beads can be dried, the drying efficiency is improved, the energy consumption is reduced, the adverse effect of the smell of the cigarette blast beads on the environment is reduced, and the environmental load is reduced.

Description

Technical Field

[0001] This invention specifically relates to a fluidized bed drying system and method for tobacco capsules. Background Technology

[0002] Cigarette flavor capsules are spherical soft capsules containing a special flavored liquid made from fragrances, herbal extracts, and appropriate solvents. This enhances the aroma of cigarettes, improves the taste, and serves as a way to compensate for the original flavor of cigarettes. Current cigarette flavor capsule forming processes produce wet capsules that are approximately three times heavier than dry capsules, with the capsule material (wall material) having a moisture content exceeding 90%. Typical rotary dryers require a long drying time (approximately 5-7 hours), resulting in prolonged processing of the capsules in a low-intensity state, posing a significant risk to the quality of the flavor capsules. Therefore, how to quickly and efficiently remove moisture from the wet capsules is an urgent problem to be solved in the production process of cigarette flavor capsules.

[0003] To address the issue of improving the production efficiency and quality of cigarette popping beads, some patented devices and processes involve fluidized bed drying technology for popping beads. However, because the diameter and sphericity of cigarette popping beads are strictly controlled, and compared to most actual solid particles encountered, cigarette popping beads are almost uniformly sized spherical particles, this raises a problem. Fluidizing the beads according to the fluidization velocity required for most actual particles with a relatively wide particle size distribution results in poor flow uniformity in existing drying devices, short gas-solid contact paths, low drying efficiency, high resistance of the air distribution plate, and high energy consumption. Moreover, the existing open-circuit direct exhaust method used in popping bead drying devices not only fails to recover the waste heat of the discharged drying airflow, but also results in the volatile odors contained in the airflow used to dry cigarette popping beads having a significant environmental impact. Summary of the Invention

[0004] The purpose of this invention is to provide a fluidized bed drying system and method for tobacco flavoring beads, which realizes the drying of tobacco flavoring beads, improves drying efficiency, reduces energy consumption, reduces the adverse environmental impact of tobacco flavoring bead odor, and reduces environmental burden.

[0005] The technical solution adopted in this invention is: A fluidized bed drying system for tobacco capsules includes a fluidized bed drying device, a fluidized bed drying ultraviolet odor degrader, a closed-loop total heat recovery heat pump, and a fan. The top outlet of the fluidized bed drying device is connected to the inlet of the fluidized bed drying ultraviolet odor degrader via a pipe. The outlet of the fluidized bed drying ultraviolet odor degrader is connected to the inlet of the closed-loop total heat recovery heat pump via a pipe and the fan. The outlet of the closed-loop total heat recovery heat pump is connected to the lower inlet of the fluidized bed drying device via a pipe.

[0006] Preferably, the connecting pipe between the fan and the closed-loop total heat recovery heat pump is equipped with an analog main air valve and an analog exhaust air valve in sequence. A simulated fresh air valve is installed on the connecting pipe between the closed-loop total heat recovery heat pump and the fluidized bed dryer. The analog fresh air valve is equipped with a fresh air filter.

[0007] Preferably, the fluidized bed drying device includes an air outlet hood, a diffuser, a fluidized bed body, an air distributor, and an air inlet base. The diffuser and the air distributor are respectively located at the upper and lower ends of the fluidized bed body. The air outlet hood is located on the diffuser, and the air inlet base is located below the air distributor. An isolation net is provided between the air outlet hood and the diffuser.

[0008] Preferably, a lifting cylinder seat is provided between the air distributor and the air inlet base.

[0009] Preferably, the fluidized bed cylinder is a straight cylinder of constant diameter, and the ratio of the diffuser diameter D1 to the fluidized bed cylinder diameter D0 is D1 / D0 = 1.2~3; the cone angle of the diffuser is α, which ranges from 20° to 180°. The ratio of the height H of the fluidized bed cylinder to the diameter D0 of the fluidized bed cylinder is H / D0 = 1~10.

[0010] Preferably, the air distributor includes a support net, a support ring, and a honeycomb cylinder, wherein the support net is on the support ring, and the support ring is on the honeycomb cylinder.

