Method and system for controlling moisture of cut tobacco at the outlet of a two-stage cut tobacco dryer for small batch production

Abstract

The present application relates to a small batch production two-stage cut tobacco dryer outlet tobacco moisture control method and system, the raw tobacco moisture is predicted before the material head stage, and the main adjustment parameters of the production stage are determined according to the deviation between the tobacco moisture obtained in the material head stage and the inlet tobacco moisture, which can timely and quickly adjust the control mode, stabilize the key process parameters affecting the product quality and style, and realize stable control of the outlet moisture. The process target value of the outlet tobacco moisture is taken as the control target in the production stage, the influence degree of hot air speed, hot air temperature, cylinder wall two zone temperature and flow parameter on the internal quality and smoking taste of tobacco is arranged to arrange the control and adjustment order of the above process parameters, the parameters with small influence on the internal quality and smoking taste of tobacco are controlled and adjusted first, and the parameters with large influence are controlled and adjusted later, which can gradually determine the process parameters that can be fixed during production through small batch production.

Description

Technical Field

[0001] This invention relates to the field of tobacco production technology, specifically to a method and system for controlling the moisture content of tobacco shreds at the outlet of a two-stage drying machine for small-batch production. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] During the development of new cigarette products, small-batch tobacco production is conducted, utilizing existing mature production lines for testing. This ensures stable tobacco quality and reliable control parameters, preparing for subsequent mass production. Mature production lines include two-stage tobacco drying machines for drying the tobacco. These machines require a considerable amount of time to reach a steady state, resulting in a limited weight of samples with acceptable moisture content when used for small-batch tobacco production.

[0004] Meanwhile, two-stage tobacco drying machines typically control the moisture content of the exit tobacco by adjusting the cylinder wall temperature, while other parameters such as airflow and velocity are fixed. This method is suitable for mature, large-scale tobacco production processes, requiring experience accumulated from prior small-batch production to determine the control parameters for the cylinder wall temperature and the set values ​​for other parameters. However, during test production of small batches of tobacco using existing mature production lines, it is difficult to control the exit moisture content of the tobacco. Therefore, in the absence of a small-batch tobacco test line, when using existing large-batch tobacco production lines for test production, the moisture control method of the drying machine in the production line conflicts with the quality requirements of small-batch tobacco production. Summary of the Invention

[0005] To address the technical problems mentioned above, this invention provides a method and system for controlling the moisture content of tobacco shreds at the outlet of a two-stage drying machine for small-batch production. This method ensures that the moisture content of the tobacco shreds at the outlet of the drying machine meets the requirements and maintains stable processing intensity, thereby ensuring that the intrinsic quality and flavor profile of the tobacco shreds are not affected and adapting to the requirements of personalized production and experimental processing.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] The first aspect of the present invention provides a method for controlling the moisture content of tobacco shreds at the outlet of a two-stage drying machine for small-batch production, comprising:

[0008] Obtain the moisture content of the tobacco shreds at the inlet of the two-stage drying machine, determine the process target value of the tobacco shred moisture content, and gradually increase the temperature of the first and second zones of the drying machine cylinder wall to enter the material head stage;

[0009] In the material head stage, based on the deviation between the detected tobacco moisture value at the outlet of the two-stage drying machine and the process target value, and the duration of the deviation, the corresponding wind speed and temperature adjustment, second-zone cylinder wall temperature adjustment, and flow rate adjustment are respectively initiated.

[0010] During the production stage, wind speed and temperature are adjusted sequentially, followed by adjustment of the cylinder wall temperature in the second zone and flow rate.

[0011] In the tail stage, the cylinder wall temperature of the first and second zones of the two-stage filament dryer is gradually reduced, and the material is prepared for discharge under the premise of stable parameters.

[0012] Furthermore, in the feed head stage, the temperature setpoints of Zone 1 and Zone 2 of the filament drying machine cylinder wall are lower than the temperature corresponding to the process target value.

[0013] Furthermore, based on the deviation between the detected tobacco moisture content at the dryer outlet and the target process value, and the duration of this deviation, corresponding adjustments are made to the air velocity and temperature, the secondary drum wall temperature, and the flow rate. Specifically:

[0014] When the deviation between the detected moisture value of the tobacco shreds at the outlet of the drying machine and the process target value is not greater than the first set value, the temperature of the cylinder wall is controlled to the temperature corresponding to the process target value, and the wind speed and temperature adjustment stage is entered.

