Early warning method for controlling the hot air temperature of tobacco leaf loosening and rehumidification device

Abstract

The early warning method of the present invention for controlling the hot air temperature of a tobacco leaf loosening and rehumidification device includes: determining the minimum CPK in the same tobacco leaf production process of at least ten qualified batches. min CPK min = (minimum CPK1) min +minimumCPK2 min +Minimum CPK3 min ...minimum CPK10 min ) / 10; During the rehumidification process of tobacco leaves in the loosening and rehumidification device, the hot air temperature CPK of the tobacco leaves is monitored at all times. When the hot air temperature CPK of the tobacco leaves reaches 10, the temperature is controlled. 实时 Less than minimum CPK min When the CPK of the tobacco leaves exceeds the threshold, the controller issues an early warning, displaying the warning information and prompts on the screen; 实时 When the value is below the threshold, the controller displays alarm information and alarm prompts on the screen.

Description

Technical Field

[0001] This invention relates to an early warning method for controlling the hot air temperature of a tobacco leaf loosening and rehumidification device, specifically to a device that provides quality early warning based on real-time production data through historical data analysis and modeling, belonging to the field of computer and automation technology in the tobacco industry. Background Technology

[0002] The working principle of loose rehydration

[0003] The working principle of the loosening and rehumidifying process is as follows: after slicing, the tobacco blocks are conveyed from the feed trough to the rotating drum. Inside the drum, rakes pick them up and slowly move them axially. They fall and are then picked up again. During this process, they are heated by circulating hot air and supplementary steam. Water and steam are evenly sprayed onto the blades through water and steam nozzles, providing the blades with the required temperature and humidity. This loosens the tobacco blocks, allowing them to gradually move forward until they are output from the outlet. The entire pipeline control system and electrical system can automatically control the water spray volume, steam flow rate, hot air circulation volume and temperature, and drum speed required for material flow changes during blade heating and humidification.

[0004] The meaning of CPK

[0005] CPK: an abbreviation for Complex Process Capability index, is a modern enterprise indicator used to represent process capability. Process capability is the ratio of the maximum allowable variation in process performance to the normal deviation of the process. Process capability studies aim to confirm the degree to which these characteristics meet specifications, ensuring that the rate of non-conforming finished products is above the required level, serving as a basis for continuous process improvement.

[0006] The calculation formula is as follows:

[0007] Sample mean: n is the number of samples

[0008] Specification tolerance T: T = USL - LSL

[0009] Specification center value C: C = (USL + LSL) / 2

[0010] Sample standard deviation:

[0011] CA:

[0012] CP:

[0013] CPK: CPK = CP * (1 - |CA|)

[0014] The CPK index for loose, rehydrated hot air has the following defects and shortcomings:

[0015] The Cpk value (CPK) of the loose, rehydrated hot air is a key indicator for evaluating process quality, affecting the aroma, smoke, and taste characteristics of cigarettes. Currently, in the cigarette manufacturing process, the Cpk value is determined by the final value after each batch. A Cpk < 1.33 is considered unqualified, 1.33 <= Cpk < 1.67 is considered good, and Cpk ≥ 1.67 is considered excellent. However, the Cpk value is no longer controllable after the batch ends, introducing uncontrollable factors into product quality. Therefore, it is necessary to monitor the Cpk trend in real time during production, providing advance warnings or alarms before the Cpk exceeds the limit, anticipating potential quality declines and taking preventative measures.

[0016] Yunnan Tobacco's various production plants use the CPK index statistical method when evaluating the hot air temperature process parameters of the leaf loosening and rehydration process in the tobacco processing line. However, the industry currently lacks devices or systems to predict the deterioration of the CPK index in advance during production. When the CPK index falls below the process parameters during production, it indicates that the current process capability is insufficient and the tobacco quality does not meet the quality requirements. Summary of the Invention

[0017] In view of the many defects and shortcomings of the above-mentioned background technology, the purpose of this application is to solve the problem of the lag in the existing system, which is unable to analyze and warn the CPK index of the loosening and rehumidifying hot air in real time, thus causing quality problems. The invention provides a warning method for controlling the hot air temperature of the tobacco loosening and rehumidifying device to ensure and improve product quality.