[0011] Preferably, the mesh size of the sieve is 2 to 150 mesh; The honeycomb tube contains a honeycomb structure, which is a regular hexagon. The side length b of the regular hexagon ranges from 0.8 mm to 49.6 mm, the diameter d of the circumscribed circle (outer circle) of the regular hexagon ranges from 1.6 mm to 99.2 mm, and the axial height h of the honeycomb structure ranges from 10 mm to 300 mm.

[0012] Preferably, the fluidized bed drying ultraviolet odor degrader includes a reflector tube, a vacuum ultraviolet lamp tube, and a quartz glass tube. The reflector tube is sleeved over the quartz glass tube, and the vacuum ultraviolet lamp tube is disposed between the reflector tube and the quartz glass tube. Both ends of the quartz glass tube are provided with air inlet and outlet pipes, which pass through the two ends of the reflector tube respectively.

[0013] Preferably, the reflector tube has a parabolic surface on its cross-section perpendicular to the axis of the ultraviolet light odor degrader of the fluidized bed dryer, corresponding to the vacuum ultraviolet lamp tube. The vacuum ultraviolet lamp tube is located at the focus of the parabola, and the ultraviolet rays radiated by the vacuum ultraviolet lamp tube are reflected parallel to the parabolic surface of the reflector tube into the drying airflow inside the quartz glass tube.

[0014] A method for operating a fluidized bed drying system for tobacco capsules includes the following implementation steps: During the drying process, the drying airflow passes sequentially through the fluidized bed drying device, the fluidized bed drying ultraviolet odor degrader, the closed-loop total heat recovery heat pump and the fan, and circulates in a closed loop. In the fluidized bed drying device, the airflow path ensures that the smoke-filled beads in the fluidized bed dryer are in full-surface contact with the drying airflow, achieving momentum transfer between the smoke-filled beads and the airflow, heat transfer through the latent heat absorbed by the smoke-filled beads from the airflow, and mass transfer through the evaporation and transfer of moisture from the smoke-filled beads to the airflow. The air distributor guides and pre-distributes the drying airflow entering the bed with extremely low resistance, enabling the fluidized bed to form a good initial fluidization state, and the particles achieve uniform fluidization and sufficient gas-solid contact within the bed. The fluidized bed dryer uses ultraviolet light to irradiate the volatile organic compounds with carbon-hydrogen and carbon-carbon double bonds in the closed-loop drying airflow, photodegrading and breaking down the molecular "skeleton" to achieve continuous in-situ degradation. The photodegradation products combine with water vapor to form hydrolysis products, which are discharged from the fluidized bed dryer with the condensate. The closed-loop total heat recovery heat pump adopts a dual closed-loop implementation method with direct expansion multi-stage evaporation, heat energy closed-loop regeneration cycle, and dry airflow closed-loop. In the dry airflow closed-loop cycle, evaporation-condensation total heat recovery is carried out, and low-humidity hot airflow is continuously provided to the closed-loop flue gas dehydration system with low energy consumption. The beneficial effects of this invention are: This invention utilizes a pre-distribution effect of a dry airflow with extremely low resistance to achieve uniform fluidization and sufficient gas-solid contact of particles within the bed, thereby drying tobacco capsules and improving drying efficiency. Ultraviolet irradiation is used to photodegrade and break down volatile odors in the closed-loop drying airflow, enabling continuous in-situ degradation of volatile odors within the closed loop. A closed-loop total heat recovery heat pump provides low-humidity and high-temperature airflow to the closed-loop drying system with low energy consumption, reducing energy consumption and minimizing the adverse environmental impact of tobacco capsule odors, thus reducing environmental impact. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the principle of the fluidized bed drying system for tobacco capsules in an embodiment of the present invention.

[0016] Figure 2 This is a schematic diagram of the structure of the fluidized bed drying device in an embodiment of the present invention.

[0017] Figure 3 This is a schematic diagram of the air distributor in an embodiment of the present invention.

[0018] Figure 4 This is a cross-sectional schematic diagram of the honeycomb structure in an embodiment of the present invention.

[0019] Figure 5 yes Figure 3 Top view.

[0020] Figure 6 This is a schematic diagram of the fluidized bed drying ultraviolet light odor degradation device in an embodiment of the present invention.

[0021] Figure 7 yes Figure 6 The left view.

