Silk tube intelligent speed measuring device, speed measuring method and silk tube air volume balance control method

Abstract

The application discloses a silk pipe intelligent speed measuring device, a speed measuring method and a silk pipe air volume balance control method, and relates to the technical field of pneumatic conveying. The device comprises an expansion flow cavity which is arranged at the upper portion of the silk pipe to form a smooth transition expansion flow area; a speed measuring mechanism which comprises a pressure sensor and a push-pull force sensor which are installed on the expansion flow cavity, the pressure sensor is used for detecting the air negative pressure size in the silk pipe, the push-pull force sensor is connected with a lever mechanism which is inserted into the expansion flow cavity, and the lever mechanism is used for detecting the air resistance size of the lever mechanism in the silk pipe; and a controller which is used for receiving the signals of the speed measuring mechanism and calculating the air speed in the silk pipe. The application skillfully utilizes the principle that the fluid in the expansion flow cavity is reduced and layered, the tobacco is slid along the bottom of the cavity due to the large density after the flow speed is reduced, and the air can pass through the whole cavity due to the small density, so that the tobacco impact on the lever mechanism is avoided, the measuring result is influenced, the device of the application can long-term, stable and accurate detect the flow speed in the silk pipe.

Description

Technical Field

[0001] This invention relates to the field of pneumatic conveying technology, and in particular to an intelligent speed measuring device, speed measuring method, and air volume balance control method for a wire tube. Background Technology

[0002] Currently, most cigarette factories in China use a combination of embedded throttling tubes and differential pressure transmitters to detect flow velocity in cigarette tubes. This structure involves installing two pressure measuring points at the inlet circular tube of the throttling tube and the embedded throat tube, respectively. The same flow rate of mixed gas will have different flow velocities when passing through different tube cross sections, thus generating a pressure difference at the two measuring ports. The differential pressure transformer transmits the value to the CPU, which then converts it into flow velocity according to Bernoulli's equation, thereby obtaining the flow rate inside the tube.

[0003] The defects and shortcomings of this structure are as follows: First, due to the roundness of the tube itself and processing errors, the embedded throat inevitably forms steps of varying sizes on the inner wall of the tube, affecting the smooth flow of tobacco and gas, and in severe cases, causing blockage; Second, the differential pressure transmitter has very high requirements for the cleanliness of the air being tested. If dust accumulates or is blocked at the detection port, it will seriously affect the detection accuracy. However, in real-world applications, the gas being tested is a mixture of tobacco and air, with a high dust content. Without filtration, the detection port will block the differential pressure transmitter, and with filtration, it is easy to block the detection port; Third, the pressure difference between the two measuring points is relatively small (normally...). (For conditions ≤200Pa), to ensure detection accuracy, the range of the differential pressure transmitter is generally not more than 1000Pa. However, when one of the two detection ports is blocked, the pressure difference between the two exceeds 5000Pa. Exceeding the range significantly can easily damage the elastic element of the differential pressure transmitter, causing plastic deformation and resulting in inaccurate detection data. Fourth, because the negative pressure inside the tube is constantly changing during the wire feeding process, the initial pressure difference between the two detection points will also change continuously, which is especially obvious when the negative pressure of the system fluctuates greatly. Therefore, it is inaccurate to calculate the wind speed based solely on the difference between the two changes.

[0004] Chinese patent CN 101862035 A discloses a differential pressure wind speed detection and control device. Its measurement method also involves setting up a split-type Venturi flowmeter pressure measuring component and a differential pressure sensor. The controller compares the airflow at two detection points and, after verifying the air leakage in the cigarette machine's tobacco collection box and tobacco conveying pipe, corrects the parameters. This structure, because it cannot operate without the setting of two interval detection points, also suffers from the aforementioned inaccurate detection data. It is evident that the current common situation is that the flowmeter in the tobacco tube is not accurate in detecting wind speed. After a period of use, dust accumulation or blockage at the detection port further reduces the accuracy. Inaccurate detection inevitably leads to inaccurate airflow control. Therefore, ensuring accurate and stable wind speed detection is an urgent problem to be solved in the airflow control during tobacco conveying. Summary of the Invention

[0005] One of the objectives of this invention is to provide an intelligent speed measuring device for wire tubes, which can detect the flow velocity and flow rate inside the wire tubes in a long-term, stable and accurate manner.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a wire tube intelligent speed measuring device, comprising:

[0007] A flow-expanding cavity is located at the top of the wire tube to form a smoothly transitioning flow-expanding region;

[0008] The speed measuring mechanism includes a pressure sensor and a push-pull force sensor installed in the flow-expanding cavity. The pressure sensor is used to detect the magnitude of the negative air pressure inside the wire tube, and the push-pull force sensor is connected to a lever mechanism that extends into the flow-expanding cavity to detect the magnitude of the wind resistance of the lever mechanism inside the wire tube.

