Tobacco stem moistening process based on ultrasonic synergistic centrifugal reinforcement

Abstract

The invention discloses a tobacco stem moistening process based on ultrasonic synergistic centrifugal reinforcement, and relates to the technical field of cigarettes. The tobacco stem moistening technology based on ultrasonic wave synergistic centrifugal strengthening comprises the steps that tobacco stems are mixed with water, the tobacco stems are treated through ultrasonic waves, and the tobacco stems are flexibly ground in the ultrasonic treatment process; the tobacco stems subjected to ultrasonic treatment are subjected to centrifugal treatment; and the moisture content of the tobacco stems subjected to centrifugal treatment is adjusted to a target value. According to the technical scheme, the ultrasonic wave-flexible rolling and collaborative centrifugation technology is adopted, permeation resistance double barriers are broken through, three-level optimization of surface wall breaking, gradient permeation and accurate water control is achieved, the tobacco stems with the uniform water content are obtained, the stem moistening time is short, and energy consumption is low.

Description

Technical Field

[0001] The present invention relates to the technical field of cigarettes, and particularly to a process for conditioning tobacco stems based on ultrasonic wave synergistic centrifugal strengthening. Background Art

[0002] Conditioning of tobacco stems is an important process in tobacco processing, mainly used to adjust the moisture content and physical state of tobacco stems, making them more suitable for subsequent processing (such as cutting, expanding, etc.), and improving the quality of the final tobacco products at the same time.

[0003] Currently, in cigarette factories, the "two-conditioning and two-storage" process is mainly used for conditioning tobacco stems. Specifically, for the first conditioning, water at 40 - 50°C is used to condition the tobacco stems for 1 - 2 hours to rapidly increase the humidity on the surface layer; for the first storage, it is stored for 4 - 6 hours under the condition of an environmental humidity of 80 - 85% for the initial moisture balance; for the second conditioning, vacuum negative pressure treatment is carried out for 20 - 40 minutes for deep penetration strengthening; for the second storage, it is stored for 6 - 8 hours for stable final moisture.

[0004] The existing conditioning process of tobacco stems relies on natural penetration or high-temperature steam, which takes a long time, consumes high energy, and has low core layer penetration efficiency, resulting in uneven moisture content distribution of tobacco stems. Summary of the Invention

[0005] The main object of the present invention is to propose a process for conditioning tobacco stems based on ultrasonic wave synergistic centrifugal strengthening, aiming to solve the problems of long time, high energy consumption, and uneven moisture content distribution of the existing tobacco stem conditioning process.

[0006] To achieve the above object, the present invention proposes a process for conditioning tobacco stems based on ultrasonic wave synergistic centrifugal strengthening, including the following steps:

[0007] Mix the tobacco stems with water, subject the tobacco stems to ultrasonic treatment, and perform flexible rolling on the tobacco stems during the ultrasonic treatment;

[0008] Centrifuge the tobacco stems after ultrasonic treatment;

[0009] Adjust the moisture content of the tobacco stems after centrifugation to the target value.

[0010] Optionally, during flexible rolling, the pressure acting on the tobacco stems is 0.1 - 0.5 N / cm 2 .

[0011] Preferably, during flexible rolling, the pressure acting on the tobacco stems is 0.3 - 0.4 N / cm 2 .

[0012] Optionally, a pressing plate is used to perform flexible rolling on the tobacco stems, and a silica gel layer or a rubber layer is provided on a surface of the pressing plate in contact with the tobacco stems.

[0013] Optionally, the pressing plate uses an intermittent rolling method to flexibly roll the tobacco stems, and the rolling frequency is 5 - 10 times / min, and the duration of each rolling is 3 - 6 s.

[0014] Preferably, the rolling frequency is 5 - 6 times / min.

[0015] Optionally, the frequency during ultrasonic treatment is 20 - 40 kHz, and the treatment time is 5 - 30 min.

[0016] Optionally, the rotation speed during centrifugal treatment is 500 - 1500 rpm, and the treatment time is 5 - 20 min.

[0017] Preferably, the rotation speed during centrifugal treatment is 1200 rpm.

[0018] Optionally, a fluidized bed dryer is used to adjust the moisture content of the tobacco stems after centrifugal treatment to 30 - 40%.

[0019] Optionally, before ultrasonic treatment, washing the tobacco stems is also included.