[0022] In the diagram: 01-Fluidized bed dryer; 02-Fluidized bed dryer with ultraviolet light odor degradation; 03-Closed-loop total heat recovery heat pump; 04-Fan; 05-Fresh air filter; 06-Analog fresh air valve; 07-Analog main air valve; 08-Analog exhaust valve; 011-Air outlet hood; 012-Isolation net; 013-Diffuser cylinder; 014-Fluidized bed cylinder body; 015-Air distributor; 016-Lifting cylinder base; 017-Air inlet base; 021-Reflector tube; 022-Vacuum UV lamp tube; 023-Quartz glass tube; 024-Air inlet / outlet connection tube; 0151-Net support; 0152-Ring support; 0153-Honeycomb tube; 01531-Honeycomb structure. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0024] In the description of this invention, it should be understood that if terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, they are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0025] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. They can refer to a mechanical connection or an electrical connection. They can refer to a direct connection or an indirect connection through an intermediate medium, and they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0026] Example 1 A fluidized bed drying system for tobacco capsules, such as Figures 1-7 As shown, the device includes a fluidized bed dryer 01, a fluidized bed dryer with ultraviolet light odor degradation 02, a closed-loop total heat recovery heat pump 03, and a fan 04. The top outlet of the fluidized bed dryer 01 is connected to the top inlet of the fluidized bed dryer with ultraviolet light odor degradation 02 via a pipe. The bottom outlet of the fluidized bed dryer with ultraviolet light odor degradation 02 is connected to the upper inlet of the closed-loop total heat recovery heat pump 03 via a pipe and the fan 04. The lower outlet of the closed-loop total heat recovery heat pump 03 is connected to the lower inlet of the fluidized bed dryer 01 via a pipe.

[0027] Furthermore, the connecting pipe between the fan 04 and the closed-loop total heat recovery heat pump 03 is sequentially equipped with an analog main air valve 07 and an analog exhaust valve 08. A simulated fresh air valve 06 is installed on the connecting pipe between the closed-loop total heat recovery heat pump 03 and the fluidized bed drying device 01. The analog fresh air valve 06 is equipped with a fresh air filter 05.

[0028] During the drying process, the analog main air valve 07 is in the open state, and the analog fresh air valve 06 and the analog exhaust valve 08 are in the closed state. When the unit needs to be cleaned and deodorized, in addition to using CIP in-situ cleaning, the unit can be air-swept cleaned by coordinating the opening of the analog fresh air valve 06, the analog main air valve 07 and the analog exhaust valve 08.

[0029] The fan 04 is controlled by a frequency converter to ensure that the flow rate of the fan 04 meets the fluidization velocity requirements of the fluidized bed, and the fluidization velocity is within the range of critical fluidization velocity and limiting fluidization velocity.

[0030] Furthermore, the fluidized bed drying device is a vertical long cylindrical fluidized bed; it has a honeycomb structure with good flow uniformity and extremely low resistance; and it has a large aspect ratio equal diameter bed structure with a long gas-solid contact path.

[0031] Furthermore, the fluidized bed drying device 01 includes an air outlet hood 011, a diffuser 013, a fluidized bed cylinder 014, an air distributor 015, and an air inlet base 017. The diffuser 013 and the air distributor 015 are respectively located at the upper and lower ends of the fluidized bed cylinder 014. The air outlet hood 011 is located on the diffuser 013, and the air inlet base 017 is located below the air distributor 015. An isolation net 012 is provided between the air outlet hood 011 and the diffuser 013. The outlet of the air outlet hood 011 is connected to the inlet of the fluidized bed drying ultraviolet light odor degrader 02 through a pipe, and the inlet of the air inlet base 017 is connected to the outlet of the closed-loop total heat recovery heat pump 03 through a pipe.

[0032] The lower section of the fluidized bed cylinder 014 can be detached from other parts and separated from the corresponding bed section. It can then be moved horizontally by a configured support trolley to load wet beads into the cylinder section or remove dried popping beads from the cylinder section. In addition, the cylinder section is equipped with a sampler, which can sample and observe the popping beads during drying at any time, such as performing infrared rapid moisture detection to determine the time for popping bead removal.

[0033] Temperature and humidity sensors are also installed at the inlet and outlet of the fluidized bed dryer 01. When the humidity value at the outlet and the humidity difference between the outlet and the inlet reach a certain set threshold, the control system will provide an audible and visual prompt that the drying process is complete.

[0034] Furthermore, the diffuser 013 is composed of a cylindrical body with a diameter of D1 and an inverted conical body with a cone angle of α.