[0018] To achieve the purpose of this invention, the following technical solution is adopted:

[0019] This invention provides an early warning method for controlling the hot air temperature of a tobacco leaf loosening and rehumidification device. A temperature sensor is installed inside the loosening and rehumidification device and connected to a hot air temperature controller via a fieldbus. The hot air temperature is acquired by a PLC, and the hot air temperature controller is adjusted via PID feedback. The method includes:

[0020] (i) Calculate the minimum CPK of the same tobacco leaves from at least ten batches of qualified hot air temperature CPK. min (a) For each qualified batch of tobacco leaves, calculate the sample mean:

[0021] n is the number of samples, X1, X2, ..., X... n The temperature of the loose moisture reabsorption device (2) is detected in real time by temperature sensors (1) with at least 30 samples;

[0022] (b) For each qualified batch of tobacco leaves, calculate the specification tolerance T:

[0023] T = USL - LSL --- Formula (2), where USL is the specified upper temperature limit and LSL is the specified lower temperature limit;

[0024] (c) For each qualified batch of tobacco leaves, calculate the specification center value C.

[0025] C=(USL+LSL) / 2---Formula (3)

[0026] (d) For each qualified batch of tobacco leaves, calculate the sample standard deviation σ:

[0027]

[0028] (e) For each qualified batch of tobacco leaves, calculate the sample's process accuracy Ca:

[0029]

[0030] (f) For each qualified batch of tobacco leaves, calculate the sample's process precision Cp:

[0031]

[0032] (g) For each qualified batch of tobacco leaves, calculate the sample's process capability index (CPK):

[0033] CPK=Cp*(|1-Ca|)----Formula (7)

[0034] (h) Repeat steps (a) to (g) above to calculate the minimum hot air temperature CPK for each of the ten tobacco leaf batches. min

[0035] Starting from the (n+1)th sample in step (a), the hot air temperature of the loose rehumidification device (2) is detected in real time; X n+1 X n+2 ... Repeat steps (b) to (g) to calculate all hot air temperatures CPK for each batch after 31 samples, compare all hot air temperature CPKs, and find the minimum hot air temperature CPK1. min Minimum hot air temperature CPK2 min Minimum hot air temperature CPK3 min ...Minimum hot air temperature CPK10 min Minimum hot air temperature CPK1 min Minimum hot air temperature CPK2 min Minimum hot air temperature CPK3 min ...Minimum hot air temperature CPK10 minThese are the minimum hot air temperature CPK for the first batch of tobacco leaves, the second batch of tobacco leaves, the third batch of tobacco leaves, ... and the tenth batch of tobacco leaves.

[0036] CPK min = (Minimum hot air temperature CPK1) min +Minimum hot air temperature CPK2 min +Minimum hot air temperature CPK3 min ...Minimum hot air temperature CPK10 min ) / 10---Formula (8)

[0037] (II) During the rehumidification process of tobacco leaves in the loosening and rehumidification device, the hot air temperature (CPK) of the tobacco leaves should be monitored at all times.

[0038] For the batch of tobacco leaves to be monitored, repeat steps (a) to (h) to monitor the hot air temperature CPK in real time using a temperature sensor. 实时 ,

[0039] (III) Hot air temperature of tobacco leaves (CPK) 实时 Less than the minimum hot air temperature CPK min When the temperature of the hot air in the tobacco leaf is greater than or equal to the threshold, the controller issues a warning; when the temperature of the hot air in the tobacco leaf, CPK, is less than the threshold, the controller (3) issues an alarm.

[0040] When the hot air temperature of the tobacco leaves in step (II) is CPK 实时 Less than the minimum hot air temperature CPK min When the temperature exceeds the threshold, the controller issues an early warning, displaying the warning information and prompts on the screen; when the hot air temperature CPK of the tobacco leaves in step (II) is... 实时 When the value is below the threshold, the controller displays alarm information and alarm prompts on the screen.

[0041] The present invention provides an early warning method for controlling the hot air temperature of a tobacco leaf loosening and rehumidification device, wherein the threshold value is 1.33.

[0042] The present invention provides an early warning method for controlling the hot air temperature of a tobacco leaf loosening and rehumidification device, wherein: the minimum hot air temperature CPK of the ten qualified batches of tobacco leaves is... min All are greater than 1.33.

[0043] The present invention provides an early warning method for controlling the hot air temperature of a tobacco leaf loosening and rehumidification device. This method monitors the change trend of CPK in real time during the production process, and provides advance warning or alarm before CPK exceeds the standard, thereby predicting potential quality decline and taking preventative measures.

[0044] This method can monitor the real-time value of the CPK index of loose and humidified hot air during the production process, issue early warnings for potential deterioration of the index, provide operators with tips and operational suggestions, thereby minimizing the possibility of quality defects during the production process and bringing positive effects to process quality control. Attached Figure Description

[0045] Figure 1 This is a frontal schematic diagram of a device used to control the loosening and rehydration of tobacco leaves.