[0009] The controller is used to receive signals from the speed measuring mechanism and calculate the wind speed inside the wire tube.

[0010] Preferably, the lever mechanism includes a counterweight ball suspended in the flow-expanding cavity and a connecting rod connecting the counterweight ball and the push-pull force sensor. The top of the flow-expanding cavity is also equipped with a support connecting the counterweight ball and the connecting rod.

[0011] More preferably, it also includes a circular tube for connecting the wire tube, and the flow-expanding cavity is disposed at the upper part of the circular tube.

[0012] More preferably, the pressure sensor is connected to the controller via a transmitter.

[0013] More preferably, the expansion cavity includes an inlet expansion section, a straight section, and an outlet contraction section, with smooth transitions between the sections. The pressure sensor is installed in the inlet expansion section, and the lever mechanism is installed in the straight section.

[0014] More preferably, the cross-sectional area of ​​the straight section cavity is 1.5 to 2 times the cross-sectional area of ​​the wire tube cavity.

[0015] More preferably, the amplification cavity, pressure sensor, push-pull force sensor, controller, connecting rod, support, and transmitter are all integrated inside the housing.

[0016] In addition, the present invention also provides a speed measuring method for the above-mentioned intelligent wire tube speed measuring device, comprising the following steps:

[0017] S1. Detect the negative air pressure in the diffuser cavity using a pressure sensor;

[0018] S2. Use a push-pull force sensor to detect the resistance of the counterweight ball inside the flow-expanding cavity;

[0019] S3. Transmit the detected signal to the controller;

[0020] S4. The controller calculates the wind speed inside the filament tube based on the air resistance formula.

[0021] Meanwhile, the present invention also provides a method for controlling the air volume balance of a wire tube. Based on the speed measurement method of the above-mentioned intelligent speed measuring device for wire tubes, after calculating the air speed of the wire tube, the calculation result is fed back to the external air volume balance control device in real time. The air volume balance control device adjusts the air volume by comparing the real-time feedback data with the set value, so as to adjust the air volume and ensure the stability of the flow rate inside the wire tube.

[0022] In addition, the present invention also provides a cigarette factory tube flow rate detection system, which includes the above-mentioned intelligent tube speed measuring device.

[0023] Compared with existing technologies, this invention utilizes the resistance changes of the lever mechanism within the expansion cavity under different wind speed conditions, converts them into electrical signals, and combines them with data from a pressure sensor to accurately calculate the real-time wind speed within the tube. This ingeniously utilizes the principle of fluid deceleration and stratification within the expansion cavity. Due to its high density, the tobacco shreds slide along the bottom of the cavity after the flow rate decreases, while air, due to its low density, can pass through the entire cavity. This effectively avoids the tobacco shreds impacting the lever mechanism and affecting the measurement results, enabling the device of this invention to detect the flow rate and velocity within the tube stably and accurately over a long period. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the intelligent speed measuring device for wire tubes in an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the intelligent speed measuring device for wire tubes after the cover has been removed in an embodiment of the present invention.

[0026] In the picture:

[0027] 1—Flow diffuser cavity; 2—Circular tube; 3—Pressure sensor

[0028] 4 – Push-pull force sensor; 5 – Controller; 6a – Counterweight ball

[0029] 6b – Connecting rod; 6c – Support; 7 – Transmitter

[0030] 8 - Housing; 9 - Signal cable; 10 - Network cable

[0031] 11——Power cord 12——Quick electrical plug. Detailed Implementation

[0032] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention.

[0033] It should be noted in advance that, in this invention, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of these terms in this invention according to the specific circumstances. Furthermore, in this invention, unless otherwise explicitly specified and limited, "on" or "under" a second feature can include direct contact between the first and second features, or contact between the first and second features not in direct contact but through another feature between them.

[0034] like Figures 1 to 2 As shown, the intelligent speed measuring device for the wire tube includes a circular tube 2 for connecting the wire tube. A flow-expanding cavity 1 is provided at the upper part of the circular tube 2 to form a smoothly transitioning flow-expanding region. The speed measuring mechanism includes a pressure sensor 3 and a push-pull force sensor 4 installed in the flow-expanding cavity 1. The pressure sensor 3 is connected to a controller 5 via a transmitter 7 to detect the magnitude of the negative air pressure inside the wire tube. The push-pull force sensor 4 is connected to a lever mechanism extending into the flow-expanding cavity 1 to detect the wind resistance of the lever mechanism inside the wire tube. The controller 5 receives signals from the speed measuring mechanism and calculates the wind speed inside the wire tube. The lever mechanism includes a counterweight ball 6a suspended inside the flow-expanding cavity 1 and a connecting rod 6b connecting the counterweight ball 6a and the push-pull force sensor 4. A support 6c connecting the counterweight ball 6a and the connecting rod 6b is also installed at the top of the flow-expanding cavity 1. In this embodiment, the counterweight ball 6a is preferably a steel ball.