[0035] Furthermore, a lifting cylinder seat 016 is provided between the air distributor 015 and the air inlet base 017.

[0036] Furthermore, the fluidized bed cylinder 014 is a straight cylinder with a diameter of D0 and a height of H, and the ratio of the diameter D1 of the diffuser cylinder 013 to the diameter D0 of the fluidized bed cylinder 014 is D1 / D0 = 1.2~3; the cone angle of the diffuser cylinder 013 is α, which ranges from 20° to 180°. The ratio of the height H of the fluidized bed cylinder 014 to the diameter D0 of the fluidized bed cylinder 014 is H / D0 = 1~10.

[0037] Preferably, D1 / D0 is 1.85; H / D0 is 3; the diameter D0 ranges from 200mm to 1200mm; and α is 90°.

[0038] Furthermore, the air distributor 015 includes a support net 0151, a support ring 0152, and a honeycomb cylinder 0153, wherein the support net 0151 is on the support ring 0152, and the support ring 0152 is on the honeycomb cylinder 0153.

[0039] Furthermore, the mesh size of the screen 0151 is 2 to 150 mesh; (preferably, the mesh size is 10 mesh). The honeycomb cylinder 0153 contains a honeycomb structure 01531, which is a regular hexagon. The side length b of the regular hexagon ranges from 0.8 mm to 49.6 mm (preferably, the side length b of the regular hexagon is 6.4 mm). The diameter d of the circumscribed circle (outer circle) of the regular hexagon ranges from 1.6 mm to 99.2 mm (preferably, the diameter d of the circumscribed circle (outer circle) of the regular hexagon is 12.8 mm). The axial height h of the honeycomb structure 01531 ranges from 10 mm to 300 mm (preferably, h is 100 mm).

[0040] Furthermore, the fluidized bed drying ultraviolet odor degrader 02 includes a reflector tube 021, a vacuum ultraviolet lamp tube 022, and a quartz glass tube 023. The reflector tube 021 is sleeved on the outside of the quartz glass tube 023, and the vacuum ultraviolet lamp tube 022 is disposed between the reflector tube 021 and the quartz glass tube 023. Both ends of the quartz glass tube 023 are provided with air inlet and outlet pipes 024. The two air inlet and outlet pipes 024 extend from both ends of the reflector tube 021, and the air inlet and outlet pipes 024 at both ends are connected to the outlet of the fluidized bed drying device 01 and the inlet of the fan 04 through pipes, respectively.

[0041] Furthermore, in the cross-section perpendicular to the axis of the ultraviolet light odor degrader 02 of the fluidized bed dryer, the wall surface of the reflector tube 021 corresponding to the vacuum ultraviolet lamp tube 022 is a parabolic surface. The vacuum ultraviolet lamp tube 022 is located at the focus of the parabola. The ultraviolet rays radiated by the vacuum ultraviolet lamp tube 022 are reflected parallel to the parabolic surface of the reflector tube 021 towards the drying airflow inside the quartz glass tube 023.

[0042] Multiple parabolic surfaces are distributed along the circumference of the quartz glass tube 023 on the wall of the reflector tube 021.

[0043] Furthermore, the vacuum ultraviolet lamp tube 022 can have wavelengths of 185nm, 254nm, 300nm, 365nm, or combinations thereof, or a band range of 250nm~400nm. Different wavelengths of ultraviolet light have different degradation efficiencies for different volatile odors. The power of each vacuum ultraviolet lamp tube 022 is 40W~200W. Preferably, a dual-band main wavelength of 254nm~185nm is used, with a power of 150W, an ultraviolet radiation illuminance of 1700mW / cm, a tube diameter of 15mm, and a tube length of 1554mm. The number of lamps is 6 to 16; preferably, the number of lamps is 10.

[0044] The quartz glass tube 023 is made of quartz glass material with high ultraviolet light transmittance, and its inner diameter is greater than or equal to the inner diameter of the inlet / outlet air pipe 024. When the drying airflow passes through the ultraviolet light odor degrader of the fluidized bed dryer, the quartz glass tube 023 isolates the airflow and transmits ultraviolet light.