[0046] exist Figure 1 In the diagram, number 1 represents the temperature sensor; number 2 represents the loosening and rehumidification device; and number 3 represents the controller. Detailed Implementation

[0047] like Figure 1 As shown, the device for controlling the loosening and rehumidification of tobacco leaves includes: a temperature sensor 1, a loosening and rehumidification device 2, and a controller 3. The temperature sensor 1 is installed inside the loosening and rehumidification device 2 and is connected to the hot air temperature controller 3 via a fieldbus. After the hot air temperature is acquired by the PLC, the hot air temperature controller 3 is adjusted through PID feedback. The early warning method for controlling the hot air temperature of the tobacco loosening and rehumidification device includes:

[0048] (i) Calculate the minimum hot air temperature (CPK) for at least ten qualified batches of the same tobacco leaves. min

[0049] (a) For each qualified batch of tobacco leaves, calculate the sample mean:

[0050] n is the number of samples, X1, X2, ..., X... n The temperatures of the loose moisture regaining device 2 are detected in real time by temperature sensor 1 with 30 samples.

[0051] (b) For each qualified batch of tobacco leaves, calculate the specification tolerance T:

[0052] T = USL - LSL --- Formula (2), where USL is the specified upper temperature limit and LSL is the specified lower temperature limit;

[0053] (c) For each qualified batch of tobacco leaves, calculate the specification center value C.

[0054] C=(USL+LSL) / 2---Formula (3)

[0055] (d) For each qualified batch of tobacco leaves, calculate the sample standard deviation σ:

[0056]

[0057] (e) For each qualified batch of tobacco leaves, calculate the sample's process accuracy Ca:

[0058]

[0059] (f) For each qualified batch of tobacco leaves, calculate the sample's process precision Cp:

[0060]

[0061] (g) For each qualified batch of tobacco leaves, calculate the sample's process capability index (CPK):

[0062] CPK=Cp*(|1-Ca|)----Formula (7)

[0063] (h) Repeat steps (a) to (g) above to calculate the minimum hot air temperature CPK for each of the ten tobacco leaf batches. min

[0064] Starting from the 31st sample in step (a), the hot air temperature of the loose rehumidification device 2 is detected in real time; X n+1 X n+2 ... Repeat steps (b) to (g) to calculate all hot air temperatures CPK for each batch after 31 samples, compare all hot air temperature CPKs, and find the minimum hot air temperature CPK1. min Minimum hot air temperature CPK2 min Minimum hot air temperature CPK3 min ...Minimum hot air temperature CPK10 min Minimum hot air temperature CPK1 min Minimum hot air temperature CPK2 min Minimum hot air temperature CPK3 min ...Minimum hot air temperature CPK10 min These are the minimum hot air temperature CPK for the first batch of tobacco leaves, the second batch of tobacco leaves, the third batch of tobacco leaves, ... and the tenth batch of tobacco leaves.

[0065] CPK min = (Minimum hot air temperature CPK1) min +Minimum hot air temperature CPK2 min +Minimum hot air temperature CPK3 min ...Minimum hot air temperature CPK10 min ) / 10---Formula (8),

[0066] For example, hot air temperature CPK min It is 1.39;

[0067] (II) During the rehumidification process of tobacco leaves in the loosening and rehumidification device, the hot air temperature (CPK) of the tobacco leaves should be monitored at all times.

[0068] For the batch of tobacco leaves to be monitored, repeat steps (a) to (h) to monitor the hot air temperature CPK in real time using temperature sensor 1. 实时 ,

[0069] (III) When monitoring the hot air temperature (CPK) of tobacco leaves 实时 Less than the minimum hot air temperature CPK min When the CPK of the tobacco leaves is greater than or equal to the threshold of 1.33, controller 3 issues a warning; when the CPK of the tobacco leaves is less than the threshold, controller 3 issues an alarm.

[0070] When step (two) requires monitoring the hot air temperature (CPK) of the tobacco leaves. 实时 It is 1.36, which is less than the minimum hot air temperature CPK. min When the temperature of the hot air in the tobacco leaves reaches 1.39 and is greater than or equal to the threshold of 1.33, controller 3 issues an early warning and displays the warning information and prompt on the screen; when the temperature of the hot air in the tobacco leaves reaches 1.39 and is greater than or equal to the threshold of 1.33, controller 3 issues an early warning and displays the warning information and prompt on the screen; 实时 The value is 1.32, and the hot air temperature is CPK. 实时 When the value is below the threshold, the controller displays alarm information and alarm prompts on the screen.