[0020] In the technical solution of the present invention, ultrasonic treatment is used for the tobacco stems. Through the cavitation effect, the waxy layer on the surface of the tobacco stems is destroyed to form microchannel pores, and the internal tissue structure of the tobacco stems is also loosened, enhancing the penetration of water. During the ultrasonic treatment process, accompanied by the flexible rolling of the tobacco stems, the tobacco stems can be immersed in water more fully. And the flexible rolling can ensure the effect of ultrasonic treatment under the condition of not damaging the surface structure of the tobacco stems and maintaining the integrity of the tissue structure of the tobacco stems. The tobacco stems immersed in water have a certain elasticity after absorbing water. Flexibly rolling the tobacco stems in water is equivalent to applying an external force of elastic deformation to the tobacco stems. During the ultrasonic treatment process, the flexible rolling helps to more fully destroy the waxy layer on the surface of the tobacco stems, form more uniform microchannel pores, and also promote the internal tissue structure of the tobacco stems to be looser, further enhancing the penetration of water.

[0021] Centrifugal treatment is carried out on the tobacco stems with microchannel pores and a relatively loose internal tissue structure. Centrifugal treatment can not only achieve solid-liquid separation, enabling the free water on the surface layer of the tobacco stems to separate, but also the pressure gradient formed by the centrifugal force on the tobacco stems can accelerate the migration of water along the microchannel pores and the loose tissue structure to the core layer, so as to improve the uniformity of the moisture content distribution of the tobacco stems. The moisture content of the tobacco stems after centrifugal treatment is adjusted by drying to meet the usage requirements.

[0022] The technical solution of the present invention breaks through the double barriers of penetration resistance by adopting ultrasonic - flexible rolling and coordinating with the centrifugal process, realizes the three - level optimization of "surface cell wall breaking - gradient penetration - precise water control", obtains tobacco stems with a relatively uniform moisture content distribution, and has a short stem - moistening time and low energy consumption. Description of the Drawings

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the structures shown in these drawings.

[0024] Figure 1 It is a schematic flow chart of a tobacco stem conditioning process based on ultrasonic wave synergistic centrifugation strengthening provided by the present invention;

[0025] Figure 2 It is a schematic structural diagram of an embodiment of the ultrasonic treatment device provided by the present invention.

[0026] Explanation of the reference numerals in the drawings:

[0027] 1. Ultrasonic treatment device; 11. Tank; 12. Ultrasonic transducer; 13. Jacket; 131. Water inlet; 132. Water outlet; 14. Liquid level sensor; 15. Pressing plate; 151. Silicone layer; 16. Water inlet pipe; 161. Control valve.

[0028] The realization, functional features and advantages of the object of the present invention will be further described with reference to the embodiments and the drawings. Detailed embodiments

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0030] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present invention, the directional indications are only used to explain the relative position relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0031] In addition, if the embodiments of the present invention involve descriptions such as "first" and "second", the descriptions of "first", "second", etc. are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel scenarios. Taking "A and / or B" as an example, it includes Scenario A, or Scenario B, or the scenario where both A and B are satisfied simultaneously. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0032] Please refer to Figure 1 , the present invention provides a process for conditioning tobacco stems based on ultrasonic wave synergistic centrifugation enhancement, comprising the following steps: mixing tobacco stems with water, subjecting the tobacco stems to ultrasonic treatment, and performing flexible rolling on the tobacco stems during the ultrasonic treatment; subjecting the tobacco stems after ultrasonic treatment to centrifugation treatment; and adjusting the moisture content of the tobacco stems after centrifugation treatment to a target value.

[0033] In the technical solution of the present invention, the tobacco stems and water are added into the tank 11 of the ultrasonic treatment device 1, the frequency of the ultrasonic wave is controlled to be 20 - 40 kHz, the power density is 0.1 - 1.0 W / cm 3 (power density = ultrasonic output power / volume of the tank), the water temperature is 30 - 50 °C, and the ultrasonic treatment is performed for 5 - 30 min. And during the ultrasonic treatment, the tobacco stems are flexibly rolled by the pressing plate 15. Through the cavitation effect of the ultrasonic wave and the flexible rolling of the pressing plate 15, the waxy layer on the surface of the tobacco stems is more fully damaged, and the inner structure is loosened, facilitating the more sufficient penetration of moisture into the core layer during subsequent centrifugation treatment, so that the moisture distribution is more uniform.

