Method and apparatus for manufacturing reconstituted tobacco leaf sheet

Abstract

The present disclosure provides a reconstituted tobacco leaf sheet manufacturing method and device, comprising: performing a crushing treatment on fibers; performing a crushing mixing of the prepared tobacco powder and the crushed fibers to form a fiber-tobacco powder mixture; mixing the fiber-tobacco powder mixture with prepared liquid material to form a powder-liquid mixture; shaping the powder-liquid mixture into a tobacco leaf sheet; and performing a drying treatment on the tobacco leaf sheet. In the embodiment of the present disclosure, a fiber dry adding method is adopted, the fibers are directly added into the tobacco powder powder (dry material), and the fiber content in the finished tobacco leaf sheet can reach up to 5%, which greatly improves the tensile strength of the sheet, increases the loft value, and improves the processability of the sheet.

Description

Technical Field

[0001] This disclosure relates to the field of tobacco manufacturing technology, and in particular to a method and apparatus for manufacturing reconstituted tobacco flakes. Background Technology

[0002] Reconstituted tobacco sheets are made from tobacco with the addition of adhesives and other additives. See also Figure 15 As shown, the existing method for producing rolled tobacco sheets utilizes recycled tobacco waste (tobacco stems, tobacco dust, etc.), which is crushed into powder. A liquid is prepared by mixing sheet adhesive, glycerin, and fibers with water. The powder and liquid are then added to a mixing device in a specific ratio and stirred. The mixed material is then subjected to multi-stage rolling pressing to form sheets of a certain thickness. The formed sheets are dried to remove excess moisture, resulting in rolled tobacco sheets. The dried sheets are then shredded to produce tobacco shreds of a specific length and width.

[0003] The existing methods for producing tobacco sheets using the roll forming process have the following main problems: 1. The fiber is added wet, meaning it's added to the liquid material. This results in a low fiber content (1-1.5%) in the tobacco sheets, leading to low tensile strength, low bulkiness, and poor reprocessability. 2. The powder and liquid materials are mixed using a stirring method, resulting in poor homogeneity and uneven distribution of components such as glycerin, fiber, and binders within the tobacco powder. This leads to low overall sheet strength and uneven flavor. 3. The large difference in rotational speed between the two rollers during roll forming creates a kneading effect, disrupting the uniform distribution of components in the tobacco powder. Glycerin easily precipitates to the surface, resulting in high hygroscopicity and difficulty in preservation. 4. The drying method is simple but time-consuming, requiring a large drying area, which is unfavorable for the layout of large-capacity production lines. Summary of the Invention

[0004] One of the technical problems this disclosure aims to solve is that using a wet-processing method results in low fiber content, low tensile strength, low bulkiness, and poor reprocessability of tobacco sheets.

[0005] To address the aforementioned technical problems, this disclosure provides a method for manufacturing reconstituted tobacco flakes, comprising:

[0006] The fibers are pulverized.

[0007] The prepared tobacco powder is pulverized and mixed with the pulverized fiber to form a fiber-tobacco powder mixture;

[0008] The fiber tobacco powder mixture is mixed with the prepared liquid to form a powder-liquid mixture;

[0009] The powder-liquid mixture is shaped into tobacco flakes; and

[0010] The tobacco leaf flakes are dried.

[0011] In some embodiments, the prepared tobacco powder is pulverized and mixed with pulverized fibers to form a fiber-tobacco powder mixture, including:

[0012] The prepared tobacco powder and fiber are fed into the fiber pulverizer at a constant flow rate, so that the tobacco powder and fiber are initially mixed while the fiber is being pulverized.

[0013] The initially mixed tobacco powder and fiber are conveyed into a cyclone separator by air power. After processing by the cyclone separator, the initially mixed tobacco powder and fiber enter a powder homogenization bin for further mixing.

[0014] The exhaust gas separated by the cyclone separator first passes through a fiber filter to remove the fibers, and then the exhaust gas is treated by a dust removal device before being discharged.

[0015] In some embodiments, the fiber tobacco powder mixture is mixed with the prepared liquid to form a powder-liquid mixture, including:

[0016] The prepared liquid material is initially atomized to form an atomized liquid material;

[0017] A measured amount of atomizing liquid and a measured amount of fiber tobacco powder mixture are simultaneously added to a turbocharged atomizing mixing device to achieve gas-phase mixing of powder and liquid to form a powder-liquid mixture; and

[0018] The powder-liquid mixture is extruded to form a solid solution state.

[0019] In some embodiments, the prepared liquid material is initially atomized to form an atomized liquid material, including:

[0020] The prepared liquid is pressurized and delivered to an atomizing device via a screw pump for initial atomization; and

[0021] Collect flow data during the booster delivery process and control the booster delivery flow rate;

[0022] The screw pump uses frequency conversion control to achieve flow control through frequency adjustment; it collects flow data during the pressurization and conveying process, compares it with the set powder-liquid ratio process flow, and adjusts the frequency of the screw pump in real time to make the pressurization and conveying flow consistent with the set powder-liquid ratio process flow.

