A method for monitoring the blockage of the outlet of a carbon dioxide expanded tobacco vibration cabinet online

Abstract

This invention provides an online monitoring method for material blockage at the outlet of a carbon dioxide expanded tobacco vibrating chamber, relating to the cigarette manufacturing industry. The method includes the following steps: S1, installing a temperature sensor on the metering tube at the outlet of the vibrating chamber and collecting the temperature of the low-temperature tobacco as it passes through the metering tube. A range is defined for the temperature of the tobacco as it smoothly passes through the metering tube, and the highest temperature within this range is set as a temperature threshold. S2, setting up a PLC control unit and connecting the temperature sensor to the PLC control unit. The temperature sensor transmits the collected temperature information to the PLC control unit, which performs low-temperature compensation and filtering on the collected information. This invention, by installing a temperature sensor on the metering tube at the outlet of the vibrating chamber and combining it with a PLC control unit for signal acquisition and processing, can monitor temperature changes in real time, accurately determine the blockage status, and avoid production interruptions caused by blockage.

Description

Technical Field

[0001] This invention relates to the field of cigarette manufacturing technology, and in particular to an online monitoring method for material blockage at the outlet of a carbon dioxide expanded tobacco vibrating cabinet. Background Technology

[0002] Carbon dioxide expanded tobacco refers to tobacco that has undergone expansion processing after being soaked in liquid carbon dioxide. The tobacco, after being soaked in liquid carbon dioxide, is buffered in a vibrating chamber. A metering tube, which is round, is installed at the lower end of the vibrating chamber outlet as the channel for tobacco output. During normal production, continuous and stable tobacco output is required.

[0003] The tobacco shreds are mainly output from the vibrating cabinet by vibration and their own weight, which makes them prone to clogging at the outlet. Currently, there is no online monitoring method for tobacco shred blockage at the outlet of the carbon dioxide expanded tobacco vibrating cabinet, and it mainly relies on on-site inspection by personnel. Once tobacco shred blockage occurs, it is difficult to detect and clear it in time, which will cause production cost losses and product quality decline. Therefore, this invention proposes an online monitoring method for tobacco shred blockage at the outlet of the carbon dioxide expanded tobacco vibrating cabinet to solve the problems existing in the prior art. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes an online monitoring method for material blockage at the outlet of a carbon dioxide expanded tobacco vibrating cabinet. This method involves installing a temperature sensor on the quantitative tube at the outlet of the vibrating cabinet and combining it with a PLC control unit for signal acquisition and processing. This allows for real-time monitoring of temperature changes, accurate determination of the blockage status, and prevention of production interruptions caused by material blockage.

[0005] To achieve the objectives of this invention, the invention is implemented through the following technical solution: an online monitoring method for material blockage at the outlet of a carbon dioxide expanded tobacco vibrating cabinet, comprising the following steps:

[0006] S1. Install a temperature sensor on the metering tube at the outlet of the vibration cabinet and collect the temperature of the low-temperature tobacco as it passes through the metering tube. Define the temperature range of the tobacco as it passes through the metering tube smoothly, and set the highest temperature in this range as the temperature threshold.

[0007] S2. Set up the PLC control unit and connect the temperature sensor to the PLC control unit. The temperature sensor will transmit the collected temperature information to the PLC control unit. The PLC control unit will perform low temperature compensation and filtering on the collected information.

[0008] S3. Based on the temperature signal measured by the temperature sensor, when the temperature rises, it is determined that the material is blocked; when the temperature changes suddenly and drastically, it is determined that the temperature sensor is frozen.

[0009] S4. Send the judgment result to the central control screen for display, and display the alarm information on the central control screen.

[0010] A further improvement is that the temperature sensor adopts a Class A precision three-wire PT100 platinum resistance temperature sensor, and the detection end of the temperature sensor is installed at an angle downwards at the lower end of the positioning tube.

[0011] A further improvement is that a protective sleeve is provided at the base of the temperature sensor probe, a heating element is provided inside the protective sleeve, and a hydrophobic coating is applied to the surface of the temperature sensor probe.