[0035] In the above structure, the expansion cavity 1 includes an inlet expansion section, a straight section, and an outlet contraction section, with smooth transitions between each section. The entire expansion cavity 1 forms an organic whole with uniform wall thickness and a smooth inner wall, ensuring smooth flow of tobacco and air. This solves problems such as uneven connections at the joints of the embedded throat, increased tobacco breakage due to steps on the inner wall, and material blockage at the throttling orifice. The pressure sensor 3 is installed in the inlet expansion section, and the lever mechanism is installed in the straight section. Those skilled in the art should know that the inlet expansion section is the starting point for fluid to enter the expansion cavity 1. The pressure sensor 3 installed here can accurately capture the pressure changes when the fluid enters, providing initial data for subsequent flow rate calculations. Moreover, the pressure measurement in the inlet expansion section can serve as a benchmark for the fluid state inside the entire expansion cavity, helping to more accurately calculate and analyze the pressure distribution and flow rate of the entire flow channel.

[0036] Preferably, the cross-sectional area of ​​the straight section cavity is 1.5 to 2 times that of the tube cavity. By cleverly utilizing the 50% to 100% increase in the cross-sectional area of ​​the expansion section cavity, the fluid velocity decreases. This velocity reduction facilitates stratification within the fluid; that is, the denser tobacco and the less dense air separate according to their density differences as the flow rate slows. Specifically, due to its higher density, the tobacco is more likely to settle at the bottom of the cavity after the flow rate decreases, while the less dense air remains within the entire cavity even at reduced velocity. This effectively prevents the tobacco from impacting the steel ball and affecting the measurement results, maintaining uniform air resistance to the speed-measuring steel ball, thus helping to maintain the stability of the measurement signal and ensure the accuracy of the measurement results. Furthermore, this design allows the speed measuring device to adapt to fluids of different densities and flow rates, not just tobacco conveying pipes, thereby improving the device's applicability and adaptability.

[0037] In this embodiment, the real-time data from pressure sensor 3 and transmitter 7 are transmitted to controller 5 via signal line 9, and the analysis and calculation results are fed back to the external airflow balancing control device in real time via network cable 10. Furthermore, network cable 10 and power cable 11 can be connected to external devices via quick-connect electrical connector 12. The diffuser 1, pressure sensor 3, push-pull force sensor 4, controller 5, connecting rod 6b, support 6c, transmitter 7, signal line 9, network cable 10, power cable 11, and quick-connect electrical connector 12 are all integrated within the housing 8, achieving a high degree of integration, reducing the complexity of external connections, and improving the overall compactness and aesthetics of the structure. Moreover, the quick-connect electrical connector 12 allows for easy connection of network cable 10 and power cable 11 to external devices, simplifying the installation process and facilitating future maintenance and upgrades, thus improving the ease of use of the equipment. Furthermore, the components integrated within the housing 8 are protected, reducing the impact of external environmental factors (such as dust and humidity) on equipment performance, thereby improving the stability and reliability of the equipment.

[0038] The method for measuring speed using the intelligent speed measuring device for wire tubes provided in the above embodiments includes the following steps:

[0039] S1. The negative air pressure in the diffuser chamber 1 is detected by pressure sensor 3;

[0040] S2. Use push-pull force sensor 4 to detect the resistance of the counterweight ball in the flow-expanding cavity 1;

[0041] S3. Transmit the detected signal to controller 5;

[0042] S4. The controller calculates the wind speed inside the filament tube based on the air resistance formula.

[0043] Specifically, according to the formula for air resistance: F=(1 / 2)CρSV²; where C is the air resistance coefficient (generally 0.47-0.50 for a sphere, which can be experimentally measured); ρ is the air density (which can be converted into real-time air density based on the negative pressure value measured by pressure sensor 3); S is the windward area of ​​the object (the cross-sectional area of ​​the steel ball is fixed); and V is the relative velocity between the steel ball and the air. Thus, when other parameters are fixed or known, the magnitude of the wind resistance F is directly proportional to the velocity V². The wind resistance F is transmitted to the push-pull force sensor 3 through the connecting rod 6b, converted into an electrical signal, amplified by the transmitter 2, and transmitted to the controller 6. The real-time wind speed can then be calculated according to the formula.