[0023] In some embodiments, forming the powder-liquid mixture into tobacco flakes includes:

[0024] The powder-liquid mixture is fed into a three-roller tablet press and extruded into thin tobacco flakes; and

[0025] A two-roll calender is used to calender tobacco flakes in multiple stages, making the tobacco flakes thinner step by step.

[0026] In some embodiments, a two-roll calender is used to perform five-stage calendering on tobacco leaf sheets, making the tobacco leaf sheets thinner step by step.

[0027] The thickness of the tobacco flakes is detected after the fifth stage of calendering, and the gap between the rollers of the two-roll press is adjusted in real time by the control system.

[0028] In some embodiments, drying the tobacco flakes includes:

[0029] The tobacco flakes are conveyed through a far-infrared heating drying zone, a hot air constant temperature drying zone, and a temperature and humidity balanced drying zone.

[0030] In some embodiments, the conveying device uses a perforated steel belt; the far-infrared heating drying zone uses far-infrared light to heat both sides of the perforated steel belt;

[0031] The hot air constant temperature drying zone uses hot air for heating and drying, forming hot air channels on both sides of the mesh steel belt. The upper hot air directly heats the tobacco leaf sheets, while the lower hot air heats the mesh steel belt.

[0032] The temperature and humidity balanced drying zone uses hot air for heating and drying, and introduces dehumidifying return air into the hot air. The dehumidifying return air is hot air that has been dehumidified and reused. By introducing dehumidifying return air, the moisture content in the hot air is adjusted, and the humidity of the hot air is regulated.

[0033] In some embodiments, drying the tobacco flakes further includes:

[0034] The moisture content of the dried tobacco flakes was measured; and

[0035] The system uses feedback control to adjust the temperature, air volume, and return air volume of the far-infrared heating drying zone, the hot air constant temperature drying zone, and the temperature and humidity balance drying zone in real time to automatically control the moisture content of the tobacco flakes.

[0036] To address the aforementioned technical problems, this disclosure also provides a reconstituted tobacco sheet manufacturing apparatus, comprising:

[0037] Fiber crushing device, used to crush fibers;

[0038] A powder mixing device is used to crush and mix the prepared tobacco powder with the pulverized fiber to form a fiber-tobacco powder mixture;

[0039] A powder and slurry mixing device is used to mix the fiber tobacco powder mixture with the prepared liquid to form a powder-liquid mixture;

[0040] Roll forming equipment is used to form powder-liquid mixtures into tobacco flakes; and

[0041] A drying device for drying tobacco flakes.

[0042] Through the above technical solution, the reconstituted tobacco sheet manufacturing method provided in this disclosure increases the fiber content in the sheet by dry mixing of fiber and tobacco powder, which can significantly improve the tensile strength of the sheet, increase the bulkiness value, and improve the processing performance of the sheet.

[0043] By using a gas-phase mixing method to uniformly mix the fiber tobacco powder mixture with the liquid material, the uniformity of the powder-liquid mixture is improved, thereby improving the strength, density, uniformity, and taste uniformity of the tobacco leaf sheets.

[0044] The tobacco flakes are pressed into tablets using a three-roller tablet press and then subjected to multi-stage calendering using a multi-stage two-roller tablet press. This process gradually thins the tobacco flakes, resulting in a more uniform distribution of components in the finished flakes. It also reduces the precipitation of glycerol during the rolling process, which helps improve the hygroscopicity of the finished flakes and enhances the uniformity of flavor absorption.

[0045] The drying process employs far-infrared heating drying zone, hot air constant temperature drying zone, and temperature and humidity balanced drying zone, which improves drying efficiency, reduces equipment footprint, and enhances the uniformity of moisture content in tobacco flakes, thus benefiting the subsequent storage and reprocessing of tobacco flake products. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a flowchart of the fiber dry splitting and dry processing method disclosed in this embodiment;

[0048] Figure 2 This is a flowchart of the powder-liquid-gas phase mixing method disclosed in this embodiment;

[0049] Figure 3 This is a flowchart of the tobacco sheet forming method disclosed in this embodiment;

[0050] Figure 4 This is a flowchart of the drying method disclosed in this embodiment;

[0051] Figure 5 This is a flowchart of the method for manufacturing reconstituted tobacco flakes disclosed in this embodiment;

[0052] Figure 6 This is a flowchart of the raw material pretreatment method disclosed in this embodiment;

[0053] Figure 7 This is a flowchart of the tobacco powder preparation method disclosed in this embodiment;

[0054] Figure 8 This is a flowchart of the fiber dry splitting and dry processing method disclosed in this embodiment;

[0055] Figure 9 This is a flowchart of the liquid preparation method disclosed in the embodiments of this disclosure;

[0056] Figure 10 This is a flowchart of the powder-liquid-gas phase mixing method disclosed in this embodiment;

[0057] Figure 11 This is a flowchart of the molding and drying method disclosed in this embodiment;

[0058] Figure 12 This is a flowchart of the post-processing method disclosed in this embodiment;

[0059] Figure 13 This is a schematic diagram of the structure of the three-roll tablet press disclosed in this embodiment;

[0060] Figure 14 This is a schematic diagram of the fiber dry homogenization method disclosed in this embodiment;

[0061] Figure 15 This is a flowchart of the existing method for producing tobacco sheets using the roll pressing method.