[0045] A method for operating a fluidized bed drying system for tobacco capsules includes the following implementation steps: During the drying process, the drying airflow passes sequentially through the unit pipeline of the flue gas decompression system consisting of the fluidized bed drying device 01, the fluidized bed drying ultraviolet light odor degrader 02, the closed-loop total heat recovery heat pump 03, and the fan 04, circulating in a closed-loop manner. In this process, through the relatively long airflow path within the fluidized bed drying device 01, the smoke-filled beads inside the fluidized bed drying device (01) come into full surface contact with the drying airflow, thereby achieving momentum transfer between the smoke-filled beads and the airflow, heat transfer through the latent heat absorbed by the smoke-filled beads from the airflow, and mass transfer through the evaporation and transfer of moisture from the smoke-filled beads to the airflow; the air distributor 015 provides a pre-distribution effect for the drying airflow entering the bed with extremely low resistance, thereby creating a good initial fluidization state in the fluidized bed, and ensuring that the particles are uniformly fluidized and have sufficient gas-solid contact within the bed. The fluidized bed dryer with ultraviolet light degrader 02 uses ultraviolet light irradiation to photodegrade the volatile organic compounds with carbon-hydrogen and carbon-carbon double bonds in the closed-loop circulating drying airflow, breaking down the molecular "skeleton" and achieving continuous in-situ degradation. The photodegradation products combine with water vapor to form hydrolysis products, which are discharged from the fluidized bed dryer unit with the condensate (the condensate can be discharged from the drain port at the bottom of the heat pump of the closed-loop total heat recovery heat pump 03, that is, the evaporated water contained in the drying airflow is continuously discharged through the heat pump). The closed-loop total heat recovery heat pump 03 uses direct expansion multi-stage evaporation to form a multi-stage efficiency, and a dual closed-loop implementation of heat energy closed loop and dry airflow closed loop in the heat recovery cycle. In the dry airflow closed loop system, evaporation-condensation total heat recovery is carried out, and low-humidity hot airflow is continuously provided to the closed loop flue gas dewatering system with low energy consumption.

[0046] Example 2 Based on Example 1, the specific parameters of the fluidized bed dryer, air distributor, fluidized bed dryer UV odor degrader, closed-loop total heat recovery heat pump and fan were further defined, and the performance of Example 2 was even better after the definition was defined.

[0047] In the fluidized bed drying device 01, the diameter D0 of the fluidized bed cylinder 014 is 520 mm, the height H of the fluidized bed cylinder 014 is 1600 mm, the diameter D1 of the diffuser cylinder 013 is 960 mm, and the cone angle α of the diffuser cylinder 013 is 90°.

[0048] The mesh size of the support net 0151 of the air distributor 015 is 10 mesh, the side length b of the regular hexagon of the honeycomb structure 01531 of the air distributor 015 is 6.4 mm, the diameter d of the circumscribed circle (outer circle) corresponding to the regular hexagon is 12.8 mm, and the axial height h of the honeycomb structure 01531 is 100 mm.

[0049] The fluidized bed drying ultraviolet odor degrader 02, wherein the cross section of the parabolic surface of the reflector tube 021 satisfies the equation y=0.02x. 2 (x=-50mm~50mm), the vacuum ultraviolet lamp 022 is located at the focal point of the parabola (p=25mm), the vacuum ultraviolet lamp 022 has a wavelength of 254nm~185nm dual-band, a power of 150W, an ultraviolet radiation illuminance of 1700mW / cm, a tube diameter of 15mm, a tube length of 1554mm, and a number of 10 lamps. The quartz glass tube 023 is a high-transmittance ultraviolet quartz glass with a tube diameter of 269mm.

[0050] The closed-loop total heat recovery heat pump 03 has a drying temperature of 20℃~45℃, a dehumidification capacity of 30kg / h~35 kg / h, and a compressor rated input power of 6.64x2 kW (dual compressor dual frequency conversion).

[0051] The fan 04 is a 9-19-5.6A induced draft fan with a flow rate of 4901 Nm³. 3 ⁄h, total pressure 6500 Pa, power 15 kW, speed controlled by frequency converter, flow rate, total pressure and power consumption are adjusted.

[0052] When the fluidized bed drying device 01 is unloaded (without popping bead bed material), the air distributor 015 is used at a maximum fluidized bed airflow of 6160.9 Nm³. 3 At 1000 h, the bed resistance is only 49 Pa, while using a DC-type air distributor with 10485 Φ2mm holes distributed in a triangular pattern (opening rate of 15.51%), the bed resistance is 1580 Pa. The bed resistance comparison test shows that the resistance of the air distributor 015 described in this invention is significantly lower than that of the existing cylindrical hole DC-type air distributor. This is the key factor that significantly reduces the drying energy consumption of the flue gas detonator fluidized bed drying system and unit and its working method described in this invention.