[0044] Furthermore, after calculating the air velocity in the filament tube, the calculation result can be fed back to the external airflow balancing control device in real time via network cable 10. The airflow balancing control device adjusts the airflow by comparing the real-time feedback data with the set value to ensure stable flow velocity and flow rate within the filament tube. By precisely controlling the flow velocity and flow rate within the filament tube, production interruptions or product quality issues caused by unstable air velocity can be avoided, thereby improving overall production efficiency. Simultaneously, it also enables automated airflow adjustment, reducing manual intervention and improving production efficiency and control precision.

[0045] The intelligent velocity measuring device for wire tubes provided by this invention achieves high-precision and high-stability detection of flow velocity and flow rate within wire tubes through innovative structural design and intelligent control. Its key features include: the smooth transition design of the flow-expanding cavity and the synergistic effect of the pressure sensor and the push-pull force sensor effectively solve the problems of clogging, decreased accuracy, and equipment damage in traditional detection methods; simultaneously, the controller's real-time data processing and feedback mechanism ensures the accuracy and response speed of airflow control, significantly improving the accuracy and reliability of wire tube flow velocity detection.

[0046] To facilitate understanding by those skilled in the art of the improvements of this invention over the prior art, some of the accompanying drawings and descriptions have been simplified. The above embodiments are preferred implementations of this invention. In addition, this invention can be implemented in other ways. Any obvious substitutions without departing from the concept of this technical solution are within the protection scope of this invention.

Claims

1. A wire tube intelligent speed measuring device, characterized in that, include: A flow-expanding cavity (1) is set at the upper part of the wire tube to form a flow-expanding area with a smooth transition; The speed measuring mechanism includes a pressure sensor (3) and a push-pull force sensor (4) installed in the expansion cavity (1). The pressure sensor (3) is used to detect the magnitude of the negative air pressure in the wire tube. The push-pull force sensor (4) is connected to a lever mechanism that extends into the expansion cavity (1) to detect the wind resistance of the lever mechanism in the wire tube. The controller (5) is used to receive the signal from the speed measuring mechanism and calculate the wind speed inside the wire tube.

2. The intelligent speed measuring device for wire tubes according to claim 1, characterized in that: The lever mechanism includes a counterweight ball (6a) suspended in the expansion cavity (1) and a connecting rod (6b) connecting the counterweight ball (6a) and the push-pull force sensor (4). The top of the expansion cavity (1) is also equipped with a support (6c) connecting the counterweight ball (6a) and the connecting rod (6b).

3. The intelligent speed measuring device for wire tubes according to claim 2, characterized in that: It also includes a circular tube (2) for connecting the wire tube, and the flow-expanding cavity (1) is located on the upper part of the circular tube (2).

4. The intelligent speed measuring device for wire tubes according to claim 3, characterized in that: The pressure sensor (3) is connected to the controller (5) via a transmitter (7).

5. The intelligent speed measuring device for wire tubes according to claim 4, characterized in that: The expansion chamber (1) includes an inlet expansion section, a straight section and an outlet contraction section, with smooth transitions between the sections. The pressure sensor (3) is installed in the inlet expansion section, and the lever mechanism is installed in the straight section.

6. The intelligent speed measuring device for wire tubes according to claim 5, characterized in that: The cross-sectional area of ​​the straight section is 1.5 to 2 times the cross-sectional area of ​​the wire tube.

7. The intelligent speed measuring device for wire tubes according to claim 6, characterized in that: The expansion cavity (1), pressure sensor (3), push-pull force sensor (4), controller (5), connecting rod (6b), support (6c) and transmitter (7) are all integrated inside the housing (8).

8. A speed measuring method for the intelligent speed measuring device for wire tubes according to any one of claims 2-7, characterized in that, Includes the following steps: S1. The negative air pressure in the diffuser cavity (1) is detected by the pressure sensor (3); S2. Use push-pull force sensor (4) to detect the resistance of the counterweight ball in the flow-expanding cavity (1); S3. Transmit the detected signal to the controller (5); S4. The controller calculates the wind speed inside the filament tube based on the air resistance formula.

9. A method for balancing airflow in a duct, characterized in that: Based on the speed measurement method of the intelligent speed measuring device for wire tubes as described in claim 8, after calculating the wind speed of the wire tube, the calculation result is fed back to the external air volume balance control device in real time. The air volume balance control device adjusts the air volume by comparing the real-time feedback data with the set value to ensure the stability of the flow rate inside the wire tube.

10. A cigarette factory tube flow rate detection system, characterized in that: The device includes the intelligent speed measuring device for wire tubes as described in any one of claims 1-7.

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