[0062] Explanation of reference numerals in the attached figures:

[0063] 1. First pressure roller; 2. Second pressure roller; 3. Third pressure roller; 4. Hopper; 5. Baffle. Detailed Implementation

[0064] The embodiments of this disclosure will be further described in detail below with reference to the accompanying drawings and examples. The detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of this disclosure by way of example, but should not be used to limit the scope of this disclosure. This disclosure can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0065] These embodiments are provided to make the disclosure thorough and complete, and to fully express the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, material composition, numerical expressions, and values ​​set forth in these embodiments should be interpreted as exemplary only and not as limiting.

[0066] It should be noted that, in the description of this disclosure, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationship, are only for the convenience of describing this disclosure 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 this disclosure. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0067] Furthermore, the terms "first," "second," and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. "Vertical" is not strictly vertical, but within the permissible margin of error. "Parallel" is not strictly parallel, but within the permissible margin of error. Terms such as "including" or "contains" mean that the element preceding the word encompasses the element listed after the word, and do not exclude the possibility of encompassing other elements as well.

[0068] It should also be noted that, in the description of this disclosure, unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" 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 direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this disclosure depending on the specific circumstances. When a particular device is described as being located between a first device and a second device, an intermediary device may or may not be present between the particular device and the first or second device.

[0069] All terms used in this disclosure have the same meaning as understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.

[0070] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0071] To address the problems in existing technologies where fibers are added wet, resulting in low fiber content, low tensile strength, low bulkiness, and poor reprocessability of tobacco sheets, such as... Figure 1 As shown, this disclosure provides a method for manufacturing reconstituted tobacco sheets, including:

[0072] The fibers are pulverized; in this embodiment, the fibers refer to added fibers, which can be a combination of high-quality softwood pulp (long fibers) and hemp pulp (short fibers). The long fibers increase the strength of the sheet, while the short fibers can form a local mesh, playing an important role in filling and retention.

[0073] The prepared tobacco powder is pulverized and mixed with the pulverized fiber to form a fiber-tobacco powder mixture;

[0074] The fiber tobacco powder mixture is mixed with the prepared liquid to form a powder-liquid mixture;

[0075] The powder-liquid mixture is shaped into tobacco flakes; and

[0076] The tobacco leaf flakes are dried.

[0077] See Figure 15 As shown, existing technologies add fibers by mixing them with sheet adhesive (binder), glycerin, and water to form a liquid. This results in low fiber content in the tobacco sheets, leading to low tensile strength, low bulkiness, and poor reprocessability. In contrast, this embodiment employs a dry fiber addition method, directly adding fibers to the tobacco powder (dry material). The fiber content in the finished tobacco sheets can reach up to 5%, significantly improving tensile strength, increasing bulkiness, and enhancing processability.

[0078] In some embodiments, see Figure 1 and Figure 8 As shown, the prepared tobacco powder is pulverized and mixed with the pulverized fibers to form a fiber-tobacco powder mixture, including:

[0079] The prepared tobacco powder and fiber are fed into the fiber pulverizer at a constant flow rate, so that the tobacco powder and fiber are initially mixed while the fiber is being pulverized. This achieves the quantitative mixing of tobacco powder and the homogeneous mixing of tobacco powder and fiber. The homogeneous mixing of tobacco powder and fiber is achieved through pulverization and mixing.

[0080] The initially mixed tobacco powder and fibers are conveyed by air into a cyclone separator. After processing by the cyclone separator, the initially mixed tobacco powder and fibers enter a powder homogenizing silo for further mixing. The pulverized and mixed fibers and tobacco powder are then buffered in the powder homogenizing silo for further mixing, achieving a second homogenization process for the fibers and tobacco powder.

[0081] The exhaust gas separated by the cyclone separator first passes through a fiber filtration device to remove the fibers, and then the exhaust gas is treated by a dust removal device before being discharged. The pulverized and mixed fibers and smoke powder are separated and then enter a powder homogenization chamber. The separated exhaust gas first passes through a fiber filtration device to remove a small amount of fibers, and then the exhaust gas is treated by a dust removal device before being discharged. The smoke powder particles in the exhaust gas can pass through the fiber filtration device and are treated by the dust removal device. Filtering the fibers before the exhaust gas undergoes dust removal treatment prevents the fibers from clogging the dust collector filter bags.

[0082] In some embodiments, the fiber pulverization process includes: using spooled fiber as raw material, feeding the spooled fiberboard into a fiber crusher at a constant rate via an unwinding device to break the fiberboard into small pieces; then, inputting it into a fiber pulverizer under negative pressure for further pulverization to achieve the required small size. The unwinding device achieves quantitative fiber feeding, the fiber crusher performs preliminary fiber crushing, and the fiber pulverizer further pulverizes the fiber. This achieves the quantitative fiber feeding, coarse fiber breaking, and fiber pulverization processes.

[0083] In some embodiments, see Figure 14 The prepared tobacco powder is pulverized and mixed with the pulverized fibers to form a fiber-tobacco powder mixture, including:

[0084] Wood pulp board is pulverized to prepare fibers with a length of 2mm-3.5mm and a coarseness of 40μm-50μm.