[0053] A series of drying tests were conducted on the fluidized bed drying system and unit for tobacco burst beads described in this invention, as well as its working method. The wet bead loading was 65-85 kg / batch, and the burst bead size was 3.4-2.65 mm, including water-washed beads and oil-impregnated beads (oil-impregnated beads were only centrifuged for oil removal). The test results showed that the drying time was 1.6-2.5 hours and the power consumption was 20-25 kw·h. Compared with the existing drying equipment and process for tobacco burst beads, the drying efficiency and energy utilization rate were greatly improved. At the same time, due to the adoption of closed-loop circulation drying and continuous in-situ degradation by ultraviolet light, the volatile odor on the working surface was significantly reduced.

[0054] The working principle of the present invention: In embodiment 1, during the drying process, the drying airflow operates in a closed-loop circulation mode within the unit. In the embodiment of the fluidized bed drying device 01, the popping beads are in full-surface contact with the drying airflow in a uniformly expanded fluidized bed with a large aspect ratio, and in a long airflow path, so as to realize the momentum transfer between the popping beads and the airflow, the heat transfer of the latent heat absorbed by the popping beads from the airflow, and the mass transfer of the moisture evaporated from the popping beads to the airflow. In embodiment 2, the air distributor 015 is implemented by combining a regular hexagonal honeycomb structure with a suitable height and aperture with a screen structure, which generates a guiding and pre-distributing effect on the dry airflow entering the bed with extremely low resistance, so that the fluidized bed forms a good initial fluidization state, and the particles are uniformly fluidized and have sufficient gas-solid contact in the bed. In embodiment 3, the ultraviolet light odor degrader 02 of the fluidized bed dryer uses ultraviolet light irradiation to photodegrade the volatile odors of organic compounds with carbon-hydrogen and carbon-carbon double bonds in the closed-loop circulating drying airflow, destroying the molecular "skeleton" and achieving continuous in-situ degradation. The photodegradation products combine with water vapor to form hydrolysis products, which are discharged from the fluidized bed dryer unit with condensate. In implementation method 4, the closed-loop total heat recovery heat pump 03 adopts a dual closed-loop implementation method of direct expansion multi-stage evaporation, heat recovery cycle heat energy closed loop and dry airflow closed loop. In the dry airflow closed loop circulation system, evaporation-condensation total heat recovery is carried out to continuously provide low-humidity hot airflow to the closed loop circulation drying system with low energy consumption. In embodiment 5, during the drying process, the analog main air valve 07 is in the open state, and the analog fresh air valve 06 and the analog exhaust valve 08 are in the closed state. When the unit needs to be cleaned and deodorized, in addition to using CIP in-situ cleaning, the unit can be air-swept cleaned by coordinating the opening of the analog fresh air valve 06, the analog main air valve 07 and the analog exhaust valve 08.

[0055] The fan 04 is controlled by a frequency converter to ensure that the flow rate of the fan 04 meets the fluidization velocity requirements of the fluidized bed, and the fluidization velocity is within the range of critical fluidization velocity and limiting fluidization velocity. In summary, this invention extends the contact path between particles and airflow through a uniformly expanded bed with a large aspect ratio. By combining a hexagonal honeycomb structure with appropriate height and pore size with a sieve structure, the drying airflow generates a pre-distribution effect with extremely low resistance, ensuring uniform fluidization and sufficient gas-solid contact of the particles within the bed. Ultraviolet irradiation photodegrades and breaks down volatile odors in the closed-loop drying airflow, achieving continuous in-situ degradation. A closed-loop total heat recovery heat pump provides low-humidity and high-temperature airflow to the closed-loop drying system with low energy consumption. Drying results for tobacco capsules show that a wet capsule loading of 65-85 kg / batch, a drying time of 1.6-2.5 hours, and a power consumption of 20-25 kWh are achieved.