[0012] A further improvement is made in that: the method for low-temperature compensation and filtering in step S2 includes the following steps:

[0013] Step 1: Signal Acquisition and Hardware Compensation. Signal acquisition is performed using the PLC's dedicated analog input module. The Class A precision three-wire PT100 platinum resistance temperature sensor employs a three-wire connection. Utilizing the differential measurement principle, the influence of lead resistance (RL) on the measurement results is eliminated at the hardware level. The original resistance value obtained after compensation is denoted as... ;

[0014] Step 2: Linear Compensation. Since the resistance-temperature characteristic of the Class A precision three-wire PT100 platinum resistance temperature sensor is non-linear in the low-temperature region (-100℃~0℃), a piecewise linear interpolation method is used by the PLC control unit to compensate for this non-linear characteristic. The -100℃~0℃ range is divided into N equal intervals, and the resistance values ​​corresponding to each boundary point are pre-stored. ) and temperature value ( Real-time data collection Then, the interval it belongs to is determined by looking up a table. Corresponding temperature range ,in , And the preliminary temperature value T_comp is calculated according to formula A;

[0015] Step 3: Zero-point drift compensation. To address the potential zero-point drift that may occur with long-term operation of the Class A precision three-wire PT100 platinum resistance temperature sensor, an automatic zero-point tracking algorithm is introduced into the PLC control unit. The PLC monitors the equipment's operating status in real time. When it detects that the vibrating cabinet has stopped operating for more than a preset time (e.g., 10 minutes), and the temperature sensor reading fluctuates less than ±0.3℃ for 5 consecutive minutes, the system is determined to be in a "stable, smoke-free" state. At this time, the current measured value T_comp is recorded as the ambient temperature reference value T_zero. In subsequent normal production, the actual effective temperature T_actual = T_comp - T_zero + T_std, where T_std is the preset standard ambient temperature reference value.

[0016] Step 4: Digital filtering processing. To suppress pulse interference and electrical noise that may occur in low-temperature environments, composite filtering is performed on T_actual.

[0017] First, median filtering is used: five T_actual values ​​are collected consecutively, sorted, and the median value is taken to eliminate instantaneous spike interference;

[0018] Then, a moving average filter is used: a queue of length 5 is established, and each time a new value enters, the arithmetic mean of all values ​​in the queue is calculated to obtain the final stable temperature value T_final;

[0019] Step 5: Use the obtained T_final value as the input value for determining material blockage in S3.

[0020] The further improvement lies in: Formula A:

[0021] ;

[0022] Where T is T_comp.

[0023] The beneficial effects of this invention are as follows: By installing a temperature sensor on the quantitative tube at the outlet of the vibration cabinet and combining it with a PLC control unit for signal acquisition and processing, this invention can monitor temperature changes in real time, accurately determine the blockage status, and avoid production interruptions caused by blockage. By employing various methods such as hardware compensation, linear compensation, zero-point drift compensation, and composite digital filtering, the invention effectively eliminates the influence of low temperature on temperature measurement and significantly improves the accuracy and stability of the temperature signal. Attached Figure Description

[0024] Figure 1 This is a flowchart of the judgment process of the present invention. Detailed Implementation

[0025] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0026] according to Figure 1 As shown in the figure, this embodiment proposes an online monitoring method for material blockage at the outlet of a carbon dioxide expanded tobacco vibrating cabinet, including the following steps:

[0027] S1. Install a temperature sensor on the metering tube at the outlet of the vibration cabinet and collect the temperature of the low-temperature tobacco as it passes through the metering tube. Define the temperature range of the tobacco as it passes through the metering tube smoothly, and set the highest temperature in this range as the temperature threshold.

[0028] S2. Set up the PLC control unit and connect the temperature sensor to the PLC control unit. The temperature sensor will transmit the collected temperature information to the PLC control unit. The PLC control unit will perform low temperature compensation and filtering on the collected information.

[0029] S3. Based on the temperature signal measured by the temperature sensor, when the temperature rises, it is determined that the material is blocked; when the temperature changes suddenly and drastically, it is determined that the temperature sensor is frozen.

[0030] S4. Send the judgment result to the central control screen for display, and display the alarm information on the central control screen.

[0031] The temperature sensor is a Class A precision three-wire PT100 platinum resistance temperature sensor, and the sensing end of the temperature sensor is installed at an angle downwards at the lower end of the positioning tube.

[0032] A protective sleeve is provided at the base of the temperature sensor probe, a heating element is provided inside the protective sleeve, and a hydrophobic coating is applied to the surface of the temperature sensor probe.