[0034] It should be noted that in the present invention, refer to Figure 2, the ultrasonic transducer 12 of the ultrasonic treatment device 1 is arranged in the sandwich structure at the bottom of the tank 11, and the ultrasonic transducer 12 is connected to the ultrasonic generator. A jacket 13 is arranged on the outer wall of the tank 11. The jacket 13 has a water inlet 131 and a water outlet 132. Water at 30 - 50 °C enters the jacket 13 through the water inlet, flows in the jacket 13, and flows out through the water outlet. The water in the jacket 13 circulates in this way to control the water temperature in the tank 11 at 30 - 50 °C. A liquid level sensor 14 is arranged in the tank 11, and the liquid level sensor 14 is arranged adjacent to the inner wall of the tank 11 to detect the liquid level in the tank 11. The liquid level sensor 14 is communicatively connected to the PLC control device to transmit the detected liquid level to the PLC control device. An inlet pipe 16 is arranged at the upper part of the tank 11, and a control valve 161 is arranged on the inlet pipe 16. The control valve 161 is electrically connected to the PLC control device. During the ultrasonic treatment process, if the liquid level in the tank 11 is too low, the PLC control device controls the control valve 161 to be in the open state to replenish water into the tank 11 until the liquid level reaches the initial liquid level, and then the PLC control device controls the control valve 161 to be in the closed state. In this way, it is ensured that there is sufficient water in the tank 11, thus ensuring the effect of ultrasonic treatment.

[0035] It can be understood that during the ultrasonic treatment process, the pressing plate 15 is used to perform flexible rolling on the tobacco stems. In the initial state, the pressing plate 15 is located above the tank 11. During the ultrasonic treatment, the pressing plate 15 is controlled to move downward to press the tobacco stems floating on the water surface into the water, and flexible rolling can also be performed on the tobacco stems in the water to ensure the effect of ultrasonic treatment. When the pressing plate 15 extends into the tank 11, there is a gap between the outer side wall of the pressing plate 15 and the inner side wall of the tank 11, which can not only avoid interference between the pressing plate 15 and the devices in the tank 11, such as the liquid level sensor 14, during the up and down movement, but also perform better flexible rolling on the tobacco stems in the tank 11. The pressing plate is coaxially arranged with the tank, and the contour of the pressing plate is adapted to the inner cavity cross-section of the tank. For example, if the inner cavity of the tank is a cylindrical structure with an open upper end and hollow, then the pressing plate is a cylindrical structure. When the pressing plate extends into the tank, the gap formed between the outer side wall of the pressing plate and the inner side wall of the tank is in a circular ring shape, and the circular ring-shaped gap should not be too large, just large enough to accommodate the devices in the tank such as the liquid level sensor.

[0036] After centrifugal treatment, the moisture content of the tobacco stems is generally higher than 50%. A fluidized bed dryer is used to adjust the moisture content of the centrifuged tobacco stems to 30 - 40% to better meet the usage requirements. Among them, during the drying process, hot air with a temperature not exceeding 50 °C is sent into the fluidized bed to adjust the moisture content of the tobacco stems and avoid damage to the internal quality of the tobacco stems due to high temperature.

[0037] Furthermore, during flexible rolling, the pressure acting on the tobacco stems is 0.1 - 0.5 N / cm 2By controlling the pressure acting on the tobacco stems, flexible rolling can be better achieved, enabling the tobacco stems to be more fully immersed in water. Under the condition that the flexible rolling does not damage the epidermal structure of the tobacco stems and maintains the integrity of the tissue structure of the tobacco stems, the effect of ultrasonic treatment is ensured.

[0038] It should be noted that a silica gel layer 151 or a rubber layer is provided on the surface of the pressing plate 15 in contact with the tobacco stems. By adopting the elastic silica gel layer 151 or rubber layer, it is ensured that the epidermal structure of the tobacco stems is not damaged, and internal fracture of the tobacco stems caused by rigid contact is avoided.

[0039] Specifically, the pressing plate 15 performs flexible rolling on the tobacco stems in an intermittent rolling manner, and the rolling frequency is 5 - 10 times / min, and the duration of each rolling is 3 - 6 s. By adopting a rolling method of 5 - 10 times per minute and controlling the duration of each rolling to be 3 - 6 s, the tobacco stems in the groove 11 can be more fully rolled.

[0040] It can be understood that "the duration of each rolling is 3 - 6 s" refers to the time when the pressing plate 15 applies pressure to the tobacco stems. After each rolling, the pressing plate 15 moves upward away from the tobacco stems until it resets. When the next rolling is performed, the pressing plate 15 moves downward to act on the tobacco stems. During the resetting process of the pressing plate 15 and when it enters the groove 11, the tobacco stems in the groove 11 are disturbed, which can promote the ultrasonic treatment effect.