[0071] Definition of a qualified batch: Data is sampled once per second during the production process. When the hot air temperature reaches the CPK calculation sampling requirement (30 data points), the real-time CPK value is calculated once per second. If the real-time CPK value during the batch production process is greater than the threshold (1.33), the batch is considered qualified; otherwise, the batch is considered unqualified. Data from unqualified batches are not subject to statistical analysis.

[0072] In the event of a warning or alarm, the corresponding warning or alarm message will pop up on the IFIX interface, and the siren of the electrical cabinet will sound and the warning light will flash. After the operator clicks the "Reset" button to confirm, the siren will turn off, but the warning light will continue to flash. If the indicator does not recover to above the warning line, the screen alarm, siren, and warning light will all sound simultaneously. The hot air temperature CPK indicator recovers to the warning line, i.e., the aforementioned CPK. min When the value is between 1.39 and 1.33, the on-screen alarm disappears, but the siren and warning lights continue to sound. When the hot air temperature CPK index exceeds the warning line, all alarms and prompts disappear.

[0073] The above description only discloses specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or modifications that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for early warning of hot air temperature in a tobacco leaf loosening and rehumidification device, wherein a temperature sensor (1) is installed inside the loosening and rehumidification device (2), and is connected to a hot air temperature controller (3) via a fieldbus; the hot air temperature is acquired by a PLC, and the hot air temperature controller (3) is adjusted by PID feedback; characterized in that: The method includes: (i) determining the minimum CPK of the same tobacco leaf of at least ten qualified batches min (a) For each qualified batch of tobacco leaves, calculate the sample mean: n is the number of samples, X1, X2, ..., X... n The temperature of the loose moisture reabsorption device (2) is detected in real time by temperature sensors (1) with at least 30 samples; (b) For each qualified batch of tobacco leaves, calculate the specification tolerance T: T = USL - LSL --- Formula (2), where USL is the specified upper temperature limit and LSL is the specified lower temperature limit; (c) For each qualified batch of tobacco leaves, calculate the specification center value C. C=(USL+LSL) / 2---Formula (3) (d) For each qualified batch of tobacco leaves, calculate the sample standard deviation σ: (e) For each qualified batch of tobacco leaves, calculate the sample's process accuracy Ca: (f) For each qualified batch of tobacco leaves, calculate the sample's process precision Cp: (g) For each qualified batch of tobacco leaves, calculate the sample's process capability index (CPK): CPK=Cp*(|1-Ca|)----Formula (7) (h) repeating steps (a) through (g) above to calculate the minimum CPK for each of ten batches of tobacco leaves min Starting from the (n+1)th sample in step (a), the temperature of the loose rehumidification device (2) is detected in real time; X n+1 X n+2 ... Repeat steps (b) to (g) to calculate all CPKs for each batch after 31 samples, compare all CPKs, and find the minimum CPK1. min , minimum CPK2 min , minimum CPK3 min ...minimum CPK10 min Minimum CPK1 min , minimum CPK2 min , minimum CPK3 min ...minimum CPK10 min These are the minimum CPK of the first batch of tobacco leaves, the minimum CPK of the second batch of tobacco leaves, the minimum CPK of the third batch of tobacco leaves, ... and the minimum CPK of the tenth batch of tobacco leaves; CPK min = (minimum CPK1) min +minimumCPK2 min +Minimum CPK3 min ...minimum CPK10 min ) / 10---Formula (8) (ii) During the rehumidification process of tobacco leaves in the loosening and rehumidification device, the CPK of the tobacco leaves should be monitored at any time. For the batch of tobacco leaves to be monitored, repeat steps (a) to (h) to monitor the CPK in real time using temperature sensor (1). 实 hour, (III) CPK of tobacco leaves 实时 Less than minimum CPK min When the value exceeds the threshold, the controller (3) issues a warning; when the CPK of the tobacco leaf is less than the threshold, the controller (3) issues an alarm. When the CPK of the tobacco leaves in step (II) 实时 Less than minimum CPK min When the value exceeds the threshold, the controller (3) issues an early warning and displays the warning information and prompts on the display screen; when the CPK of the tobacco leaves in step (II) 实时 When the value is below the threshold, the controller displays alarm information and alarm prompts on the screen.

2. The early warning method for controlling the hot air temperature of a tobacco leaf loosening and rehumidification device as described in claim 1, characterized in that: The threshold is 1.

33.

3. The early warning method for controlling the hot air temperature of a tobacco leaf loosening and rehumidification device as described in claim 2, characterized in that: The minimum CPK of the ten qualified batches of tobacco leaves min All are greater than 1.33.

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