[0085] The prepared tobacco powder, CMC (carboxymethyl cellulose), and prepared fiber are mixed to form a fiber-tobacco powder mixture;

[0086] The fiber tobacco powder mixture is mixed with the prepared liquid to obtain a mixed slurry; and

[0087] The mixed slurry is processed to form tobacco flakes;

[0088] The fiber content in tobacco flakes is 2%-7%, and the CMC content is 3%-5%.

[0089] In this embodiment, the fibers obtained by crushing wood pulp fiberboard are directly mixed with the prepared tobacco powder, and then mixed with the prepared liquid to obtain a mixed pulp. Unlike the existing technology that adds fibers to the liquid and limits the fiber content, the dry fiber addition homogenization method can increase the fiber content in reconstituted tobacco sheets as needed, and can make the fiber ratio in reconstituted tobacco sheets reach 2%-7%.

[0090] In some embodiments, see Figure 2 As shown, the fiber tobacco powder mixture is mixed with the prepared liquid to form a powder-liquid mixture, including:

[0091] The prepared liquid material is initially atomized to form an atomized liquid material;

[0092] A measured amount of atomized liquid and a measured amount of fiber tobacco powder mixture are simultaneously added to a turbocharged atomizing mixing device to achieve gas-phase mixing of powder and liquid to form a powder-liquid mixture. The fiber tobacco powder mixture is continuously fed into the turbocharged atomizing mixing device by a powder metering feeder, which is an output device with flow metering and control functions, enabling high-precision quantitative output of powder.

[0093] The process involves extruding the powder-liquid mixture to form a solid solution state. A solid solution state refers to a state where a solid solute dissolves in a solid solvent while the material as a whole retains its solid solvent state. After the powder and liquid are mixed in the gas phase, they undergo intense extrusion, causing the powder and liquid mixture to knead and fuse together, ultimately forming a solid solution state, which facilitates subsequent processing.

[0094] In this embodiment, a fixed amount of liquid and a fixed amount of powder are simultaneously added to the turbine pressurized atomizing mixing device. Under the action of the high-speed turbine, the powder exists in a suspended state, and the liquid exists in an atomized state. The powder and liquid are in a similar gas-phase state, which optimizes their fluidity. Under the high-speed stirring action of the turbine, they are fully mixed, achieving rapid gas-phase mixing of powder and liquid. By using the gas-phase mixing method to uniformly mix the fiber tobacco powder mixture with the liquid, the uniformity of powder-liquid mixing is improved, thereby improving the strength, density, uniformity, and flavor uniformity of the tobacco leaf sheets.

[0095] In some embodiments, the prepared liquid material is initially atomized to form an atomized liquid material, including:

[0096] The prepared liquid is pressurized and delivered to an atomizing device via a screw pump for initial atomization; and

[0097] Collect flow data during the booster delivery process and control the booster delivery flow rate.

[0098] The screw pump uses frequency conversion control to achieve flow control through frequency adjustment; it collects flow data during the pressurization and conveying process, compares it with the set powder-liquid ratio process flow, and adjusts the frequency of the screw pump in real time to make the pressurization and conveying flow consistent with the set powder-liquid ratio process flow.

[0099] In this embodiment, the liquid material is pressurized and conveyed, its flow rate is measured, and then it is atomized before entering the turbocharged atomizing device. The screw pump used for pressurization is frequency-controlled, and the flow rate is controlled by adjusting the frequency. The device collects the flow rate measurement data and compares it with the set powder-liquid ratio process flow rate. It then adjusts the frequency of the pressurized screw pump in real time to make the conveying flow rate of the screw pump consistent with the process flow rate, thereby achieving high-precision quantitative output of the liquid material. The atomized liquid material undergoes secondary atomization under the action of the turbocharged atomizing mixing device, resulting in better flowability.

[0100] In some embodiments, see Figure 3 As shown, the process of molding the powder-liquid mixture into tobacco flakes includes:

[0101] The powder-liquid mixture is fed into a three-roller blister press and extruded into thin tobacco flakes; the solid solution powder-liquid mixture enters an extrusion molding machine consisting of three pressure rollers. There is a certain speed difference between the three pressure rollers, with the feeding group being faster than the discharging group. The material forms a pressure boosting effect in the internal cavity formed by the three pressure rollers, and the material is extruded into a regular sheet shape and discharged.

[0102] Furthermore, a two-roll calender is used to perform multi-stage calendering of tobacco flakes, making the tobacco flakes progressively thinner. The two-roll calender uses upper and lower pressure rollers arranged in a corresponding manner for pressing, and can also be called a vertical calendering forming machine. By adjusting the speed difference between the rollers in the vertical calendering forming machine, the speed difference between the rollers is made small, and the tobacco flakes are formed by calendering, which maximizes the uniform distribution of each component in the mixture.