[0015] When the deviation between the detected value of tobacco moisture at the outlet of the drying machine and the process target value is greater than the first set value, and the deviation exceeds the set first time period, the second zone cylinder wall temperature adjustment stage is entered.

[0016] When the deviation between the detected moisture content of the tobacco shreds at the outlet of the drying machine and the process target value is greater than the second set value, and this deviation exceeds the set second time period, the flow rate adjustment stage is entered.

[0017] Furthermore, the wind speed and temperature are adjusted as follows: when the moisture content of the tobacco at the outlet of the drying machine is greater than the target value, the wind speed and temperature are increased; conversely, the wind speed and temperature are decreased.

[0018] Furthermore, the temperature regulation of the second zone cylinder wall is specifically as follows: during the third time period of continuous wind speed and temperature regulation, if the deviation between the detected value of tobacco moisture at the outlet of the drying machine and the process target value is greater than the third set value, the temperature of the second zone cylinder wall of the drying machine is controlled to rise to the temperature corresponding to the process target value, and vice versa.

[0019] Furthermore, the flow rate adjustment is as follows: the second zone cylinder wall temperature adjustment is continuously set for the fourth time period, and the deviation between the detected value of tobacco moisture at the outlet of the drying machine and the process target value is greater than the fourth set value, the mass flow rate of the feed to the drying machine is controlled to decrease, and vice versa.

[0020] Furthermore, during the flow rate adjustment period, the cylinder wall temperatures in zones one and two of the yarn drying machine are stabilized to the temperatures corresponding to the process target values.

[0021] A second aspect of the present invention provides a control system for implementing the above-described method, comprising:

[0022] The tobacco drying machine has a drum, which is divided into two zones. The tobacco shreds pass through the two zones in sequence to reach the outlet. The drum is connected to a hot air unit, which is used to provide hot air. The two zones are equipped with corresponding temperature sensors, and the hot air unit is equipped with a wind speed sensor and a wind temperature sensor.

[0023] The controller is connected to the yarn drying machine and the hot air unit. By acquiring the temperatures of the first and second zones inside the drum, as well as the wind speed and temperature of the hot air generated by the hot air unit, the controller changes the working state of the yarn drying machine.

[0024] Compared with existing technologies, one or more of the above technical solutions have the following beneficial effects:

[0025] 1. Predict the moisture content of raw tobacco before the initial feeding stage, and determine the main adjustment parameters for the production stage based on the deviation between the moisture content of the tobacco obtained at the initial feeding stage and the moisture content of the inlet tobacco. This enables timely and rapid adjustment of the control method, stabilizing key process parameters that have a significant impact on the internal quality and style of the product, and achieving stable control of the outlet moisture content.

[0026] 2. During the production stage, the target value of the moisture content of the exported tobacco is used as the control target. Based on the degree of influence of hot air velocity, hot air temperature, temperature of the second zone of the cylinder wall, and flow rate on the internal quality and taste of the tobacco, the order of controlling and adjusting the above process parameters is arranged. Parameters with less impact on the internal quality and taste of the tobacco are controlled and adjusted first, while parameters with greater impact are controlled and adjusted later. Through small-batch production, process parameters that can be fixed during the production period can be gradually determined.

[0027] 3. Compared with the existing drying machine method, the processing intensity in this embodiment remains basically stable during the production process, and the adjustment response is fast. This is conducive to maintaining the stability and consistency of the intrinsic quality and style of cigarette products during the processing. At the same time, it can realize small-batch classification processing of two-stage drying machine, providing technical means for personalized production and experimental processing of cigarette products. Attached Figure Description

[0028] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0029] Figure 1 This is a schematic diagram of the moisture control process of the tobacco shreds at the outlet of a two-stage drying machine for small-batch production, provided by one or more embodiments of the present invention. Detailed Implementation

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0031] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0032] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0033] The cylinder wall temperature is the most influential factor on the intrinsic quality and flavor profile of cigarette products among all parameters of the tobacco drying machine. Large fluctuations in cylinder wall temperature during processing mean that the intrinsic quality and flavor profile of the tobacco are unstable. Currently, in mass production of tobacco, the production control method of two-stage tobacco drying machines uses fixed parameters such as hot air damper and dehumidification damper, hot air temperature, and cylinder rotation speed, and only adjusts the cylinder wall temperature to control the moisture content of the tobacco at the outlet.