[0041] Furthermore, the tobacco stems are subjected to centrifugal treatment in a centrifuge. During centrifugal treatment, the rotation speed of the centrifuge is controlled to be 500 - 1500 rpm (rpm refers to revolutions per minute), and the treatment time is 5 - 20 min. Specifically, the centrifuge can be a basket centrifuge or a horizontal centrifuge, or other types of centrifuges can also be used. This application does not limit it here.

[0042] Furthermore, before ultrasonic treatment, washing the tobacco stems is also included. Before ultrasonic treatment, the tobacco stems are immersed in warm water at 40 - 50 °C for 2 - 4 min to remove impurities such as sediment on the surface of the tobacco stems. After immersion, filtration is performed to achieve solid-liquid separation to obtain the tobacco stems. The tobacco stems and water are added to the groove 11 of the ultrasonic treatment device 1 for ultrasonic treatment.

[0043] The technical solutions of the present invention will be further described in detail below in conjunction with specific embodiments and the accompanying drawings. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0044] Embodiment 1

[0045] A tobacco stem conditioning process based on ultrasonic wave synergistic centrifugal strengthening includes the following steps:

[0046] Provide reconstituted tobacco stems from central Yunnan. The moisture content of the tobacco stems is 12%, the length of the tobacco stems is 10 - 15 mm, and the diameter is 4 - 6 mm. Immerse the tobacco stems in water at 40°C for 3 minutes, filter to achieve solid-liquid separation, and obtain the washed tobacco stems.

[0047] Add 10 kg of the washed tobacco stems and 80 kg of water to the tank of the ultrasonic treatment device. Control the frequency of the ultrasonic wave to be 28 kHz and the power density to be 0.4 W / cm 3 , and the temperature of the circulating water entering the jacket is 40°C to carry out ultrasonic treatment. During the ultrasonic treatment, the pressing plate (with a silica gel layer at the bottom) presses the tobacco stems in the tank with a pressure of 0.3 N / cm 2 for flexible rolling. The rolling frequency is 6 times / min, and the duration of each rolling is 5 s. Carry out ultrasonic treatment for 5 minutes.

[0048] To ensure sufficient water in the tank, during the ultrasonic treatment, water needs to be replenished into the tank. The water replenishment condition: After the washed tobacco stems and water are put into the tank, the initial liquid level h1 in the tank is used as the reference liquid level. During the ultrasonic treatment, if it is detected that the liquid level h2 in the tank is lower than the initial liquid level h1, and the difference between h2 and h1 reaches 1 / 8 h0 (h0 is the depth of the tank), then water is replenished into the tank until the liquid level reaches the initial liquid level, and the water replenishment into the tank stops.

[0049] After ultrasonic treatment, carry out solid-liquid separation to obtain the tobacco stems after ultrasonic treatment. Put the tobacco stems after ultrasonic treatment into a basket centrifuge, control the rotation speed of the centrifuge to be 1200 rpm, and carry out centrifugation for 10 minutes.

[0050] Put the centrifuged tobacco stems into a fluidized bed, and input hot air at 40°C into the fluidized bed to adjust the moisture content of the tobacco stems to 35%.

[0051] Examples 2 - 4

[0052] Examples 2 - 4 are based on Example 1, and the difference is that the pressure during flexible rolling is different, and the others are the same as Example 1.

[0053] Example 2: The pressure during flexible rolling is 0.1 N / cm 2 .

[0054] Example 3: The pressure during flexible rolling is 0.4 N / cm 2 .

[0055] Example 4: The pressure during flexible rolling is 0.5 N / cm 2 .

[0056] Examples 5 - 6

[0057] Examples 5 to 6 are based on Example 3, the difference being that the frequency of flexible rolling is different, and the others are the same as Example 3.

[0058] Example 5: The frequency of flexible rolling is 5 times / min.

[0059] Example 6: The frequency of flexible rolling is 8 times / min.

[0060] Examples 7 to 8

[0061] Examples 7 to 8 are based on Example 3, the difference being that the rotation speed of the centrifuge is different during centrifugation, and the others are the same as Example 3.

[0062] Example 7: During centrifugation, the rotation speed of the centrifuge is 500 rpm.

[0063] Example 8: During centrifugation, the rotation speed of the centrifuge is 1500 rpm.