[0103] In this embodiment, the tobacco flakes are first pressed using a three-roller tablet press, and then subjected to multi-stage calendering using a multi-stage two-roller tablet press. This process gradually thins the tobacco flakes, resulting in a more uniform distribution of components in the finished flakes. It also reduces glycerol precipitation during the rolling process, which improves the hygroscopicity of the finished flakes and enhances the uniformity of flavor absorption. Figure 13 As shown, the three-roll tablet press consists of a first pressure roller 1, a second pressure roller 2, a third pressure roller 3, a hopper 4, a baffle 5, and a transmission device. The first pressure roller 1 and the second pressure roller 2 form a primary roller press, creating a feeding gap &1; the second pressure roller 2 and the third pressure roller 3 form a secondary roller press, creating a discharge gap &2; wherein the feeding gap &1 is greater than the discharge gap &2. A speed difference is formed between the first pressure roller 1, the second pressure roller 2, and the third pressure roller 3 through gear transmission, with the first pressure roller speed n1 < the second pressure roller speed n2 < the third pressure roller speed n3. The material enters the feeding gap &1 from the hopper 4. By adjusting the gap and speed difference, the feeding volume is made slightly larger than the discharge volume, resulting in a pressure boosting effect within the cavity between the three pressure rollers and the baffle 5. The material is compressed and extruded into tablets through the discharge gap &2.

[0104] The first pressure roller speed n1 < the second pressure roller speed n2 causes the material to be transferred between the second pressure roller 2 and the third pressure roller 3 along with the second pressure roller 2. The second pressure roller speed n2 < the third pressure roller speed n3 causes the material to be squeezed out by the third pressure roller 3.

[0105] In some embodiments, a two-roll calender is used to perform five stages of calendering on tobacco flakes, making the tobacco flakes progressively thinner. The thickness of the tobacco flakes is measured after the fifth stage of calendering, and the gap between the pressure rollers of the two-roll calender is adjusted in real time by the control system.

[0106] In this embodiment, a thickness detection device is installed after the fifth-stage vertical calender to detect the thickness of the sheet in real time. The control system then adjusts the gap between the pressure rollers in real time to ensure that the sheet thickness is uniform.

[0107] In some embodiments, see Figure 4 As shown, the drying process for tobacco leaf flakes includes:

[0108] The tobacco flakes are conveyed through a far-infrared heating drying zone, a hot air constant temperature drying zone, and a temperature and humidity balanced drying zone.

[0109] After being formed, the tobacco flakes are dried in a drying device to remove excess moisture and ensure that the moisture content meets the process requirements. The drying process uses a far-infrared heating drying zone, a hot air constant temperature drying zone, and a temperature and humidity balanced drying zone, which improves drying efficiency, reduces equipment footprint, and improves the uniformity of moisture content in the tobacco flakes, which is beneficial for the subsequent storage and reprocessing of the tobacco flake products.

[0110] In some embodiments, the conveying device uses a perforated steel belt. The perforated steel belt serves as the sheet conveying carrier, and laser perforation is used to form a uniformly dense mesh on the stainless steel belt to facilitate the uniformity of the drying of both sides of the sheet.

[0111] The far-infrared heating and drying zone uses far-infrared light to heat both sides of the perforated steel strip. The wavelength of far-infrared light is more sensitive to moisture, causing the wet sheet to heat up rapidly and quickly reach the temperature equilibrium point for moisture evaporation.

[0112] The hot air constant temperature drying zone uses hot air for heating and drying. Hot air channels are formed on both sides of the mesh steel belt. The upper hot air directly heats the tobacco leaf sheets, while the lower hot air heats the mesh steel belt. Moisture evaporates into the hot air and is discharged through the dehumidification device. The portion of the dehumidified hot air containing higher calorific value is reused and introduced into the hot air device for secondary utilization, achieving the goal of energy saving. During this drying stage, since the heat absorbed by the hot air is equal to the heat discharged by the moisture evaporation, the heat absorption and heat discharge reach a balance, and the temperature of the sheet remains constant.

[0113] The temperature and humidity balancing drying zone uses hot air for heating and drying. Dehumidified return air is introduced into the hot air to increase its moisture content and humidity. This dehumidified return air is hot air that has been dehumidified and reused. The temperature and humidity balancing drying zone uses the same drying and dehumidification method as the hot air constant temperature drying zone, but it introduces a large amount of dehumidified return air. Because most of the moisture in the sheet has been removed during this drying stage, the moisture content on the surface and inside of the sheet is uneven, creating a large humidity gradient. By introducing dehumidified return air into the hot air, increasing its moisture content and humidity, the evaporation rate of moisture inside and outside the sheet can be effectively balanced, resulting in more uniform moisture content.

[0114] In some embodiments, drying the tobacco flakes further includes:

[0115] The moisture content of the dried tobacco flakes was measured; and

[0116] The system uses feedback control to adjust the temperature, air volume, and return air volume of the far-infrared heating drying zone, the hot air constant temperature drying zone, and the temperature and humidity balance drying zone in real time, so as to automatically control the moisture content of the tobacco leaf sheets.

[0117] In this embodiment, a moisture meter can be installed at the discharge end of the drying device to detect the moisture content of the sheets. The control system can then provide feedback control to adjust parameters such as temperature, airflow, and return airflow in each drying zone in real time, thereby achieving automatic moisture control.