[0056] The first technical problem solved by this invention is that, based on the fluidization velocity corresponding to uniformly sized spherical particles, the fluidized bed above the air distributor is designed as a uniform-diameter cylinder throughout. The spherical particles can achieve uniform fluidization along the entire length of the cylinder, enabling the fluidized bed to reach or approach a stable, dispersed fluidization state with uniform gas-solid mixing. This eliminates the uneven airflow distribution, particle agglomeration and turbulence, and poor stability of the "three-transmission" (air, gas, and airflow) caused by fluidization velocity fluctuations due to cross-sectional area changes in the conical section. Uniform fluidization creates conditions for using a high aspect ratio expansion bed, which can extend the contact path between the burst beads and the airflow, thereby enhancing the "three-transmission" effect within the bed and improving drying efficiency. The second technical problem solved by this invention is to replace the existing direct-flow air distributor with triangularly distributed cylindrical small holes using a composite hexagonal honeycomb structure and a screen structure of suitable height, including replacing the tongue-shaped orifice side-flow air distributor used for fluidized bed drying of burst beads in tobacco products. The air distributor, featuring a composite screen with a certain height and a hexagonal honeycomb structure, not only provides excellent pre-distribution and guidance for the drying airflow entering the bed but also exhibits superior low-resistance characteristics. This ensures a good initial fluidization state in the fluidized bed, allowing particles to be uniformly fluidized within the bed and forming a good gas-solid contact state. This overcomes the shortcomings of existing fluidized bed dryers for tobacco granules, such as high resistance, high energy consumption, and weak pre-distribution and guidance effects. The third technical problem solved by this invention is the use of a low-humidity, hot airflow provided by a multi-effect closed-loop heat pump as the coupling medium for fluidized bed drying. The fluidized bed unit, including the fluidized bed device, heat pump, fan, and airflow regulating valve, forms a closed-loop circulation system for the drying airflow. Using a heat pump and a closed-loop circulation system further reduces energy consumption, improving the high energy consumption and environmentally unfriendly odor caused by the use of convection heating and open-circuit direct exhaust in existing granule drying devices. The fourth technical problem solved by this invention is the accumulation of volatile odors in the airflow of the closed-loop circulating drying system used in fluidized bed dryers. This is addressed by using ultraviolet light to continuously degrade the circulating drying airflow in situ. Specifically, high-energy photons from ultraviolet light photolyze and break down the carbon-hydrogen and carbon-carbon double bonds in volatile organic compounds, disrupting the molecular "skeleton" and achieving photodegradation. The photodegradation products readily combine with water vapor to form hydrolysis products, which are then discharged from the drying system with the condensate, thus reducing odors at the work surface and lowering the environmental impact.

[0057] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0058] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A fluidized bed drying system for tobacco capsules, characterized in that: The device includes a fluidized bed dryer (01), a fluidized bed dryer UV odor degrader (02), a closed-loop total heat recovery heat pump (03), and a fan (04). The top outlet of the fluidized bed dryer (01) is connected to the inlet of the fluidized bed dryer UV odor degrader (02) via a pipe. The outlet of the fluidized bed dryer UV odor degrader (02) is connected to the inlet of the closed-loop total heat recovery heat pump (03) via a pipe and the fan (04). The outlet of the closed-loop total heat recovery heat pump (03) is connected to the lower inlet of the fluidized bed dryer (01) via a pipe.

2. The fluidized bed drying system for tobacco capsules as described in claim 1, characterized in that: The connecting pipe between the fan (04) and the closed-loop total heat recovery heat pump (03) is equipped with an analog main air valve (07) and an analog exhaust valve (08) in sequence. A simulated fresh air valve (06) is installed on the connecting pipe between the closed-loop total heat recovery heat pump (03) and the fluidized bed drying device (01). The analog fresh air valve (06) is equipped with a fresh air filter (05).

3. The fluidized bed drying system for tobacco capsules as described in claim 1, characterized in that: The fluidized bed drying device (01) includes an air outlet hood (011), a diffuser (013), a fluidized bed cylinder (014), an air distributor (015), and an air inlet base (017). The diffuser (013) and the air distributor (015) are respectively located at the upper and lower ends of the fluidized bed cylinder (014). The air outlet hood (011) is located on the diffuser (013), and the air inlet base (017) is located below the air distributor (015). An isolation net (012) is provided between the air outlet hood (011) and the diffuser (013).

4. The fluidized bed drying system for tobacco capsules as described in claim 3, characterized in that: A lifting cylinder seat (016) is provided between the air distributor (015) and the air inlet base (017).