[0034] Under this method of controlling the tobacco drying machine, all parameters except the cylinder wall temperature are fixed, making it suitable for large-scale production of tobacco with stable quality. However, adjusting only the cylinder wall temperature can significantly impact the internal quality of the tobacco if the processing intensity changes during production. Therefore, in the absence of a small-batch tobacco testing line, there is a conflict between the moisture control method of the drying machine and the quality requirements of small-batch samples when using existing large-batch tobacco production lines for testing.

[0035] To address this issue, the following embodiments provide a method and system for controlling the moisture content of tobacco shreds at the outlet of a two-stage drying machine for small-batch production. This method ensures that the moisture content of the tobacco shreds at the outlet of the drying machine meets the requirements and maintains stable processing intensity, thereby ensuring that the intrinsic quality and flavor of the tobacco shreds are not affected and adapting to the requirements of personalized production and experimental processing.

[0036] Example 1:

[0037] like Figure 1 As shown, the method for controlling the moisture content of tobacco shreds at the outlet of a two-stage tobacco drying machine for small-batch production includes the following steps:

[0038] Obtain the moisture content of the tobacco shreds at the inlet of the drying machine, determine the process target value of the tobacco shred moisture content, and gradually increase the temperature of the first and second zones of the drying machine cylinder wall to enter the material head stage;

[0039] In the material head stage, based on the deviation between the detected tobacco moisture value at the outlet of the drying machine and the process target value, and the duration of the deviation, the corresponding wind speed and temperature adjustment, secondary cylinder wall temperature adjustment, and flow rate adjustment are initiated respectively.

[0040] During the production stage, wind speed and temperature are adjusted sequentially, followed by adjustment of the cylinder wall temperature in the second zone and flow rate.

[0041] In the tail stage, the temperature of the first and second zones of the drum wall of the filament dryer is gradually reduced, while the feeding speed and drum speed are increased, and the material is prepared for discharge under the premise of stable parameters.

[0042] In this embodiment, the tobacco production process includes the material head stage, the production stage and the material tail stage. The two-stage drying machine has two areas, Zone 1 and Zone 2, through which the tobacco passes in turn.

[0043] During the material head stage, the set values ​​for the cylinder wall temperature in Zone 1 and Zone 2 are lower than the temperature corresponding to the process target value, for example, by 10 degrees.

[0044] Entering the production stage, the target value for the moisture content of the exported tobacco is taken as the process target value. Based on the degree of influence of hot air velocity, hot air temperature, temperature of the second zone of the cylinder wall, and flow rate on the internal quality and taste of the tobacco, the order of controlling and adjusting the above process parameters is arranged. The general principle is to control and adjust the parameters with less impact on the internal quality and taste of the tobacco first, and control and adjust the parameters with greater impact later. Among them, the temperature of the first zone of the cylinder wall has the most significant impact on sensory quality, so it remains unchanged.

[0045] During the production phase, the process parameters are controlled and adjusted in the following order:

[0046] (1) Adjust the hot air speed and hot air temperature;

[0047] (2) When the hot air velocity and hot air temperature are adjusted for a set period of time, such as 2 minutes, and the moisture content of the tobacco at the outlet is greater than the set percentage of the process target value, such as 0.2%, adjust the temperature of the cylinder wall in Zone 2.

[0048] (3) Adjust the flow rate. After the temperature of the second zone cylinder wall is adjusted for 2 minutes, when the moisture content of the tobacco at the outlet is greater than the process target value by 0.2%, adjust the inlet flow rate of the drying machine and gradually adjust the temperature of the second zone cylinder wall to the temperature corresponding to the process target value. The temperature of the first zone cylinder wall should always be kept at the temperature corresponding to the process target value.

[0049] This embodiment achieves control through the following specific steps:

[0050] (1) Feedforward control and adjustment of wind speed. The moisture content of the tobacco at the inlet of the drying machine is detected and compared with the process requirement value. When the moisture content of the inlet tobacco is higher than the process requirement value, the wind speed is increased; otherwise, the wind speed is reduced. The wind speed is further adjusted according to the moisture content changes during the production stage.