[0064] Comparative Example 1

[0065] This comparative example is based on Example 1, the difference being that it does not include the flexible rolling step, that is, during ultrasonic treatment, the tobacco stems are not flexibly rolled, and the others are the same as Example 1.

[0066] Performance test

[0067] The time, energy consumption consumed by the tobacco stem conditioning process in Examples 1 to 8 and Comparative Example 1, and the moisture content CV value of the tobacco stems after conditioning are detected, and the detection results are shown in Table 1 below.

[0068] Table 1 Conditioning consumption time, energy consumption, and tobacco stem moisture content CV value

[0069]

[0070]

[0071] It can be seen from the test results in Table 1 that the tobacco stem conditioning process proposed in this application uses ultrasonic - flexible rolling and coordinates with the centrifugation process to break through the double barriers of penetration resistance, achieve three - level optimization of "surface cell wall breaking - gradient penetration - precise water control", obtain tobacco stems with relatively uniform moisture content, and has a short conditioning time and low energy consumption.

[0072] Examples 1 to 4 investigated the influence of the pressure during flexible rolling on the conditioning uniformity. If the force during flexible rolling is too low, the effect of ultrasonic cell wall breaking cannot be well enhanced, affecting the uniformity of the final moisture content; if the force during flexible rolling is too high, it is easy to damage the epidermal structure of the tobacco stems. Therefore, in this application, the pressure during rolling is controlled to be 0.1 - 0.5 N / cm 2, so as to better achieve flexible rolling and thus strengthen the effect of ultrasonic cell wall breaking.

[0073] Based on Example 3, Examples 5-6 investigated the influence of the frequency of flexible rolling on the water content uniformity of tobacco stems during conditioning. The effects of rolling 6 times and 8 times per minute were relatively close. However, the energy consumption caused by rolling 8 times per minute was higher than that of 6 times. Therefore, Example 3 is the preferred example. Based on Example 3, Examples 7-8 investigated the influence of the rotation speed of the centrifuge on the uniformity of water distribution during centrifugation. If the rotation speed of the centrifuge is too low, it cannot penetrate sufficiently into the core layer, thus affecting the uniformity of water distribution. Since penetration takes time, if the rotation speed of the centrifuge is too high, some water will leave the tobacco stem quickly before it has fully penetrated into the core, which will also affect the distribution of water.

[0074] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the patent protection scope of the present invention.

Claims

1. A tobacco stem moistening process based on ultrasonic assisted centrifugal strengthening, characterized in that: The following steps are involved: The tobacco stems are mixed with water, ultrasonically treated, and the tobacco stems are flexibly rolled during the ultrasonic treatment; The tobacco stems after ultrasonic treatment are centrifuged; Adjust the moisture content of the centrifuged tobacco stems to the target value.

2. The process for moistening tobacco stems based on ultrasonic assisted centrifugal strengthening according to claim 1, characterized in that: During flexible rolling, the pressure acting on the tobacco stem is 0.1-0.5N / cm 2 .

3. The process for moistening tobacco stems based on ultrasonic assisted centrifugal strengthening according to claim 2, characterized in that: A pressing plate is used to flexibly roll the tobacco stems, and a surface of the pressing plate in contact with the tobacco stems is provided with a silicone layer or a rubber layer.

4. The process for moistening tobacco stems based on ultrasonic assisted centrifugal strengthening according to claim 3, characterized in that: The pressing plate flexibly rolls the tobacco stems in an intermittent rolling manner, and the rolling frequency is 5 to 10 times / min, and each rolling time is 3 to 6 seconds.

5. The process for moistening tobacco stems based on ultrasonic assisted centrifugal strengthening according to claim 1, characterized in that: The frequency of ultrasonic treatment is 20 to 40 kHz, and the treatment time is 5 to 30 minutes.

6. The process for moistening tobacco stems based on ultrasonic assisted centrifugal strengthening according to claim 1, characterized in that: The rotation speed during the centrifugal treatment is 500 to 1500 rpm, and the treatment time is 5 to 20 minutes.

7. The process for moistening tobacco stems based on ultrasonic assisted centrifugal strengthening according to claim 1, characterized in that: The moisture content of the tobacco stems after centrifugal treatment is adjusted to 30-40% by a fluidized bed dryer.

8. The process for moistening tobacco stems based on ultrasonic assisted centrifugal strengthening according to claim 1, characterized in that: Before the ultrasonic treatment, the tobacco stems are also washed.

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