5. The fluidized bed drying system for tobacco capsules as described in claim 3, characterized in that: The fluidized bed cylinder (014) is a straight cylinder with a constant diameter. The ratio of the diameter D1 of the diffuser cylinder (013) to the diameter D0 of the fluidized bed cylinder (014) is D1 / D0 = 1.2~3. The cone angle of the diffuser cylinder (013) is α, which ranges from 20° to 180°. The ratio of the height H of the fluidized bed cylinder (014) to the diameter D0 of the fluidized bed cylinder (014) is H / D0 = 1~10.

6. The fluidized bed drying system for tobacco capsules as described in claim 3, characterized in that: The air distributor (015) includes a support net (0151), a support ring (0152), and a honeycomb cylinder (0153), wherein the support net (0151) is above the support ring (0152), and the support ring (0152) is above the honeycomb cylinder (0153).

7. The fluidized bed drying system for tobacco capsules as described in claim 6, characterized in that: The mesh size of the aforementioned support net (0151) is 2 mesh to 150 mesh; The honeycomb tube (0153) contains a honeycomb structure (01531), which is a regular hexagon. The side length b of the regular hexagon ranges from 0.8 mm to 49.6 mm, the diameter d of the circumscribed circle (outer circle) of the regular hexagon ranges from 1.6 mm to 99.2 mm, and the axial height h of the honeycomb structure (01531) ranges from 10 mm to 300 mm.

8. The fluidized bed drying system for tobacco capsules as described in claim 1, characterized in that: The fluidized bed drying ultraviolet light odor degrader (02) includes a reflector tube (021), a vacuum ultraviolet lamp tube (022) and a quartz glass tube (023). The reflector tube (021) is sleeved on the outside of the quartz glass tube (023). The vacuum ultraviolet lamp tube (022) is located between the reflector tube (021) and the quartz glass tube (023). Both ends of the quartz glass tube (023) are provided with air inlet and outlet pipes (024). The two air inlet and outlet pipes (024) pass through the two ends of the reflector tube (021) respectively.

9. The fluidized bed drying system for tobacco capsules as described in claim 8, characterized in that: On the cross-section perpendicular to the axis of the ultraviolet light odor degrader (02) of the fluidized bed dryer, the wall surface of the reflector tube (021) corresponding to the vacuum ultraviolet lamp tube (022) is a parabolic surface. The vacuum ultraviolet lamp tube (022) is located at the focus of the parabola. The ultraviolet rays radiated by the vacuum ultraviolet lamp tube (022) are reflected parallel to the parabolic surface of the reflector tube (021) towards the drying airflow inside the quartz glass tube (023).

10. A method of operating the fluidized bed drying system for tobacco capsules as described in any one of claims 1 to 9, characterized in that: The following implementation methods are included: During the drying process, the drying airflow passes through the fluidized bed drying device (01), the fluidized bed drying ultraviolet light odor degrader (02), the closed-loop total heat recovery heat pump (03) and the fan (04) in sequence and circulates in a closed loop. In the airflow path within the fluidized bed drying device (01), the smoke-filled beads in the fluidized bed drying device (01) come into full-surface contact with the drying airflow, thereby achieving momentum transfer between the smoke-filled beads and the airflow, heat transfer from the latent heat absorbed by the smoke-filled beads from the airflow, and mass transfer from the evaporation of moisture in the smoke-filled beads to the airflow. The air distributor (015) provides a pre-distribution effect for the drying airflow entering the bed with extremely low resistance, thereby enabling the fluidized bed to form a good initial fluidization state, and the particles achieve uniform fluidization and sufficient gas-solid contact within the bed. The fluidized bed dryer (02) uses ultraviolet light to irradiate the volatile organic compounds with carbon-hydrogen and carbon-carbon double bonds in the closed-loop circulating drying airflow, photodegrading the chain and destroying the molecular "skeleton" to achieve continuous in-situ degradation. The photodegradation chain products combine with water vapor to form hydrolysis products, which are discharged from the fluidized bed dryer with condensate. The closed-loop total heat recovery heat pump (03) adopts a dual closed-loop implementation method with direct expansion multi-stage evaporation, heat energy closed loop and dry airflow closed loop. In the dry airflow closed loop, evaporation-condensation total heat recovery is carried out, and low-humidity hot airflow is continuously provided to the closed loop flue gas dewatering system with low energy consumption.

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