[0051] (2) In the material head stage, the cylinder wall temperature is gradually increased while the dehumidification damper and hot air damper remain stable. When the deviation between the moisture detection value and the moisture requirement value at the drying outlet is not greater than the first set value, for example, 0.5%, the cylinder wall temperature is adjusted to the standard value and kept stable, and the hot air speed and temperature adjustment stage is entered. When the deviation between the moisture detection value and the moisture requirement value at the drying outlet is greater than the first set value, for example, 0.5%, and the moisture content of the material detected at the drying machine outlet exceeds the first set time period, for example, 2 minutes, the stage of adjusting the cylinder wall temperature in the second zone is entered. When the deviation between the moisture detection value and the moisture requirement value at the drying outlet is greater than the second set value, for example, 1%, and the moisture content of the material detected at the drying machine outlet exceeds the second set time period, for example, 2 minutes, the stage of adjusting the flow rate is entered.

[0052] (3) Production stage

[0053] First, control the hot air speed and temperature. Based on the detection data, when the moisture content of the tobacco at the outlet is greater than the process target value, control the fan speed to increase and the air temperature to rise; conversely, control the fan speed to decrease and the air temperature to drop.

[0054] Then, the second zone cylinder wall temperature control and adjustment are started. According to the detection data, when the moisture content of the tobacco at the outlet is greater than the third set value of the process target (in this embodiment, the third set value is selected as 0.2%), and the duration exceeds the set third time period (e.g., more than 2 minutes), the cylinder wall temperature is controlled to rise to the temperature corresponding to the process target value. Otherwise, the cylinder wall temperature is controlled to drop.

[0055] Finally, flow regulation is initiated. Based on the detection data, when the moisture content of the tobacco at the outlet exceeds the fourth set value of the process target (in this embodiment, the fourth set value is selected as 0.2%), and the duration exceeds the set fourth time period (e.g., more than 2 minutes), the flow rate is controlled to decrease (referring to the mass flow rate of the tobacco entering the drying machine, generally in kg / h). Conversely, the flow rate is controlled to increase. During this period, the temperature of Zone 2 is stabilized to the temperature corresponding to the process target value, and the temperature of the cylinder wall in Zone 1 is maintained at the temperature corresponding to the process target value.

[0056] (4) Material tail stage

[0057] The cylinder wall temperature in Zone 1 and Zone 2 is gradually reduced. The frequency of the feeder bottom belt and the lifting belt in front of the drum is increased, the drum speed is increased, and other parameters are stabilized in preparation for discharge.

[0058] Predicting the moisture content of raw silk before the raw material stage, adjusting the air speed, and promptly adjusting the control method stabilizes key process parameters that have a significant impact on the internal quality and style of the product, thereby achieving stable control of the moisture content at the outlet.

[0059] Five batches of samples, each weighing less than 500 kg, were randomly selected consecutively. Data from the original control method and the existing two-stage control method for the wire drying machine were analyzed, as shown in Table 1.

[0060]

[0061] Compared with existing methods for tobacco drying machines, this embodiment maintains a relatively stable processing intensity and a rapid adjustment response during the production process. This is beneficial for maintaining the stability and consistency of the intrinsic quality and style of cigarette products during processing. At the same time, it can realize small-batch classification processing of two-stage tobacco drying machines, providing technical means for personalized production and experimental processing of cigarette products.

[0062] Example 2:

[0063] This embodiment provides the system required to implement the above control method, including:

[0064] The tobacco drying machine has a drum, which is divided into two zones. The tobacco shreds pass through the two zones in sequence to reach the outlet. The drum is connected to a hot air unit, which is used to provide hot air. The two zones are equipped with corresponding temperature sensors, and the hot air unit is equipped with a wind speed sensor and a wind temperature sensor.

[0065] The controller is connected to the tobacco drying machine and the hot air unit. By acquiring the temperatures of the first and second zones inside the drum, the wind speed and temperature of the hot air generated by the hot air unit, and the moisture content of the tobacco, the controller changes the working state of the tobacco drying machine.