[0033] In step S2, the method for low-temperature compensation and filtering includes the following steps:

[0034] Step 1: Signal Acquisition and Hardware Compensation. Signal acquisition is performed using the PLC's dedicated analog input module. The Class A precision three-wire PT100 platinum resistance temperature sensor employs a three-wire connection. Utilizing the differential measurement principle, the influence of lead resistance (RL) on the measurement results is eliminated at the hardware level. The original resistance value obtained after compensation is denoted as... ;

[0035] Step 2: Linear Compensation. Since the resistance-temperature characteristic of the Class A precision three-wire PT100 platinum resistance temperature sensor is non-linear in the low-temperature region (-100℃~0℃), a piecewise linear interpolation method is used by the PLC control unit to compensate for this non-linear characteristic. The -100℃~0℃ range is divided into N equal intervals, and the resistance values ​​corresponding to each boundary point are pre-stored. ) and temperature value ( Real-time data collection Then, the interval it belongs to is determined by looking up a table. Corresponding temperature range ,in , And the preliminary temperature value T_comp is calculated according to formula A;

[0036] Step 3: Zero-point drift compensation. To address the potential zero-point drift that may occur with long-term operation of the Class A precision three-wire PT100 platinum resistance temperature sensor, an automatic zero-point tracking algorithm is introduced into the PLC control unit. The PLC monitors the equipment's operating status in real time. When it detects that the vibrating cabinet has stopped operating for more than a preset time (e.g., 10 minutes), and the temperature sensor reading fluctuates less than ±0.3℃ for 5 consecutive minutes, the system is determined to be in a "stable, smoke-free" state. At this time, the current measured value T_comp is recorded as the ambient temperature reference value T_zero. In subsequent normal production, the actual effective temperature T_actual = T_comp - T_zero + T_std, where T_std is the preset standard ambient temperature reference value.

[0037] Step 4: Digital filtering processing. To suppress pulse interference and electrical noise that may occur in low-temperature environments, composite filtering is performed on T_actual.

[0038] First, median filtering is used: five T_actual values ​​are collected consecutively, sorted, and the median value is taken to eliminate instantaneous spike interference;

[0039] Then, a moving average filter is used: a queue of length 5 is established, and each time a new value enters, the arithmetic mean of all values ​​in the queue is calculated to obtain the final stable temperature value T_final;

[0040] Step 5: Use the obtained T_final value as the input value for determining material blockage in S3.

[0041] Formula A:

[0042] ;

[0043] Where T is T_comp.

[0044] Before using this online monitoring method for material blockage at the outlet of the carbon dioxide expanded tobacco vibrating cabinet, preliminary data collection and statistics must be completed. This involves collecting and statistically analyzing the temperature range inside the quantitative tube under normal production conditions. This temperature range serves as the temperature setpoint for subsequent judgment on whether tobacco blockage has occurred. When using this method, the temperature inside the quantitative tube, collected in real time by a temperature sensor (range -100℃ to +100℃, measurement accuracy 0.1℃, temperature acquisition frequency 5 times / second), is transmitted to the PLC control unit. The PLC control unit compares the real-time temperature collected by the temperature sensor with the set temperature and determines whether tobacco blockage has occurred. The determination result is sent to the central control computer screen for real-time display. When tobacco blockage occurs, an alarm message is displayed on the computer screen.

[0045] Under normal production conditions, the low-temperature tobacco shreds fill the metering tube, and the temperature sensor measures the temperature of the low-temperature tobacco shreds. The temperature value is within the set temperature range. Therefore, if the real-time temperature is within the set range, it is judged to be under normal production conditions.

[0046] When the tobacco is blocked, the low-temperature tobacco is blocked at the outlet of the vibrating cabinet. There is no low-temperature tobacco in the metering tube and belt conveyor. The temperature sensor measures the air temperature. Alternatively, the metering tube is blocked and the tobacco does not flow. The temperature of the blocked tobacco begins to rise and its temperature value is higher than the set temperature. Therefore, if the real-time temperature is higher than the set range, it is judged to be a tobacco blockage state.

[0047] If the temperature sensor is frozen, and the temperature measured by the temperature sensor suddenly changes drastically, it is determined that the temperature sensor is frozen. At this point, the feeding of tobacco is stopped, and the heating element is activated to de-ice the temperature sensor probe.