[0118] To address the problems in existing technologies where fibers are added wet, resulting in low fiber content, low tensile strength, low bulkiness, and poor reprocessability of tobacco sheets, such as... Figure 14 As shown, this disclosure provides an apparatus for manufacturing reconstituted tobacco flakes, comprising:

[0119] Fiber crushing device, used to crush fibers;

[0120] A powder mixing device is used to crush and mix the prepared tobacco powder with the pulverized fiber to form a fiber-tobacco powder mixture;

[0121] A powder and slurry mixing device is used to mix the fiber tobacco powder mixture with the prepared liquid to form a powder-liquid mixture;

[0122] Roll forming equipment is used to form powder-liquid mixtures into tobacco flakes; and

[0123] A drying device for drying tobacco flakes.

[0124] The reconstituted tobacco sheet manufacturing apparatus disclosed herein adopts a dry fiber addition method, directly adding fibers to tobacco powder (dry material). The fiber content in the finished tobacco sheet can reach up to 5%, which greatly improves the tensile strength of the sheet, increases the bulkiness value, and improves the processing performance of the sheet.

[0125] In some embodiments, the powder mixing device includes a fiber pulverizer, a cyclone separator, and a filter. The fiber pulverizer, cyclone separator, and filter are connected by a conveying pipeline. The prepared tobacco powder and fibers are conveyed to the fiber pulverizer at a constant flow rate, achieving preliminary mixing of the tobacco powder and fibers while pulverizing the fibers. The preliminarily mixed tobacco powder and fibers are then conveyed by air into the cyclone separator. After processing by the cyclone separator, the preliminarily mixed tobacco powder and fibers enter a powder homogenizing chamber for further mixing. The exhaust gas separated by the cyclone separator first passes through the fiber filter to remove the fibers, and then the exhaust gas is treated by a dust removal device before being discharged.

[0126] In some embodiments, the powder and slurry mixing device includes a liquid atomizing device, a turbo-pressurized atomizing mixing device, and a powder-liquid mixture extrusion device. The liquid atomizing device is connected to the turbo-pressurized atomizing mixing device via a conveying pipe, and performs preliminary atomization of the prepared liquid to form atomized liquid. The turbo-pressurized atomizing mixing device can employ existing technology, simultaneously adding a measured amount of atomized liquid and a measured amount of fiber tobacco powder mixture into the turbo-pressurized atomizing mixing device to achieve gas-phase mixing of powder and liquid to form a powder-liquid mixture. The powder-liquid mixture extrusion device is connected to the output end of the turbo-pressurized atomizing mixing device, and extrudes the powder-liquid mixture to form a solid solution state.

[0127] In some embodiments, the liquid atomizing device includes a screw pump, a flow data acquisition unit, and a frequency converter. Both the flow data acquisition unit and the frequency converter are connected to the screw pump. The flow data acquisition unit collects the flow data of the screw pump and sends it to the frequency converter, which controls the flow rate by adjusting the frequency of the screw pump. The flow rate is compared with the set powder-liquid mixing process flow rate, and the frequency of the screw pump is adjusted in real time to ensure that the boosted delivery flow rate matches the set powder-liquid mixing process flow rate.

[0128] In some embodiments, the drying apparatus includes a perforated steel belt conveyor, a far-infrared dryer, a hot air dryer, and a dehumidification and return air device. The perforated steel belt conveyor is used to transport tobacco flakes; the far-infrared dryer is located in the far-infrared heating drying zone and arranged on both sides of the perforated steel belt. The hot air dryer is located in the hot air constant temperature drying zone and arranged on both sides of the perforated steel belt. The temperature and humidity balancing drying zone is equipped with both a hot air dryer and a dehumidification and return air device. The dehumidification and return air device dehumidifies the hot air mixed with moisture and then blows it out to mix with the hot air from the hot air dryer for reuse, adjusting the moisture content and humidity of the hot air.

[0129] In some embodiments, see Figures 5 to 12 As shown, the reconstituted tobacco sheet manufacturing method uses the following equipment for process processing: raw material pretreatment equipment, tobacco powder preparation equipment, fiber dry splitting and dry processing equipment, liquid material preparation equipment, powder-liquid-gas phase mixing equipment, forming and drying equipment, and post-processing equipment.

[0130] See Figure 6 As shown, the raw material pretreatment device is used to coarsely crush, dry, and remove impurities from tobacco powder. The tobacco powder raw materials can include whole materials (boxed tobacco flakes, long tobacco stems), loose materials (tobacco flakes, long tobacco stems), and fragmented materials (recycled fragmented tobacco stems, tobacco dust, and tobacco shreds, etc.). The processing method for whole materials is: loosening, quantitative feeding, coarse crushing, drying, impurity removal, and buffering for later use. The processing method for loose materials is: quantitative feeding, coarse crushing, drying, impurity removal, and buffering for later use. The processing method for fragmented materials is: quantitative feeding, coarse crushing, drying, impurity removal, and buffering for later use. Notably, tobacco flakes and tobacco stems are processed and stored separately.