[0066] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method of controlling the moisture of the cut filler at the outlet of a two-stage cut tobacco factory, characterised in that, The method comprises the following steps: obtaining the moisture content of the cut tobacco at the inlet of the two-stage cut tobacco drying machine, determining a process target value of the moisture content of the cut tobacco, gradually increasing the temperature of the first zone and the second zone of the cylinder wall of the cut tobacco drying machine, and entering a material head stage; in the material head stage, according to the deviation between the detected value of the moisture content of the cut tobacco at the outlet of the two-stage cut tobacco drying machine and the process target value and the duration of the deviation, entering corresponding wind speed and wind temperature adjustment, second zone cylinder wall temperature adjustment and flow adjustment respectively; the cut tobacco passes through the first zone and the second zone in sequence to reach the outlet; according to the deviation between the detected value of the moisture content of the cut tobacco at the outlet of the cut tobacco drying machine and the process target value and the duration of the deviation, entering corresponding wind speed and wind temperature adjustment, second zone cylinder wall temperature adjustment and flow adjustment respectively, comprising: when the deviation between the detected value of the moisture content of the cut tobacco at the outlet of the cut tobacco drying machine and the process target value is not greater than a first set value of 0.5%, the cylinder wall temperature is controlled to the temperature corresponding to the process target value, and a wind speed and wind temperature adjustment stage is entered; when the deviation between the detected value of the moisture content of the cut tobacco at the outlet of the cut tobacco drying machine and the process target value is greater than the first set value of 0.5% and the deviation exists for more than a set first time period, a second zone cylinder wall temperature adjustment stage is entered; when the deviation between the detected value of the moisture content of the cut tobacco at the outlet of the cut tobacco drying machine and the process target value is greater than a second set value of 1% and the deviation exists for more than a set second time period, a flow adjustment stage is entered; in the production stage, wind speed and wind temperature adjustment, second zone cylinder wall temperature adjustment and flow adjustment are performed in sequence, and the first zone cylinder wall temperature is unchanged; in the material tail stage, the first zone and the second zone cylinder wall temperatures of the two-stage cut tobacco drying machine are gradually reduced, and the parameters are stabilized to prepare for discharging.

2. A small batch production two-stage cut tobacco rod outlet tobacco moisture control method according to claim 1, characterised in that, In the material head stage, the temperature set value of the first zone and the second zone of the cylinder wall of the cut tobacco drying machine is less than the temperature corresponding to the process target value.

3. A small batch production two-stage cut tobacco rod outlet tobacco moisture control method according to claim 1, characterized in that, The wind speed and wind temperature adjustment is specifically: when the detected value of the moisture content of the cut tobacco at the outlet of the cut tobacco drying machine is greater than the process target value, the wind speed and the wind temperature are increased, and vice versa.

4. A small batch production two-stage cut tobacco rod outlet tobacco moisture control method according to claim 1, characterized in that, The second zone cylinder wall temperature adjustment is specifically: the wind speed and wind temperature adjustment lasts for a set third time period, and the deviation between the detected value of the moisture content of the cut tobacco at the outlet of the cut tobacco drying machine and the process target value is greater than a third set value of 0.2%, the second zone cylinder wall temperature of the cut tobacco drying machine is controlled to rise to the temperature corresponding to the process target value, and vice versa.

5. A small batch production two-stage cut tobacco rod outlet tobacco moisture control method as defined in claim 1, characterized in that, The flow adjustment is specifically: the second zone cylinder wall temperature adjustment lasts for a set fourth time period, and the deviation between the detected value of the moisture content of the cut tobacco at the outlet of the cut tobacco drying machine and the process target value is greater than a fourth set value of 0.2%, the mass flow of the cut tobacco drying machine is controlled to decrease, and vice versa.

6. A small batch production two-stage tobacco rod outlet tobacco moisture control method as claimed in claim 5, characterised in that, During the flow adjustment, the first zone and the second zone temperatures of the cylinder wall of the cut tobacco drying machine are stabilized to the temperature corresponding to the process target value.

7. A moisture control system for the cut tobacco at the outlet of a small-batch production two-stage tobacco cutter implementing the control method according to any one of claims 1 to 6, characterized in that, The method comprises the following steps: a cut tobacco drying machine having a cylinder, the cylinder being divided into a first zone and a second zone, cut tobacco passing through the first zone and the second zone in sequence to reach an outlet, the cylinder being connected with a hot air unit, the hot air unit being used to provide hot air; the first zone and the second zone are provided with corresponding temperature sensors, and the hot air unit is provided with a wind speed sensor and a wind temperature sensor; a controller connected with the cut tobacco drying machine and the hot air unit, the moisture content of the cut tobacco being obtained by acquiring the temperature of the first zone and the second zone in the cylinder, the wind speed and the wind temperature of the hot air unit generating hot air, and the working state of the cut tobacco drying machine being changed.

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