[0048] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for online monitoring of material blockage at the outlet of a carbon dioxide expanded tobacco vibrating cabinet, characterized in that: Includes the following steps: S1. Install a temperature sensor on the metering tube at the outlet of the vibration cabinet and collect the temperature of the low-temperature tobacco as it passes through the metering tube. Define the temperature range of the tobacco as it passes through the metering tube smoothly, and set the highest temperature in this range as the temperature threshold. S2. Set up the PLC control unit and connect the temperature sensor to the PLC control unit. The temperature sensor will transmit the collected temperature information to the PLC control unit. The PLC control unit will perform low temperature compensation and filtering on the collected information. S3. Based on the temperature signal measured by the temperature sensor, when the temperature rises, it is determined that the material is blocked; when the temperature changes suddenly and drastically, it is determined that the temperature sensor is frozen. S4. Send the judgment result to the central control screen for display, and display the alarm information on the central control screen.

2. The method for online monitoring of material blockage at the outlet of a carbon dioxide expanded tobacco vibrating cabinet according to claim 1, characterized in that: The temperature sensor is a Class A precision three-wire PT100 platinum resistance temperature sensor, and the sensing end of the temperature sensor is installed at an angle downwards at the lower end of the positioning tube.

3. The method for online monitoring of material blockage at the outlet of a carbon dioxide expanded tobacco vibrating cabinet according to claim 1, characterized in that: A protective sleeve is provided at the base of the temperature sensor probe, a heating element is provided inside the protective sleeve, and a hydrophobic coating is applied to the surface of the temperature sensor probe.

4. The method for online monitoring of material blockage at the outlet of a carbon dioxide expanded tobacco vibrating cabinet according to claim 1, characterized in that: In step S2, the method for low-temperature compensation and filtering includes the following steps: Step 1: Signal Acquisition and Hardware Compensation. Signal acquisition is performed using the PLC's dedicated analog input module. The Class A precision three-wire PT100 platinum resistance temperature sensor employs a three-wire connection. Utilizing the differential measurement principle, the influence of lead resistance (RL) on the measurement results is eliminated at the hardware level. The original resistance value obtained after compensation is denoted as... ; Step 2: Linear Compensation. Since the resistance-temperature characteristic of the Class A precision three-wire PT100 platinum resistance temperature sensor is non-linear in the low-temperature region (-100℃~0℃), a piecewise linear interpolation method is used by the PLC control unit to compensate for this non-linear characteristic. The -100℃~0℃ range is divided into N equal intervals, and the resistance values ​​corresponding to each boundary point are pre-stored. ) and temperature value ( Real-time data collection Then, the interval it belongs to is determined by looking up a table. Corresponding temperature range ,in , And the preliminary temperature value T_comp is calculated according to formula A; Step 3: Zero-point drift compensation. To address the potential zero-point drift that may occur with long-term operation of the Class A precision three-wire PT100 platinum resistance temperature sensor, an automatic zero-point tracking algorithm is introduced into the PLC control unit. The PLC monitors the equipment's operating status in real time. When it detects that the vibrating cabinet has stopped operating for more than a preset time (e.g., 10 minutes), and the temperature sensor reading fluctuates less than ±0.3℃ for 5 consecutive minutes, the system is determined to be in a "stable, smoke-free" state. At this time, the current measured value T_comp is recorded as the ambient temperature reference value T_zero. In subsequent normal production, the actual effective temperature T_actual = T_comp - T_zero + T_std, where T_std is the preset standard ambient temperature reference value. Step 4: Digital filtering processing. To suppress pulse interference and electrical noise that may occur in low-temperature environments, composite filtering is performed on T_actual. First, median filtering is used: five T_actual values ​​are collected consecutively, sorted, and the median value is taken to eliminate instantaneous spike interference; Then, a moving average filter is used: a queue of length 5 is established, and each time a new value enters, the arithmetic mean of all values ​​in the queue is calculated to obtain the final stable temperature value T_final; Step 5: Use the obtained T_final value as the input value for determining material blockage in S3.

5. The method for online monitoring of material blockage at the outlet of a carbon dioxide expanded tobacco vibrating cabinet according to claim 4, characterized in that: Formula A: ； Where T is T_comp.

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