[0131] The tobacco powder preparation apparatus is used for the proportioning, mixing, pulverizing, and buffering of sheet tobacco and stem tobacco raw materials to produce tobacco powder. (See also...) Figure 7 As shown, the method includes:

[0132] The raw materials for sheet tobacco and stem tobacco are discharged in fixed quantities, and the discharge flow rate of each is controllable and adjustable, which can achieve the raw material ratio required by the process formula;

[0133] The raw materials for sheet tobacco and stem tobacco are initially mixed during transportation, then subjected to micro-pulverization. The pulverized tobacco powder is then separated by pneumatic conveying, and the exhaust gas is discharged to a dust removal device for treatment. After screening and filtration, the tobacco powder with qualified particle size is mixed and homogenized and then buffered for later use; the coarse powder is returned for further pulverization.

[0134] To ensure continuous production, the tobacco powder preparation device is equipped with two homogenization buffer chambers. One buffer chamber is used during production, while the other is kept on standby.

[0135] The fiber dry-dissolving and dry-processing device is used for fiber crushing (also known as dry dissolving), proportioning and mixing of tobacco powder and fiber, and homogenization processes to form a fiber-tobacco powder mixture. See [link to relevant documentation]. Figure 8 As shown, the method includes:

[0136] The continuously quantitatively output fibers are crushed into small fiber pieces, which are then further pulverized.

[0137] The prepared tobacco powder is continuously and quantitatively output to the fiber pulverizer, and the tobacco powder and fiber are homogeneously mixed while the fiber is being pulverized. The adjustable amount of fiber and adjustable amount of powder are controlled by the system to achieve proportioning, mixing and homogenization in the fiber pulverization process, so as to achieve the process objective of dry addition of fiber to tobacco powder.

[0138] The pulverized and mixed fiber-smoke mixture is conveyed by wind power. After gas-solid separation, the dust-laden exhaust gas is first treated by fiber filtration to remove the fibers from the exhaust gas, and then treated by dust removal to avoid fiber clogging of the dust collector filter bag. The fiber-smoke mixture is weighed, metered, and buffered for later use.

[0139] The buffered fiber tobacco powder mixture is weighed and measured, and a certain amount of binder is added according to the proportion required by the process formula. Then it is mixed and homogenized, and buffered for later use.

[0140] To ensure continuous production, the tobacco powder preparation device is equipped with two homogenization buffer chambers. One buffer chamber is used during production, while the other is kept on standby.

[0141] The liquid preparation device is used for liquid preparation and buffering processes. Liquid refers to a liquid material formed by homogenizing and mixing water, glycerin, and flavorings. See [link to related documentation]. Figure 9 As shown, the method includes:

[0142] Water, glycerin, and fragrance are mixed, stirred, and homogenized according to the quantitative proportions of the process formula.

[0143] While the liquid is being stirred and mixed, it is also being defoamed.

[0144] Prepared liquid buffer for later use.

[0145] The powder-liquid-gas phase mixing device is used for the quantitative proportioning and gas phase mixing process of fiber tobacco powder mixtures (powder) and liquid materials. See [link to relevant documentation]. Figure 10 As shown, the method includes:

[0146] A fixed amount of powder and a fixed amount of atomized liquid are simultaneously and continuously added to the turbine pressurized atomizing mixing device; under the action of the high-speed turbine, the powder and liquid are rapidly fused in a gas-like form, realizing continuous gas-phase mixing of powder and liquid.

[0147] After the powder and liquid are mixed in the gas phase, they form extremely small particles. After being subjected to strong extrusion, the powder and liquid mixture is kneaded and fused together, finally forming a solid solution state.

[0148] The forming and drying device is used for the forming and drying process of tobacco flakes. See [link / reference]. Figure 11 As shown, the method includes:

[0149] The solid solution powder-liquid mixture is extruded into sheets by a three-roller tablet press, and then vertically rolled into sheets by a five-stage two-roller tablet press. The tobacco sheets gradually become thinner, forming wet tobacco sheets of uniform thickness.

[0150] A thickness detection device is installed after the fifth-stage calendering to detect the thickness of the sheet in real time. The control device then adjusts the gap between the pressure rollers of the fifth-stage calendering machine in real time to ensure that the sheet thickness is uniform.

[0151] The formed tobacco flakes undergo drying using a three-zone combined drying method: an infrared heating drying zone, a hot air balancing drying zone, and a temperature and humidity balancing drying zone. This method can quickly remove excess moisture from the flakes, resulting in a more uniform moisture content.

[0152] The dried tobacco flakes are tested for moisture content and thickness. The moisture content is controlled by a feedback system that adjusts parameters such as temperature, airflow, and return airflow in each drying zone in real time to achieve automatic moisture control.

[0153] The post-processing unit is used for the cooling, shredding, and winding of tobacco sheets. See [link to relevant documentation]. Figure 11 As shown, the method includes:

[0154] After the dried tobacco leaves are transported and cooled, they are shredded. The shredded tobacco is then screened to remove debris before being collected in containers.

[0155] When it is necessary to roll up the tobacco leaves, the thin sheets are rolled up.

[0156] Tension control ensures that the tobacco sheets are under appropriate tension, making it easier to cut and roll the tobacco sheets.

[0157] The embodiments of this disclosure have now been described in detail. To avoid obscuring the concept of this disclosure, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0158] While specific embodiments of this disclosure have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this disclosure. In particular, as long as there is no structural conflict, the technical features mentioned in the various embodiments can be combined in any manner.

Claims

1. A method for manufacturing reconstituted tobacco flakes, characterized in that, include: The fibers are pulverized. The prepared tobacco powder is pulverized and mixed with the pulverized fiber to form a fiber-tobacco powder mixture; The fiber tobacco powder mixture is mixed with the prepared liquid to form a powder-liquid mixture; The powder-liquid mixture is shaped into tobacco flakes; and The tobacco leaf sheets are dried. The fiber content in tobacco flakes is 2%-7%; The step of pulverizing and mixing the prepared tobacco powder with the pulverized fibers to form a fiber-tobacco powder mixture includes: The prepared tobacco powder and fiber are fed into a fiber pulverizer at a constant flow rate, so as to achieve preliminary mixing of tobacco powder and fiber while pulverizing fiber; The initially mixed tobacco powder and fibers are conveyed into a cyclone separator by air power. After being processed by the cyclone separator, the initially mixed tobacco powder and fibers enter a powder homogenization bin for further mixing. The waste gas separated by the cyclone separator first passes through a fiber filter to filter out the fibers in the waste gas, and then the waste gas is treated by a dust removal device before being discharged. The step of mixing the fiber tobacco powder mixture with the prepared liquid to form a powder-liquid mixture includes: The prepared liquid material is initially atomized to form an atomized liquid material; A measured amount of the atomizing liquid and a measured amount of the fiber tobacco powder mixture are simultaneously added to a turbocharged atomizing mixing device to achieve gas-phase mixing of powder and liquid to form the powder-liquid mixture; and The powder-liquid mixture is extruded to form a solid solution state.

2. The method for manufacturing reconstituted tobacco sheets according to claim 1, characterized in that, The step of initially atomizing the prepared liquid to form an atomized liquid includes: The prepared liquid is pressurized and delivered to an atomizing device via a screw pump for initial atomization; and Collect flow data during the booster delivery process and control the booster delivery flow rate; The screw pump is equipped with frequency conversion control, and the flow rate is controlled by frequency adjustment. The flow rate data during the pressurization and conveying process is collected and compared with the set powder-liquid ratio process flow rate. The frequency of the screw pump is adjusted in real time to make the pressurization and conveying flow rate consistent with the set powder-liquid ratio process flow rate.

3. The method for manufacturing reconstituted tobacco sheets according to claim 1, characterized in that, The step of molding the powder-liquid mixture into tobacco flakes includes: The powder-liquid mixture is fed into a three-roller tablet press and extruded into thin tobacco flakes; and A two-roll calender is used to calender tobacco flakes in multiple stages, making the tobacco flakes thinner step by step.

4. The method for manufacturing reconstituted tobacco sheets according to claim 3, characterized in that, The tobacco leaf sheets are calendered in five stages using a two-roll press, making the tobacco leaf sheets thinner step by step; The thickness of the tobacco sheet is detected after the fifth stage of calendering, and the gap between the rollers of the two-roll press is adjusted in real time by the control system.

5. The method for manufacturing reconstituted tobacco sheets according to claim 1, characterized in that, The drying process of the tobacco leaf sheets includes: The tobacco leaf sheets are conveyed sequentially through a far-infrared heating drying zone, a hot air constant temperature drying zone, and a temperature and humidity balanced drying zone.

6. The method for manufacturing reconstituted tobacco sheets according to claim 5, characterized in that, The conveying device uses a perforated steel belt, and the far-infrared heating and drying zone uses far-infrared light to heat both sides of the perforated steel belt; The hot air constant temperature drying zone uses hot air for heating and drying, and hot air channels are formed on both sides of the mesh steel belt. The upper hot air directly heats the tobacco leaf sheets, and the lower hot air heats the mesh steel belt. The temperature and humidity balanced drying zone uses hot air for heating and drying, and dehumidifying return air is introduced into the hot air to increase the moisture content and humidity of the hot air; the dehumidifying return air is hot air that has been dehumidified and reused after being mixed with moisture.

7. The method for manufacturing reconstituted tobacco sheets according to claim 6, characterized in that, The drying process for the tobacco leaf sheets further includes: The moisture content of the dried tobacco flakes was measured; and The system uses feedback control to adjust the temperature, air volume, and return air volume of the far-infrared heating drying zone, the hot air constant temperature drying zone, and the temperature and humidity balance drying zone in real time, so as to automatically control the moisture content of the tobacco leaf sheets.

8. An apparatus for manufacturing reconstituted tobacco flakes, characterized in that, The reconstituted tobacco sheet manufacturing apparatus is used to implement the reconstituted tobacco sheet manufacturing method according to any one of claims 1 to 7, and the reconstituted tobacco sheet manufacturing apparatus comprises: Fiber crushing device, used to crush fibers; A powder mixing device is used to crush and mix the prepared tobacco powder with the pulverized fiber to form a fiber-tobacco powder mixture; A powder and slurry mixing device is used to mix the fiber tobacco powder mixture with the prepared liquid to form a powder-liquid mixture; A roll forming apparatus for forming the powder-liquid mixture into tobacco flakes; and A drying device for drying the tobacco leaf sheets.

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